xref: /freebsd/sys/dev/ath/ath_rate/amrr/amrr.c (revision e17f5b1d)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2004 INRIA
5  * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer,
13  *    without modification.
14  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
15  *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
16  *    redistribution must be conditioned upon including a substantially
17  *    similar Disclaimer requirement for further binary redistribution.
18  * 3. Neither the names of the above-listed copyright holders nor the names
19  *    of any contributors may be used to endorse or promote products derived
20  *    from this software without specific prior written permission.
21  *
22  * Alternatively, this software may be distributed under the terms of the
23  * GNU General Public License ("GPL") version 2 as published by the Free
24  * Software Foundation.
25  *
26  * NO WARRANTY
27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29  * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
30  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
31  * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
32  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
35  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
37  * THE POSSIBILITY OF SUCH DAMAGES.
38  *
39  */
40 
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 /*
45  * AMRR rate control. See:
46  * http://www-sop.inria.fr/rapports/sophia/RR-5208.html
47  * "IEEE 802.11 Rate Adaptation: A Practical Approach" by
48  *    Mathieu Lacage, Hossein Manshaei, Thierry Turletti
49  */
50 #include "opt_ath.h"
51 #include "opt_inet.h"
52 #include "opt_wlan.h"
53 
54 #include <sys/param.h>
55 #include <sys/systm.h>
56 #include <sys/sysctl.h>
57 #include <sys/kernel.h>
58 #include <sys/lock.h>
59 #include <sys/mutex.h>
60 #include <sys/errno.h>
61 
62 #include <machine/bus.h>
63 #include <machine/resource.h>
64 #include <sys/bus.h>
65 
66 #include <sys/socket.h>
67 
68 #include <net/if.h>
69 #include <net/if_media.h>
70 #include <net/if_arp.h>
71 
72 #include <net80211/ieee80211_var.h>
73 
74 #include <net/bpf.h>
75 
76 #ifdef INET
77 #include <netinet/in.h>
78 #include <netinet/if_ether.h>
79 #endif
80 
81 #include <dev/ath/if_athvar.h>
82 #include <dev/ath/ath_rate/amrr/amrr.h>
83 #include <dev/ath/ath_hal/ah_desc.h>
84 
85 static	int ath_rateinterval = 1000;		/* rate ctl interval (ms)  */
86 static	int ath_rate_max_success_threshold = 10;
87 static	int ath_rate_min_success_threshold = 1;
88 
89 static void	ath_rate_update(struct ath_softc *, struct ieee80211_node *,
90 			int rate);
91 static void	ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
92 static void	ath_rate_ctl(void *, struct ieee80211_node *);
93 
94 void
95 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
96 {
97 	/* NB: assumed to be zero'd by caller */
98 }
99 
100 void
101 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
102 {
103 }
104 
105 void
106 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
107 	int shortPreamble, size_t frameLen, int tid, int is_aggr,
108 	u_int8_t *rix, int *try0, u_int8_t *txrate, int *maxdur,
109 	int *maxpktlen)
110 {
111 	struct amrr_node *amn = ATH_NODE_AMRR(an);
112 
113 	*rix = amn->amn_tx_rix0;
114 	*try0 = amn->amn_tx_try0;
115 	if (shortPreamble)
116 		*txrate = amn->amn_tx_rate0sp;
117 	else
118 		*txrate = amn->amn_tx_rate0;
119 	maxdur = -1;
120 	maxpktlen = -1;
121 }
122 
123 /*
124  * Get the TX rates.
125  *
126  * The short preamble bits aren't set here; the caller should augment
127  * the returned rate with the relevant preamble rate flag.
128  */
129 void
130 ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
131     uint8_t rix0, int is_aggr, struct ath_rc_series *rc)
132 {
133 	struct amrr_node *amn = ATH_NODE_AMRR(an);
134 
135 	rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0;
136 
137 	rc[0].rix = amn->amn_tx_rate0;
138 	rc[1].rix = amn->amn_tx_rate1;
139 	rc[2].rix = amn->amn_tx_rate2;
140 	rc[3].rix = amn->amn_tx_rate3;
141 
142 	rc[0].tries = amn->amn_tx_try0;
143 	rc[1].tries = amn->amn_tx_try1;
144 	rc[2].tries = amn->amn_tx_try2;
145 	rc[3].tries = amn->amn_tx_try3;
146 }
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 amrr_node *amn = ATH_NODE_AMRR(an);
154 
155 	ath_hal_setupxtxdesc(sc->sc_ah, ds
156 		, amn->amn_tx_rate1sp, amn->amn_tx_try1	/* series 1 */
157 		, amn->amn_tx_rate2sp, amn->amn_tx_try2	/* series 2 */
158 		, amn->amn_tx_rate3sp, amn->amn_tx_try3	/* series 3 */
159 	);
160 }
161 
162 void
163 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
164 	const struct ath_rc_series *rc, const struct ath_tx_status *ts,
165 	int frame_size, int rc_framesize, int nframes, int nbad)
166 {
167 	struct amrr_node *amn = ATH_NODE_AMRR(an);
168 	int sr = ts->ts_shortretry;
169 	int lr = ts->ts_longretry;
170 	int retry_count = sr + lr;
171 
172 	amn->amn_tx_try0_cnt++;
173 	if (retry_count == 1) {
174 		amn->amn_tx_try1_cnt++;
175 	} else if (retry_count == 2) {
176 		amn->amn_tx_try1_cnt++;
177 		amn->amn_tx_try2_cnt++;
178 	} else if (retry_count == 3) {
179 		amn->amn_tx_try1_cnt++;
180 		amn->amn_tx_try2_cnt++;
181 		amn->amn_tx_try3_cnt++;
182 	} else if (retry_count > 3) {
183 		amn->amn_tx_try1_cnt++;
184 		amn->amn_tx_try2_cnt++;
185 		amn->amn_tx_try3_cnt++;
186 		amn->amn_tx_failure_cnt++;
187 	}
188 	if (amn->amn_interval != 0 &&
189 	    ticks - amn->amn_ticks > amn->amn_interval) {
190 		ath_rate_ctl(sc, &an->an_node);
191 		amn->amn_ticks = ticks;
192 	}
193 }
194 
195 void
196 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
197 {
198 	if (isnew)
199 		ath_rate_ctl_start(sc, &an->an_node);
200 }
201 
202 void
203 ath_rate_update_rx_rssi(struct ath_softc *sc, struct ath_node *an, int rssi)
204 {
205 }
206 
207 static void
208 node_reset(struct amrr_node *amn)
209 {
210 	amn->amn_tx_try0_cnt = 0;
211 	amn->amn_tx_try1_cnt = 0;
212 	amn->amn_tx_try2_cnt = 0;
213 	amn->amn_tx_try3_cnt = 0;
214 	amn->amn_tx_failure_cnt = 0;
215   	amn->amn_success = 0;
216   	amn->amn_recovery = 0;
217   	amn->amn_success_threshold = ath_rate_min_success_threshold;
218 }
219 
220 
221 /**
222  * The code below assumes that we are dealing with hardware multi rate retry
223  * I have no idea what will happen if you try to use this module with another
224  * type of hardware. Your machine might catch fire or it might work with
225  * horrible performance...
226  */
227 static void
228 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
229 {
230 	struct ath_node *an = ATH_NODE(ni);
231 	struct amrr_node *amn = ATH_NODE_AMRR(an);
232 	struct ieee80211vap *vap = ni->ni_vap;
233 	const HAL_RATE_TABLE *rt = sc->sc_currates;
234 	u_int8_t rix;
235 
236 	KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
237 
238 	IEEE80211_NOTE(vap, IEEE80211_MSG_RATECTL, ni,
239 	    "%s: set xmit rate to %dM", __func__,
240 	    ni->ni_rates.rs_nrates > 0 ?
241 		(ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
242 
243 	amn->amn_rix = rate;
244 	/*
245 	 * Before associating a node has no rate set setup
246 	 * so we can't calculate any transmit codes to use.
247 	 * This is ok since we should never be sending anything
248 	 * but management frames and those always go at the
249 	 * lowest hardware rate.
250 	 */
251 	if (ni->ni_rates.rs_nrates > 0) {
252 		ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL;
253 		amn->amn_tx_rix0 = sc->sc_rixmap[ni->ni_txrate];
254 		amn->amn_tx_rate0 = rt->info[amn->amn_tx_rix0].rateCode;
255 		amn->amn_tx_rate0sp = amn->amn_tx_rate0 |
256 			rt->info[amn->amn_tx_rix0].shortPreamble;
257 		if (sc->sc_mrretry) {
258 			amn->amn_tx_try0 = 1;
259 			amn->amn_tx_try1 = 1;
260 			amn->amn_tx_try2 = 1;
261 			amn->amn_tx_try3 = 1;
262 			if (--rate >= 0) {
263 				rix = sc->sc_rixmap[
264 						    ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
265 				amn->amn_tx_rate1 = rt->info[rix].rateCode;
266 				amn->amn_tx_rate1sp = amn->amn_tx_rate1 |
267 					rt->info[rix].shortPreamble;
268 			} else {
269 				amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
270 			}
271 			if (--rate >= 0) {
272 				rix = sc->sc_rixmap[
273 						    ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
274 				amn->amn_tx_rate2 = rt->info[rix].rateCode;
275 				amn->amn_tx_rate2sp = amn->amn_tx_rate2 |
276 					rt->info[rix].shortPreamble;
277 			} else {
278 				amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
279 			}
280 			if (rate > 0) {
281 				/* NB: only do this if we didn't already do it above */
282 				amn->amn_tx_rate3 = rt->info[0].rateCode;
283 				amn->amn_tx_rate3sp =
284 					amn->amn_tx_rate3 | rt->info[0].shortPreamble;
285 			} else {
286 				amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
287 			}
288 		} else {
289 			amn->amn_tx_try0 = ATH_TXMAXTRY;
290 			/* theorically, these statements are useless because
291 			 *  the code which uses them tests for an_tx_try0 == ATH_TXMAXTRY
292 			 */
293 			amn->amn_tx_try1 = 0;
294 			amn->amn_tx_try2 = 0;
295 			amn->amn_tx_try3 = 0;
296 			amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
297 			amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
298 			amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
299 		}
300 	}
301 	node_reset(amn);
302 
303 	amn->amn_interval = ath_rateinterval;
304 	if (vap->iv_opmode == IEEE80211_M_STA)
305 		amn->amn_interval /= 2;
306 	amn->amn_interval = (amn->amn_interval * hz) / 1000;
307 }
308 
309 /*
310  * Set the starting transmit rate for a node.
311  */
312 static void
313 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
314 {
315 #define	RATE(_ix)	(ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
316 	const struct ieee80211_txparam *tp = ni->ni_txparms;
317 	int srate;
318 
319 	KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
320 	if (tp == NULL || tp->ucastrate == IEEE80211_FIXED_RATE_NONE) {
321 		/*
322 		 * No fixed rate is requested. For 11b start with
323 		 * the highest negotiated rate; otherwise, for 11g
324 		 * and 11a, we start "in the middle" at 24Mb or 36Mb.
325 		 */
326 		srate = ni->ni_rates.rs_nrates - 1;
327 		if (sc->sc_curmode != IEEE80211_MODE_11B) {
328 			/*
329 			 * Scan the negotiated rate set to find the
330 			 * closest rate.
331 			 */
332 			/* NB: the rate set is assumed sorted */
333 			for (; srate >= 0 && RATE(srate) > 72; srate--)
334 				;
335 		}
336 	} else {
337 		/*
338 		 * A fixed rate is to be used; ic_fixed_rate is the
339 		 * IEEE code for this rate (sans basic bit).  Convert this
340 		 * to the index into the negotiated rate set for
341 		 * the node.  We know the rate is there because the
342 		 * rate set is checked when the station associates.
343 		 */
344 		/* NB: the rate set is assumed sorted */
345 		srate = ni->ni_rates.rs_nrates - 1;
346 		for (; srate >= 0 && RATE(srate) != tp->ucastrate; srate--)
347 			;
348 	}
349 	/*
350 	 * The selected rate may not be available due to races
351 	 * and mode settings.  Also orphaned nodes created in
352 	 * adhoc mode may not have any rate set so this lookup
353 	 * can fail.  This is not fatal.
354 	 */
355 	ath_rate_update(sc, ni, srate < 0 ? 0 : srate);
356 #undef RATE
357 }
358 
359 /*
360  * Examine and potentially adjust the transmit rate.
361  */
362 static void
363 ath_rate_ctl(void *arg, struct ieee80211_node *ni)
364 {
365 	struct ath_softc *sc = arg;
366 	struct amrr_node *amn = ATH_NODE_AMRR(ATH_NODE (ni));
367 	int rix;
368 
369 #define is_success(amn) \
370 (amn->amn_tx_try1_cnt  < (amn->amn_tx_try0_cnt/10))
371 #define is_enough(amn) \
372 (amn->amn_tx_try0_cnt > 10)
373 #define is_failure(amn) \
374 (amn->amn_tx_try1_cnt > (amn->amn_tx_try0_cnt/3))
375 
376 	rix = amn->amn_rix;
377 
378   	IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
379 	    "cnt0: %d cnt1: %d cnt2: %d cnt3: %d -- threshold: %d",
380 	    amn->amn_tx_try0_cnt, amn->amn_tx_try1_cnt, amn->amn_tx_try2_cnt,
381 	    amn->amn_tx_try3_cnt, amn->amn_success_threshold);
382   	if (is_success (amn) && is_enough (amn)) {
383 		amn->amn_success++;
384 		if (amn->amn_success == amn->amn_success_threshold &&
385 		    rix + 1 < ni->ni_rates.rs_nrates) {
386   			amn->amn_recovery = 1;
387   			amn->amn_success = 0;
388   			rix++;
389 			IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
390 			    "increase rate to %d", rix);
391   		} else {
392 			amn->amn_recovery = 0;
393 		}
394   	} else if (is_failure (amn)) {
395   		amn->amn_success = 0;
396 		if (rix > 0) {
397   			if (amn->amn_recovery) {
398   				/* recovery failure. */
399   				amn->amn_success_threshold *= 2;
400   				amn->amn_success_threshold = min (amn->amn_success_threshold,
401 								  (u_int)ath_rate_max_success_threshold);
402 				IEEE80211_NOTE(ni->ni_vap,
403 				    IEEE80211_MSG_RATECTL, ni,
404 				    "decrease rate recovery thr: %d",
405 				    amn->amn_success_threshold);
406   			} else {
407   				/* simple failure. */
408  				amn->amn_success_threshold = ath_rate_min_success_threshold;
409 				IEEE80211_NOTE(ni->ni_vap,
410 				    IEEE80211_MSG_RATECTL, ni,
411 				    "decrease rate normal thr: %d",
412 				    amn->amn_success_threshold);
413   			}
414 			amn->amn_recovery = 0;
415   			rix--;
416    		} else {
417 			amn->amn_recovery = 0;
418 		}
419 
420    	}
421 	if (is_enough (amn) || rix != amn->amn_rix) {
422 		/* reset counters. */
423 		amn->amn_tx_try0_cnt = 0;
424 		amn->amn_tx_try1_cnt = 0;
425 		amn->amn_tx_try2_cnt = 0;
426 		amn->amn_tx_try3_cnt = 0;
427 		amn->amn_tx_failure_cnt = 0;
428 	}
429 	if (rix != amn->amn_rix) {
430 		ath_rate_update(sc, ni, rix);
431 	}
432 }
433 
434 static int
435 ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
436     struct ath_rateioctl *re)
437 {
438 
439 	return (EINVAL);
440 }
441 
442 static void
443 ath_rate_sysctlattach(struct ath_softc *sc)
444 {
445 	struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
446 	struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
447 
448 	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
449 		"rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
450 		"rate control: operation interval (ms)");
451 	/* XXX bounds check values */
452 	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
453 		"max_sucess_threshold", CTLFLAG_RW,
454 		&ath_rate_max_success_threshold, 0, "");
455 	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
456 		"min_sucess_threshold", CTLFLAG_RW,
457 		&ath_rate_min_success_threshold, 0, "");
458 }
459 
460 struct ath_ratectrl *
461 ath_rate_attach(struct ath_softc *sc)
462 {
463 	struct amrr_softc *asc;
464 
465 	asc = malloc(sizeof(struct amrr_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
466 	if (asc == NULL)
467 		return NULL;
468 	asc->arc.arc_space = sizeof(struct amrr_node);
469 	ath_rate_sysctlattach(sc);
470 
471 	return &asc->arc;
472 }
473 
474 void
475 ath_rate_detach(struct ath_ratectrl *arc)
476 {
477 	struct amrr_softc *asc = (struct amrr_softc *) arc;
478 
479 	free(asc, M_DEVBUF);
480 }
481