/*- * Copyright (c) 2002-2004 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,v 1.1.1.1 2006/09/12 03:45:29 steven Exp $ *//* * Atsushi Onoe's rate control algorithm. */#include <linux/config.h>#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 "if_athrate.h"#include "if_athvar.h"#include "ah_desc.h"#include "onoe.h"#define	ONOE_DEBUG#ifdef ONOE_DEBUGenum {	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 rate);static void	ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);static void	ath_rate_ctl(void *, struct ieee80211_node *);voidath_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);}EXPORT_SYMBOL(ath_rate_node_init);voidath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an){}EXPORT_SYMBOL(ath_rate_node_cleanup);voidath_rate_findrate(struct ath_softc *sc, struct ath_node *an,	int shortPreamble, size_t frameLen,	u_int8_t *rix, 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;}EXPORT_SYMBOL(ath_rate_findrate);voidath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,	struct ath_desc *ds, int shortPreamble, u_int8_t rix){	struct onoe_node *on = ATH_NODE_ONOE(an);	ath_hal_setupxtxdesc(sc->sc_ah, ds		, on->on_tx_rate1sp, 2	/* series 1 */		, on->on_tx_rate2sp, 2	/* series 2 */		, on->on_tx_rate3sp, 2	/* series 3 */	);}EXPORT_SYMBOL(ath_rate_setupxtxdesc);voidath_rate_tx_complete(struct ath_softc *sc,	struct ath_node *an, const struct ath_desc *ds){	struct onoe_node *on = ATH_NODE_ONOE(an);	if (ds->ds_txstat.ts_status == 0)		on->on_tx_ok++;	else		on->on_tx_err++;	on->on_tx_retr += ds->ds_txstat.ts_shortretry			+ ds->ds_txstat.ts_longretry;	if (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;	}}EXPORT_SYMBOL(ath_rate_tx_complete);voidath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew){	if (isnew)		ath_rate_ctl_start(sc, &an->an_node);}EXPORT_SYMBOL(ath_rate_newassoc);static voidath_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 %s to %dM\n",	    __func__, ether_sprintf(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 voidath_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 */			for (; srate >= 0 && RATE(srate) > 72; srate--)				;			KASSERT(srate >= 0, ("bogus rate set"));		}	} else {		/*		 * A fixed rate is to be used; iv_fixed_rate is the		 * 802.11 rate code.  Convert this to the index into		 * the negotiated rate set for the node.  We know the		 * rate is there because the rate set is checked when		 * the station associates.		 */		/* NB: the rate set is assumed sorted */		srate = ni->ni_rates.rs_nrates - 1;		for (; srate >= 0 && RATE(srate) != vap->iv_fixed_rate; srate--)			;		KASSERT(srate >= 0,			("fixed rate %d not in rate set", vap->iv_fixed_rate));	}	ath_rate_update(sc, ni, srate);#undef RATE}static voidath_rate_cb(void *arg, struct ieee80211_node *ni){	ath_rate_update(ni->ni_ic->ic_dev->priv, ni, (int) arg);}/* * Reset the rate control state for each 802.11 state transition. */voidath_rate_newstate(struct ieee80211vap *vap, enum ieee80211_state state){	struct ieee80211com *ic = vap->iv_ic;	struct ath_softc *sc = ic->ic_dev->priv;	struct ieee80211_node *ni;	if (state == IEEE80211_S_INIT)		return;	if (vap->iv_opmode == IEEE80211_M_STA) {		/*		 * Reset local xmit state; this is really only		 * meaningful when operating in station mode.		 */		ni = vap->iv_bss;		if (state == IEEE80211_S_RUN) {			ath_rate_ctl_start(sc, ni);		} else {			ath_rate_update(sc, ni, 0);		}	} else {		/*		 * When operating as a station the node table holds		 * the AP's that were discovered during scanning.		 * For any other operating mode we want to reset the		 * tx rate state of each node.		 */		ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, 0);		ath_rate_update(sc, vap->iv_bss, 0);	}}EXPORT_SYMBOL(ath_rate_newstate);/*  * Examine and potentially adjust the transmit rate. */static voidath_rate_ctl(void *arg, struct ieee80211_node *ni){	struct ath_softc *sc = arg;	struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni));	struct ieee80211_rateset *rs = &ni->ni_rates;	int dir = 0, nrate, enough;	sc->sc_stats.ast_rate_calls++;	/*	 * Rate control	 * XXX: very primitive version.	 */	enough = (on->on_tx_ok + on->on_tx_err >= 10);	/* no packet reached -> down */	if (on->on_tx_err > 0 && on->on_tx_ok == 0)		dir = -1;	/* all packets needs retry in average -> down */	if (enough && on->on_tx_ok < on->on_tx_retr)		dir = -1;	/* no error and less than rate_raise% of packets need retry -> up */	if (enough && on->on_tx_err == 0 &&	    on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100)		dir = 1;	DPRINTF(sc, "%s: ok %d err %d retr %d upper %d dir %d\n",		ether_sprintf(ni->ni_macaddr),		on->on_tx_ok, on->on_tx_err, on->on_tx_retr,		on->on_tx_upper, dir);	nrate = ni->ni_txrate;	switch (dir) {	case 0:		if (enough && on->on_tx_upper > 0)			on->on_tx_upper--;		break;	case -1:		if (nrate > 0) {			nrate--;			sc->sc_stats.ast_rate_drop++;		}		on->on_tx_upper = 0;		break;	case 1:		/* raise rate if we hit rate_raise_threshold */		if (++on->on_tx_upper < ath_rate_raise_threshold)			break;		on->on_tx_upper = 0;		if (nrate + 1 < rs->rs_nrates) {			nrate++;			sc->sc_stats.ast_rate_raise++;		}		break;	}	if (nrate != ni->ni_txrate) {		DPRINTF(sc, "%s: %dM -> %dM (%d ok, %d err, %d retr)\n",		    __func__,		    (rs->rs_rates[ni->ni_txrate] & IEEE80211_RATE_VAL) / 2,		    (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2,		    on->on_tx_ok, on->on_tx_err, on->on_tx_retr);		ath_rate_update(sc, ni, nrate);	} else if (enough)		on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0;}struct ath_ratectrl *ath_rate_attach(struct ath_softc *sc){	struct onoe_softc *osc;	osc = kmalloc(sizeof(struct onoe_softc), GFP_ATOMIC);	if (osc == NULL)		return NULL;	osc->arc.arc_space = sizeof(struct onoe_node);	osc->arc.arc_vap_space = 0;	return &osc->arc;}EXPORT_SYMBOL(ath_rate_attach);voidath_rate_detach(struct ath_ratectrl *arc){	struct onoe_softc *osc = (struct onoe_softc *) arc;	kfree(osc);}EXPORT_SYMBOL(ath_rate_detach);static	int minrateinterval = 500;		/* 500ms */static	int maxpercent = 100;			/* 100% */static	int minpercent = 0;			/* 0% */static	int maxint = 0x7fffffff;		/* 32-bit big */#define	CTL_AUTO	-2	/* cannot be CTL_ANY or CTL_NONE *//* * Static (i.e. global) sysctls. */enum {	DEV_ATH		= 9,			/* XXX known by many */};static ctl_table ath_rate_static_sysctls[] = {	{ .ctl_name	= CTL_AUTO,	  .procname	= "interval",	  .mode		= 0644,	  .data		= &ath_rateinterval,	  .maxlen	= sizeof(ath_rateinterval),	  .extra1	= &minrateinterval,	  .extra2	= &maxint,	  .proc_handler	= proc_dointvec_minmax	},	{ .ctl_name	= CTL_AUTO,	  .procname	= "raise",	  .mode		= 0644,	  .data		= &ath_rate_raise,	  .maxlen	= sizeof(ath_rate_raise),	  .extra1	= &minpercent,	  .extra2	= &maxpercent,	  .proc_handler	= proc_dointvec_minmax	},	{ .ctl_name	= CTL_AUTO,	  .procname	= "raise_threshold",	  .mode		= 0644,	  .data		= &ath_rate_raise_threshold,	  .maxlen	= sizeof(ath_rate_raise_threshold),	  .proc_handler	= proc_dointvec	},	{ 0 }};static ctl_table ath_rate_table[] = {	{ .ctl_name	= CTL_AUTO,	  .procname	= "rate",	  .mode		= 0555,	  .child	= ath_rate_static_sysctls	}, { 0 }};static ctl_table ath_ath_table[] = {	{ .ctl_name	= DEV_ATH,	  .procname	= "ath",	  .mode		= 0555,	  .child	= ath_rate_table	}, { 0 }};static ctl_table ath_root_table[] = {	{ .ctl_name	= CTL_DEV,	  .procname	= "dev",	  .mode		= 0555,	  .child	= ath_ath_table	}, { 0 }};static struct ctl_table_header *ath_sysctl_header;MODULE_AUTHOR("Errno Consulting, Sam Leffler");MODULE_DESCRIPTION("Atsushi Onoe's rate control algorithm for Atheros devices");#ifdef MODULE_LICENSEMODULE_LICENSE("Dual BSD/GPL");#endifstatic char *version = "1.0";static char *dev_info = "ath_rate_onoe";static int __initinit_ath_rate_onoe(void){	printk(KERN_INFO "%s: %s\n", dev_info, version);#ifdef CONFIG_SYSCTL	ath_sysctl_header = register_sysctl_table(ath_root_table, 1);#endif	return (0);}module_init(init_ath_rate_onoe);static void __exitexit_ath_rate_onoe(void){#ifdef CONFIG_SYSCTL	if (ath_sysctl_header != NULL)		unregister_sysctl_table(ath_sysctl_header);#endif	printk(KERN_INFO "%s: unloaded\n", dev_info);}module_exit(exit_ath_rate_onoe);