2 * Copyright (c) 2004 INRIA
3 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer,
11 * without modification.
12 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
13 * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
14 * redistribution must be conditioned upon including a substantially
15 * similar Disclaimer requirement for further binary redistribution.
16 * 3. Neither the names of the above-listed copyright holders nor the names
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.
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
28 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
29 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
30 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
33 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
35 * THE POSSIBILITY OF SUCH DAMAGES.
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
43 * AMRR rate control. See:
44 * http://www-sop.inria.fr/rapports/sophia/RR-5208.html
45 * "IEEE 802.11 Rate Adaptation: A Practical Approach" by
46 * Mathieu Lacage, Hossein Manshaei, Thierry Turletti
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/sysctl.h>
53 #include <sys/module.h>
54 #include <sys/kernel.h>
56 #include <sys/mutex.h>
57 #include <sys/errno.h>
59 #include <machine/bus.h>
60 #include <machine/resource.h>
63 #include <sys/socket.h>
66 #include <net/if_media.h>
67 #include <net/if_arp.h>
68 #include <net/ethernet.h> /* XXX for ether_sprintf */
70 #include <net80211/ieee80211_var.h>
75 #include <netinet/in.h>
76 #include <netinet/if_ether.h>
79 #include <dev/ath/if_athvar.h>
80 #include <dev/ath/ath_rate/amrr/amrr.h>
81 #include <contrib/dev/ath/ah_desc.h>
85 #define DPRINTF(sc, _fmt, ...) do { \
86 if (sc->sc_debug & 0x10) \
87 printf(_fmt, __VA_ARGS__); \
90 #define DPRINTF(sc, _fmt, ...)
93 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */
94 static int ath_rate_max_success_threshold = 10;
95 static int ath_rate_min_success_threshold = 1;
97 static void ath_ratectl(void *);
98 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *,
100 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
101 static void ath_rate_ctl(void *, struct ieee80211_node *);
104 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
106 /* NB: assumed to be zero'd by caller */
107 ath_rate_update(sc, &an->an_node, 0);
111 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
116 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
117 int shortPreamble, size_t frameLen,
118 u_int8_t *rix, int *try0, u_int8_t *txrate)
120 struct amrr_node *amn = ATH_NODE_AMRR(an);
122 *rix = amn->amn_tx_rix0;
123 *try0 = amn->amn_tx_try0;
125 *txrate = amn->amn_tx_rate0sp;
127 *txrate = amn->amn_tx_rate0;
131 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
132 struct ath_desc *ds, int shortPreamble, u_int8_t rix)
134 struct amrr_node *amn = ATH_NODE_AMRR(an);
136 ath_hal_setupxtxdesc(sc->sc_ah, ds
137 , amn->amn_tx_rate1sp, amn->amn_tx_try1 /* series 1 */
138 , amn->amn_tx_rate2sp, amn->amn_tx_try2 /* series 2 */
139 , amn->amn_tx_rate3sp, amn->amn_tx_try3 /* series 3 */
144 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
145 const struct ath_buf *bf)
147 struct amrr_node *amn = ATH_NODE_AMRR(an);
148 const struct ath_tx_status *ts = &bf->bf_status.ds_txstat;
149 int sr = ts->ts_shortretry;
150 int lr = ts->ts_longretry;
151 int retry_count = sr + lr;
153 amn->amn_tx_try0_cnt++;
154 if (retry_count == 1) {
155 amn->amn_tx_try1_cnt++;
156 } else if (retry_count == 2) {
157 amn->amn_tx_try1_cnt++;
158 amn->amn_tx_try2_cnt++;
159 } else if (retry_count == 3) {
160 amn->amn_tx_try1_cnt++;
161 amn->amn_tx_try2_cnt++;
162 amn->amn_tx_try3_cnt++;
163 } else if (retry_count > 3) {
164 amn->amn_tx_try1_cnt++;
165 amn->amn_tx_try2_cnt++;
166 amn->amn_tx_try3_cnt++;
167 amn->amn_tx_failure_cnt++;
172 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
175 ath_rate_ctl_start(sc, &an->an_node);
179 node_reset (struct amrr_node *amn)
181 amn->amn_tx_try0_cnt = 0;
182 amn->amn_tx_try1_cnt = 0;
183 amn->amn_tx_try2_cnt = 0;
184 amn->amn_tx_try3_cnt = 0;
185 amn->amn_tx_failure_cnt = 0;
186 amn->amn_success = 0;
187 amn->amn_recovery = 0;
188 amn->amn_success_threshold = ath_rate_min_success_threshold;
193 * The code below assumes that we are dealing with hardware multi rate retry
194 * I have no idea what will happen if you try to use this module with another
195 * type of hardware. Your machine might catch fire or it might work with
196 * horrible performance...
199 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
201 struct ath_node *an = ATH_NODE(ni);
202 struct amrr_node *amn = ATH_NODE_AMRR(an);
203 const HAL_RATE_TABLE *rt = sc->sc_currates;
206 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
208 DPRINTF(sc, "%s: set xmit rate for %s to %dM\n",
209 __func__, ether_sprintf(ni->ni_macaddr),
210 ni->ni_rates.rs_nrates > 0 ?
211 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
213 ni->ni_txrate = rate;
215 * Before associating a node has no rate set setup
216 * so we can't calculate any transmit codes to use.
217 * This is ok since we should never be sending anything
218 * but management frames and those always go at the
219 * lowest hardware rate.
221 if (ni->ni_rates.rs_nrates > 0) {
222 amn->amn_tx_rix0 = sc->sc_rixmap[
223 ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL];
224 amn->amn_tx_rate0 = rt->info[amn->amn_tx_rix0].rateCode;
225 amn->amn_tx_rate0sp = amn->amn_tx_rate0 |
226 rt->info[amn->amn_tx_rix0].shortPreamble;
227 if (sc->sc_mrretry) {
228 amn->amn_tx_try0 = 1;
229 amn->amn_tx_try1 = 1;
230 amn->amn_tx_try2 = 1;
231 amn->amn_tx_try3 = 1;
234 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
235 amn->amn_tx_rate1 = rt->info[rix].rateCode;
236 amn->amn_tx_rate1sp = amn->amn_tx_rate1 |
237 rt->info[rix].shortPreamble;
239 amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
243 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
244 amn->amn_tx_rate2 = rt->info[rix].rateCode;
245 amn->amn_tx_rate2sp = amn->amn_tx_rate2 |
246 rt->info[rix].shortPreamble;
248 amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
251 /* NB: only do this if we didn't already do it above */
252 amn->amn_tx_rate3 = rt->info[0].rateCode;
253 amn->amn_tx_rate3sp =
254 amn->amn_tx_rate3 | rt->info[0].shortPreamble;
256 amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
259 amn->amn_tx_try0 = ATH_TXMAXTRY;
260 /* theorically, these statements are useless because
261 * the code which uses them tests for an_tx_try0 == ATH_TXMAXTRY
263 amn->amn_tx_try1 = 0;
264 amn->amn_tx_try2 = 0;
265 amn->amn_tx_try3 = 0;
266 amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
267 amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
268 amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
275 * Set the starting transmit rate for a node.
278 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
280 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
281 struct ieee80211com *ic = &sc->sc_ic;
284 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
285 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE) {
287 * No fixed rate is requested. For 11b start with
288 * the highest negotiated rate; otherwise, for 11g
289 * and 11a, we start "in the middle" at 24Mb or 36Mb.
291 srate = ni->ni_rates.rs_nrates - 1;
292 if (sc->sc_curmode != IEEE80211_MODE_11B) {
294 * Scan the negotiated rate set to find the
297 /* NB: the rate set is assumed sorted */
298 for (; srate >= 0 && RATE(srate) > 72; srate--)
300 KASSERT(srate >= 0, ("bogus rate set"));
304 * A fixed rate is to be used; ic_fixed_rate is an
305 * index into the supported rate set. Convert this
306 * to the index into the negotiated rate set for
307 * the node. We know the rate is there because the
308 * rate set is checked when the station associates.
310 const struct ieee80211_rateset *rs =
311 &ic->ic_sup_rates[ic->ic_curmode];
312 int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL;
313 /* NB: the rate set is assumed sorted */
314 srate = ni->ni_rates.rs_nrates - 1;
315 for (; srate >= 0 && RATE(srate) != r; srate--)
318 ("fixed rate %d not in rate set", ic->ic_fixed_rate));
320 ath_rate_update(sc, ni, srate);
325 ath_rate_cb(void *arg, struct ieee80211_node *ni)
327 struct ath_softc *sc = arg;
329 ath_rate_update(sc, ni, 0);
333 * Reset the rate control state for each 802.11 state transition.
336 ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state)
338 struct amrr_softc *asc = (struct amrr_softc *) sc->sc_rc;
339 struct ieee80211com *ic = &sc->sc_ic;
340 struct ieee80211_node *ni;
342 if (state == IEEE80211_S_INIT) {
343 callout_stop(&asc->timer);
346 if (ic->ic_opmode == IEEE80211_M_STA) {
348 * Reset local xmit state; this is really only
349 * meaningful when operating in station mode.
352 if (state == IEEE80211_S_RUN) {
353 ath_rate_ctl_start(sc, ni);
355 ath_rate_update(sc, ni, 0);
359 * When operating as a station the node table holds
360 * the AP's that were discovered during scanning.
361 * For any other operating mode we want to reset the
362 * tx rate state of each node.
364 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, sc);
365 ath_rate_update(sc, ic->ic_bss, 0);
367 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE &&
368 state == IEEE80211_S_RUN) {
371 * Start the background rate control thread if we
372 * are not configured to use a fixed xmit rate.
374 interval = ath_rateinterval;
375 if (ic->ic_opmode == IEEE80211_M_STA)
377 callout_reset(&asc->timer, (interval * hz) / 1000,
378 ath_ratectl, sc->sc_ifp);
383 * Examine and potentially adjust the transmit rate.
386 ath_rate_ctl(void *arg, struct ieee80211_node *ni)
388 struct ath_softc *sc = arg;
389 struct amrr_node *amn = ATH_NODE_AMRR(ATH_NODE (ni));
392 #define is_success(amn) \
393 (amn->amn_tx_try1_cnt < (amn->amn_tx_try0_cnt/10))
394 #define is_enough(amn) \
395 (amn->amn_tx_try0_cnt > 10)
396 #define is_failure(amn) \
397 (amn->amn_tx_try1_cnt > (amn->amn_tx_try0_cnt/3))
398 #define is_max_rate(ni) \
399 ((ni->ni_txrate + 1) >= ni->ni_rates.rs_nrates)
400 #define is_min_rate(ni) \
403 old_rate = ni->ni_txrate;
405 DPRINTF (sc, "cnt0: %d cnt1: %d cnt2: %d cnt3: %d -- threshold: %d\n",
406 amn->amn_tx_try0_cnt,
407 amn->amn_tx_try1_cnt,
408 amn->amn_tx_try2_cnt,
409 amn->amn_tx_try3_cnt,
410 amn->amn_success_threshold);
411 if (is_success (amn) && is_enough (amn)) {
413 if (amn->amn_success == amn->amn_success_threshold &&
415 amn->amn_recovery = 1;
416 amn->amn_success = 0;
418 DPRINTF (sc, "increase rate to %d\n", ni->ni_txrate);
420 amn->amn_recovery = 0;
422 } else if (is_failure (amn)) {
423 amn->amn_success = 0;
424 if (!is_min_rate (ni)) {
425 if (amn->amn_recovery) {
426 /* recovery failure. */
427 amn->amn_success_threshold *= 2;
428 amn->amn_success_threshold = min (amn->amn_success_threshold,
429 (u_int)ath_rate_max_success_threshold);
430 DPRINTF (sc, "decrease rate recovery thr: %d\n", amn->amn_success_threshold);
432 /* simple failure. */
433 amn->amn_success_threshold = ath_rate_min_success_threshold;
434 DPRINTF (sc, "decrease rate normal thr: %d\n", amn->amn_success_threshold);
436 amn->amn_recovery = 0;
439 amn->amn_recovery = 0;
443 if (is_enough (amn) || old_rate != ni->ni_txrate) {
444 /* reset counters. */
445 amn->amn_tx_try0_cnt = 0;
446 amn->amn_tx_try1_cnt = 0;
447 amn->amn_tx_try2_cnt = 0;
448 amn->amn_tx_try3_cnt = 0;
449 amn->amn_tx_failure_cnt = 0;
451 if (old_rate != ni->ni_txrate) {
452 ath_rate_update(sc, ni, ni->ni_txrate);
457 ath_ratectl(void *arg)
459 struct ifnet *ifp = arg;
460 struct ath_softc *sc = ifp->if_softc;
461 struct amrr_softc *asc = (struct amrr_softc *) sc->sc_rc;
462 struct ieee80211com *ic = &sc->sc_ic;
465 if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
466 sc->sc_stats.ast_rate_calls++;
468 if (ic->ic_opmode == IEEE80211_M_STA)
469 ath_rate_ctl(sc, ic->ic_bss); /* NB: no reference */
471 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_ctl, sc);
473 interval = ath_rateinterval;
474 if (ic->ic_opmode == IEEE80211_M_STA)
476 callout_reset(&asc->timer, (interval * hz) / 1000,
477 ath_ratectl, sc->sc_ifp);
481 ath_rate_sysctlattach(struct ath_softc *sc)
483 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
484 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
486 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
487 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
488 "rate control: operation interval (ms)");
489 /* XXX bounds check values */
490 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
491 "max_sucess_threshold", CTLFLAG_RW,
492 &ath_rate_max_success_threshold, 0, "");
493 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
494 "min_sucess_threshold", CTLFLAG_RW,
495 &ath_rate_min_success_threshold, 0, "");
498 struct ath_ratectrl *
499 ath_rate_attach(struct ath_softc *sc)
501 struct amrr_softc *asc;
503 asc = malloc(sizeof(struct amrr_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
506 asc->arc.arc_space = sizeof(struct amrr_node);
507 callout_init(&asc->timer, debug_mpsafenet ? CALLOUT_MPSAFE : 0);
508 ath_rate_sysctlattach(sc);
514 ath_rate_detach(struct ath_ratectrl *arc)
516 struct amrr_softc *asc = (struct amrr_softc *) arc;
518 callout_drain(&asc->timer);
526 amrr_modevent(module_t mod, int type, void *unused)
531 printf("ath_rate: <AMRR rate control algorithm> version 0.1\n");
539 static moduledata_t amrr_mod = {
544 DECLARE_MODULE(ath_rate, amrr_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
545 MODULE_VERSION(ath_rate, 1);
546 MODULE_DEPEND(ath_rate, wlan, 1, 1, 1);