iwl-3945-rs.c

linux内核源码

/******************************************************************************
 *
 * Copyright(c) 2005 - 2007 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
 *
 * The full GNU General Public License is included in this distribution in the
 * file called LICENSE.
 *
 * Contact Information:
 * James P. Ketrenos <[e-mail]>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 *****************************************************************************/

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/wireless.h>
#include <net/mac80211.h>
#include <net/ieee80211.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/delay.h>

#include <linux/workqueue.h>

#define IWL 3945

#include "../net/mac80211/ieee80211_rate.h"

#include "iwlwifi.h"

#define RS_NAME "iwl-3945-rs"

struct iwl_rate_scale_data {
	u64 data;
	s32 success_counter;
	s32 success_ratio;
	s32 counter;
	s32 average_tpt;
	unsigned long stamp;
};

struct iwl_rate_scale_priv {
	spinlock_t lock;
	s32 *expected_tpt;
	unsigned long last_partial_flush;
	unsigned long last_flush;
	u32 flush_time;
	u32 last_tx_packets;
	u32 tx_packets;
	u8 tgg;
	u8 flush_pending;
	u8 start_rate;
	u8 ibss_sta_added;
	struct timer_list rate_scale_flush;
	struct iwl_rate_scale_data win[IWL_RATE_COUNT];
};

static s32 iwl_expected_tpt_g[IWL_RATE_COUNT] = {
	7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
};

static s32 iwl_expected_tpt_g_prot[IWL_RATE_COUNT] = {
	7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
};

static s32 iwl_expected_tpt_a[IWL_RATE_COUNT] = {
	0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
};

static s32 iwl_expected_tpt_b[IWL_RATE_COUNT] = {
	7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
};

struct iwl_tpt_entry {
	s8 min_rssi;
	u8 index;
};

static struct iwl_tpt_entry iwl_tpt_table_a[] = {
	{-60, IWL_RATE_54M_INDEX},
	{-64, IWL_RATE_48M_INDEX},
	{-72, IWL_RATE_36M_INDEX},
	{-80, IWL_RATE_24M_INDEX},
	{-84, IWL_RATE_18M_INDEX},
	{-85, IWL_RATE_12M_INDEX},
	{-87, IWL_RATE_9M_INDEX},
	{-89, IWL_RATE_6M_INDEX}
};

static struct iwl_tpt_entry iwl_tpt_table_b[] = {
	{-86, IWL_RATE_11M_INDEX},
	{-88, IWL_RATE_5M_INDEX},
	{-90, IWL_RATE_2M_INDEX},
	{-92, IWL_RATE_1M_INDEX}

};

static struct iwl_tpt_entry iwl_tpt_table_g[] = {
	{-60, IWL_RATE_54M_INDEX},
	{-64, IWL_RATE_48M_INDEX},
	{-68, IWL_RATE_36M_INDEX},
	{-80, IWL_RATE_24M_INDEX},
	{-84, IWL_RATE_18M_INDEX},
	{-85, IWL_RATE_12M_INDEX},
	{-86, IWL_RATE_11M_INDEX},
	{-88, IWL_RATE_5M_INDEX},
	{-90, IWL_RATE_2M_INDEX},
	{-92, IWL_RATE_1M_INDEX}
};

#define IWL_RATE_MAX_WINDOW          62
#define IWL_RATE_FLUSH        (3*HZ/10)
#define IWL_RATE_WIN_FLUSH       (HZ/2)
#define IWL_RATE_HIGH_TH          11520
#define IWL_RATE_MIN_FAILURE_TH       8
#define IWL_RATE_MIN_SUCCESS_TH       8
#define IWL_RATE_DECREASE_TH       1920

static u8 iwl_get_rate_index_by_rssi(s32 rssi, u8 mode)
{
	u32 index = 0;
	u32 table_size = 0;
	struct iwl_tpt_entry *tpt_table = NULL;

	if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
		rssi = IWL_MIN_RSSI_VAL;

	switch (mode) {
	case MODE_IEEE80211G:
		tpt_table = iwl_tpt_table_g;
		table_size = ARRAY_SIZE(iwl_tpt_table_g);
		break;

	case MODE_IEEE80211A:
		tpt_table = iwl_tpt_table_a;
		table_size = ARRAY_SIZE(iwl_tpt_table_a);
		break;

	default:
	case MODE_IEEE80211B:
		tpt_table = iwl_tpt_table_b;
		table_size = ARRAY_SIZE(iwl_tpt_table_b);
		break;
	}

	while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
		index++;

	index = min(index, (table_size - 1));

	return tpt_table[index].index;
}

static void iwl_clear_window(struct iwl_rate_scale_data *window)
{
	window->data = 0;
	window->success_counter = 0;
	window->success_ratio = IWL_INVALID_VALUE;
	window->counter = 0;
	window->average_tpt = IWL_INVALID_VALUE;
	window->stamp = 0;
}

/**
 * iwl_rate_scale_flush_windows - flush out the rate scale windows
 *
 * Returns the number of windows that have gathered data but were
 * not flushed.  If there were any that were not flushed, then
 * reschedule the rate flushing routine.
 */
static int iwl_rate_scale_flush_windows(struct iwl_rate_scale_priv *rs_priv)
{
	int unflushed = 0;
	int i;
	unsigned long flags;

	/*
	 * For each rate, if we have collected data on that rate
	 * and it has been more than IWL_RATE_WIN_FLUSH
	 * since we flushed, clear out the gathered statistics
	 */
	for (i = 0; i < IWL_RATE_COUNT; i++) {
		if (!rs_priv->win[i].counter)
			continue;

		spin_lock_irqsave(&rs_priv->lock, flags);
		if (time_after(jiffies, rs_priv->win[i].stamp +
			       IWL_RATE_WIN_FLUSH)) {
			IWL_DEBUG_RATE("flushing %d samples of rate "
				       "index %d\n",
				       rs_priv->win[i].counter, i);
			iwl_clear_window(&rs_priv->win[i]);
		} else
			unflushed++;
		spin_unlock_irqrestore(&rs_priv->lock, flags);
	}

	return unflushed;
}

#define IWL_RATE_FLUSH_MAX              5000	/* msec */
#define IWL_RATE_FLUSH_MIN              50	/* msec */

static void iwl_bg_rate_scale_flush(unsigned long data)
{
	struct iwl_rate_scale_priv *rs_priv = (void *)data;
	int unflushed = 0;
	unsigned long flags;
	u32 packet_count, duration, pps;

	IWL_DEBUG_RATE("enter\n");

	unflushed = iwl_rate_scale_flush_windows(rs_priv);

	spin_lock_irqsave(&rs_priv->lock, flags);

	rs_priv->flush_pending = 0;

	/* Number of packets Rx'd since last time this timer ran */
	packet_count = (rs_priv->tx_packets - rs_priv->last_tx_packets) + 1;

	rs_priv->last_tx_packets = rs_priv->tx_packets + 1;

	if (unflushed) {
		duration =
		    jiffies_to_msecs(jiffies - rs_priv->last_partial_flush);
/*              duration = jiffies_to_msecs(rs_priv->flush_time); */

		IWL_DEBUG_RATE("Tx'd %d packets in %dms\n",
			       packet_count, duration);

		/* Determine packets per second */
		if (duration)
			pps = (packet_count * 1000) / duration;
		else
			pps = 0;

		if (pps) {
			duration = IWL_RATE_FLUSH_MAX / pps;
			if (duration < IWL_RATE_FLUSH_MIN)
				duration = IWL_RATE_FLUSH_MIN;
		} else
			duration = IWL_RATE_FLUSH_MAX;

		rs_priv->flush_time = msecs_to_jiffies(duration);

		IWL_DEBUG_RATE("new flush period: %d msec ave %d\n",
			       duration, packet_count);

		mod_timer(&rs_priv->rate_scale_flush, jiffies +
			  rs_priv->flush_time);

		rs_priv->last_partial_flush = jiffies;
	}

	/* If there weren't any unflushed entries, we don't schedule the timer
	 * to run again */

	rs_priv->last_flush = jiffies;

	spin_unlock_irqrestore(&rs_priv->lock, flags);

	IWL_DEBUG_RATE("leave\n");
}

/**
 * iwl_collect_tx_data - Update the success/failure sliding window
 *
 * We keep a sliding window of the last 64 packets transmitted
 * at this rate.  window->data contains the bitmask of successful
 * packets.
 */
static void iwl_collect_tx_data(struct iwl_rate_scale_priv *rs_priv,
				struct iwl_rate_scale_data *window,
				int success, int retries)
{
	unsigned long flags;

	if (!retries) {
		IWL_DEBUG_RATE("leave: retries == 0 -- should be at least 1\n");
		return;
	}

	while (retries--) {
		spin_lock_irqsave(&rs_priv->lock, flags);

		/* If we have filled up the window then subtract one from the
		 * success counter if the high-bit is counting toward
		 * success */
		if (window->counter == IWL_RATE_MAX_WINDOW) {
			if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1)))
				window->success_counter--;
		} else
			window->counter++;

		/* Slide the window to the left one bit */
		window->data = (window->data << 1);

		/* If this packet was a success then set the low bit high */
		if (success) {
			window->success_counter++;
			window->data |= 1;
		}

		/* window->counter can't be 0 -- it is either >0 or
		 * IWL_RATE_MAX_WINDOW */
		window->success_ratio = 12800 * window->success_counter /
		    window->counter;

		/* Tag this window as having been updated */
		window->stamp = jiffies;

		spin_unlock_irqrestore(&rs_priv->lock, flags);
	}
}

static void rs_rate_init(void *priv_rate, void *priv_sta,
			 struct ieee80211_local *local, struct sta_info *sta)
{
	int i;

	IWL_DEBUG_RATE("enter\n");

	/* TODO: what is a good starting rate for STA? About middle? Maybe not
	 * the lowest or the highest rate.. Could consider using RSSI from
	 * previous packets? Need to have IEEE 802.1X auth succeed immediately
	 * after assoc.. */

	for (i = IWL_RATE_COUNT - 1; i >= 0; i--) {
		if (sta->supp_rates & (1 << i)) {
			sta->txrate = i;
			break;
		}
	}

	sta->last_txrate = sta->txrate;

	/* For MODE_IEEE80211A mode it start at IWL_FIRST_OFDM_RATE */
        if (local->hw.conf.phymode == MODE_IEEE80211A)
                sta->last_txrate += IWL_FIRST_OFDM_RATE;

	IWL_DEBUG_RATE("leave\n");
}

static void *rs_alloc(struct ieee80211_local *local)
{
	return local->hw.priv;
}

/* rate scale requires free function to be implmented */
static void rs_free(void *priv)
{
	return;
}
static void rs_clear(void *priv)
{
	return;
}


static void *rs_alloc_sta(void *priv, gfp_t gfp)
{
	struct iwl_rate_scale_priv *rs_priv;
	int i;

	IWL_DEBUG_RATE("enter\n");

	rs_priv = kzalloc(sizeof(struct iwl_rate_scale_priv), gfp);
	if (!rs_priv) {
		IWL_DEBUG_RATE("leave: ENOMEM\n");
		return NULL;
	}

	spin_lock_init(&rs_priv->lock);

	rs_priv->start_rate = IWL_RATE_INVALID;

	/* default to just 802.11b */
	rs_priv->expected_tpt = iwl_expected_tpt_b;

	rs_priv->last_partial_flush = jiffies;
	rs_priv->last_flush = jiffies;
	rs_priv->flush_time = IWL_RATE_FLUSH;
	rs_priv->last_tx_packets = 0;
	rs_priv->ibss_sta_added = 0;

	init_timer(&rs_priv->rate_scale_flush);
	rs_priv->rate_scale_flush.data = (unsigned long)rs_priv;
	rs_priv->rate_scale_flush.function = &iwl_bg_rate_scale_flush;

	for (i = 0; i < IWL_RATE_COUNT; i++)
		iwl_clear_window(&rs_priv->win[i]);

	IWL_DEBUG_RATE("leave\n");

	return rs_priv;
}

static void rs_free_sta(void *priv, void *priv_sta)
{
	struct iwl_rate_scale_priv *rs_priv = priv_sta;

	IWL_DEBUG_RATE("enter\n");
	del_timer_sync(&rs_priv->rate_scale_flush);
	kfree(rs_priv);
	IWL_DEBUG_RATE("leave\n");
}


/*
 * get ieee prev rate from rate scale table.
 * for A and B mode we need to overright prev
 * value
 */
static int rs_adjust_next_rate(struct iwl_priv *priv, int rate)
{
	int next_rate = iwl_get_prev_ieee_rate(rate);

	switch (priv->phymode) {
	case MODE_IEEE80211A:
		if (rate == IWL_RATE_12M_INDEX)
			next_rate = IWL_RATE_9M_INDEX;
		else if (rate == IWL_RATE_6M_INDEX)
			next_rate = IWL_RATE_6M_INDEX;
		break;
	case MODE_IEEE80211B:
		if (rate == IWL_RATE_11M_INDEX_TABLE)
			next_rate = IWL_RATE_5M_INDEX_TABLE;
		break;
	default:
		break;
	}

	return next_rate;
}
/**
 * rs_tx_status - Update rate control values based on Tx results
 *
 * NOTE: Uses iwl_priv->retry_rate for the # of retries attempted by
 * the hardware for each rate.
 */
static void rs_tx_status(void *priv_rate,
			 struct net_device *dev,
			 struct sk_buff *skb,
			 struct ieee80211_tx_status *tx_resp)
{
	u8 retries, current_count;
	int scale_rate_index, first_index, last_index;
	unsigned long flags;
	struct sta_info *sta;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
	struct iwl_priv *priv = (struct iwl_priv *)priv_rate;
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct iwl_rate_scale_priv *rs_priv;

	IWL_DEBUG_RATE("enter\n");

	retries = tx_resp->retry_count;

	first_index = tx_resp->control.tx_rate;
	if ((first_index < 0) || (first_index >= IWL_RATE_COUNT)) {
		IWL_DEBUG_RATE("leave: Rate out of bounds: %0x for %d\n",
			       tx_resp->control.tx_rate, first_index);
		return;
	}

	sta = sta_info_get(local, hdr->addr1);
	if (!sta || !sta->rate_ctrl_priv) {
		if (sta)
			sta_info_put(sta);
		IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
		return;
	}

	rs_priv = (void *)sta->rate_ctrl_priv;

	rs_priv->tx_packets++;

	scale_rate_index = first_index;
	last_index = first_index;

	/*
	 * Update the window for each rate.  We determine which rates
	 * were Tx'd based on the total number of retries vs. the number
	 * of retries configured for each rate -- currently set to the
	 * priv value 'retry_rate' vs. rate specific
	 *
	 * On exit from this while loop last_index indicates the rate
	 * at which the frame was finally transmitted (or failed if no
	 * ACK)
	 */
	while (retries > 0) {
		if (retries < priv->retry_rate) {
			current_count = retries;
			last_index = scale_rate_index;