onoe.c

最新之atheros芯片driver source code, 基于linux操作系统,內含atheros芯片HAL全部代码

/*-
 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
 *    redistribution must be conditioned upon including a substantially
 *    similar Disclaimer requirement for further binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGES.
 *
 * $Id: onoe.c 3906 2009-01-14 02:54:40Z proski $
 */

/*
 * Atsushi Onoe's rate control algorithm.
 */
#ifndef AUTOCONF_INCLUDED
#include <linux/config.h>
#endif
#include <linux/version.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/random.h>
#include <linux/delay.h>
#include <linux/cache.h>
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/if_arp.h>

#include <asm/uaccess.h>

#include <net80211/if_media.h>
#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_rate.h>

#include "if_athvar.h"
#include "if_ath_hal.h"
#include "ah_desc.h"

#include "onoe.h"

#define	ONOE_DEBUG
#ifdef ONOE_DEBUG
enum {
	ATH_DEBUG_RATE	= 0x00000010,	/* rate control */
};
#define	DPRINTF(sc, _fmt, ...) do {				\
	if (sc->sc_debug & ATH_DEBUG_RATE)			\
		printk(_fmt, __VA_ARGS__);			\
} while (0)
#else
#define	DPRINTF(sc, _fmt, ...)
#endif

/*
 * Default parameters for the rate control algorithm.  These are
 * all tunable with sysctls.  The rate controller runs periodically
 * (each ath_rateinterval ms) analyzing transmit statistics for each
 * neighbor/station (when operating in station mode this is only the AP).
 * If transmits look to be working well over a sampling period then
 * it gives a "raise rate credit".  If transmits look to not be working
 * well than it deducts a credit.  If the credits cross a threshold then
 * the transmit rate is raised.  Various error conditions force the
 * the transmit rate to be dropped.
 *
 * The decision to issue/deduct a credit is based on the errors and
 * retries accumulated over the sampling period.  ath_rate_raise defines
 * the percent of retransmits for which a credit is issued/deducted.
 * ath_rate_raise_threshold defines the threshold on credits at which
 * the transmit rate is increased.
 *
 * XXX this algorithm is flawed.
 */
static int ath_rateinterval = 1000;		/* rate ctl interval (ms) */
static int ath_rate_raise = 10;			/* add credit threshold */
static int ath_rate_raise_threshold = 10;	/* rate ctl raise threshold */

static void ath_rate_update(struct ath_softc *, struct ieee80211_node *, int);
static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
static void ath_rate_ctl(void *, struct ieee80211_node *);

static void
ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
{
	/* NB: assumed to be zero'd by caller */
	ath_rate_update(sc, &an->an_node, 0);
}

static void
ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
{
}

static void
ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
	int shortPreamble, size_t frameLen,
	u_int8_t *rix, unsigned int *try0, u_int8_t *txrate)
{
	struct onoe_node *on = ATH_NODE_ONOE(an);

	*rix = on->on_tx_rix0;
	*try0 = on->on_tx_try0;
	if (shortPreamble)
		*txrate = on->on_tx_rate0sp;
	else
		*txrate = on->on_tx_rate0;
}

static void
ath_rate_get_mrr(struct ath_softc *sc, struct ath_node *an, int shortPreamble,
		 size_t frame_size, u_int8_t rix, struct ieee80211_mrr *mrr)
{
	struct onoe_node *on = ATH_NODE_ONOE(an);

	mrr->rate1 = on->on_tx_rate1sp;
	mrr->retries1 = 2;
	mrr->rate2 = on->on_tx_rate2sp;
	mrr->retries2 = 2;
	mrr->rate3 = on->on_tx_rate3sp;
	mrr->retries3 = 2;
}

static void
ath_rate_tx_complete(struct ath_softc *sc,
	struct ath_node *an, const struct ath_buf *bf)
{
	struct onoe_node *on = ATH_NODE_ONOE(an);
	const struct ath_tx_status *ts = &bf->bf_dsstatus.ds_txstat;

	if (ts->ts_status == 0)
		on->on_tx_ok++;
	else
		on->on_tx_err++;
	on->on_tx_retr += ts->ts_shortretry
			+ ts->ts_longretry;
	if (time_after_eq(jiffies, on->on_nextcheck)) {
		ath_rate_ctl(sc, &an->an_node);
		/* XXX halve rate for station mode */
		on->on_nextcheck = jiffies + (ath_rateinterval * HZ) / 1000;
	}
}

static void
ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
{
	if (isnew)
		ath_rate_ctl_start(sc, &an->an_node);
}

static void
ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
{
	struct ath_node *an = ATH_NODE(ni);
	struct onoe_node *on = ATH_NODE_ONOE(an);
	const HAL_RATE_TABLE *rt = sc->sc_currates;
	u_int8_t rix;

	KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));

	DPRINTF(sc, "%s: set xmit rate for " MAC_FMT " to %dM\n",
		__func__, MAC_ADDR(ni->ni_macaddr),
		ni->ni_rates.rs_nrates > 0 ?
			(ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);

	ni->ni_txrate = rate;
	/*
	 * Before associating a node has no rate set setup
	 * so we can't calculate any transmit codes to use.
	 * This is ok since we should never be sending anything
	 * but management frames and those always go at the
	 * lowest hardware rate.
	 */
	if (ni->ni_rates.rs_nrates == 0)
		goto done;
	on->on_tx_rix0 = sc->sc_rixmap[ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL];
	on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode;

	on->on_tx_rate0sp = on->on_tx_rate0 |
		rt->info[on->on_tx_rix0].shortPreamble;
	if (sc->sc_mrretry) {
		/*
		 * Hardware supports multi-rate retry; setup two
		 * step-down retry rates and make the lowest rate
		 * be the ``last chance''.  We use 4, 2, 2, 2 tries
		 * respectively (4 is set here, the rest are fixed
		 * in the xmit routine).
		 */
		on->on_tx_try0 = 1 + 3;		/* 4 tries at rate 0 */
		if (--rate >= 0) {
			rix = sc->sc_rixmap[ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL];
			on->on_tx_rate1 = rt->info[rix].rateCode;
			on->on_tx_rate1sp = on->on_tx_rate1 |
				rt->info[rix].shortPreamble;
		} else
			on->on_tx_rate1 = on->on_tx_rate1sp = 0;
		if (--rate >= 0) {
			rix = sc->sc_rixmap[ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL];
			on->on_tx_rate2 = rt->info[rix].rateCode;
			on->on_tx_rate2sp = on->on_tx_rate2 |
				rt->info[rix].shortPreamble;
		} else
			on->on_tx_rate2 = on->on_tx_rate2sp = 0;
		if (rate > 0) {
			/* NB: only do this if we didn't already do it above */
			on->on_tx_rate3 = rt->info[0].rateCode;
			on->on_tx_rate3sp =
				on->on_tx_rate3 | rt->info[0].shortPreamble;
		} else
			on->on_tx_rate3 = on->on_tx_rate3sp = 0;
	} else {
		on->on_tx_try0 = ATH_TXMAXTRY;	/* max tries at rate 0 */
		on->on_tx_rate1 = on->on_tx_rate1sp = 0;
		on->on_tx_rate2 = on->on_tx_rate2sp = 0;
		on->on_tx_rate3 = on->on_tx_rate3sp = 0;
	}
done:
	on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0;
}

/*
 * Set the starting transmit rate for a node.
 */
static void
ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
{
#define	RATE(_ix)	(ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
	struct ieee80211vap *vap = ni->ni_vap;
	int srate;

	KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
	if (vap->iv_fixed_rate == IEEE80211_FIXED_RATE_NONE) {
		/*
		 * No fixed rate is requested. For 11b start with
		 * the highest negotiated rate; otherwise, for 11g
		 * and 11a, we start "in the middle" at 24Mb or 36Mb.
		 */
		srate = ni->ni_rates.rs_nrates - 1;
		if (sc->sc_curmode != IEEE80211_MODE_11B) {
			/*
			 * Scan the negotiated rate set to find the
			 * closest rate.
			 */
			/* NB: the rate set is assumed sorted */