amrr.c

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/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2004 INRIA
 * 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.
 *
 */
 
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
 
/*
 * AMRR rate control. See:
 * http://www-sop.inria.fr/rapports/sophia/RR-5208.html
 * "IEEE 802.11 Rate Adaptation: A Practical Approach" by
 *    Mathieu Lacage, Hossein Manshaei, Thierry Turletti
 */
#include "opt_ath.h"
#include "opt_inet.h"
#include "opt_wlan.h"
 
#include <sys/param.h>
#include <sys/systm.h> 
#include <sys/sysctl.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/errno.h>
 
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/bus.h>
 
#include <sys/socket.h>
 
#include <net/if.h>
#include <net/if_media.h>
#include <net/if_arp.h>
 
#include <net80211/ieee80211_var.h>
 
#include <net/bpf.h>
 
#ifdef INET
#include <netinet/in.h> 
#include <netinet/if_ether.h>
#endif
 
#include <dev/ath/if_athvar.h>
#include <dev/ath/ath_rate/amrr/amrr.h>
#include <dev/ath/ath_hal/ah_desc.h>
 
static  int ath_rateinterval = 1000;            /* rate ctl interval (ms)  */
static  int ath_rate_max_success_threshold = 10;
static  int ath_rate_min_success_threshold = 1;
 
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 *);
 
void
ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
{
        /* NB: assumed to be zero'd by caller */
}
 
void
ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
{
}
 
void
ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
        int shortPreamble, size_t frameLen, int tid, int is_aggr,
        u_int8_t *rix, int *try0, u_int8_t *txrate, int *maxdur,
        int *maxpktlen)
{
        struct amrr_node *amn = ATH_NODE_AMRR(an);
 
        *rix = amn->amn_tx_rix0;
        *try0 = amn->amn_tx_try0;
        if (shortPreamble)
                *txrate = amn->amn_tx_rate0sp;
        else
                *txrate = amn->amn_tx_rate0;
        maxdur = -1;
        maxpktlen = -1;
}
 
/*
 * Get the TX rates.
 *
 * The short preamble bits aren't set here; the caller should augment
 * the returned rate with the relevant preamble rate flag.
 */
void
ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
    uint8_t rix0, int is_aggr, struct ath_rc_series *rc)
{
        struct amrr_node *amn = ATH_NODE_AMRR(an);
 
        rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0;
 
        rc[0].rix = amn->amn_tx_rate0;
        rc[1].rix = amn->amn_tx_rate1;
        rc[2].rix = amn->amn_tx_rate2;
        rc[3].rix = amn->amn_tx_rate3;
 
        rc[0].tries = amn->amn_tx_try0;
        rc[1].tries = amn->amn_tx_try1;
        rc[2].tries = amn->amn_tx_try2;
        rc[3].tries = amn->amn_tx_try3;
}
 
void
ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
        struct ath_desc *ds, int shortPreamble, u_int8_t rix)
{
        struct amrr_node *amn = ATH_NODE_AMRR(an);
 
        ath_hal_setupxtxdesc(sc->sc_ah, ds
                , amn->amn_tx_rate1sp, amn->amn_tx_try1 /* series 1 */
                , amn->amn_tx_rate2sp, amn->amn_tx_try2 /* series 2 */
                , amn->amn_tx_rate3sp, amn->amn_tx_try3 /* series 3 */
        );
}
 
void
ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
        const struct ath_rc_series *rc, const struct ath_tx_status *ts,
        int frame_size, int rc_framesize, int nframes, int nbad)
{
        struct amrr_node *amn = ATH_NODE_AMRR(an);
        int sr = ts->ts_shortretry;
        int lr = ts->ts_longretry;
        int retry_count = sr + lr;
 
        amn->amn_tx_try0_cnt++;
        if (retry_count == 1) {
                amn->amn_tx_try1_cnt++;
        } else if (retry_count == 2) {
                amn->amn_tx_try1_cnt++;
                amn->amn_tx_try2_cnt++;
        } else if (retry_count == 3) {
                amn->amn_tx_try1_cnt++;
                amn->amn_tx_try2_cnt++;
                amn->amn_tx_try3_cnt++;
        } else if (retry_count > 3) {
                amn->amn_tx_try1_cnt++;
                amn->amn_tx_try2_cnt++;
                amn->amn_tx_try3_cnt++;
                amn->amn_tx_failure_cnt++;
        }
        if (amn->amn_interval != 0 &&
            ticks - amn->amn_ticks > amn->amn_interval) {
                ath_rate_ctl(sc, &an->an_node);
                amn->amn_ticks = ticks;
        }
}
 
void
ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
{
        if (isnew)
                ath_rate_ctl_start(sc, &an->an_node);
}
 
void
ath_rate_update_rx_rssi(struct ath_softc *sc, struct ath_node *an, int rssi)
{
}
 
static void 
node_reset(struct amrr_node *amn)
{
        amn->amn_tx_try0_cnt = 0;
        amn->amn_tx_try1_cnt = 0;
        amn->amn_tx_try2_cnt = 0;
        amn->amn_tx_try3_cnt = 0;
        amn->amn_tx_failure_cnt = 0;
        amn->amn_success = 0;
        amn->amn_recovery = 0;
        amn->amn_success_threshold = ath_rate_min_success_threshold;
}
 
static void
ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
{
        struct ath_node *an = ATH_NODE(ni);
        struct amrr_node *amn = ATH_NODE_AMRR(an);
        struct ieee80211vap *vap = ni->ni_vap;
        const HAL_RATE_TABLE *rt = sc->sc_currates;
        u_int8_t rix;
 
        KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
 
        IEEE80211_NOTE(vap, IEEE80211_MSG_RATECTL, ni,
            "%s: set xmit rate to %dM", __func__, 
            ni->ni_rates.rs_nrates > 0 ?
                (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
 
        amn->amn_rix = 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) {
                ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL;
                amn->amn_tx_rix0 = sc->sc_rixmap[ni->ni_txrate];
                amn->amn_tx_rate0 = rt->info[amn->amn_tx_rix0].rateCode;
                amn->amn_tx_rate0sp = amn->amn_tx_rate0 |
                        rt->info[amn->amn_tx_rix0].shortPreamble;
                if (sc->sc_mrretry) {
                        amn->amn_tx_try0 = 1;
                        amn->amn_tx_try1 = 1;
                        amn->amn_tx_try2 = 1;
                        amn->amn_tx_try3 = 1;
                        if (--rate >= 0) {
                                rix = sc->sc_rixmap[
                                                    ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
                                amn->amn_tx_rate1 = rt->info[rix].rateCode;
                                amn->amn_tx_rate1sp = amn->amn_tx_rate1 |
                                        rt->info[rix].shortPreamble;
                        } else {
                                amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
                        }
                        if (--rate >= 0) {
                                rix = sc->sc_rixmap[
                                                    ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
                                amn->amn_tx_rate2 = rt->info[rix].rateCode;
                                amn->amn_tx_rate2sp = amn->amn_tx_rate2 |
                                        rt->info[rix].shortPreamble;
                        } else {
                                amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
                        }
                        if (rate > 0) {
                                /* NB: only do this if we didn't already do it above */
                                amn->amn_tx_rate3 = rt->info[0].rateCode;
                                amn->amn_tx_rate3sp =
                                        amn->amn_tx_rate3 | rt->info[0].shortPreamble;
                        } else {
                                amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
                        }
                } else {
                        amn->amn_tx_try0 = ATH_TXMAXTRY;
                        /* theorically, these statements are useless because
                         *  the code which uses them tests for an_tx_try0 == ATH_TXMAXTRY
                         */
                        amn->amn_tx_try1 = 0;
                        amn->amn_tx_try2 = 0;
                        amn->amn_tx_try3 = 0;
                        amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
                        amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
                        amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
                }
        }
        node_reset(amn);
 
        amn->amn_interval = ath_rateinterval;
        if (vap->iv_opmode == IEEE80211_M_STA)
                amn->amn_interval /= 2;
        amn->amn_interval = (amn->amn_interval * hz) / 1000;
}
 
/*
 * 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)
        const struct ieee80211_txparam *tp = ni->ni_txparms;
        int srate;
 
        KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
        if (tp == NULL || tp->ucastrate == 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--)
                                ;
                }
        } else {
                /*
                 * A fixed rate is to be used; ic_fixed_rate is the
                 * IEEE code for this rate (sans basic bit).  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) != tp->ucastrate; srate--)
                        ;
        }
        /*
         * The selected rate may not be available due to races
         * and mode settings.  Also orphaned nodes created in
         * adhoc mode may not have any rate set so this lookup
         * can fail.  This is not fatal.
         */
        ath_rate_update(sc, ni, srate < 0 ? 0 : srate);
#undef RATE
}
 
/* 
 * Examine and potentially adjust the transmit rate.
 */
static void
ath_rate_ctl(void *arg, struct ieee80211_node *ni)
{
        struct ath_softc *sc = arg;
        struct amrr_node *amn = ATH_NODE_AMRR(ATH_NODE (ni));
        int rix;
 
#define is_success(amn) \
(amn->amn_tx_try1_cnt  < (amn->amn_tx_try0_cnt/10))
#define is_enough(amn) \
(amn->amn_tx_try0_cnt > 10)
#define is_failure(amn) \
(amn->amn_tx_try1_cnt > (amn->amn_tx_try0_cnt/3))
 
        rix = amn->amn_rix;
  
        IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
            "cnt0: %d cnt1: %d cnt2: %d cnt3: %d -- threshold: %d",
            amn->amn_tx_try0_cnt, amn->amn_tx_try1_cnt, amn->amn_tx_try2_cnt,
            amn->amn_tx_try3_cnt, amn->amn_success_threshold);
        if (is_success (amn) && is_enough (amn)) {
                amn->amn_success++;
                if (amn->amn_success == amn->amn_success_threshold &&
                    rix + 1 < ni->ni_rates.rs_nrates) {
                        amn->amn_recovery = 1;
                        amn->amn_success = 0;
                        rix++;
                        IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
                            "increase rate to %d", rix);
                } else {
                        amn->amn_recovery = 0;
                }
        } else if (is_failure (amn)) {
                amn->amn_success = 0;
                if (rix > 0) {
                        if (amn->amn_recovery) {
                                /* recovery failure. */
                                amn->amn_success_threshold *= 2;
                                amn->amn_success_threshold = min (amn->amn_success_threshold,
                                                                  (u_int)ath_rate_max_success_threshold);
                                IEEE80211_NOTE(ni->ni_vap,
                                    IEEE80211_MSG_RATECTL, ni,
                                    "decrease rate recovery thr: %d",
                                    amn->amn_success_threshold);
                        } else {
                                /* simple failure. */
                                amn->amn_success_threshold = ath_rate_min_success_threshold;
                                IEEE80211_NOTE(ni->ni_vap,
                                    IEEE80211_MSG_RATECTL, ni,
                                    "decrease rate normal thr: %d",
                                    amn->amn_success_threshold);
                        }
                        amn->amn_recovery = 0;
                        rix--;
                } else {
                        amn->amn_recovery = 0;
                }
        }
        if (is_enough (amn) || rix != amn->amn_rix) {
                /* reset counters. */
                amn->amn_tx_try0_cnt = 0;
                amn->amn_tx_try1_cnt = 0;
                amn->amn_tx_try2_cnt = 0;
                amn->amn_tx_try3_cnt = 0;
                amn->amn_tx_failure_cnt = 0;
        }
        if (rix != amn->amn_rix) {
                ath_rate_update(sc, ni, rix);
        }
}
 
static int
ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
    struct ath_rateioctl *re)
{
 
        return (EINVAL);
}
 
static void
ath_rate_sysctlattach(struct ath_softc *sc)
{
        struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
        struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
 
        SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
                "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
                "rate control: operation interval (ms)");
        /* XXX bounds check values */
        SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
                "max_sucess_threshold", CTLFLAG_RW,
                &ath_rate_max_success_threshold, 0, "");
        SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
                "min_sucess_threshold", CTLFLAG_RW,
                &ath_rate_min_success_threshold, 0, "");
}
 
struct ath_ratectrl *
ath_rate_attach(struct ath_softc *sc)
{
        struct amrr_softc *asc;
 
        asc = malloc(sizeof(struct amrr_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
        if (asc == NULL)
                return NULL;
        asc->arc.arc_space = sizeof(struct amrr_node);
        ath_rate_sysctlattach(sc);
 
        return &asc->arc;
}
 
void
ath_rate_detach(struct ath_ratectrl *arc)
{
        struct amrr_softc *asc = (struct amrr_softc *) arc;
 
        free(asc, M_DEVBUF);
}