1 /* $NetBSD: athrate-onoe.c,v 1.9 2006/04/02 05:52:50 gdamore 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 1.9 2006/04/02 05:52:50 gdamore 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/lock.h>
57 #include <sys/errno.h>
58 #include <sys/device.h>
59
60 #include <machine/bus.h>
61
62 #include <sys/socket.h>
63
64 #include <net/if.h>
65 #include <net/if_media.h>
66 #include <net/if_arp.h>
67 #include <net/if_ether.h> /* XXX for ether_sprintf */
68
69 #include <net80211/ieee80211_var.h>
70
71 #include <net/bpf.h>
72
73 #ifdef INET
74 #include <netinet/in.h>
75 #endif
76
77 #include <dev/ic/ath_netbsd.h>
78 #include <dev/ic/athvar.h>
79 #include <dev/ic/athrate-onoe.h>
80 #include <contrib/dev/ath/ah_desc.h>
81
82 #define ONOE_DEBUG
83 #ifdef ONOE_DEBUG
84 enum {
85 ATH_DEBUG_RATE = 0x00000010, /* rate control */
86 };
87 #define DPRINTF(sc, _fmt, ...) do { \
88 if (sc->sc_debug & ATH_DEBUG_RATE) \
89 printf(_fmt, __VA_ARGS__); \
90 } while (0)
91 #else
92 #define DPRINTF(sc, _fmt, ...)
93 #endif
94
95 /*
96 * Default parameters for the rate control algorithm. These are
97 * all tunable with sysctls. The rate controller runs periodically
98 * (each ath_rateinterval ms) analyzing transmit statistics for each
99 * neighbor/station (when operating in station mode this is only the AP).
100 * If transmits look to be working well over a sampling period then
101 * it gives a "raise rate credit". If transmits look to not be working
102 * well than it deducts a credit. If the credits cross a threshold then
103 * the transmit rate is raised. Various error conditions force the
104 * the transmit rate to be dropped.
105 *
106 * The decision to issue/deduct a credit is based on the errors and
107 * retries accumulated over the sampling period. ath_rate_raise defines
108 * the percent of retransmits for which a credit is issued/deducted.
109 * ath_rate_raise_threshold defines the threshold on credits at which
110 * the transmit rate is increased.
111 *
112 * XXX this algorithm is flawed.
113 */
114 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */
115 static int ath_rate_raise = 10; /* add credit threshold */
116 static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */
117
118 static void ath_ratectl(void *);
119 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *,
120 int rate);
121 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
122 static void ath_rate_ctl(void *, struct ieee80211_node *);
123
124 void
125 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
126 {
127 /* NB: assumed to be zero'd by caller */
128 ath_rate_update(sc, &an->an_node, 0);
129 }
130
131 void
132 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
133 {
134 }
135
136 void
137 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
138 int shortPreamble, size_t frameLen,
139 u_int8_t *rix, int *try0, u_int8_t *txrate)
140 {
141 struct onoe_node *on = ATH_NODE_ONOE(an);
142
143 *rix = on->on_tx_rix0;
144 *try0 = on->on_tx_try0;
145 if (shortPreamble)
146 *txrate = on->on_tx_rate0sp;
147 else
148 *txrate = on->on_tx_rate0;
149 }
150
151 void
152 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
153 struct ath_desc *ds, int shortPreamble, u_int8_t rix)
154 {
155 struct onoe_node *on = ATH_NODE_ONOE(an);
156
157 ath_hal_setupxtxdesc(sc->sc_ah, ds
158 , on->on_tx_rate1sp, 2 /* series 1 */
159 , on->on_tx_rate2sp, 2 /* series 2 */
160 , on->on_tx_rate3sp, 2 /* series 3 */
161 );
162 }
163
164 void
165 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
166 const struct ath_desc *ds, const struct ath_desc *ds0)
167 {
168 struct onoe_node *on = ATH_NODE_ONOE(an);
169
170 if (ds->ds_txstat.ts_status == 0)
171 on->on_tx_ok++;
172 else
173 on->on_tx_err++;
174 on->on_tx_retr += ds->ds_txstat.ts_shortretry
175 + ds->ds_txstat.ts_longretry;
176 }
177
178 void
179 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
180 {
181 if (isnew)
182 ath_rate_ctl_start(sc, &an->an_node);
183 }
184
185 static void
186 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
187 {
188 struct ath_node *an = ATH_NODE(ni);
189 struct onoe_node *on = ATH_NODE_ONOE(an);
190 const HAL_RATE_TABLE *rt = sc->sc_currates;
191 u_int8_t rix;
192
193 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
194
195 DPRINTF(sc, "%s: set xmit rate for %s to %dM\n",
196 __func__, ether_sprintf(ni->ni_macaddr),
197 ni->ni_rates.rs_nrates > 0 ?
198 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
199
200 ni->ni_txrate = rate;
201 /*
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.
207 */
208 if (ni->ni_rates.rs_nrates == 0)
209 goto done;
210 on->on_tx_rix0 = sc->sc_rixmap[
211 ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL];
212 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode;
213
214 on->on_tx_rate0sp = on->on_tx_rate0 |
215 rt->info[on->on_tx_rix0].shortPreamble;
216 if (sc->sc_mrretry) {
217 /*
218 * Hardware supports multi-rate retry; setup two
219 * step-down retry rates and make the lowest rate
220 * be the ``last chance''. We use 4, 2, 2, 2 tries
221 * respectively (4 is set here, the rest are fixed
222 * in the xmit routine).
223 */
224 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */
225 if (--rate >= 0) {
226 rix = sc->sc_rixmap[
227 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
228 on->on_tx_rate1 = rt->info[rix].rateCode;
229 on->on_tx_rate1sp = on->on_tx_rate1 |
230 rt->info[rix].shortPreamble;
231 } else {
232 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
233 }
234 if (--rate >= 0) {
235 rix = sc->sc_rixmap[
236 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
237 on->on_tx_rate2 = rt->info[rix].rateCode;
238 on->on_tx_rate2sp = on->on_tx_rate2 |
239 rt->info[rix].shortPreamble;
240 } else {
241 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
242 }
243 if (rate > 0) {
244 /* NB: only do this if we didn't already do it above */
245 on->on_tx_rate3 = rt->info[0].rateCode;
246 on->on_tx_rate3sp =
247 an->an_tx_rate3 | rt->info[0].shortPreamble;
248 } else {
249 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
250 }
251 } else {
252 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */
253 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
254 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
255 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
256 }
257 done:
258 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0;
259 }
260
261 /*
262 * Set the starting transmit rate for a node.
263 */
264 static void
265 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
266 {
267 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
268 struct ieee80211com *ic = &sc->sc_ic;
269 int srate;
270
271 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
272 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE) {
273 /*
274 * No fixed rate is requested. For 11b start with
275 * the highest negotiated rate; otherwise, for 11g
276 * and 11a, we start "in the middle" at 24Mb or 36Mb.
277 */
278 srate = ni->ni_rates.rs_nrates - 1;
279 if (sc->sc_curmode != IEEE80211_MODE_11B) {
280 /*
281 * Scan the negotiated rate set to find the
282 * closest rate.
283 */
284 /* NB: the rate set is assumed sorted */
285 for (; srate >= 0 && RATE(srate) > 72; srate--)
286 ;
287 KASSERT(srate >= 0, ("bogus rate set"));
288 }
289 } else {
290 /*
291 * A fixed rate is to be used; ic_fixed_rate is an
292 * index into the supported rate set. Convert this
293 * to the index into the negotiated rate set for
294 * the node. We know the rate is there because the
295 * rate set is checked when the station associates.
296 */
297 const struct ieee80211_rateset *rs =
298 &ic->ic_sup_rates[ic->ic_curmode];
299 int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL;
300 /* NB: the rate set is assumed sorted */
301 srate = ni->ni_rates.rs_nrates - 1;
302 for (; srate >= 0 && RATE(srate) != r; srate--)
303 ;
304 KASSERT(srate >= 0,
305 ("fixed rate %d not in rate set", ic->ic_fixed_rate));
306 }
307 ath_rate_update(sc, ni, srate);
308 #undef RATE
309 }
310
311 static void
312 ath_rate_cb(void *arg, struct ieee80211_node *ni)
313 {
314 struct ath_softc *sc = arg;
315
316 ath_rate_update(sc, ni, 0);
317 }
318
319 /*
320 * Reset the rate control state for each 802.11 state transition.
321 */
322 void
323 ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state)
324 {
325 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc;
326 struct ieee80211com *ic = &sc->sc_ic;
327 struct ieee80211_node *ni;
328
329 if (state == IEEE80211_S_INIT) {
330 callout_stop(&osc->timer);
331 return;
332 }
333 if (ic->ic_opmode == IEEE80211_M_STA) {
334 /*
335 * Reset local xmit state; this is really only
336 * meaningful when operating in station mode.
337 */
338 ni = ic->ic_bss;
339 if (state == IEEE80211_S_RUN) {
340 ath_rate_ctl_start(sc, ni);
341 } else {
342 ath_rate_update(sc, ni, 0);
343 }
344 } else {
345 /*
346 * When operating as a station the node table holds
347 * the AP's that were discovered during scanning.
348 * For any other operating mode we want to reset the
349 * tx rate state of each node.
350 */
351 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, sc);
352 ath_rate_update(sc, ic->ic_bss, 0);
353 }
354 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE &&
355 state == IEEE80211_S_RUN) {
356 int interval;
357 /*
358 * Start the background rate control thread if we
359 * are not configured to use a fixed xmit rate.
360 */
361 interval = ath_rateinterval;
362 if (ic->ic_opmode == IEEE80211_M_STA)
363 interval /= 2;
364 callout_reset(&osc->timer, (interval * hz) / 1000,
365 ath_ratectl, &sc->sc_if);
366 }
367 }
368
369 /*
370 * Examine and potentially adjust the transmit rate.
371 */
372 static void
373 ath_rate_ctl(void *arg, struct ieee80211_node *ni)
374 {
375 struct ath_softc *sc = arg;
376 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni));
377 struct ieee80211_rateset *rs = &ni->ni_rates;
378 int dir = 0, nrate, enough;
379
380 /*
381 * Rate control
382 * XXX: very primitive version.
383 */
384 enough = (on->on_tx_ok + on->on_tx_err >= 10);
385
386 /* no packet reached -> down */
387 if (on->on_tx_err > 0 && on->on_tx_ok == 0)
388 dir = -1;
389
390 /* all packets needs retry in average -> down */
391 if (enough && on->on_tx_ok < on->on_tx_retr)
392 dir = -1;
393
394 /* no error and less than rate_raise% of packets need retry -> up */
395 if (enough && on->on_tx_err == 0 &&
396 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100)
397 dir = 1;
398
399 DPRINTF(sc, "%s: ok %d err %d retr %d upper %d dir %d\n",
400 ether_sprintf(ni->ni_macaddr),
401 on->on_tx_ok, on->on_tx_err, on->on_tx_retr,
402 on->on_tx_upper, dir);
403
404 nrate = ni->ni_txrate;
405 switch (dir) {
406 case 0:
407 if (enough && on->on_tx_upper > 0)
408 on->on_tx_upper--;
409 break;
410 case -1:
411 if (nrate > 0) {
412 nrate--;
413 sc->sc_stats.ast_rate_drop++;
414 }
415 on->on_tx_upper = 0;
416 break;
417 case 1:
418 /* raise rate if we hit rate_raise_threshold */
419 if (++on->on_tx_upper < ath_rate_raise_threshold)
420 break;
421 on->on_tx_upper = 0;
422 if (nrate + 1 < rs->rs_nrates) {
423 nrate++;
424 sc->sc_stats.ast_rate_raise++;
425 }
426 break;
427 }
428
429 if (nrate != ni->ni_txrate) {
430 DPRINTF(sc, "%s: %dM -> %dM (%d ok, %d err, %d retr)\n",
431 __func__,
432 (rs->rs_rates[ni->ni_txrate] & IEEE80211_RATE_VAL) / 2,
433 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2,
434 on->on_tx_ok, on->on_tx_err, on->on_tx_retr);
435 ath_rate_update(sc, ni, nrate);
436 } else if (enough)
437 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0;
438 }
439
440 static void
441 ath_ratectl(void *arg)
442 {
443 struct ifnet *ifp = arg;
444 struct ath_softc *sc = ifp->if_softc;
445 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc;
446 struct ieee80211com *ic = &sc->sc_ic;
447 int interval;
448
449 if (ifp->if_flags & IFF_RUNNING) {
450 sc->sc_stats.ast_rate_calls++;
451
452 if (ic->ic_opmode == IEEE80211_M_STA)
453 ath_rate_ctl(sc, ic->ic_bss); /* NB: no reference */
454 else
455 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_ctl, sc);
456 }
457 interval = ath_rateinterval;
458 if (ic->ic_opmode == IEEE80211_M_STA)
459 interval /= 2;
460 callout_reset(&osc->timer, (interval * hz) / 1000,
461 ath_ratectl, &sc->sc_if);
462 }
463
464 static void
465 ath_rate_sysctlattach(struct ath_softc *sc)
466 {
467 struct sysctllog **clog = &sc->sc_sysctllog;
468 const struct sysctlnode *cnode, *rnode;
469
470 if ((rnode = ath_sysctl_treetop(NULL)) == NULL)
471 return;
472
473 SYSCTL_GLOBAL_INT(CTLFLAG_READWRITE, "rate_interval",
474 "rate control: operation interval (ms)", rateinterval);
475 /* XXX bounds check values */
476 SYSCTL_GLOBAL_INT(CTLFLAG_READWRITE, "rate_raise",
477 "rate control: retry threshold to credit rate raise (%%)",
478 rate_raise);
479 SYSCTL_GLOBAL_INT(CTLFLAG_READWRITE, "rate_raise_threshold",
480 "rate control: # good periods before raising rate",
481 rate_raise_threshold);
482 }
483
484 struct ath_ratectrl *
485 ath_rate_attach(struct ath_softc *sc)
486 {
487 struct onoe_softc *osc;
488
489 osc = malloc(sizeof(struct onoe_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
490 if (osc == NULL)
491 return NULL;
492 osc->arc.arc_space = sizeof(struct onoe_node);
493 ATH_CALLOUT_INIT(&osc->timer, debug_mpsafenet ? CALLOUT_MPSAFE : 0);
494 ath_rate_sysctlattach(sc);
495
496 return &osc->arc;
497 }
498
499 void
500 ath_rate_detach(struct ath_ratectrl *arc)
501 {
502 struct onoe_softc *osc = (struct onoe_softc *) arc;
503
504 callout_stop(&osc->timer);
505 free(osc, M_DEVBUF);
506 }
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