2 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer,
10 * without modification.
11 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12 * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
13 * redistribution must be conditioned upon including a substantially
14 * similar Disclaimer requirement for further binary redistribution.
15 * 3. Neither the names of the above-listed copyright holders nor the names
16 * of any contributors may be used to endorse or promote products derived
17 * from this software without specific prior written permission.
19 * Alternatively, this software may be distributed under the terms of the
20 * GNU General Public License ("GPL") version 2 as published by the Free
21 * Software Foundation.
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
27 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
28 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
29 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
32 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
34 * THE POSSIBILITY OF SUCH DAMAGES.
36 * $FreeBSD: src/sys/dev/ath/ath_rate/onoe/onoe.c,v 1.12 2006/12/13 19:34:35 sam Exp $
40 * Atsushi Onoe's rate control algorithm.
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/sysctl.h>
46 #include <sys/module.h>
47 #include <sys/kernel.h>
49 #include <sys/errno.h>
50 #include <sys/serialize.h>
53 #include <sys/socket.h>
56 #include <net/if_media.h>
57 #include <net/if_arp.h>
58 #include <net/ethernet.h> /* XXX for ether_sprintf */
60 #include <netproto/802_11/ieee80211_var.h>
64 #include <dev/netif/ath/ath/if_athvar.h>
65 #include <dev/netif/ath/rate_onoe/onoe.h>
66 #include <dev/netif/ath/hal/ath_hal/ah_desc.h>
71 ATH_DEBUG_RATE = 0x00000010, /* rate control */
73 #define DPRINTF(sc, _fmt, ...) do { \
74 if (sc->sc_debug & ATH_DEBUG_RATE) \
75 kprintf(_fmt, __VA_ARGS__); \
78 #define DPRINTF(sc, _fmt, ...)
82 * Default parameters for the rate control algorithm. These are
83 * all tunable with sysctls. The rate controller runs periodically
84 * (each ath_rateinterval ms) analyzing transmit statistics for each
85 * neighbor/station (when operating in station mode this is only the AP).
86 * If transmits look to be working well over a sampling period then
87 * it gives a "raise rate credit". If transmits look to not be working
88 * well than it deducts a credit. If the credits cross a threshold then
89 * the transmit rate is raised. Various error conditions force the
90 * the transmit rate to be dropped.
92 * The decision to issue/deduct a credit is based on the errors and
93 * retries accumulated over the sampling period. ath_rate_raise defines
94 * the percent of retransmits for which a credit is issued/deducted.
95 * ath_rate_raise_threshold defines the threshold on credits at which
96 * the transmit rate is increased.
98 * XXX this algorithm is flawed.
100 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */
101 static int ath_rate_raise = 10; /* add credit threshold */
102 static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */
104 static void ath_ratectl_callout(void *);
105 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *,
107 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
108 static void ath_rate_ctl(void *, struct ieee80211_node *);
111 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
113 /* NB: assumed to be zero'd by caller */
114 ath_rate_update(sc, &an->an_node, 0);
118 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
123 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
124 int shortPreamble, size_t frameLen,
125 uint8_t *rix, int *try0, uint8_t *txrate)
127 struct onoe_node *on = ATH_NODE_ONOE(an);
129 *rix = on->on_tx_rix0;
130 *try0 = on->on_tx_try0;
132 *txrate = on->on_tx_rate0sp;
134 *txrate = on->on_tx_rate0;
138 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
139 struct ath_desc *ds, int shortPreamble, uint8_t rix)
141 struct onoe_node *on = ATH_NODE_ONOE(an);
143 ath_hal_setupxtxdesc(sc->sc_ah, ds
144 , on->on_tx_rate1sp, 2 /* series 1 */
145 , on->on_tx_rate2sp, 2 /* series 2 */
146 , on->on_tx_rate3sp, 2 /* series 3 */
151 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
152 const struct ath_buf *bf)
154 struct onoe_node *on = ATH_NODE_ONOE(an);
155 const struct ath_tx_status *ts = &bf->bf_status.ds_txstat;
157 if (ts->ts_status == 0)
161 on->on_tx_retr += ts->ts_shortretry + ts->ts_longretry;
165 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
168 ath_rate_ctl_start(sc, &an->an_node);
172 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
174 struct ath_node *an = ATH_NODE(ni);
175 struct onoe_node *on = ATH_NODE_ONOE(an);
176 const HAL_RATE_TABLE *rt = sc->sc_currates;
177 char ethstr[ETHER_ADDRSTRLEN + 1];
180 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
182 DPRINTF(sc, "%s: set xmit rate for %s to %dM\n",
183 __func__, kether_ntoa(ni->ni_macaddr, ethstr),
184 ni->ni_rates.rs_nrates > 0 ?
185 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
187 ni->ni_txrate = rate;
189 * Before associating a node has no rate set setup
190 * so we can't calculate any transmit codes to use.
191 * This is ok since we should never be sending anything
192 * but management frames and those always go at the
193 * lowest hardware rate.
195 if (ni->ni_rates.rs_nrates == 0)
197 on->on_tx_rix0 = sc->sc_rixmap[
198 ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL];
199 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode;
201 on->on_tx_rate0sp = on->on_tx_rate0 |
202 rt->info[on->on_tx_rix0].shortPreamble;
203 if (sc->sc_mrretry) {
205 * Hardware supports multi-rate retry; setup two
206 * step-down retry rates and make the lowest rate
207 * be the ``last chance''. We use 4, 2, 2, 2 tries
208 * respectively (4 is set here, the rest are fixed
209 * in the xmit routine).
211 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */
214 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
215 on->on_tx_rate1 = rt->info[rix].rateCode;
216 on->on_tx_rate1sp = on->on_tx_rate1 |
217 rt->info[rix].shortPreamble;
219 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
223 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
224 on->on_tx_rate2 = rt->info[rix].rateCode;
225 on->on_tx_rate2sp = on->on_tx_rate2 |
226 rt->info[rix].shortPreamble;
228 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
231 /* NB: only do this if we didn't already do it above */
232 on->on_tx_rate3 = rt->info[0].rateCode;
234 on->on_tx_rate3 | rt->info[0].shortPreamble;
236 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
239 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */
240 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
241 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
242 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
245 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0;
249 * Set the starting transmit rate for a node.
252 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
254 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
255 struct ieee80211com *ic = &sc->sc_ic;
258 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
259 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE) {
261 * No fixed rate is requested. For 11b start with
262 * the highest negotiated rate; otherwise, for 11g
263 * and 11a, we start "in the middle" at 24Mb or 36Mb.
265 srate = ni->ni_rates.rs_nrates - 1;
266 if (sc->sc_curmode != IEEE80211_MODE_11B) {
268 * Scan the negotiated rate set to find the
271 /* NB: the rate set is assumed sorted */
272 for (; srate >= 0 && RATE(srate) > 72; srate--)
274 KASSERT(srate >= 0, ("bogus rate set"));
278 * A fixed rate is to be used; ic_fixed_rate is an
279 * index into the supported rate set. Convert this
280 * to the index into the negotiated rate set for
281 * the node. We know the rate is there because the
282 * rate set is checked when the station associates.
284 const struct ieee80211_rateset *rs =
285 &ic->ic_sup_rates[ic->ic_curmode];
286 int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL;
287 /* NB: the rate set is assumed sorted */
288 srate = ni->ni_rates.rs_nrates - 1;
289 for (; srate >= 0 && RATE(srate) != r; srate--)
292 ("fixed rate %d not in rate set", ic->ic_fixed_rate));
294 ath_rate_update(sc, ni, srate);
299 ath_rate_cb(void *arg, struct ieee80211_node *ni)
301 struct ath_softc *sc = arg;
303 ath_rate_update(sc, ni, 0);
307 * Reset the rate control state for each 802.11 state transition.
310 ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state)
312 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc;
313 struct ieee80211com *ic = &sc->sc_ic;
314 struct ifnet *ifp = &ic->ic_if;
315 struct ieee80211_node *ni;
317 ASSERT_SERIALIZED(ifp->if_serializer);
319 if (state == IEEE80211_S_INIT) {
320 callout_stop(&osc->timer);
323 if (ic->ic_opmode == IEEE80211_M_STA) {
325 * Reset local xmit state; this is really only
326 * meaningful when operating in station mode.
329 if (state == IEEE80211_S_RUN) {
330 ath_rate_ctl_start(sc, ni);
332 ath_rate_update(sc, ni, 0);
336 * When operating as a station the node table holds
337 * the AP's that were discovered during scanning.
338 * For any other operating mode we want to reset the
339 * tx rate state of each node.
341 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, sc);
342 ath_rate_update(sc, ic->ic_bss, 0);
344 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE &&
345 state == IEEE80211_S_RUN) {
348 * Start the background rate control thread if we
349 * are not configured to use a fixed xmit rate.
351 interval = ath_rateinterval;
352 if (ic->ic_opmode == IEEE80211_M_STA)
354 callout_reset(&osc->timer, (interval * hz) / 1000,
355 ath_ratectl_callout, ifp);
360 * Examine and potentially adjust the transmit rate.
363 ath_rate_ctl(void *arg, struct ieee80211_node *ni)
365 struct ath_softc *sc = arg;
366 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni));
367 struct ieee80211_rateset *rs = &ni->ni_rates;
368 char ethstr[ETHER_ADDRSTRLEN + 1];
369 int dir = 0, nrate, enough;
373 * XXX: very primitive version.
375 enough = (on->on_tx_ok + on->on_tx_err >= 10);
377 /* no packet reached -> down */
378 if (on->on_tx_err > 0 && on->on_tx_ok == 0)
381 /* all packets needs retry in average -> down */
382 if (enough && on->on_tx_ok < on->on_tx_retr)
385 /* no error and less than rate_raise% of packets need retry -> up */
386 if (enough && on->on_tx_err == 0 &&
387 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100)
390 DPRINTF(sc, "%s: ok %d err %d retr %d upper %d dir %d\n",
391 kether_ntoa(ni->ni_macaddr, ethstr),
392 on->on_tx_ok, on->on_tx_err, on->on_tx_retr,
393 on->on_tx_upper, dir);
395 nrate = ni->ni_txrate;
398 if (enough && on->on_tx_upper > 0)
404 sc->sc_stats.ast_rate_drop++;
409 /* raise rate if we hit rate_raise_threshold */
410 if (++on->on_tx_upper < ath_rate_raise_threshold)
413 if (nrate + 1 < rs->rs_nrates) {
415 sc->sc_stats.ast_rate_raise++;
420 if (nrate != ni->ni_txrate) {
421 DPRINTF(sc, "%s: %dM -> %dM (%d ok, %d err, %d retr)\n",
423 (rs->rs_rates[ni->ni_txrate] & IEEE80211_RATE_VAL) / 2,
424 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2,
425 on->on_tx_ok, on->on_tx_err, on->on_tx_retr);
426 ath_rate_update(sc, ni, nrate);
428 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0;
433 ath_ratectl_callout(void *arg)
435 struct ifnet *ifp = arg;
436 struct ath_softc *sc = ifp->if_softc;
437 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc;
438 struct ieee80211com *ic = &sc->sc_ic;
441 wlan_serialize_enter();
442 if (ifp->if_flags & IFF_RUNNING) {
443 sc->sc_stats.ast_rate_calls++;
445 if (ic->ic_opmode == IEEE80211_M_STA)
446 ath_rate_ctl(sc, ic->ic_bss); /* NB: no reference */
448 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_ctl, sc);
450 interval = ath_rateinterval;
451 if (ic->ic_opmode == IEEE80211_M_STA)
453 callout_reset(&osc->timer, (interval * hz) / 1000,
454 ath_ratectl_callout, ifp);
456 wlan_serialize_exit();
460 ath_rate_sysctlattach(struct ath_softc *sc)
462 struct sysctl_ctx_list *ctx = &sc->sc_sysctl_ctx;
463 struct sysctl_oid *tree = sc->sc_sysctl_tree;
465 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
466 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
467 "rate control: operation interval (ms)");
468 /* XXX bounds check values */
469 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
470 "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0,
471 "rate control: retry threshold to credit rate raise (%%)");
472 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
473 "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0,
474 "rate control: # good periods before raising rate");
477 struct ath_ratectrl *
478 ath_rate_attach(struct ath_softc *sc)
480 struct onoe_softc *osc;
482 osc = kmalloc(sizeof(struct onoe_softc), M_DEVBUF, M_WAITOK | M_ZERO);
483 osc->arc.arc_space = sizeof(struct onoe_node);
484 callout_init(&osc->timer);
485 ath_rate_sysctlattach(sc);
490 ath_rate_detach(struct ath_ratectrl *arc)
492 struct onoe_softc *osc = (struct onoe_softc *) arc;
494 kfree(osc, M_DEVBUF);
498 ath_rate_stop(struct ath_ratectrl *arc)
500 struct onoe_softc *osc = (struct onoe_softc *) arc;
502 /* ASSERT_SERIALIZED */
503 callout_stop(&osc->timer);
510 onoe_modevent(module_t mod, int type, void *unused)
514 wlan_serialize_enter();
519 kprintf("ath_rate: <Atsushi Onoe's rate "
520 "control algorithm>\n");
531 wlan_serialize_exit();
536 static moduledata_t onoe_mod = {
541 DECLARE_MODULE(ath_rate, onoe_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
542 MODULE_VERSION(ath_rate, 1);
543 MODULE_DEPEND(ath_rate, wlan, 1, 1, 1);