rc80211_pid_debugfs.c

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/*
 * Copyright 2007, Mattias Nissler <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/poll.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/export.h>

#include <net/mac80211.h>
#include "rate.h"

#include "rc80211_pid.h"

static void rate_control_pid_event(struct rc_pid_event_buffer *buf,
                   enum rc_pid_event_type type,
                   union rc_pid_event_data *data)
{
    struct rc_pid_event *ev;
    unsigned long status;

    spin_lock_irqsave(&buf->lock, status);
    ev = &(buf->ring[buf->next_entry]);
    buf->next_entry = (buf->next_entry + 1) % RC_PID_EVENT_RING_SIZE;

    ev->timestamp = jiffies;
    ev->id = buf->ev_count++;
    ev->type = type;
    ev->data = *data;

    spin_unlock_irqrestore(&buf->lock, status);

    wake_up_all(&buf->waitqueue);
}

void rate_control_pid_event_tx_status(struct rc_pid_event_buffer *buf,
                      struct ieee80211_tx_info *stat)
{
    union rc_pid_event_data evd;

    evd.flags = stat->flags;
    memcpy(&evd.tx_status, stat, sizeof(struct ieee80211_tx_info));
    rate_control_pid_event(buf, RC_PID_EVENT_TYPE_TX_STATUS, &evd);
}

void rate_control_pid_event_rate_change(struct rc_pid_event_buffer *buf,
                           int index, int rate)
{
    union rc_pid_event_data evd;

    evd.index = index;
    evd.rate = rate;
    rate_control_pid_event(buf, RC_PID_EVENT_TYPE_RATE_CHANGE, &evd);
}

void rate_control_pid_event_tx_rate(struct rc_pid_event_buffer *buf,
                       int index, int rate)
{
    union rc_pid_event_data evd;

    evd.index = index;
    evd.rate = rate;
    rate_control_pid_event(buf, RC_PID_EVENT_TYPE_TX_RATE, &evd);
}

void rate_control_pid_event_pf_sample(struct rc_pid_event_buffer *buf,
                         s32 pf_sample, s32 prop_err,
                         s32 int_err, s32 der_err)
{
    union rc_pid_event_data evd;

    evd.pf_sample = pf_sample;
    evd.prop_err = prop_err;
    evd.int_err = int_err;
    evd.der_err = der_err;
    rate_control_pid_event(buf, RC_PID_EVENT_TYPE_PF_SAMPLE, &evd);
}

static int rate_control_pid_events_open(struct inode *inode, struct file *file)
{
    struct rc_pid_sta_info *sinfo = inode->i_private;
    struct rc_pid_event_buffer *events = &sinfo->events;
    struct rc_pid_events_file_info *file_info;
    unsigned long status;

    /* Allocate a state struct */
    file_info = kmalloc(sizeof(*file_info), GFP_KERNEL);
    if (file_info == NULL)
        return -ENOMEM;

    spin_lock_irqsave(&events->lock, status);

    file_info->next_entry = events->next_entry;
    file_info->events = events;

    spin_unlock_irqrestore(&events->lock, status);

    file->private_data = file_info;

    return 0;
}

static int rate_control_pid_events_release(struct inode *inode,
                       struct file *file)
{
    struct rc_pid_events_file_info *file_info = file->private_data;

    kfree(file_info);

    return 0;
}

static unsigned int rate_control_pid_events_poll(struct file *file,
                         poll_table *wait)
{
    struct rc_pid_events_file_info *file_info = file->private_data;

    poll_wait(file, &file_info->events->waitqueue, wait);

    return POLLIN | POLLRDNORM;
}

#define RC_PID_PRINT_BUF_SIZE 64

static ssize_t rate_control_pid_events_read(struct file *file, char __user *buf,
                        size_t length, loff_t *offset)
{
    struct rc_pid_events_file_info *file_info = file->private_data;
    struct rc_pid_event_buffer *events = file_info->events;
    struct rc_pid_event *ev;
    char pb[RC_PID_PRINT_BUF_SIZE];
    int ret;
    int p;
    unsigned long status;

    /* Check if there is something to read. */
    if (events->next_entry == file_info->next_entry) {
        if (file->f_flags & O_NONBLOCK)
            return -EAGAIN;

        /* Wait */
        ret = wait_event_interruptible(events->waitqueue,
                events->next_entry != file_info->next_entry);

        if (ret)
            return ret;
    }

    /* Write out one event per call. I don't care whether it's a little
     * inefficient, this is debugging code anyway. */
    spin_lock_irqsave(&events->lock, status);

    /* Get an event */
    ev = &(events->ring[file_info->next_entry]);
    file_info->next_entry = (file_info->next_entry + 1) %
                RC_PID_EVENT_RING_SIZE;

    /* Print information about the event. Note that userspace needs to
     * provide large enough buffers. */
    length = length < RC_PID_PRINT_BUF_SIZE ?
         length : RC_PID_PRINT_BUF_SIZE;
    p = snprintf(pb, length, "%u %lu ", ev->id, ev->timestamp);
    switch (ev->type) {
    case RC_PID_EVENT_TYPE_TX_STATUS:
        p += snprintf(pb + p, length - p, "tx_status %u %u",
                  !(ev->data.flags & IEEE80211_TX_STAT_ACK),
                  ev->data.tx_status.status.rates[0].idx);
        break;
    case RC_PID_EVENT_TYPE_RATE_CHANGE:
        p += snprintf(pb + p, length - p, "rate_change %d %d",
                  ev->data.index, ev->data.rate);
        break;
    case RC_PID_EVENT_TYPE_TX_RATE:
        p += snprintf(pb + p, length - p, "tx_rate %d %d",
                  ev->data.index, ev->data.rate);
        break;
    case RC_PID_EVENT_TYPE_PF_SAMPLE:
        p += snprintf(pb + p, length - p,
                  "pf_sample %d %d %d %d",
                  ev->data.pf_sample, ev->data.prop_err,
                  ev->data.int_err, ev->data.der_err);
        break;
    }
    p += snprintf(pb + p, length - p, "\n");

    spin_unlock_irqrestore(&events->lock, status);

    if (copy_to_user(buf, pb, p))
        return -EFAULT;

    return p;
}

#undef RC_PID_PRINT_BUF_SIZE

static const struct file_operations rc_pid_fop_events = {
    .owner = THIS_MODULE,
    .read = rate_control_pid_events_read,
    .poll = rate_control_pid_events_poll,
    .open = rate_control_pid_events_open,
    .release = rate_control_pid_events_release,
    .llseek = noop_llseek,
};

void rate_control_pid_add_sta_debugfs(void *priv, void *priv_sta,
                         struct dentry *dir)
{
    struct rc_pid_sta_info *spinfo = priv_sta;

    spinfo->events_entry = debugfs_create_file("rc_pid_events", S_IRUGO,
                           dir, spinfo,
                           &rc_pid_fop_events);
}

void rate_control_pid_remove_sta_debugfs(void *priv, void *priv_sta)
{
    struct rc_pid_sta_info *spinfo = priv_sta;

    debugfs_remove(spinfo->events_entry);
}