FreeBSD/Linux Kernel Cross Reference
sys/dev/ath/ath_rate/onoe/onoe.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2002-2007 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.
     *
     * 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("$FreeBSD$");
    
    /*
     * Atsushi Onoe's rate control algorithm.
     */
    #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 <net/ethernet.h>               /* XXX for ether_sprintf */
    
    #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/onoe/onoe.h>
    #include <dev/ath/ath_hal/ah_desc.h>
    
    /*
     * 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 *);
   
   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 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;
           *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 onoe_node *on = ATH_NODE_ONOE(an);
   
           rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0;
   
           rc[0].rix = on->on_tx_rate0;
           rc[1].rix = on->on_tx_rate1;
           rc[2].rix = on->on_tx_rate2;
           rc[3].rix = on->on_tx_rate3;
   
           rc[0].tries = on->on_tx_try0;
           rc[1].tries = 2;
           rc[2].tries = 2;
           rc[3].tries = 2;
   }
   
   void
   ath_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 */
           );
   }
   
   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 onoe_node *on = ATH_NODE_ONOE(an);
   
           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 (on->on_interval != 0 && ticks - on->on_ticks > on->on_interval) {
                   ath_rate_ctl(sc, &an->an_node);
                   on->on_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
   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);
           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);
   
           /*
            * 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_rix = rate;
           ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL;
           on->on_tx_rix0 = sc->sc_rixmap[ni->ni_txrate];
           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;
   
           on->on_interval = ath_rateinterval;
           if (vap->iv_opmode == IEEE80211_M_STA)
                   on->on_interval /= 2;
           on->on_interval = (on->on_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 onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni));
           struct ieee80211_rateset *rs = &ni->ni_rates;
           int dir = 0, nrate, enough;
   
           /*
            * 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;
   
           IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
               "ok %d err %d retr %d upper %d dir %d",
               on->on_tx_ok, on->on_tx_err, on->on_tx_retr, on->on_tx_upper, dir);
   
           nrate = on->on_rix;
           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 != on->on_rix) {
                   IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
                       "%s: %dM -> %dM (%d ok, %d err, %d retr)", __func__,
                       ni->ni_txrate / 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;
   }
   
   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,
                   "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0,
                   "rate control: retry threshold to credit rate raise (%%)");
           SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
                   "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0,
                   "rate control: # good periods before raising rate");
   }
   
   static int
   ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
       struct ath_rateioctl *re)
   {
   
           return (EINVAL);
   }
   
   struct ath_ratectrl *
   ath_rate_attach(struct ath_softc *sc)
   {
           struct onoe_softc *osc;
   
           osc = malloc(sizeof(struct onoe_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
           if (osc == NULL)
                   return NULL;
           osc->arc.arc_space = sizeof(struct onoe_node);
           ath_rate_sysctlattach(sc);
   
           return &osc->arc;
   }
   
   void
   ath_rate_detach(struct ath_ratectrl *arc)
   {
           struct onoe_softc *osc = (struct onoe_softc *) arc;
   
           free(osc, M_DEVBUF);
   }

Cache object: 2aa649cfc46eee96c2af647cfe3fb175