39
40/*
41 * Atsushi Onoe's rate control algorithm.
42 */
43#include "opt_inet.h"
44
45#include <sys/param.h>
46#include <sys/systm.h>
47#include <sys/sysctl.h>
48#include <sys/module.h>
49#include <sys/kernel.h>
50#include <sys/lock.h>
51#include <sys/mutex.h>
52#include <sys/errno.h>
53
54#include <machine/bus.h>
55#include <machine/resource.h>
56#include <sys/bus.h>
57
58#include <sys/socket.h>
59
60#include <net/if.h>
61#include <net/if_media.h>
62#include <net/if_arp.h>
63#include <net/ethernet.h> /* XXX for ether_sprintf */
64
65#include <net80211/ieee80211_var.h>
66
67#include <net/bpf.h>
68
69#ifdef INET
70#include <netinet/in.h>
71#include <netinet/if_ether.h>
72#endif
73
74#include <dev/ath/if_athvar.h>
75#include <dev/ath/ath_rate/onoe/onoe.h>
76#include <contrib/dev/ath/ah_desc.h>
77
78#define ONOE_DEBUG
79#ifdef ONOE_DEBUG
80enum {
81 ATH_DEBUG_RATE = 0x00000010, /* rate control */
82};
83#define DPRINTF(sc, _fmt, ...) do { \
84 if (sc->sc_debug & ATH_DEBUG_RATE) \
85 printf(_fmt, __VA_ARGS__); \
86} while (0)
87#else
88#define DPRINTF(sc, _fmt, ...)
89#endif
90
91/*
92 * Default parameters for the rate control algorithm. These are
93 * all tunable with sysctls. The rate controller runs periodically
94 * (each ath_rateinterval ms) analyzing transmit statistics for each
95 * neighbor/station (when operating in station mode this is only the AP).
96 * If transmits look to be working well over a sampling period then
97 * it gives a "raise rate credit". If transmits look to not be working
98 * well than it deducts a credit. If the credits cross a threshold then
99 * the transmit rate is raised. Various error conditions force the
100 * the transmit rate to be dropped.
101 *
102 * The decision to issue/deduct a credit is based on the errors and
103 * retries accumulated over the sampling period. ath_rate_raise defines
104 * the percent of retransmits for which a credit is issued/deducted.
105 * ath_rate_raise_threshold defines the threshold on credits at which
106 * the transmit rate is increased.
107 *
108 * XXX this algorithm is flawed.
109 */
110static int ath_rateinterval = 1000; /* rate ctl interval (ms) */
111static int ath_rate_raise = 10; /* add credit threshold */
112static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */
113
114static void ath_ratectl(void *);
115static void ath_rate_update(struct ath_softc *, struct ieee80211_node *,
116 int rate);
117static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
118static void ath_rate_ctl(void *, struct ieee80211_node *);
119
120void
121ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
122{
123 /* NB: assumed to be zero'd by caller */
124 ath_rate_update(sc, &an->an_node, 0);
125}
126
127void
128ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
129{
130}
131
132void
133ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
134 HAL_BOOL shortPreamble, size_t frameLen,
135 u_int8_t *rix, int *try0, u_int8_t *txrate)
136{
137 struct onoe_node *on = ATH_NODE_ONOE(an);
138
139 *rix = on->on_tx_rix0;
140 *try0 = on->on_tx_try0;
141 if (shortPreamble)
142 *txrate = on->on_tx_rate0sp;
143 else
144 *txrate = on->on_tx_rate0;
145}
146
147void
148ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
149 struct ath_desc *ds, HAL_BOOL shortPreamble, u_int8_t rix)
150{
151 struct onoe_node *on = ATH_NODE_ONOE(an);
152
153 ath_hal_setupxtxdesc(sc->sc_ah, ds
154 , on->on_tx_rate1sp, 2 /* series 1 */
155 , on->on_tx_rate2sp, 2 /* series 2 */
156 , on->on_tx_rate3sp, 2 /* series 3 */
157 );
158}
159
160void
161ath_rate_tx_complete(struct ath_softc *sc,
162 struct ath_node *an, const struct ath_desc *ds)
163{
164 struct onoe_node *on = ATH_NODE_ONOE(an);
165
166 if (ds->ds_txstat.ts_status == 0)
167 on->on_tx_ok++;
168 else
169 on->on_tx_err++;
170 on->on_tx_retr += ds->ds_txstat.ts_shortretry
171 + ds->ds_txstat.ts_longretry;
172}
173
174void
175ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
176{
177 if (isnew)
178 ath_rate_ctl_start(sc, &an->an_node);
179}
180
181static void
182ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
183{
184 struct ath_node *an = ATH_NODE(ni);
185 struct onoe_node *on = ATH_NODE_ONOE(an);
186 const HAL_RATE_TABLE *rt = sc->sc_currates;
187 u_int8_t rix;
188
189 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
190
191 DPRINTF(sc, "%s: set xmit rate for %s to %dM\n",
192 __func__, ether_sprintf(ni->ni_macaddr),
193 ni->ni_rates.rs_nrates > 0 ?
194 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
195
196 ni->ni_txrate = rate;
197 /* XXX management/control frames always go at the lowest speed */
198 an->an_tx_mgtrate = rt->info[0].rateCode;
199 an->an_tx_mgtratesp = an->an_tx_mgtrate | rt->info[0].shortPreamble;
200 /*
201 * Before associating a node has no rate set setup
202 * so we can't calculate any transmit codes to use.
203 * This is ok since we should never be sending anything
204 * but management frames and those always go at the
205 * lowest hardware rate.
206 */
207 if (ni->ni_rates.rs_nrates == 0)
208 goto done;
209 on->on_tx_rix0 = sc->sc_rixmap[
210 ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL];
211 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode;
212
213 on->on_tx_rate0sp = on->on_tx_rate0 |
214 rt->info[on->on_tx_rix0].shortPreamble;
215 if (sc->sc_mrretry) {
216 /*
217 * Hardware supports multi-rate retry; setup two
218 * step-down retry rates and make the lowest rate
219 * be the ``last chance''. We use 4, 2, 2, 2 tries
220 * respectively (4 is set here, the rest are fixed
221 * in the xmit routine).
222 */
223 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */
224 if (--rate >= 0) {
225 rix = sc->sc_rixmap[
226 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
227 on->on_tx_rate1 = rt->info[rix].rateCode;
228 on->on_tx_rate1sp = on->on_tx_rate1 |
229 rt->info[rix].shortPreamble;
230 } else {
231 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
232 }
233 if (--rate >= 0) {
234 rix = sc->sc_rixmap[
235 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
236 on->on_tx_rate2 = rt->info[rix].rateCode;
237 on->on_tx_rate2sp = on->on_tx_rate2 |
238 rt->info[rix].shortPreamble;
239 } else {
240 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
241 }
242 if (rate > 0) {
243 /* NB: only do this if we didn't already do it above */
244 on->on_tx_rate3 = rt->info[0].rateCode;
245 on->on_tx_rate3sp =
246 an->an_tx_mgtrate | rt->info[0].shortPreamble;
247 } else {
248 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
249 }
250 } else {
251 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */
252 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
253 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
254 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
255 }
256done:
257 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0;
258}
259
260/*
261 * Set the starting transmit rate for a node.
262 */
263static void
264ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
265{
266#define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
267 struct ieee80211com *ic = &sc->sc_ic;
268 int srate;
269
270 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
271 if (ic->ic_fixed_rate == -1) {
272 /*
273 * No fixed rate is requested. For 11b start with
274 * the highest negotiated rate; otherwise, for 11g
275 * and 11a, we start "in the middle" at 24Mb or 36Mb.
276 */
277 srate = ni->ni_rates.rs_nrates - 1;
278 if (sc->sc_curmode != IEEE80211_MODE_11B) {
279 /*
280 * Scan the negotiated rate set to find the
281 * closest rate.
282 */
283 /* NB: the rate set is assumed sorted */
284 for (; srate >= 0 && RATE(srate) > 72; srate--)
285 ;
286 KASSERT(srate >= 0, ("bogus rate set"));
287 }
288 } else {
289 /*
290 * A fixed rate is to be used; ic_fixed_rate is an
291 * index into the supported rate set. Convert this
292 * to the index into the negotiated rate set for
293 * the node. We know the rate is there because the
294 * rate set is checked when the station associates.
295 */
296 const struct ieee80211_rateset *rs =
297 &ic->ic_sup_rates[ic->ic_curmode];
298 int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL;
299 /* NB: the rate set is assumed sorted */
300 srate = ni->ni_rates.rs_nrates - 1;
301 for (; srate >= 0 && RATE(srate) != r; srate--)
302 ;
303 KASSERT(srate >= 0,
304 ("fixed rate %d not in rate set", ic->ic_fixed_rate));
305 }
306 ath_rate_update(sc, ni, srate);
307#undef RATE
308}
309
310static void
311ath_rate_cb(void *arg, struct ieee80211_node *ni)
312{
313 ath_rate_update(ni->ni_ic->ic_ifp->if_softc, ni, (int)(uintptr_t) arg);
314}
315
316/*
317 * Reset the rate control state for each 802.11 state transition.
318 */
319void
320ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state)
321{
322 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc;
323 struct ieee80211com *ic = &sc->sc_ic;
324 struct ieee80211_node *ni;
325
326 if (state == IEEE80211_S_INIT) {
327 callout_stop(&osc->timer);
328 return;
329 }
330 if (ic->ic_opmode == IEEE80211_M_STA) {
331 /*
332 * Reset local xmit state; this is really only
333 * meaningful when operating in station mode.
334 */
335 ni = ic->ic_bss;
336 if (state == IEEE80211_S_RUN) {
337 ath_rate_ctl_start(sc, ni);
338 } else {
339 ath_rate_update(sc, ni, 0);
340 }
341 } else {
342 /*
343 * When operating as a station the node table holds
344 * the AP's that were discovered during scanning.
345 * For any other operating mode we want to reset the
346 * tx rate state of each node.
347 */
348 if (ic->ic_sta != NULL)
349 ieee80211_iterate_nodes(ic->ic_sta, ath_rate_cb, 0);
350 ath_rate_update(sc, ic->ic_bss, 0);
351 }
352 if (ic->ic_fixed_rate == -1 && state == IEEE80211_S_RUN) {
353 int interval;
354 /*
355 * Start the background rate control thread if we
356 * are not configured to use a fixed xmit rate.
357 */
358 interval = ath_rateinterval;
359 if (ic->ic_opmode == IEEE80211_M_STA)
360 interval /= 2;
361 callout_reset(&osc->timer, (interval * hz) / 1000,
362 ath_ratectl, &sc->sc_if);
363 }
364}
365
366/*
367 * Examine and potentially adjust the transmit rate.
368 */
369static void
370ath_rate_ctl(void *arg, struct ieee80211_node *ni)
371{
372 struct ath_softc *sc = arg;
373 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni));
374 struct ieee80211_rateset *rs = &ni->ni_rates;
375 int dir = 0, nrate, enough;
376
377 /*
378 * Rate control
379 * XXX: very primitive version.
380 */
381 enough = (on->on_tx_ok + on->on_tx_err >= 10);
382
383 /* no packet reached -> down */
384 if (on->on_tx_err > 0 && on->on_tx_ok == 0)
385 dir = -1;
386
387 /* all packets needs retry in average -> down */
388 if (enough && on->on_tx_ok < on->on_tx_retr)
389 dir = -1;
390
391 /* no error and less than rate_raise% of packets need retry -> up */
392 if (enough && on->on_tx_err == 0 &&
393 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100)
394 dir = 1;
395
396 DPRINTF(sc, "%s: ok %d err %d retr %d upper %d dir %d\n",
397 ether_sprintf(ni->ni_macaddr),
398 on->on_tx_ok, on->on_tx_err, on->on_tx_retr,
399 on->on_tx_upper, dir);
400
401 nrate = ni->ni_txrate;
402 switch (dir) {
403 case 0:
404 if (enough && on->on_tx_upper > 0)
405 on->on_tx_upper--;
406 break;
407 case -1:
408 if (nrate > 0) {
409 nrate--;
410 sc->sc_stats.ast_rate_drop++;
411 }
412 on->on_tx_upper = 0;
413 break;
414 case 1:
415 /* raise rate if we hit rate_raise_threshold */
416 if (++on->on_tx_upper < ath_rate_raise_threshold)
417 break;
418 on->on_tx_upper = 0;
419 if (nrate + 1 < rs->rs_nrates) {
420 nrate++;
421 sc->sc_stats.ast_rate_raise++;
422 }
423 break;
424 }
425
426 if (nrate != ni->ni_txrate) {
427 DPRINTF(sc, "%s: %dM -> %dM (%d ok, %d err, %d retr)\n",
428 __func__,
429 (rs->rs_rates[ni->ni_txrate] & IEEE80211_RATE_VAL) / 2,
430 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2,
431 on->on_tx_ok, on->on_tx_err, on->on_tx_retr);
432 ath_rate_update(sc, ni, nrate);
433 } else if (enough)
434 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0;
435}
436
437static void
438ath_ratectl(void *arg)
439{
440 struct ifnet *ifp = arg;
441 struct ath_softc *sc = ifp->if_softc;
442 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc;
443 struct ieee80211com *ic = &sc->sc_ic;
444 int interval;
445
446 if (ifp->if_flags & IFF_RUNNING) {
447 sc->sc_stats.ast_rate_calls++;
448
449 if (ic->ic_opmode == IEEE80211_M_STA)
450 ath_rate_ctl(sc, ic->ic_bss); /* NB: no reference */
451 else if (ic->ic_sta != NULL)
452 ieee80211_iterate_nodes(ic->ic_sta, ath_rate_ctl, sc);
453 }
454 interval = ath_rateinterval;
455 if (ic->ic_opmode == IEEE80211_M_STA)
456 interval /= 2;
457 callout_reset(&osc->timer, (interval * hz) / 1000,
458 ath_ratectl, &sc->sc_if);
459}
460
461static void
462ath_rate_sysctlattach(struct ath_softc *sc)
463{
464 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
465 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
466
467 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
468 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
469 "rate control: operation interval (ms)");
470 /* XXX bounds check values */
471 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
472 "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0,
473 "rate control: retry threshold to credit rate raise (%%)");
474 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
475 "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0,
476 "rate control: # good periods before raising rate");
477}
478
479struct ath_ratectrl *
480ath_rate_attach(struct ath_softc *sc)
481{
482 struct onoe_softc *osc;
483
484 osc = malloc(sizeof(struct onoe_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
485 if (osc == NULL)
486 return NULL;
487 osc->arc.arc_space = sizeof(struct onoe_node);
488 callout_init(&osc->timer, debug_mpsafenet ? CALLOUT_MPSAFE : 0);
489 ath_rate_sysctlattach(sc);
490
491 return &osc->arc;
492}
493
494void
495ath_rate_detach(struct ath_ratectrl *arc)
496{
497 struct onoe_softc *osc = (struct onoe_softc *) arc;
498
499 callout_drain(&osc->timer);
500 free(osc, M_DEVBUF);
501}
502
503/*
504 * Module glue.
505 */
506static int
507onoe_modevent(module_t mod, int type, void *unused)
508{
509 switch (type) {
510 case MOD_LOAD:
511 if (bootverbose)
512 printf("ath_rate: <Atsushi Onoe's rate control algorithm>\n");
513 return 0;
514 case MOD_UNLOAD:
515 return 0;
516 }
517 return EINVAL;
518}
519
520static moduledata_t onoe_mod = {
521 "ath_rate",
522 onoe_modevent,
523 0
524};
525DECLARE_MODULE(ath_rate, onoe_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
526MODULE_VERSION(ath_rate, 1);
527MODULE_DEPEND(ath_rate, wlan, 1, 1, 1);
| 39
40/*
41 * Atsushi Onoe's rate control algorithm.
42 */
43#include "opt_inet.h"
44
45#include <sys/param.h>
46#include <sys/systm.h>
47#include <sys/sysctl.h>
48#include <sys/module.h>
49#include <sys/kernel.h>
50#include <sys/lock.h>
51#include <sys/mutex.h>
52#include <sys/errno.h>
53
54#include <machine/bus.h>
55#include <machine/resource.h>
56#include <sys/bus.h>
57
58#include <sys/socket.h>
59
60#include <net/if.h>
61#include <net/if_media.h>
62#include <net/if_arp.h>
63#include <net/ethernet.h> /* XXX for ether_sprintf */
64
65#include <net80211/ieee80211_var.h>
66
67#include <net/bpf.h>
68
69#ifdef INET
70#include <netinet/in.h>
71#include <netinet/if_ether.h>
72#endif
73
74#include <dev/ath/if_athvar.h>
75#include <dev/ath/ath_rate/onoe/onoe.h>
76#include <contrib/dev/ath/ah_desc.h>
77
78#define ONOE_DEBUG
79#ifdef ONOE_DEBUG
80enum {
81 ATH_DEBUG_RATE = 0x00000010, /* rate control */
82};
83#define DPRINTF(sc, _fmt, ...) do { \
84 if (sc->sc_debug & ATH_DEBUG_RATE) \
85 printf(_fmt, __VA_ARGS__); \
86} while (0)
87#else
88#define DPRINTF(sc, _fmt, ...)
89#endif
90
91/*
92 * Default parameters for the rate control algorithm. These are
93 * all tunable with sysctls. The rate controller runs periodically
94 * (each ath_rateinterval ms) analyzing transmit statistics for each
95 * neighbor/station (when operating in station mode this is only the AP).
96 * If transmits look to be working well over a sampling period then
97 * it gives a "raise rate credit". If transmits look to not be working
98 * well than it deducts a credit. If the credits cross a threshold then
99 * the transmit rate is raised. Various error conditions force the
100 * the transmit rate to be dropped.
101 *
102 * The decision to issue/deduct a credit is based on the errors and
103 * retries accumulated over the sampling period. ath_rate_raise defines
104 * the percent of retransmits for which a credit is issued/deducted.
105 * ath_rate_raise_threshold defines the threshold on credits at which
106 * the transmit rate is increased.
107 *
108 * XXX this algorithm is flawed.
109 */
110static int ath_rateinterval = 1000; /* rate ctl interval (ms) */
111static int ath_rate_raise = 10; /* add credit threshold */
112static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */
113
114static void ath_ratectl(void *);
115static void ath_rate_update(struct ath_softc *, struct ieee80211_node *,
116 int rate);
117static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
118static void ath_rate_ctl(void *, struct ieee80211_node *);
119
120void
121ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
122{
123 /* NB: assumed to be zero'd by caller */
124 ath_rate_update(sc, &an->an_node, 0);
125}
126
127void
128ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
129{
130}
131
132void
133ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
134 HAL_BOOL shortPreamble, size_t frameLen,
135 u_int8_t *rix, int *try0, u_int8_t *txrate)
136{
137 struct onoe_node *on = ATH_NODE_ONOE(an);
138
139 *rix = on->on_tx_rix0;
140 *try0 = on->on_tx_try0;
141 if (shortPreamble)
142 *txrate = on->on_tx_rate0sp;
143 else
144 *txrate = on->on_tx_rate0;
145}
146
147void
148ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
149 struct ath_desc *ds, HAL_BOOL shortPreamble, u_int8_t rix)
150{
151 struct onoe_node *on = ATH_NODE_ONOE(an);
152
153 ath_hal_setupxtxdesc(sc->sc_ah, ds
154 , on->on_tx_rate1sp, 2 /* series 1 */
155 , on->on_tx_rate2sp, 2 /* series 2 */
156 , on->on_tx_rate3sp, 2 /* series 3 */
157 );
158}
159
160void
161ath_rate_tx_complete(struct ath_softc *sc,
162 struct ath_node *an, const struct ath_desc *ds)
163{
164 struct onoe_node *on = ATH_NODE_ONOE(an);
165
166 if (ds->ds_txstat.ts_status == 0)
167 on->on_tx_ok++;
168 else
169 on->on_tx_err++;
170 on->on_tx_retr += ds->ds_txstat.ts_shortretry
171 + ds->ds_txstat.ts_longretry;
172}
173
174void
175ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
176{
177 if (isnew)
178 ath_rate_ctl_start(sc, &an->an_node);
179}
180
181static void
182ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
183{
184 struct ath_node *an = ATH_NODE(ni);
185 struct onoe_node *on = ATH_NODE_ONOE(an);
186 const HAL_RATE_TABLE *rt = sc->sc_currates;
187 u_int8_t rix;
188
189 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
190
191 DPRINTF(sc, "%s: set xmit rate for %s to %dM\n",
192 __func__, ether_sprintf(ni->ni_macaddr),
193 ni->ni_rates.rs_nrates > 0 ?
194 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
195
196 ni->ni_txrate = rate;
197 /* XXX management/control frames always go at the lowest speed */
198 an->an_tx_mgtrate = rt->info[0].rateCode;
199 an->an_tx_mgtratesp = an->an_tx_mgtrate | rt->info[0].shortPreamble;
200 /*
201 * Before associating a node has no rate set setup
202 * so we can't calculate any transmit codes to use.
203 * This is ok since we should never be sending anything
204 * but management frames and those always go at the
205 * lowest hardware rate.
206 */
207 if (ni->ni_rates.rs_nrates == 0)
208 goto done;
209 on->on_tx_rix0 = sc->sc_rixmap[
210 ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL];
211 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode;
212
213 on->on_tx_rate0sp = on->on_tx_rate0 |
214 rt->info[on->on_tx_rix0].shortPreamble;
215 if (sc->sc_mrretry) {
216 /*
217 * Hardware supports multi-rate retry; setup two
218 * step-down retry rates and make the lowest rate
219 * be the ``last chance''. We use 4, 2, 2, 2 tries
220 * respectively (4 is set here, the rest are fixed
221 * in the xmit routine).
222 */
223 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */
224 if (--rate >= 0) {
225 rix = sc->sc_rixmap[
226 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
227 on->on_tx_rate1 = rt->info[rix].rateCode;
228 on->on_tx_rate1sp = on->on_tx_rate1 |
229 rt->info[rix].shortPreamble;
230 } else {
231 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
232 }
233 if (--rate >= 0) {
234 rix = sc->sc_rixmap[
235 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
236 on->on_tx_rate2 = rt->info[rix].rateCode;
237 on->on_tx_rate2sp = on->on_tx_rate2 |
238 rt->info[rix].shortPreamble;
239 } else {
240 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
241 }
242 if (rate > 0) {
243 /* NB: only do this if we didn't already do it above */
244 on->on_tx_rate3 = rt->info[0].rateCode;
245 on->on_tx_rate3sp =
246 an->an_tx_mgtrate | rt->info[0].shortPreamble;
247 } else {
248 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
249 }
250 } else {
251 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */
252 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
253 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
254 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
255 }
256done:
257 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0;
258}
259
260/*
261 * Set the starting transmit rate for a node.
262 */
263static void
264ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
265{
266#define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
267 struct ieee80211com *ic = &sc->sc_ic;
268 int srate;
269
270 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
271 if (ic->ic_fixed_rate == -1) {
272 /*
273 * No fixed rate is requested. For 11b start with
274 * the highest negotiated rate; otherwise, for 11g
275 * and 11a, we start "in the middle" at 24Mb or 36Mb.
276 */
277 srate = ni->ni_rates.rs_nrates - 1;
278 if (sc->sc_curmode != IEEE80211_MODE_11B) {
279 /*
280 * Scan the negotiated rate set to find the
281 * closest rate.
282 */
283 /* NB: the rate set is assumed sorted */
284 for (; srate >= 0 && RATE(srate) > 72; srate--)
285 ;
286 KASSERT(srate >= 0, ("bogus rate set"));
287 }
288 } else {
289 /*
290 * A fixed rate is to be used; ic_fixed_rate is an
291 * index into the supported rate set. Convert this
292 * to the index into the negotiated rate set for
293 * the node. We know the rate is there because the
294 * rate set is checked when the station associates.
295 */
296 const struct ieee80211_rateset *rs =
297 &ic->ic_sup_rates[ic->ic_curmode];
298 int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL;
299 /* NB: the rate set is assumed sorted */
300 srate = ni->ni_rates.rs_nrates - 1;
301 for (; srate >= 0 && RATE(srate) != r; srate--)
302 ;
303 KASSERT(srate >= 0,
304 ("fixed rate %d not in rate set", ic->ic_fixed_rate));
305 }
306 ath_rate_update(sc, ni, srate);
307#undef RATE
308}
309
310static void
311ath_rate_cb(void *arg, struct ieee80211_node *ni)
312{
313 ath_rate_update(ni->ni_ic->ic_ifp->if_softc, ni, (int)(uintptr_t) arg);
314}
315
316/*
317 * Reset the rate control state for each 802.11 state transition.
318 */
319void
320ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state)
321{
322 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc;
323 struct ieee80211com *ic = &sc->sc_ic;
324 struct ieee80211_node *ni;
325
326 if (state == IEEE80211_S_INIT) {
327 callout_stop(&osc->timer);
328 return;
329 }
330 if (ic->ic_opmode == IEEE80211_M_STA) {
331 /*
332 * Reset local xmit state; this is really only
333 * meaningful when operating in station mode.
334 */
335 ni = ic->ic_bss;
336 if (state == IEEE80211_S_RUN) {
337 ath_rate_ctl_start(sc, ni);
338 } else {
339 ath_rate_update(sc, ni, 0);
340 }
341 } else {
342 /*
343 * When operating as a station the node table holds
344 * the AP's that were discovered during scanning.
345 * For any other operating mode we want to reset the
346 * tx rate state of each node.
347 */
348 if (ic->ic_sta != NULL)
349 ieee80211_iterate_nodes(ic->ic_sta, ath_rate_cb, 0);
350 ath_rate_update(sc, ic->ic_bss, 0);
351 }
352 if (ic->ic_fixed_rate == -1 && state == IEEE80211_S_RUN) {
353 int interval;
354 /*
355 * Start the background rate control thread if we
356 * are not configured to use a fixed xmit rate.
357 */
358 interval = ath_rateinterval;
359 if (ic->ic_opmode == IEEE80211_M_STA)
360 interval /= 2;
361 callout_reset(&osc->timer, (interval * hz) / 1000,
362 ath_ratectl, &sc->sc_if);
363 }
364}
365
366/*
367 * Examine and potentially adjust the transmit rate.
368 */
369static void
370ath_rate_ctl(void *arg, struct ieee80211_node *ni)
371{
372 struct ath_softc *sc = arg;
373 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni));
374 struct ieee80211_rateset *rs = &ni->ni_rates;
375 int dir = 0, nrate, enough;
376
377 /*
378 * Rate control
379 * XXX: very primitive version.
380 */
381 enough = (on->on_tx_ok + on->on_tx_err >= 10);
382
383 /* no packet reached -> down */
384 if (on->on_tx_err > 0 && on->on_tx_ok == 0)
385 dir = -1;
386
387 /* all packets needs retry in average -> down */
388 if (enough && on->on_tx_ok < on->on_tx_retr)
389 dir = -1;
390
391 /* no error and less than rate_raise% of packets need retry -> up */
392 if (enough && on->on_tx_err == 0 &&
393 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100)
394 dir = 1;
395
396 DPRINTF(sc, "%s: ok %d err %d retr %d upper %d dir %d\n",
397 ether_sprintf(ni->ni_macaddr),
398 on->on_tx_ok, on->on_tx_err, on->on_tx_retr,
399 on->on_tx_upper, dir);
400
401 nrate = ni->ni_txrate;
402 switch (dir) {
403 case 0:
404 if (enough && on->on_tx_upper > 0)
405 on->on_tx_upper--;
406 break;
407 case -1:
408 if (nrate > 0) {
409 nrate--;
410 sc->sc_stats.ast_rate_drop++;
411 }
412 on->on_tx_upper = 0;
413 break;
414 case 1:
415 /* raise rate if we hit rate_raise_threshold */
416 if (++on->on_tx_upper < ath_rate_raise_threshold)
417 break;
418 on->on_tx_upper = 0;
419 if (nrate + 1 < rs->rs_nrates) {
420 nrate++;
421 sc->sc_stats.ast_rate_raise++;
422 }
423 break;
424 }
425
426 if (nrate != ni->ni_txrate) {
427 DPRINTF(sc, "%s: %dM -> %dM (%d ok, %d err, %d retr)\n",
428 __func__,
429 (rs->rs_rates[ni->ni_txrate] & IEEE80211_RATE_VAL) / 2,
430 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2,
431 on->on_tx_ok, on->on_tx_err, on->on_tx_retr);
432 ath_rate_update(sc, ni, nrate);
433 } else if (enough)
434 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0;
435}
436
437static void
438ath_ratectl(void *arg)
439{
440 struct ifnet *ifp = arg;
441 struct ath_softc *sc = ifp->if_softc;
442 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc;
443 struct ieee80211com *ic = &sc->sc_ic;
444 int interval;
445
446 if (ifp->if_flags & IFF_RUNNING) {
447 sc->sc_stats.ast_rate_calls++;
448
449 if (ic->ic_opmode == IEEE80211_M_STA)
450 ath_rate_ctl(sc, ic->ic_bss); /* NB: no reference */
451 else if (ic->ic_sta != NULL)
452 ieee80211_iterate_nodes(ic->ic_sta, ath_rate_ctl, sc);
453 }
454 interval = ath_rateinterval;
455 if (ic->ic_opmode == IEEE80211_M_STA)
456 interval /= 2;
457 callout_reset(&osc->timer, (interval * hz) / 1000,
458 ath_ratectl, &sc->sc_if);
459}
460
461static void
462ath_rate_sysctlattach(struct ath_softc *sc)
463{
464 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
465 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
466
467 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
468 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
469 "rate control: operation interval (ms)");
470 /* XXX bounds check values */
471 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
472 "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0,
473 "rate control: retry threshold to credit rate raise (%%)");
474 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
475 "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0,
476 "rate control: # good periods before raising rate");
477}
478
479struct ath_ratectrl *
480ath_rate_attach(struct ath_softc *sc)
481{
482 struct onoe_softc *osc;
483
484 osc = malloc(sizeof(struct onoe_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
485 if (osc == NULL)
486 return NULL;
487 osc->arc.arc_space = sizeof(struct onoe_node);
488 callout_init(&osc->timer, debug_mpsafenet ? CALLOUT_MPSAFE : 0);
489 ath_rate_sysctlattach(sc);
490
491 return &osc->arc;
492}
493
494void
495ath_rate_detach(struct ath_ratectrl *arc)
496{
497 struct onoe_softc *osc = (struct onoe_softc *) arc;
498
499 callout_drain(&osc->timer);
500 free(osc, M_DEVBUF);
501}
502
503/*
504 * Module glue.
505 */
506static int
507onoe_modevent(module_t mod, int type, void *unused)
508{
509 switch (type) {
510 case MOD_LOAD:
511 if (bootverbose)
512 printf("ath_rate: <Atsushi Onoe's rate control algorithm>\n");
513 return 0;
514 case MOD_UNLOAD:
515 return 0;
516 }
517 return EINVAL;
518}
519
520static moduledata_t onoe_mod = {
521 "ath_rate",
522 onoe_modevent,
523 0
524};
525DECLARE_MODULE(ath_rate, onoe_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
526MODULE_VERSION(ath_rate, 1);
527MODULE_DEPEND(ath_rate, wlan, 1, 1, 1);
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