rc80211_pid_debugfs.c

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/*
 * Copyright 2007, Mattias Nissler <mattias.nissler@gmx.de>
 *
 * 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);
}