2 * Copyright (c) 2002-2007 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.
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
22 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
25 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27 * THE POSSIBILITY OF SUCH DAMAGES.
30 #include <sys/cdefs.h>
33 * Atsushi Onoe's rate control algorithm.
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/sysctl.h>
42 #include <sys/kernel.h>
44 #include <sys/mutex.h>
45 #include <sys/errno.h>
47 #include <sys/socket.h>
50 #include <net/if_media.h>
51 #include <net/if_arp.h>
52 #include <net/ethernet.h> /* XXX for ether_sprintf */
54 #include <netproto/802_11/ieee80211_var.h>
59 #include <netinet/in.h>
60 #include <netinet/if_ether.h>
63 #include <dev/netif/ath/ath/if_athvar.h>
64 #include <dev/netif/ath/ath_rate/onoe/onoe.h>
65 #include <dev/netif/ath/ath_hal/ah_desc.h>
68 * Default parameters for the rate control algorithm. These are
69 * all tunable with sysctls. The rate controller runs periodically
70 * (each ath_rateinterval ms) analyzing transmit statistics for each
71 * neighbor/station (when operating in station mode this is only the AP).
72 * If transmits look to be working well over a sampling period then
73 * it gives a "raise rate credit". If transmits look to not be working
74 * well than it deducts a credit. If the credits cross a threshold then
75 * the transmit rate is raised. Various error conditions force the
76 * the transmit rate to be dropped.
78 * The decision to issue/deduct a credit is based on the errors and
79 * retries accumulated over the sampling period. ath_rate_raise defines
80 * the percent of retransmits for which a credit is issued/deducted.
81 * ath_rate_raise_threshold defines the threshold on credits at which
82 * the transmit rate is increased.
84 * XXX this algorithm is flawed.
86 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */
87 static int ath_rate_raise = 10; /* add credit threshold */
88 static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */
90 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *,
92 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
93 static void ath_rate_ctl(void *, struct ieee80211_node *);
96 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
98 /* NB: assumed to be zero'd by caller */
102 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
107 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
108 int shortPreamble, size_t frameLen,
109 u_int8_t *rix, int *try0, u_int8_t *txrate)
111 struct onoe_node *on = ATH_NODE_ONOE(an);
113 *rix = on->on_tx_rix0;
114 *try0 = on->on_tx_try0;
116 *txrate = on->on_tx_rate0sp;
118 *txrate = on->on_tx_rate0;
124 * The short preamble bits aren't set here; the caller should augment
125 * the returned rate with the relevant preamble rate flag.
128 ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
129 uint8_t rix0, struct ath_rc_series *rc)
131 struct onoe_node *on = ATH_NODE_ONOE(an);
133 rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0;
135 rc[0].rix = on->on_tx_rate0;
136 rc[1].rix = on->on_tx_rate1;
137 rc[2].rix = on->on_tx_rate2;
138 rc[3].rix = on->on_tx_rate3;
140 rc[0].tries = on->on_tx_try0;
147 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
148 struct ath_desc *ds, int shortPreamble, u_int8_t rix)
150 struct onoe_node *on = ATH_NODE_ONOE(an);
152 ath_hal_setupxtxdesc(sc->sc_ah, ds
153 , on->on_tx_rate1sp, 2 /* series 1 */
154 , on->on_tx_rate2sp, 2 /* series 2 */
155 , on->on_tx_rate3sp, 2 /* series 3 */
160 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
161 const struct ath_rc_series *rc, const struct ath_tx_status *ts,
162 int frame_size, int nframes, int nbad)
164 struct onoe_node *on = ATH_NODE_ONOE(an);
166 if (ts->ts_status == 0)
170 on->on_tx_retr += ts->ts_shortretry
172 if (on->on_interval != 0 && ticks - on->on_ticks > on->on_interval) {
173 ath_rate_ctl(sc, &an->an_node);
174 on->on_ticks = ticks;
179 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
182 ath_rate_ctl_start(sc, &an->an_node);
186 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
188 struct ath_node *an = ATH_NODE(ni);
189 struct onoe_node *on = ATH_NODE_ONOE(an);
190 struct ieee80211vap *vap = ni->ni_vap;
191 const HAL_RATE_TABLE *rt = sc->sc_currates;
194 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
196 IEEE80211_NOTE(vap, IEEE80211_MSG_RATECTL, ni,
197 "%s: set xmit rate to %dM", __func__,
198 ni->ni_rates.rs_nrates > 0 ?
199 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
202 * Before associating a node has no rate set setup
203 * so we can't calculate any transmit codes to use.
204 * This is ok since we should never be sending anything
205 * but management frames and those always go at the
206 * lowest hardware rate.
208 if (ni->ni_rates.rs_nrates == 0)
211 ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL;
212 on->on_tx_rix0 = sc->sc_rixmap[ni->ni_txrate];
213 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode;
215 on->on_tx_rate0sp = on->on_tx_rate0 |
216 rt->info[on->on_tx_rix0].shortPreamble;
217 if (sc->sc_mrretry) {
219 * Hardware supports multi-rate retry; setup two
220 * step-down retry rates and make the lowest rate
221 * be the ``last chance''. We use 4, 2, 2, 2 tries
222 * respectively (4 is set here, the rest are fixed
223 * in the xmit routine).
225 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */
228 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
229 on->on_tx_rate1 = rt->info[rix].rateCode;
230 on->on_tx_rate1sp = on->on_tx_rate1 |
231 rt->info[rix].shortPreamble;
233 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
237 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
238 on->on_tx_rate2 = rt->info[rix].rateCode;
239 on->on_tx_rate2sp = on->on_tx_rate2 |
240 rt->info[rix].shortPreamble;
242 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
245 /* NB: only do this if we didn't already do it above */
246 on->on_tx_rate3 = rt->info[0].rateCode;
248 on->on_tx_rate3 | rt->info[0].shortPreamble;
250 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
253 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */
254 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
255 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
256 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
259 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0;
261 on->on_interval = ath_rateinterval;
262 if (vap->iv_opmode == IEEE80211_M_STA)
263 on->on_interval /= 2;
264 on->on_interval = (on->on_interval * hz) / 1000;
268 * Set the starting transmit rate for a node.
271 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
273 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
274 const struct ieee80211_txparam *tp = ni->ni_txparms;
277 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
278 if (tp == NULL || tp->ucastrate == IEEE80211_FIXED_RATE_NONE) {
280 * No fixed rate is requested. For 11b start with
281 * the highest negotiated rate; otherwise, for 11g
282 * and 11a, we start "in the middle" at 24Mb or 36Mb.
284 srate = ni->ni_rates.rs_nrates - 1;
285 if (sc->sc_curmode != IEEE80211_MODE_11B) {
287 * Scan the negotiated rate set to find the
290 /* NB: the rate set is assumed sorted */
291 for (; srate >= 0 && RATE(srate) > 72; srate--)
296 * A fixed rate is to be used; ic_fixed_rate is the
297 * IEEE code for this rate (sans basic bit). Convert this
298 * to the index into the negotiated rate set for
299 * the node. We know the rate is there because the
300 * rate set is checked when the station associates.
302 /* NB: the rate set is assumed sorted */
303 srate = ni->ni_rates.rs_nrates - 1;
304 for (; srate >= 0 && RATE(srate) != tp->ucastrate; srate--)
308 * The selected rate may not be available due to races
309 * and mode settings. Also orphaned nodes created in
310 * adhoc mode may not have any rate set so this lookup
311 * can fail. This is not fatal.
313 ath_rate_update(sc, ni, srate < 0 ? 0 : srate);
318 * Examine and potentially adjust the transmit rate.
321 ath_rate_ctl(void *arg, struct ieee80211_node *ni)
323 struct ath_softc *sc = arg;
324 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni));
325 struct ieee80211_rateset *rs = &ni->ni_rates;
326 int dir = 0, nrate, enough;
330 * XXX: very primitive version.
332 enough = (on->on_tx_ok + on->on_tx_err >= 10);
334 /* no packet reached -> down */
335 if (on->on_tx_err > 0 && on->on_tx_ok == 0)
338 /* all packets needs retry in average -> down */
339 if (enough && on->on_tx_ok < on->on_tx_retr)
342 /* no error and less than rate_raise% of packets need retry -> up */
343 if (enough && on->on_tx_err == 0 &&
344 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100)
347 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
348 "ok %d err %d retr %d upper %d dir %d",
349 on->on_tx_ok, on->on_tx_err, on->on_tx_retr, on->on_tx_upper, dir);
354 if (enough && on->on_tx_upper > 0)
360 sc->sc_stats.ast_rate_drop++;
365 /* raise rate if we hit rate_raise_threshold */
366 if (++on->on_tx_upper < ath_rate_raise_threshold)
369 if (nrate + 1 < rs->rs_nrates) {
371 sc->sc_stats.ast_rate_raise++;
376 if (nrate != on->on_rix) {
377 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
378 "%s: %dM -> %dM (%d ok, %d err, %d retr)", __func__,
380 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2,
381 on->on_tx_ok, on->on_tx_err, on->on_tx_retr);
382 ath_rate_update(sc, ni, nrate);
384 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0;
388 ath_rate_sysctlattach(struct ath_softc *sc)
390 struct sysctl_ctx_list *ctx = &sc->sc_sysctl_ctx;
391 struct sysctl_oid *tree = sc->sc_sysctl_tree;
393 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
394 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
395 "rate control: operation interval (ms)");
396 /* XXX bounds check values */
397 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
398 "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0,
399 "rate control: retry threshold to credit rate raise (%%)");
400 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
401 "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0,
402 "rate control: # good periods before raising rate");
406 ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
407 struct ath_rateioctl *re)
413 struct ath_ratectrl *
414 ath_rate_attach(struct ath_softc *sc)
416 struct onoe_softc *osc;
418 osc = kmalloc(sizeof(struct onoe_softc), M_DEVBUF, M_INTWAIT|M_ZERO);
421 osc->arc.arc_space = sizeof(struct onoe_node);
422 ath_rate_sysctlattach(sc);
428 ath_rate_detach(struct ath_ratectrl *arc)
430 struct onoe_softc *osc = (struct onoe_softc *) arc;
432 kfree(osc, M_DEVBUF);
439 onoe_modevent(module_t mod, int type, void *unused)
443 wlan_serialize_enter();
448 kprintf("ath_rate: <Atsushi Onoe's rate "
449 "control algorithm>\n");
460 wlan_serialize_exit();
465 static moduledata_t onoe_mod = {
471 DECLARE_MODULE(ath_rate, onoe_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
472 MODULE_VERSION(ath_rate, 1);
473 MODULE_DEPEND(ath_rate, ath_hal, 1, 1, 1);
474 MODULE_DEPEND(ath_rate, wlan, 1, 1, 1);