2 * Copyright (c) 2004 INRIA
3 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
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7 * modification, are permitted provided that the following conditions
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15 * similar Disclaimer requirement for further binary redistribution.
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17 * of any contributors may be used to endorse or promote products derived
18 * from this software without specific prior written permission.
20 * Alternatively, this software may be distributed under the terms of the
21 * GNU General Public License ("GPL") version 2 as published by the Free
22 * Software Foundation.
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37 * $FreeBSD: src/sys/dev/ath/ath_rate/amrr/amrr.c,v 1.12 2006/12/13 19:34:34 sam Exp $
41 * AMRR rate control. See:
42 * http://www-sop.inria.fr/rapports/sophia/RR-5208.html
43 * "IEEE 802.11 Rate Adaptation: A Practical Approach" by
44 * Mathieu Lacage, Hossein Manshaei, Thierry Turletti
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/sysctl.h>
50 #include <sys/module.h>
51 #include <sys/kernel.h>
53 #include <sys/errno.h>
54 #include <sys/serialize.h>
57 #include <sys/socket.h>
60 #include <net/if_media.h>
61 #include <net/if_arp.h>
63 #include <netproto/802_11/ieee80211_var.h>
67 #include <dev/netif/ath/ath/if_athvar.h>
68 #include <dev/netif/ath/rate_amrr/amrr.h>
69 #include <dev/netif/ath/hal/ath_hal/ah_desc.h>
73 #define DPRINTF(sc, _fmt, ...) do { \
74 if (sc->sc_debug & 0x10) \
75 kprintf(_fmt, __VA_ARGS__); \
78 #define DPRINTF(sc, _fmt, ...)
81 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */
82 static int ath_rate_max_success_threshold = 10;
83 static int ath_rate_min_success_threshold = 1;
85 static void ath_ratectl_callout(void *);
86 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *,
88 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
89 static void ath_rate_ctl(void *, struct ieee80211_node *);
92 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
94 /* NB: assumed to be zero'd by caller */
95 ath_rate_update(sc, &an->an_node, 0);
99 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
104 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
105 int shortPreamble, size_t frameLen,
106 uint8_t *rix, int *try0, uint8_t *txrate)
108 struct amrr_node *amn = ATH_NODE_AMRR(an);
110 *rix = amn->amn_tx_rix0;
111 *try0 = amn->amn_tx_try0;
113 *txrate = amn->amn_tx_rate0sp;
115 *txrate = amn->amn_tx_rate0;
119 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
120 struct ath_desc *ds, int shortPreamble, uint8_t rix)
122 struct amrr_node *amn = ATH_NODE_AMRR(an);
124 ath_hal_setupxtxdesc(sc->sc_ah, ds
125 , amn->amn_tx_rate1sp, amn->amn_tx_try1 /* series 1 */
126 , amn->amn_tx_rate2sp, amn->amn_tx_try2 /* series 2 */
127 , amn->amn_tx_rate3sp, amn->amn_tx_try3 /* series 3 */
132 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
133 const struct ath_buf *bf)
135 struct amrr_node *amn = ATH_NODE_AMRR(an);
136 const struct ath_tx_status *ts = &bf->bf_status.ds_txstat;
137 int sr = ts->ts_shortretry;
138 int lr = ts->ts_longretry;
139 int retry_count = sr + lr;
141 amn->amn_tx_try0_cnt++;
142 if (retry_count == 1) {
143 amn->amn_tx_try1_cnt++;
144 } else if (retry_count == 2) {
145 amn->amn_tx_try1_cnt++;
146 amn->amn_tx_try2_cnt++;
147 } else if (retry_count == 3) {
148 amn->amn_tx_try1_cnt++;
149 amn->amn_tx_try2_cnt++;
150 amn->amn_tx_try3_cnt++;
151 } else if (retry_count > 3) {
152 amn->amn_tx_try1_cnt++;
153 amn->amn_tx_try2_cnt++;
154 amn->amn_tx_try3_cnt++;
155 amn->amn_tx_failure_cnt++;
160 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
163 ath_rate_ctl_start(sc, &an->an_node);
167 node_reset (struct amrr_node *amn)
169 amn->amn_tx_try0_cnt = 0;
170 amn->amn_tx_try1_cnt = 0;
171 amn->amn_tx_try2_cnt = 0;
172 amn->amn_tx_try3_cnt = 0;
173 amn->amn_tx_failure_cnt = 0;
174 amn->amn_success = 0;
175 amn->amn_recovery = 0;
176 amn->amn_success_threshold = ath_rate_min_success_threshold;
181 * The code below assumes that we are dealing with hardware multi rate retry
182 * I have no idea what will happen if you try to use this module with another
183 * type of hardware. Your machine might catch fire or it might work with
184 * horrible performance...
187 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
189 struct ath_node *an = ATH_NODE(ni);
190 struct amrr_node *amn = ATH_NODE_AMRR(an);
191 const HAL_RATE_TABLE *rt = sc->sc_currates;
192 char ethstr[ETHER_ADDRSTRLEN + 1];
195 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
197 DPRINTF(sc, "%s: set xmit rate for %s to %dM\n",
198 __func__, kether_ntoa(ni->ni_macaddr, ethstr),
199 ni->ni_rates.rs_nrates > 0 ?
200 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
202 ni->ni_txrate = rate;
204 * Before associating a node has no rate set setup
205 * so we can't calculate any transmit codes to use.
206 * This is ok since we should never be sending anything
207 * but management frames and those always go at the
208 * lowest hardware rate.
210 if (ni->ni_rates.rs_nrates > 0) {
211 amn->amn_tx_rix0 = sc->sc_rixmap[
212 ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL];
213 amn->amn_tx_rate0 = rt->info[amn->amn_tx_rix0].rateCode;
214 amn->amn_tx_rate0sp = amn->amn_tx_rate0 |
215 rt->info[amn->amn_tx_rix0].shortPreamble;
216 if (sc->sc_mrretry) {
217 amn->amn_tx_try0 = 1;
218 amn->amn_tx_try1 = 1;
219 amn->amn_tx_try2 = 1;
220 amn->amn_tx_try3 = 1;
223 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
224 amn->amn_tx_rate1 = rt->info[rix].rateCode;
225 amn->amn_tx_rate1sp = amn->amn_tx_rate1 |
226 rt->info[rix].shortPreamble;
228 amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
232 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
233 amn->amn_tx_rate2 = rt->info[rix].rateCode;
234 amn->amn_tx_rate2sp = amn->amn_tx_rate2 |
235 rt->info[rix].shortPreamble;
237 amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
240 /* NB: only do this if we didn't already do it above */
241 amn->amn_tx_rate3 = rt->info[0].rateCode;
242 amn->amn_tx_rate3sp =
243 amn->amn_tx_rate3 | rt->info[0].shortPreamble;
245 amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
248 amn->amn_tx_try0 = ATH_TXMAXTRY;
249 /* theorically, these statements are useless because
250 * the code which uses them tests for an_tx_try0 == ATH_TXMAXTRY
252 amn->amn_tx_try1 = 0;
253 amn->amn_tx_try2 = 0;
254 amn->amn_tx_try3 = 0;
255 amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
256 amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
257 amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
264 * Set the starting transmit rate for a node.
267 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
269 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
270 struct ieee80211com *ic = &sc->sc_ic;
273 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
274 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE) {
276 * No fixed rate is requested. For 11b start with
277 * the highest negotiated rate; otherwise, for 11g
278 * and 11a, we start "in the middle" at 24Mb or 36Mb.
280 srate = ni->ni_rates.rs_nrates - 1;
281 if (sc->sc_curmode != IEEE80211_MODE_11B) {
283 * Scan the negotiated rate set to find the
286 /* NB: the rate set is assumed sorted */
287 for (; srate >= 0 && RATE(srate) > 72; srate--)
289 KASSERT(srate >= 0, ("bogus rate set"));
293 * A fixed rate is to be used; ic_fixed_rate is an
294 * index into the supported rate set. Convert this
295 * to the index into the negotiated rate set for
296 * the node. We know the rate is there because the
297 * rate set is checked when the station associates.
299 const struct ieee80211_rateset *rs =
300 &ic->ic_sup_rates[ic->ic_curmode];
301 int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL;
302 /* NB: the rate set is assumed sorted */
303 srate = ni->ni_rates.rs_nrates - 1;
304 for (; srate >= 0 && RATE(srate) != r; srate--)
307 ("fixed rate %d not in rate set", ic->ic_fixed_rate));
309 ath_rate_update(sc, ni, srate);
314 ath_rate_cb(void *arg, struct ieee80211_node *ni)
316 struct ath_softc *sc = arg;
318 ath_rate_update(sc, ni, 0);
322 * Reset the rate control state for each 802.11 state transition.
325 ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state)
327 struct amrr_softc *asc = (struct amrr_softc *) sc->sc_rc;
328 struct ieee80211com *ic = &sc->sc_ic;
329 struct ifnet *ifp = &ic->ic_if;
330 struct ieee80211_node *ni;
332 ASSERT_SERIALIZED(ifp->if_serializer);
334 if (state == IEEE80211_S_INIT) {
335 callout_stop(&asc->timer);
338 if (ic->ic_opmode == IEEE80211_M_STA) {
340 * Reset local xmit state; this is really only
341 * meaningful when operating in station mode.
344 if (state == IEEE80211_S_RUN) {
345 ath_rate_ctl_start(sc, ni);
347 ath_rate_update(sc, ni, 0);
351 * When operating as a station the node table holds
352 * the AP's that were discovered during scanning.
353 * For any other operating mode we want to reset the
354 * tx rate state of each node.
356 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, sc);
357 ath_rate_update(sc, ic->ic_bss, 0);
359 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE &&
360 state == IEEE80211_S_RUN) {
363 * Start the background rate control thread if we
364 * are not configured to use a fixed xmit rate.
366 interval = ath_rateinterval;
367 if (ic->ic_opmode == IEEE80211_M_STA)
369 callout_reset(&asc->timer, (interval * hz) / 1000,
370 ath_ratectl_callout, ifp);
375 * Examine and potentially adjust the transmit rate.
378 ath_rate_ctl(void *arg, struct ieee80211_node *ni)
380 struct ath_softc *sc = arg;
381 struct amrr_node *amn = ATH_NODE_AMRR(ATH_NODE (ni));
384 #define is_success(amn) \
385 (amn->amn_tx_try1_cnt < (amn->amn_tx_try0_cnt/10))
386 #define is_enough(amn) \
387 (amn->amn_tx_try0_cnt > 10)
388 #define is_failure(amn) \
389 (amn->amn_tx_try1_cnt > (amn->amn_tx_try0_cnt/3))
390 #define is_max_rate(ni) \
391 ((ni->ni_txrate + 1) >= ni->ni_rates.rs_nrates)
392 #define is_min_rate(ni) \
395 old_rate = ni->ni_txrate;
397 DPRINTF (sc, "cnt0: %d cnt1: %d cnt2: %d cnt3: %d -- threshold: %d\n",
398 amn->amn_tx_try0_cnt,
399 amn->amn_tx_try1_cnt,
400 amn->amn_tx_try2_cnt,
401 amn->amn_tx_try3_cnt,
402 amn->amn_success_threshold);
403 if (is_success (amn) && is_enough (amn)) {
405 if (amn->amn_success == amn->amn_success_threshold &&
407 amn->amn_recovery = 1;
408 amn->amn_success = 0;
410 DPRINTF (sc, "increase rate to %d\n", ni->ni_txrate);
412 amn->amn_recovery = 0;
414 } else if (is_failure (amn)) {
415 amn->amn_success = 0;
416 if (!is_min_rate (ni)) {
417 if (amn->amn_recovery) {
418 /* recovery failure. */
419 amn->amn_success_threshold *= 2;
420 amn->amn_success_threshold = min (amn->amn_success_threshold,
421 (u_int)ath_rate_max_success_threshold);
422 DPRINTF (sc, "decrease rate recovery thr: %d\n", amn->amn_success_threshold);
424 /* simple failure. */
425 amn->amn_success_threshold = ath_rate_min_success_threshold;
426 DPRINTF (sc, "decrease rate normal thr: %d\n", amn->amn_success_threshold);
428 amn->amn_recovery = 0;
431 amn->amn_recovery = 0;
435 if (is_enough (amn) || old_rate != ni->ni_txrate) {
436 /* reset counters. */
437 amn->amn_tx_try0_cnt = 0;
438 amn->amn_tx_try1_cnt = 0;
439 amn->amn_tx_try2_cnt = 0;
440 amn->amn_tx_try3_cnt = 0;
441 amn->amn_tx_failure_cnt = 0;
443 if (old_rate != ni->ni_txrate) {
444 ath_rate_update(sc, ni, ni->ni_txrate);
449 ath_ratectl_callout(void *arg)
451 struct ifnet *ifp = arg;
452 struct ath_softc *sc = ifp->if_softc;
453 struct amrr_softc *asc = (struct amrr_softc *)sc->sc_rc;
454 struct ieee80211com *ic = &sc->sc_ic;
457 wlan_serialize_enter();
458 if (ifp->if_flags & IFF_RUNNING) {
459 sc->sc_stats.ast_rate_calls++;
461 if (ic->ic_opmode == IEEE80211_M_STA)
462 ath_rate_ctl(sc, ic->ic_bss); /* NB: no reference */
464 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_ctl, sc);
466 interval = ath_rateinterval;
467 if (ic->ic_opmode == IEEE80211_M_STA)
469 callout_reset(&asc->timer, (interval * hz) / 1000,
470 ath_ratectl_callout, ifp);
472 wlan_serialize_exit();
476 ath_rate_sysctlattach(struct ath_softc *sc)
478 struct sysctl_ctx_list *ctx = &sc->sc_sysctl_ctx;
479 struct sysctl_oid *tree = sc->sc_sysctl_tree;
481 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
482 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
483 "rate control: operation interval (ms)");
484 /* XXX bounds check values */
485 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
486 "max_sucess_threshold", CTLFLAG_RW,
487 &ath_rate_max_success_threshold, 0, "");
488 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
489 "min_sucess_threshold", CTLFLAG_RW,
490 &ath_rate_min_success_threshold, 0, "");
493 struct ath_ratectrl *
494 ath_rate_attach(struct ath_softc *sc)
496 struct amrr_softc *asc;
498 asc = kmalloc(sizeof(struct amrr_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
501 asc->arc.arc_space = sizeof(struct amrr_node);
502 callout_init(&asc->timer);
503 ath_rate_sysctlattach(sc);
509 ath_rate_detach(struct ath_ratectrl *arc)
511 struct amrr_softc *asc = (struct amrr_softc *)arc;
513 kfree(asc, M_DEVBUF);
517 ath_rate_stop(struct ath_ratectrl *arc)
519 struct amrr_softc *asc = (struct amrr_softc *)arc;
521 /* ASSERT_SERIALIZED */
522 callout_stop(&asc->timer);
529 amrr_modevent(module_t mod, int type, void *unused)
533 wlan_serialize_enter();
538 kprintf("ath_rate: <AMRR rate control "
539 "algorithm> version 0.1\n");
550 wlan_serialize_exit();
554 static moduledata_t amrr_mod = {
559 DECLARE_MODULE(ath_rate, amrr_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
560 MODULE_VERSION(ath_rate, 1);
561 MODULE_DEPEND(ath_rate, wlan, 1, 1, 1);