1 /*-
2 * Copyright (c) 2002-2007 Sam Leffler, Errno Consulting
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
15 *
16 * NO WARRANTY
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, MERCHANTABILITY
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.
28 */
29
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32
33 /*
34 * Atsushi Onoe's rate control algorithm.
35 */
36 #include "opt_ath.h"
37 #include "opt_inet.h"
38 #include "opt_wlan.h"
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/sysctl.h>
43 #include <sys/kernel.h>
44 #include <sys/lock.h>
45 #include <sys/errno.h>
46
47 #if defined(__DragonFly__)
48 /* empty */
49 #else
50 #include <machine/bus.h>
51 #include <machine/resource.h>
52 #endif
53 #include <sys/bus.h>
54
55 #include <sys/socket.h>
56
57 #include <net/if.h>
58 #include <net/if_media.h>
59 #include <net/if_arp.h>
60 #include <net/ethernet.h> /* XXX for ether_sprintf */
61
62 #include <netproto/802_11/ieee80211_var.h>
63
64 #include <net/bpf.h>
65
66 #ifdef INET
67 #include <netinet/in.h>
68 #include <netinet/if_ether.h>
69 #endif
70
71 #include <dev/netif/ath/ath/if_athvar.h>
72 #include <dev/netif/ath/ath_rate/onoe/onoe.h>
73 #include <dev/netif/ath/ath_hal/ah_desc.h>
74
75 /*
76 * Default parameters for the rate control algorithm. These are
77 * all tunable with sysctls. The rate controller runs periodically
78 * (each ath_rateinterval ms) analyzing transmit statistics for each
79 * neighbor/station (when operating in station mode this is only the AP).
80 * If transmits look to be working well over a sampling period then
81 * it gives a "raise rate credit". If transmits look to not be working
82 * well than it deducts a credit. If the credits cross a threshold then
83 * the transmit rate is raised. Various error conditions force the
84 * the transmit rate to be dropped.
85 *
86 * The decision to issue/deduct a credit is based on the errors and
87 * retries accumulated over the sampling period. ath_rate_raise defines
88 * the percent of retransmits for which a credit is issued/deducted.
89 * ath_rate_raise_threshold defines the threshold on credits at which
90 * the transmit rate is increased.
91 *
92 * XXX this algorithm is flawed.
93 */
94 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */
95 static int ath_rate_raise = 10; /* add credit threshold */
96 static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */
97
98 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *,
99 int rate);
100 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
101 static void ath_rate_ctl(void *, struct ieee80211_node *);
102
103 void
ath_rate_node_init(struct ath_softc * sc,struct ath_node * an)104 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
105 {
106 /* NB: assumed to be zero'd by caller */
107 }
108
109 void
ath_rate_node_cleanup(struct ath_softc * sc,struct ath_node * an)110 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
111 {
112 }
113
114 void
ath_rate_findrate(struct ath_softc * sc,struct ath_node * an,int shortPreamble,size_t frameLen,u_int8_t * rix,int * try0,u_int8_t * txrate)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)
118 {
119 struct onoe_node *on = ATH_NODE_ONOE(an);
120
121 *rix = on->on_tx_rix0;
122 *try0 = on->on_tx_try0;
123 if (shortPreamble)
124 *txrate = on->on_tx_rate0sp;
125 else
126 *txrate = on->on_tx_rate0;
127 }
128
129 /*
130 * Get the TX rates.
131 *
132 * The short preamble bits aren't set here; the caller should augment
133 * the returned rate with the relevant preamble rate flag.
134 */
135 void
ath_rate_getxtxrates(struct ath_softc * sc,struct ath_node * an,uint8_t rix0,struct ath_rc_series * rc)136 ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
137 uint8_t rix0, struct ath_rc_series *rc)
138 {
139 struct onoe_node *on = ATH_NODE_ONOE(an);
140
141 rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0;
142
143 rc[0].rix = on->on_tx_rate0;
144 rc[1].rix = on->on_tx_rate1;
145 rc[2].rix = on->on_tx_rate2;
146 rc[3].rix = on->on_tx_rate3;
147
148 rc[0].tries = on->on_tx_try0;
149 rc[1].tries = 2;
150 rc[2].tries = 2;
151 rc[3].tries = 2;
152 }
153
154 void
ath_rate_setupxtxdesc(struct ath_softc * sc,struct ath_node * an,struct ath_desc * ds,int shortPreamble,u_int8_t rix)155 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
156 struct ath_desc *ds, int shortPreamble, u_int8_t rix)
157 {
158 struct onoe_node *on = ATH_NODE_ONOE(an);
159
160 ath_hal_setupxtxdesc(sc->sc_ah, ds
161 , on->on_tx_rate1sp, 2 /* series 1 */
162 , on->on_tx_rate2sp, 2 /* series 2 */
163 , on->on_tx_rate3sp, 2 /* series 3 */
164 );
165 }
166
167 void
ath_rate_tx_complete(struct ath_softc * sc,struct ath_node * an,const struct ath_rc_series * rc,const struct ath_tx_status * ts,int frame_size,int nframes,int nbad)168 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
169 const struct ath_rc_series *rc, const struct ath_tx_status *ts,
170 int frame_size, int nframes, int nbad)
171 {
172 struct onoe_node *on = ATH_NODE_ONOE(an);
173
174 if (ts->ts_status == 0)
175 on->on_tx_ok++;
176 else
177 on->on_tx_err++;
178 on->on_tx_retr += ts->ts_shortretry
179 + ts->ts_longretry;
180 if (on->on_interval != 0 && ticks - on->on_ticks > on->on_interval) {
181 ath_rate_ctl(sc, &an->an_node);
182 on->on_ticks = ticks;
183 }
184 }
185
186 void
ath_rate_newassoc(struct ath_softc * sc,struct ath_node * an,int isnew)187 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
188 {
189 if (isnew)
190 ath_rate_ctl_start(sc, &an->an_node);
191 }
192
193 static void
ath_rate_update(struct ath_softc * sc,struct ieee80211_node * ni,int rate)194 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
195 {
196 struct ath_node *an = ATH_NODE(ni);
197 struct onoe_node *on = ATH_NODE_ONOE(an);
198 struct ieee80211vap *vap = ni->ni_vap;
199 const HAL_RATE_TABLE *rt = sc->sc_currates;
200 u_int8_t rix;
201
202 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
203
204 IEEE80211_NOTE(vap, IEEE80211_MSG_RATECTL, ni,
205 "%s: set xmit rate to %dM", __func__,
206 ni->ni_rates.rs_nrates > 0 ?
207 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
208
209 /*
210 * Before associating a node has no rate set setup
211 * so we can't calculate any transmit codes to use.
212 * This is ok since we should never be sending anything
213 * but management frames and those always go at the
214 * lowest hardware rate.
215 */
216 if (ni->ni_rates.rs_nrates == 0)
217 goto done;
218 on->on_rix = rate;
219 ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL;
220 on->on_tx_rix0 = sc->sc_rixmap[ni->ni_txrate];
221 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode;
222
223 on->on_tx_rate0sp = on->on_tx_rate0 |
224 rt->info[on->on_tx_rix0].shortPreamble;
225 if (sc->sc_mrretry) {
226 /*
227 * Hardware supports multi-rate retry; setup two
228 * step-down retry rates and make the lowest rate
229 * be the ``last chance''. We use 4, 2, 2, 2 tries
230 * respectively (4 is set here, the rest are fixed
231 * in the xmit routine).
232 */
233 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */
234 if (--rate >= 0) {
235 rix = sc->sc_rixmap[
236 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
237 on->on_tx_rate1 = rt->info[rix].rateCode;
238 on->on_tx_rate1sp = on->on_tx_rate1 |
239 rt->info[rix].shortPreamble;
240 } else {
241 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
242 }
243 if (--rate >= 0) {
244 rix = sc->sc_rixmap[
245 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
246 on->on_tx_rate2 = rt->info[rix].rateCode;
247 on->on_tx_rate2sp = on->on_tx_rate2 |
248 rt->info[rix].shortPreamble;
249 } else {
250 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
251 }
252 if (rate > 0) {
253 /* NB: only do this if we didn't already do it above */
254 on->on_tx_rate3 = rt->info[0].rateCode;
255 on->on_tx_rate3sp =
256 on->on_tx_rate3 | rt->info[0].shortPreamble;
257 } else {
258 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
259 }
260 } else {
261 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */
262 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
263 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
264 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
265 }
266 done:
267 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0;
268
269 on->on_interval = ath_rateinterval;
270 if (vap->iv_opmode == IEEE80211_M_STA)
271 on->on_interval /= 2;
272 on->on_interval = (on->on_interval * hz) / 1000;
273 }
274
275 /*
276 * Set the starting transmit rate for a node.
277 */
278 static void
ath_rate_ctl_start(struct ath_softc * sc,struct ieee80211_node * ni)279 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
280 {
281 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
282 const struct ieee80211_txparam *tp = ni->ni_txparms;
283 int srate;
284
285 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
286 if (tp == NULL || tp->ucastrate == IEEE80211_FIXED_RATE_NONE) {
287 /*
288 * No fixed rate is requested. For 11b start with
289 * the highest negotiated rate; otherwise, for 11g
290 * and 11a, we start "in the middle" at 24Mb or 36Mb.
291 */
292 srate = ni->ni_rates.rs_nrates - 1;
293 if (sc->sc_curmode != IEEE80211_MODE_11B) {
294 /*
295 * Scan the negotiated rate set to find the
296 * closest rate.
297 */
298 /* NB: the rate set is assumed sorted */
299 for (; srate >= 0 && RATE(srate) > 72; srate--)
300 ;
301 }
302 } else {
303 /*
304 * A fixed rate is to be used; ic_fixed_rate is the
305 * IEEE code for this rate (sans basic bit). 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.
309 */
310 /* NB: the rate set is assumed sorted */
311 srate = ni->ni_rates.rs_nrates - 1;
312 for (; srate >= 0 && RATE(srate) != tp->ucastrate; srate--)
313 ;
314 }
315 /*
316 * The selected rate may not be available due to races
317 * and mode settings. Also orphaned nodes created in
318 * adhoc mode may not have any rate set so this lookup
319 * can fail. This is not fatal.
320 */
321 ath_rate_update(sc, ni, srate < 0 ? 0 : srate);
322 #undef RATE
323 }
324
325 /*
326 * Examine and potentially adjust the transmit rate.
327 */
328 static void
ath_rate_ctl(void * arg,struct ieee80211_node * ni)329 ath_rate_ctl(void *arg, struct ieee80211_node *ni)
330 {
331 struct ath_softc *sc = arg;
332 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni));
333 struct ieee80211_rateset *rs = &ni->ni_rates;
334 int dir = 0, nrate, enough;
335
336 /*
337 * Rate control
338 * XXX: very primitive version.
339 */
340 enough = (on->on_tx_ok + on->on_tx_err >= 10);
341
342 /* no packet reached -> down */
343 if (on->on_tx_err > 0 && on->on_tx_ok == 0)
344 dir = -1;
345
346 /* all packets needs retry in average -> down */
347 if (enough && on->on_tx_ok < on->on_tx_retr)
348 dir = -1;
349
350 /* no error and less than rate_raise% of packets need retry -> up */
351 if (enough && on->on_tx_err == 0 &&
352 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100)
353 dir = 1;
354
355 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
356 "ok %d err %d retr %d upper %d dir %d",
357 on->on_tx_ok, on->on_tx_err, on->on_tx_retr, on->on_tx_upper, dir);
358
359 nrate = on->on_rix;
360 switch (dir) {
361 case 0:
362 if (enough && on->on_tx_upper > 0)
363 on->on_tx_upper--;
364 break;
365 case -1:
366 if (nrate > 0) {
367 nrate--;
368 sc->sc_stats.ast_rate_drop++;
369 }
370 on->on_tx_upper = 0;
371 break;
372 case 1:
373 /* raise rate if we hit rate_raise_threshold */
374 if (++on->on_tx_upper < ath_rate_raise_threshold)
375 break;
376 on->on_tx_upper = 0;
377 if (nrate + 1 < rs->rs_nrates) {
378 nrate++;
379 sc->sc_stats.ast_rate_raise++;
380 }
381 break;
382 }
383
384 if (nrate != on->on_rix) {
385 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
386 "%s: %dM -> %dM (%d ok, %d err, %d retr)", __func__,
387 ni->ni_txrate / 2,
388 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2,
389 on->on_tx_ok, on->on_tx_err, on->on_tx_retr);
390 ath_rate_update(sc, ni, nrate);
391 } else if (enough)
392 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0;
393 }
394
395 static void
ath_rate_sysctlattach(struct ath_softc * sc)396 ath_rate_sysctlattach(struct ath_softc *sc)
397 {
398 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
399 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
400
401 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
402 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
403 "rate control: operation interval (ms)");
404 /* XXX bounds check values */
405 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
406 "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0,
407 "rate control: retry threshold to credit rate raise (%%)");
408 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
409 "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0,
410 "rate control: # good periods before raising rate");
411 }
412
413 static int
ath_rate_fetch_node_stats(struct ath_softc * sc,struct ath_node * an,struct ath_rateioctl * re)414 ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
415 struct ath_rateioctl *re)
416 {
417
418 return (EINVAL);
419 }
420
421 struct ath_ratectrl *
ath_rate_attach(struct ath_softc * sc)422 ath_rate_attach(struct ath_softc *sc)
423 {
424 struct onoe_softc *osc;
425
426 osc = kmalloc(sizeof(struct onoe_softc), M_DEVBUF, M_INTWAIT|M_ZERO);
427 if (osc == NULL)
428 return NULL;
429 osc->arc.arc_space = sizeof(struct onoe_node);
430 ath_rate_sysctlattach(sc);
431
432 return &osc->arc;
433 }
434
435 void
ath_rate_detach(struct ath_ratectrl * arc)436 ath_rate_detach(struct ath_ratectrl *arc)
437 {
438 struct onoe_softc *osc = (struct onoe_softc *) arc;
439
440 kfree(osc, M_DEVBUF);
441 }
442
443 #if defined(__DragonFly__)
444
445 /*
446 * Module glue.
447 */
448 static int
onoe_modevent(module_t mod,int type,void * unused)449 onoe_modevent(module_t mod, int type, void *unused)
450 {
451 int error;
452
453 wlan_serialize_enter();
454
455 switch (type) {
456 case MOD_LOAD:
457 if (bootverbose) {
458 kprintf("ath_rate: <Atsushi Onoe's rate "
459 "control algorithm>\n");
460 }
461 error = 0;
462 break;
463 case MOD_UNLOAD:
464 error = 0;
465 break;
466 default:
467 error = EINVAL;
468 break;
469 }
470 wlan_serialize_exit();
471
472 return error;
473 }
474
475 static moduledata_t onoe_mod = {
476 "ath_rate",
477 onoe_modevent,
478 0
479 };
480
481 DECLARE_MODULE(ath_rate, onoe_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
482 MODULE_VERSION(ath_rate, 1);
483 MODULE_DEPEND(ath_rate, ath_hal, 1, 1, 1);
484 MODULE_DEPEND(ath_rate, wlan, 1, 1, 1);
485
486 #endif
487