1 /* $NetBSD: athrate-onoe.c,v 1.12.20.1 2009/08/07 06:43:27 snj Exp $ */
2
3 /*-
4 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer,
12 * without modification.
13 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
14 * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
15 * redistribution must be conditioned upon including a substantially
16 * similar Disclaimer requirement for further binary redistribution.
17 * 3. Neither the names of the above-listed copyright holders nor the names
18 * of any contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * Alternatively, this software may be distributed under the terms of the
22 * GNU General Public License ("GPL") version 2 as published by the Free
23 * Software Foundation.
24 *
25 * NO WARRANTY
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
28 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
29 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
30 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
31 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
34 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
36 * THE POSSIBILITY OF SUCH DAMAGES.
37 */
38
39 #include <sys/cdefs.h>
40 #ifdef __FreeBSD__
41 __FBSDID("$FreeBSD: src/sys/dev/ath/ath_rate/onoe/onoe.c,v 1.10 2005/08/09 10:19:43 rwatson Exp $");
42 #endif
43 #ifdef __NetBSD__
44 __KERNEL_RCSID(0, "$NetBSD: athrate-onoe.c,v 1.12.20.1 2009/08/07 06:43:27 snj Exp $");
45 #endif
46
47 /*
48 * Atsushi Onoe's rate control algorithm.
49 */
50 #include "opt_inet.h"
51
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/sysctl.h>
55 #include <sys/kernel.h>
56 #include <sys/errno.h>
57 #include <sys/device.h>
58 #include <sys/bus.h>
59 #include <sys/socket.h>
60
61 #include <net/if.h>
62 #include <net/if_media.h>
63 #include <net/if_arp.h>
64 #include <net/if_ether.h> /* XXX for ether_sprintf */
65
66 #include <net80211/ieee80211_var.h>
67
68 #include <net/bpf.h>
69
70 #ifdef INET
71 #include <netinet/in.h>
72 #endif
73
74 #include <dev/ic/ath_netbsd.h>
75 #include <dev/ic/athvar.h>
76 #include <dev/ic/athrate-onoe.h>
77
78 #include <external/isc/atheros_hal/dist/ah.h>
79
80 #define ONOE_DEBUG
81 #ifdef ONOE_DEBUG
82 enum {
83 ATH_DEBUG_RATE = 0x00000010, /* rate control */
84 };
85 #define DPRINTF(sc, _fmt, ...) do { \
86 if (sc->sc_debug & ATH_DEBUG_RATE) \
87 printf(_fmt, __VA_ARGS__); \
88 } while (0)
89 #else
90 #define DPRINTF(sc, _fmt, ...)
91 #endif
92
93 /*
94 * Default parameters for the rate control algorithm. These are
95 * all tunable with sysctls. The rate controller runs periodically
96 * (each ath_rateinterval ms) analyzing transmit statistics for each
97 * neighbor/station (when operating in station mode this is only the AP).
98 * If transmits look to be working well over a sampling period then
99 * it gives a "raise rate credit". If transmits look to not be working
100 * well than it deducts a credit. If the credits cross a threshold then
101 * the transmit rate is raised. Various error conditions force the
102 * the transmit rate to be dropped.
103 *
104 * The decision to issue/deduct a credit is based on the errors and
105 * retries accumulated over the sampling period. ath_rate_raise defines
106 * the percent of retransmits for which a credit is issued/deducted.
107 * ath_rate_raise_threshold defines the threshold on credits at which
108 * the transmit rate is increased.
109 *
110 * XXX this algorithm is flawed.
111 */
112 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */
113 static int ath_rate_raise = 10; /* add credit threshold */
114 static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */
115
116 static void ath_ratectl(void *);
117 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *,
118 int rate);
119 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
120 static void ath_rate_ctl(void *, struct ieee80211_node *);
121
122 void
123 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
124 {
125 /* NB: assumed to be zero'd by caller */
126 ath_rate_update(sc, &an->an_node, 0);
127 }
128
129 void
130 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
131 {
132 }
133
134 void
135 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
136 int shortPreamble, size_t frameLen,
137 u_int8_t *rix, int *try0, u_int8_t *txrate)
138 {
139 struct onoe_node *on = ATH_NODE_ONOE(an);
140
141 *rix = on->on_tx_rix0;
142 *try0 = on->on_tx_try0;
143 if (shortPreamble)
144 *txrate = on->on_tx_rate0sp;
145 else
146 *txrate = on->on_tx_rate0;
147 }
148
149 void
150 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
151 struct ath_desc *ds, int shortPreamble, u_int8_t rix)
152 {
153 struct onoe_node *on = ATH_NODE_ONOE(an);
154
155 ath_hal_setupxtxdesc(sc->sc_ah, ds
156 , on->on_tx_rate1sp, 2 /* series 1 */
157 , on->on_tx_rate2sp, 2 /* series 2 */
158 , on->on_tx_rate3sp, 2 /* series 3 */
159 );
160 }
161
162 void
163 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
164 const struct ath_desc *ds, const struct ath_desc *ds0)
165 {
166 struct onoe_node *on = ATH_NODE_ONOE(an);
167
168 if (ds->ds_txstat.ts_status == 0)
169 on->on_tx_ok++;
170 else
171 on->on_tx_err++;
172 on->on_tx_retr += ds->ds_txstat.ts_shortretry
173 + ds->ds_txstat.ts_longretry;
174 }
175
176 void
177 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
178 {
179 if (isnew)
180 ath_rate_ctl_start(sc, &an->an_node);
181 }
182
183 static void
184 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
185 {
186 struct ath_node *an = ATH_NODE(ni);
187 struct onoe_node *on = ATH_NODE_ONOE(an);
188 const HAL_RATE_TABLE *rt = sc->sc_currates;
189 u_int8_t rix;
190
191 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
192
193 DPRINTF(sc, "%s: set xmit rate for %s to %dM\n",
194 __func__, ether_sprintf(ni->ni_macaddr),
195 ni->ni_rates.rs_nrates > 0 ?
196 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
197
198 ni->ni_txrate = rate;
199 /*
200 * Before associating a node has no rate set setup
201 * so we can't calculate any transmit codes to use.
202 * This is ok since we should never be sending anything
203 * but management frames and those always go at the
204 * lowest hardware rate.
205 */
206 if (ni->ni_rates.rs_nrates == 0)
207 goto done;
208 on->on_tx_rix0 = sc->sc_rixmap[
209 ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL];
210 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode;
211
212 on->on_tx_rate0sp = on->on_tx_rate0 |
213 rt->info[on->on_tx_rix0].shortPreamble;
214 if (sc->sc_mrretry) {
215 /*
216 * Hardware supports multi-rate retry; setup two
217 * step-down retry rates and make the lowest rate
218 * be the ``last chance''. We use 4, 2, 2, 2 tries
219 * respectively (4 is set here, the rest are fixed
220 * in the xmit routine).
221 */
222 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */
223 if (--rate >= 0) {
224 rix = sc->sc_rixmap[
225 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
226 on->on_tx_rate1 = rt->info[rix].rateCode;
227 on->on_tx_rate1sp = on->on_tx_rate1 |
228 rt->info[rix].shortPreamble;
229 } else {
230 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
231 }
232 if (--rate >= 0) {
233 rix = sc->sc_rixmap[
234 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
235 on->on_tx_rate2 = rt->info[rix].rateCode;
236 on->on_tx_rate2sp = on->on_tx_rate2 |
237 rt->info[rix].shortPreamble;
238 } else {
239 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
240 }
241 if (rate > 0) {
242 /* NB: only do this if we didn't already do it above */
243 on->on_tx_rate3 = rt->info[0].rateCode;
244 on->on_tx_rate3sp =
245 on->on_tx_rate3 | rt->info[0].shortPreamble;
246 } else {
247 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
248 }
249 } else {
250 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */
251 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
252 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
253 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
254 }
255 done:
256 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0;
257 }
258
259 /*
260 * Set the starting transmit rate for a node.
261 */
262 static void
263 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
264 {
265 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
266 struct ieee80211com *ic = &sc->sc_ic;
267 int srate;
268
269 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
270 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE) {
271 /*
272 * No fixed rate is requested. For 11b start with
273 * the highest negotiated rate; otherwise, for 11g
274 * and 11a, we start "in the middle" at 24Mb or 36Mb.
275 */
276 srate = ni->ni_rates.rs_nrates - 1;
277 if (sc->sc_curmode != IEEE80211_MODE_11B) {
278 /*
279 * Scan the negotiated rate set to find the
280 * closest rate.
281 */
282 /* NB: the rate set is assumed sorted */
283 for (; srate >= 0 && RATE(srate) > 72; srate--)
284 ;
285 KASSERT(srate >= 0, ("bogus rate set"));
286 }
287 } else {
288 /*
289 * A fixed rate is to be used; ic_fixed_rate is an
290 * index into the supported rate set. Convert this
291 * to the index into the negotiated rate set for
292 * the node. We know the rate is there because the
293 * rate set is checked when the station associates.
294 */
295 const struct ieee80211_rateset *rs =
296 &ic->ic_sup_rates[ic->ic_curmode];
297 int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL;
298 /* NB: the rate set is assumed sorted */
299 srate = ni->ni_rates.rs_nrates - 1;
300 for (; srate >= 0 && RATE(srate) != r; srate--)
301 ;
302 KASSERT(srate >= 0,
303 ("fixed rate %d not in rate set", ic->ic_fixed_rate));
304 }
305 ath_rate_update(sc, ni, srate);
306 #undef RATE
307 }
308
309 static void
310 ath_rate_cb(void *arg, struct ieee80211_node *ni)
311 {
312 struct ath_softc *sc = arg;
313
314 ath_rate_update(sc, ni, 0);
315 }
316
317 /*
318 * Reset the rate control state for each 802.11 state transition.
319 */
320 void
321 ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state)
322 {
323 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc;
324 struct ieee80211com *ic = &sc->sc_ic;
325 struct ieee80211_node *ni;
326
327 if (state == IEEE80211_S_INIT) {
328 callout_stop(&osc->timer);
329 return;
330 }
331 if (ic->ic_opmode == IEEE80211_M_STA) {
332 /*
333 * Reset local xmit state; this is really only
334 * meaningful when operating in station mode.
335 */
336 ni = ic->ic_bss;
337 if (state == IEEE80211_S_RUN) {
338 ath_rate_ctl_start(sc, ni);
339 } else {
340 ath_rate_update(sc, ni, 0);
341 }
342 } else {
343 /*
344 * When operating as a station the node table holds
345 * the AP's that were discovered during scanning.
346 * For any other operating mode we want to reset the
347 * tx rate state of each node.
348 */
349 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, sc);
350 ath_rate_update(sc, ic->ic_bss, 0);
351 }
352 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE &&
353 state == IEEE80211_S_RUN) {
354 int interval;
355 /*
356 * Start the background rate control thread if we
357 * are not configured to use a fixed xmit rate.
358 */
359 interval = ath_rateinterval;
360 if (ic->ic_opmode == IEEE80211_M_STA)
361 interval /= 2;
362 callout_reset(&osc->timer, (interval * hz) / 1000,
363 ath_ratectl, &sc->sc_if);
364 }
365 }
366
367 /*
368 * Examine and potentially adjust the transmit rate.
369 */
370 static void
371 ath_rate_ctl(void *arg, struct ieee80211_node *ni)
372 {
373 struct ath_softc *sc = arg;
374 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni));
375 struct ieee80211_rateset *rs = &ni->ni_rates;
376 int dir = 0, nrate, enough;
377
378 /*
379 * Rate control
380 * XXX: very primitive version.
381 */
382 enough = (on->on_tx_ok + on->on_tx_err >= 10);
383
384 /* no packet reached -> down */
385 if (on->on_tx_err > 0 && on->on_tx_ok == 0)
386 dir = -1;
387
388 /* all packets needs retry in average -> down */
389 if (enough && on->on_tx_ok < on->on_tx_retr)
390 dir = -1;
391
392 /* no error and less than rate_raise% of packets need retry -> up */
393 if (enough && on->on_tx_err == 0 &&
394 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100)
395 dir = 1;
396
397 DPRINTF(sc, "%s: ok %d err %d retr %d upper %d dir %d\n",
398 ether_sprintf(ni->ni_macaddr),
399 on->on_tx_ok, on->on_tx_err, on->on_tx_retr,
400 on->on_tx_upper, dir);
401
402 nrate = ni->ni_txrate;
403 switch (dir) {
404 case 0:
405 if (enough && on->on_tx_upper > 0)
406 on->on_tx_upper--;
407 break;
408 case -1:
409 if (nrate > 0) {
410 nrate--;
411 sc->sc_stats.ast_rate_drop++;
412 }
413 on->on_tx_upper = 0;
414 break;
415 case 1:
416 /* raise rate if we hit rate_raise_threshold */
417 if (++on->on_tx_upper < ath_rate_raise_threshold)
418 break;
419 on->on_tx_upper = 0;
420 if (nrate + 1 < rs->rs_nrates) {
421 nrate++;
422 sc->sc_stats.ast_rate_raise++;
423 }
424 break;
425 }
426
427 if (nrate != ni->ni_txrate) {
428 DPRINTF(sc, "%s: %dM -> %dM (%d ok, %d err, %d retr)\n",
429 __func__,
430 (rs->rs_rates[ni->ni_txrate] & IEEE80211_RATE_VAL) / 2,
431 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2,
432 on->on_tx_ok, on->on_tx_err, on->on_tx_retr);
433 ath_rate_update(sc, ni, nrate);
434 } else if (enough)
435 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0;
436 }
437
438 static void
439 ath_ratectl(void *arg)
440 {
441 struct ifnet *ifp = arg;
442 struct ath_softc *sc = ifp->if_softc;
443 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc;
444 struct ieee80211com *ic = &sc->sc_ic;
445 int interval;
446
447 if (ifp->if_flags & IFF_RUNNING) {
448 sc->sc_stats.ast_rate_calls++;
449
450 if (ic->ic_opmode == IEEE80211_M_STA)
451 ath_rate_ctl(sc, ic->ic_bss); /* NB: no reference */
452 else
453 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_ctl, sc);
454 }
455 interval = ath_rateinterval;
456 if (ic->ic_opmode == IEEE80211_M_STA)
457 interval /= 2;
458 callout_reset(&osc->timer, (interval * hz) / 1000,
459 ath_ratectl, &sc->sc_if);
460 }
461
462 static void
463 ath_rate_sysctlattach(struct ath_softc *sc)
464 {
465 struct sysctllog **clog = &sc->sc_sysctllog;
466 const struct sysctlnode *cnode, *rnode;
467
468 if ((rnode = ath_sysctl_treetop(NULL)) == NULL)
469 return;
470
471 SYSCTL_GLOBAL_INT(CTLFLAG_READWRITE, "rate_interval",
472 "rate control: operation interval (ms)", rateinterval);
473 /* XXX bounds check values */
474 SYSCTL_GLOBAL_INT(CTLFLAG_READWRITE, "rate_raise",
475 "rate control: retry threshold to credit rate raise (%%)",
476 rate_raise);
477 SYSCTL_GLOBAL_INT(CTLFLAG_READWRITE, "rate_raise_threshold",
478 "rate control: # good periods before raising rate",
479 rate_raise_threshold);
480 }
481
482 struct ath_ratectrl *
483 ath_rate_attach(struct ath_softc *sc)
484 {
485 struct onoe_softc *osc;
486
487 osc = malloc(sizeof(struct onoe_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
488 if (osc == NULL)
489 return NULL;
490 osc->arc.arc_space = sizeof(struct onoe_node);
491 callout_init(&osc->timer, 0);
492 ath_rate_sysctlattach(sc);
493
494 return &osc->arc;
495 }
496
497 void
498 ath_rate_detach(struct ath_ratectrl *arc)
499 {
500 struct onoe_softc *osc = (struct onoe_softc *) arc;
501
502 callout_stop(&osc->timer);
503 free(osc, M_DEVBUF);
504 }
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