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
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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/kernel.h>
55 #include <sys/mutex.h>
56 #include <sys/errno.h>
58 #include <machine/bus.h>
59 #include <machine/resource.h>
62 #include <sys/socket.h>
65 #include <net/if_media.h>
66 #include <net/if_arp.h>
67 #include <net/ethernet.h> /* XXX for ether_sprintf */
69 #include <net80211/ieee80211_var.h>
74 #include <netinet/in.h>
75 #include <netinet/if_ether.h>
78 #include <dev/ath/if_athvar.h>
79 #include <dev/ath/ath_rate/amrr/amrr.h>
80 #include <dev/ath/ath_hal/ah_desc.h>
84 #define DPRINTF(sc, _fmt, ...) do { \
85 if (sc->sc_debug & 0x10) \
86 printf(_fmt, __VA_ARGS__); \
89 #define DPRINTF(sc, _fmt, ...)
92 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */
93 static int ath_rate_max_success_threshold = 10;
94 static int ath_rate_min_success_threshold = 1;
96 static void ath_ratectl(void *);
97 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *,
99 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
100 static void ath_rate_ctl(void *, struct ieee80211_node *);
103 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
105 /* NB: assumed to be zero'd by caller */
106 ath_rate_update(sc, &an->an_node, 0);
110 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
115 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
116 int shortPreamble, size_t frameLen,
117 u_int8_t *rix, int *try0, u_int8_t *txrate)
119 struct amrr_node *amn = ATH_NODE_AMRR(an);
121 *rix = amn->amn_tx_rix0;
122 *try0 = amn->amn_tx_try0;
124 *txrate = amn->amn_tx_rate0sp;
126 *txrate = amn->amn_tx_rate0;
130 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
131 struct ath_desc *ds, int shortPreamble, u_int8_t rix)
133 struct amrr_node *amn = ATH_NODE_AMRR(an);
135 ath_hal_setupxtxdesc(sc->sc_ah, ds
136 , amn->amn_tx_rate1sp, amn->amn_tx_try1 /* series 1 */
137 , amn->amn_tx_rate2sp, amn->amn_tx_try2 /* series 2 */
138 , amn->amn_tx_rate3sp, amn->amn_tx_try3 /* series 3 */
143 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
144 const struct ath_buf *bf)
146 struct amrr_node *amn = ATH_NODE_AMRR(an);
147 const struct ath_tx_status *ts = &bf->bf_status.ds_txstat;
148 int sr = ts->ts_shortretry;
149 int lr = ts->ts_longretry;
150 int retry_count = sr + lr;
152 amn->amn_tx_try0_cnt++;
153 if (retry_count == 1) {
154 amn->amn_tx_try1_cnt++;
155 } else if (retry_count == 2) {
156 amn->amn_tx_try1_cnt++;
157 amn->amn_tx_try2_cnt++;
158 } else if (retry_count == 3) {
159 amn->amn_tx_try1_cnt++;
160 amn->amn_tx_try2_cnt++;
161 amn->amn_tx_try3_cnt++;
162 } else if (retry_count > 3) {
163 amn->amn_tx_try1_cnt++;
164 amn->amn_tx_try2_cnt++;
165 amn->amn_tx_try3_cnt++;
166 amn->amn_tx_failure_cnt++;
171 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
174 ath_rate_ctl_start(sc, &an->an_node);
178 node_reset (struct amrr_node *amn)
180 amn->amn_tx_try0_cnt = 0;
181 amn->amn_tx_try1_cnt = 0;
182 amn->amn_tx_try2_cnt = 0;
183 amn->amn_tx_try3_cnt = 0;
184 amn->amn_tx_failure_cnt = 0;
185 amn->amn_success = 0;
186 amn->amn_recovery = 0;
187 amn->amn_success_threshold = ath_rate_min_success_threshold;
192 * The code below assumes that we are dealing with hardware multi rate retry
193 * I have no idea what will happen if you try to use this module with another
194 * type of hardware. Your machine might catch fire or it might work with
195 * horrible performance...
198 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
200 struct ath_node *an = ATH_NODE(ni);
201 struct amrr_node *amn = ATH_NODE_AMRR(an);
202 const HAL_RATE_TABLE *rt = sc->sc_currates;
205 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
207 DPRINTF(sc, "%s: set xmit rate for %s to %dM\n",
208 __func__, ether_sprintf(ni->ni_macaddr),
209 ni->ni_rates.rs_nrates > 0 ?
210 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
212 ni->ni_txrate = rate;
214 * Before associating a node has no rate set setup
215 * so we can't calculate any transmit codes to use.
216 * This is ok since we should never be sending anything
217 * but management frames and those always go at the
218 * lowest hardware rate.
220 if (ni->ni_rates.rs_nrates > 0) {
221 amn->amn_tx_rix0 = sc->sc_rixmap[
222 ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL];
223 amn->amn_tx_rate0 = rt->info[amn->amn_tx_rix0].rateCode;
224 amn->amn_tx_rate0sp = amn->amn_tx_rate0 |
225 rt->info[amn->amn_tx_rix0].shortPreamble;
226 if (sc->sc_mrretry) {
227 amn->amn_tx_try0 = 1;
228 amn->amn_tx_try1 = 1;
229 amn->amn_tx_try2 = 1;
230 amn->amn_tx_try3 = 1;
233 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
234 amn->amn_tx_rate1 = rt->info[rix].rateCode;
235 amn->amn_tx_rate1sp = amn->amn_tx_rate1 |
236 rt->info[rix].shortPreamble;
238 amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
242 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
243 amn->amn_tx_rate2 = rt->info[rix].rateCode;
244 amn->amn_tx_rate2sp = amn->amn_tx_rate2 |
245 rt->info[rix].shortPreamble;
247 amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
250 /* NB: only do this if we didn't already do it above */
251 amn->amn_tx_rate3 = rt->info[0].rateCode;
252 amn->amn_tx_rate3sp =
253 amn->amn_tx_rate3 | rt->info[0].shortPreamble;
255 amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
258 amn->amn_tx_try0 = ATH_TXMAXTRY;
259 /* theorically, these statements are useless because
260 * the code which uses them tests for an_tx_try0 == ATH_TXMAXTRY
262 amn->amn_tx_try1 = 0;
263 amn->amn_tx_try2 = 0;
264 amn->amn_tx_try3 = 0;
265 amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
266 amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
267 amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
274 * Set the starting transmit rate for a node.
277 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
279 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
280 struct ieee80211com *ic = &sc->sc_ic;
283 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
284 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE) {
286 * No fixed rate is requested. For 11b start with
287 * the highest negotiated rate; otherwise, for 11g
288 * and 11a, we start "in the middle" at 24Mb or 36Mb.
290 srate = ni->ni_rates.rs_nrates - 1;
291 if (sc->sc_curmode != IEEE80211_MODE_11B) {
293 * Scan the negotiated rate set to find the
296 /* NB: the rate set is assumed sorted */
297 for (; srate >= 0 && RATE(srate) > 72; srate--)
302 * A fixed rate is to be used; ic_fixed_rate is the
303 * IEEE code for this rate (sans basic bit). Convert this
304 * to the index into the negotiated rate set for
305 * the node. We know the rate is there because the
306 * rate set is checked when the station associates.
308 /* NB: the rate set is assumed sorted */
309 srate = ni->ni_rates.rs_nrates - 1;
310 for (; srate >= 0 && RATE(srate) != ic->ic_fixed_rate; srate--)
314 * The selected rate may not be available due to races
315 * and mode settings. Also orphaned nodes created in
316 * adhoc mode may not have any rate set so this lookup
317 * can fail. This is not fatal.
319 ath_rate_update(sc, ni, srate < 0 ? 0 : srate);
324 ath_rate_cb(void *arg, struct ieee80211_node *ni)
326 struct ath_softc *sc = arg;
328 ath_rate_update(sc, ni, 0);
332 * Reset the rate control state for each 802.11 state transition.
335 ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state)
337 struct amrr_softc *asc = (struct amrr_softc *) sc->sc_rc;
338 struct ieee80211com *ic = &sc->sc_ic;
339 struct ieee80211_node *ni;
341 if (state == IEEE80211_S_INIT) {
342 callout_stop(&asc->timer);
345 if (ic->ic_opmode == IEEE80211_M_STA) {
347 * Reset local xmit state; this is really only
348 * meaningful when operating in station mode.
351 if (state == IEEE80211_S_RUN) {
352 ath_rate_ctl_start(sc, ni);
354 ath_rate_update(sc, ni, 0);
358 * When operating as a station the node table holds
359 * the AP's that were discovered during scanning.
360 * For any other operating mode we want to reset the
361 * tx rate state of each node.
363 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, sc);
364 ath_rate_update(sc, ic->ic_bss, 0);
366 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE &&
367 state == IEEE80211_S_RUN) {
370 * Start the background rate control thread if we
371 * are not configured to use a fixed xmit rate.
373 interval = ath_rateinterval;
374 if (ic->ic_opmode == IEEE80211_M_STA)
376 callout_reset(&asc->timer, (interval * hz) / 1000,
377 ath_ratectl, sc->sc_ifp);
382 * Examine and potentially adjust the transmit rate.
385 ath_rate_ctl(void *arg, struct ieee80211_node *ni)
387 struct ath_softc *sc = arg;
388 struct amrr_node *amn = ATH_NODE_AMRR(ATH_NODE (ni));
391 #define is_success(amn) \
392 (amn->amn_tx_try1_cnt < (amn->amn_tx_try0_cnt/10))
393 #define is_enough(amn) \
394 (amn->amn_tx_try0_cnt > 10)
395 #define is_failure(amn) \
396 (amn->amn_tx_try1_cnt > (amn->amn_tx_try0_cnt/3))
397 #define is_max_rate(ni) \
398 ((ni->ni_txrate + 1) >= ni->ni_rates.rs_nrates)
399 #define is_min_rate(ni) \
402 old_rate = ni->ni_txrate;
404 DPRINTF (sc, "cnt0: %d cnt1: %d cnt2: %d cnt3: %d -- threshold: %d\n",
405 amn->amn_tx_try0_cnt,
406 amn->amn_tx_try1_cnt,
407 amn->amn_tx_try2_cnt,
408 amn->amn_tx_try3_cnt,
409 amn->amn_success_threshold);
410 if (is_success (amn) && is_enough (amn)) {
412 if (amn->amn_success == amn->amn_success_threshold &&
414 amn->amn_recovery = 1;
415 amn->amn_success = 0;
417 DPRINTF (sc, "increase rate to %d\n", ni->ni_txrate);
419 amn->amn_recovery = 0;
421 } else if (is_failure (amn)) {
422 amn->amn_success = 0;
423 if (!is_min_rate (ni)) {
424 if (amn->amn_recovery) {
425 /* recovery failure. */
426 amn->amn_success_threshold *= 2;
427 amn->amn_success_threshold = min (amn->amn_success_threshold,
428 (u_int)ath_rate_max_success_threshold);
429 DPRINTF (sc, "decrease rate recovery thr: %d\n", amn->amn_success_threshold);
431 /* simple failure. */
432 amn->amn_success_threshold = ath_rate_min_success_threshold;
433 DPRINTF (sc, "decrease rate normal thr: %d\n", amn->amn_success_threshold);
435 amn->amn_recovery = 0;
438 amn->amn_recovery = 0;
442 if (is_enough (amn) || old_rate != ni->ni_txrate) {
443 /* reset counters. */
444 amn->amn_tx_try0_cnt = 0;
445 amn->amn_tx_try1_cnt = 0;
446 amn->amn_tx_try2_cnt = 0;
447 amn->amn_tx_try3_cnt = 0;
448 amn->amn_tx_failure_cnt = 0;
450 if (old_rate != ni->ni_txrate) {
451 ath_rate_update(sc, ni, ni->ni_txrate);
456 ath_ratectl(void *arg)
458 struct ifnet *ifp = arg;
459 struct ath_softc *sc = ifp->if_softc;
460 struct amrr_softc *asc = (struct amrr_softc *) sc->sc_rc;
461 struct ieee80211com *ic = &sc->sc_ic;
464 if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
465 sc->sc_stats.ast_rate_calls++;
467 if (ic->ic_opmode == IEEE80211_M_STA)
468 ath_rate_ctl(sc, ic->ic_bss); /* NB: no reference */
470 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_ctl, sc);
472 interval = ath_rateinterval;
473 if (ic->ic_opmode == IEEE80211_M_STA)
475 callout_reset(&asc->timer, (interval * hz) / 1000,
476 ath_ratectl, sc->sc_ifp);
480 ath_rate_sysctlattach(struct ath_softc *sc)
482 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
483 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
485 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
486 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
487 "rate control: operation interval (ms)");
488 /* XXX bounds check values */
489 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
490 "max_sucess_threshold", CTLFLAG_RW,
491 &ath_rate_max_success_threshold, 0, "");
492 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
493 "min_sucess_threshold", CTLFLAG_RW,
494 &ath_rate_min_success_threshold, 0, "");
497 struct ath_ratectrl *
498 ath_rate_attach(struct ath_softc *sc)
500 struct amrr_softc *asc;
502 asc = malloc(sizeof(struct amrr_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
505 asc->arc.arc_space = sizeof(struct amrr_node);
506 callout_init(&asc->timer, CALLOUT_MPSAFE);
507 ath_rate_sysctlattach(sc);
513 ath_rate_detach(struct ath_ratectrl *arc)
515 struct amrr_softc *asc = (struct amrr_softc *) arc;
517 callout_drain(&asc->timer);