xref: /freebsd/sys/dev/ath/ath_rate/amrr/amrr.c (revision f3c5273d315a64826d2149ac453ff8c4583ddbe8)
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,
108 	u_int8_t *rix, int *try0, u_int8_t *txrate)
109 {
110 	struct amrr_node *amn = ATH_NODE_AMRR(an);
111 
112 	*rix = amn->amn_tx_rix0;
113 	*try0 = amn->amn_tx_try0;
114 	if (shortPreamble)
115 		*txrate = amn->amn_tx_rate0sp;
116 	else
117 		*txrate = amn->amn_tx_rate0;
118 }
119 
120 /*
121  * Get the TX rates.
122  *
123  * The short preamble bits aren't set here; the caller should augment
124  * the returned rate with the relevant preamble rate flag.
125  */
126 void
127 ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
128     uint8_t rix0, struct ath_rc_series *rc)
129 {
130 	struct amrr_node *amn = ATH_NODE_AMRR(an);
131 
132 	rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0;
133 
134 	rc[0].rix = amn->amn_tx_rate0;
135 	rc[1].rix = amn->amn_tx_rate1;
136 	rc[2].rix = amn->amn_tx_rate2;
137 	rc[3].rix = amn->amn_tx_rate3;
138 
139 	rc[0].tries = amn->amn_tx_try0;
140 	rc[1].tries = amn->amn_tx_try1;
141 	rc[2].tries = amn->amn_tx_try2;
142 	rc[3].tries = amn->amn_tx_try3;
143 }
144 
145 
146 void
147 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
148 	struct ath_desc *ds, int shortPreamble, u_int8_t rix)
149 {
150 	struct amrr_node *amn = ATH_NODE_AMRR(an);
151 
152 	ath_hal_setupxtxdesc(sc->sc_ah, ds
153 		, amn->amn_tx_rate1sp, amn->amn_tx_try1	/* series 1 */
154 		, amn->amn_tx_rate2sp, amn->amn_tx_try2	/* series 2 */
155 		, amn->amn_tx_rate3sp, amn->amn_tx_try3	/* series 3 */
156 	);
157 }
158 
159 void
160 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
161 	const struct ath_rc_series *rc, const struct ath_tx_status *ts,
162 	int frame_size, int nframes, int nbad)
163 {
164 	struct amrr_node *amn = ATH_NODE_AMRR(an);
165 	int sr = ts->ts_shortretry;
166 	int lr = ts->ts_longretry;
167 	int retry_count = sr + lr;
168 
169 	amn->amn_tx_try0_cnt++;
170 	if (retry_count == 1) {
171 		amn->amn_tx_try1_cnt++;
172 	} else if (retry_count == 2) {
173 		amn->amn_tx_try1_cnt++;
174 		amn->amn_tx_try2_cnt++;
175 	} else if (retry_count == 3) {
176 		amn->amn_tx_try1_cnt++;
177 		amn->amn_tx_try2_cnt++;
178 		amn->amn_tx_try3_cnt++;
179 	} else if (retry_count > 3) {
180 		amn->amn_tx_try1_cnt++;
181 		amn->amn_tx_try2_cnt++;
182 		amn->amn_tx_try3_cnt++;
183 		amn->amn_tx_failure_cnt++;
184 	}
185 	if (amn->amn_interval != 0 &&
186 	    ticks - amn->amn_ticks > amn->amn_interval) {
187 		ath_rate_ctl(sc, &an->an_node);
188 		amn->amn_ticks = ticks;
189 	}
190 }
191 
192 void
193 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
194 {
195 	if (isnew)
196 		ath_rate_ctl_start(sc, &an->an_node);
197 }
198 
199 static void
200 node_reset(struct amrr_node *amn)
201 {
202 	amn->amn_tx_try0_cnt = 0;
203 	amn->amn_tx_try1_cnt = 0;
204 	amn->amn_tx_try2_cnt = 0;
205 	amn->amn_tx_try3_cnt = 0;
206 	amn->amn_tx_failure_cnt = 0;
207   	amn->amn_success = 0;
208   	amn->amn_recovery = 0;
209   	amn->amn_success_threshold = ath_rate_min_success_threshold;
210 }
211 
212 
213 /**
214  * The code below assumes that we are dealing with hardware multi rate retry
215  * I have no idea what will happen if you try to use this module with another
216  * type of hardware. Your machine might catch fire or it might work with
217  * horrible performance...
218  */
219 static void
220 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
221 {
222 	struct ath_node *an = ATH_NODE(ni);
223 	struct amrr_node *amn = ATH_NODE_AMRR(an);
224 	struct ieee80211vap *vap = ni->ni_vap;
225 	const HAL_RATE_TABLE *rt = sc->sc_currates;
226 	u_int8_t rix;
227 
228 	KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
229 
230 	IEEE80211_NOTE(vap, IEEE80211_MSG_RATECTL, ni,
231 	    "%s: set xmit rate to %dM", __func__,
232 	    ni->ni_rates.rs_nrates > 0 ?
233 		(ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
234 
235 	amn->amn_rix = rate;
236 	/*
237 	 * Before associating a node has no rate set setup
238 	 * so we can't calculate any transmit codes to use.
239 	 * This is ok since we should never be sending anything
240 	 * but management frames and those always go at the
241 	 * lowest hardware rate.
242 	 */
243 	if (ni->ni_rates.rs_nrates > 0) {
244 		ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL;
245 		amn->amn_tx_rix0 = sc->sc_rixmap[ni->ni_txrate];
246 		amn->amn_tx_rate0 = rt->info[amn->amn_tx_rix0].rateCode;
247 		amn->amn_tx_rate0sp = amn->amn_tx_rate0 |
248 			rt->info[amn->amn_tx_rix0].shortPreamble;
249 		if (sc->sc_mrretry) {
250 			amn->amn_tx_try0 = 1;
251 			amn->amn_tx_try1 = 1;
252 			amn->amn_tx_try2 = 1;
253 			amn->amn_tx_try3 = 1;
254 			if (--rate >= 0) {
255 				rix = sc->sc_rixmap[
256 						    ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
257 				amn->amn_tx_rate1 = rt->info[rix].rateCode;
258 				amn->amn_tx_rate1sp = amn->amn_tx_rate1 |
259 					rt->info[rix].shortPreamble;
260 			} else {
261 				amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
262 			}
263 			if (--rate >= 0) {
264 				rix = sc->sc_rixmap[
265 						    ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
266 				amn->amn_tx_rate2 = rt->info[rix].rateCode;
267 				amn->amn_tx_rate2sp = amn->amn_tx_rate2 |
268 					rt->info[rix].shortPreamble;
269 			} else {
270 				amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
271 			}
272 			if (rate > 0) {
273 				/* NB: only do this if we didn't already do it above */
274 				amn->amn_tx_rate3 = rt->info[0].rateCode;
275 				amn->amn_tx_rate3sp =
276 					amn->amn_tx_rate3 | rt->info[0].shortPreamble;
277 			} else {
278 				amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
279 			}
280 		} else {
281 			amn->amn_tx_try0 = ATH_TXMAXTRY;
282 			/* theorically, these statements are useless because
283 			 *  the code which uses them tests for an_tx_try0 == ATH_TXMAXTRY
284 			 */
285 			amn->amn_tx_try1 = 0;
286 			amn->amn_tx_try2 = 0;
287 			amn->amn_tx_try3 = 0;
288 			amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
289 			amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
290 			amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
291 		}
292 	}
293 	node_reset(amn);
294 
295 	amn->amn_interval = ath_rateinterval;
296 	if (vap->iv_opmode == IEEE80211_M_STA)
297 		amn->amn_interval /= 2;
298 	amn->amn_interval = (amn->amn_interval * hz) / 1000;
299 }
300 
301 /*
302  * Set the starting transmit rate for a node.
303  */
304 static void
305 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
306 {
307 #define	RATE(_ix)	(ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
308 	const struct ieee80211_txparam *tp = ni->ni_txparms;
309 	int srate;
310 
311 	KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
312 	if (tp == NULL || tp->ucastrate == IEEE80211_FIXED_RATE_NONE) {
313 		/*
314 		 * No fixed rate is requested. For 11b start with
315 		 * the highest negotiated rate; otherwise, for 11g
316 		 * and 11a, we start "in the middle" at 24Mb or 36Mb.
317 		 */
318 		srate = ni->ni_rates.rs_nrates - 1;
319 		if (sc->sc_curmode != IEEE80211_MODE_11B) {
320 			/*
321 			 * Scan the negotiated rate set to find the
322 			 * closest rate.
323 			 */
324 			/* NB: the rate set is assumed sorted */
325 			for (; srate >= 0 && RATE(srate) > 72; srate--)
326 				;
327 		}
328 	} else {
329 		/*
330 		 * A fixed rate is to be used; ic_fixed_rate is the
331 		 * IEEE code for this rate (sans basic bit).  Convert this
332 		 * to the index into the negotiated rate set for
333 		 * the node.  We know the rate is there because the
334 		 * rate set is checked when the station associates.
335 		 */
336 		/* NB: the rate set is assumed sorted */
337 		srate = ni->ni_rates.rs_nrates - 1;
338 		for (; srate >= 0 && RATE(srate) != tp->ucastrate; srate--)
339 			;
340 	}
341 	/*
342 	 * The selected rate may not be available due to races
343 	 * and mode settings.  Also orphaned nodes created in
344 	 * adhoc mode may not have any rate set so this lookup
345 	 * can fail.  This is not fatal.
346 	 */
347 	ath_rate_update(sc, ni, srate < 0 ? 0 : srate);
348 #undef RATE
349 }
350 
351 /*
352  * Examine and potentially adjust the transmit rate.
353  */
354 static void
355 ath_rate_ctl(void *arg, struct ieee80211_node *ni)
356 {
357 	struct ath_softc *sc = arg;
358 	struct amrr_node *amn = ATH_NODE_AMRR(ATH_NODE (ni));
359 	int rix;
360 
361 #define is_success(amn) \
362 (amn->amn_tx_try1_cnt  < (amn->amn_tx_try0_cnt/10))
363 #define is_enough(amn) \
364 (amn->amn_tx_try0_cnt > 10)
365 #define is_failure(amn) \
366 (amn->amn_tx_try1_cnt > (amn->amn_tx_try0_cnt/3))
367 
368 	rix = amn->amn_rix;
369 
370   	IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
371 	    "cnt0: %d cnt1: %d cnt2: %d cnt3: %d -- threshold: %d",
372 	    amn->amn_tx_try0_cnt, amn->amn_tx_try1_cnt, amn->amn_tx_try2_cnt,
373 	    amn->amn_tx_try3_cnt, amn->amn_success_threshold);
374   	if (is_success (amn) && is_enough (amn)) {
375 		amn->amn_success++;
376 		if (amn->amn_success == amn->amn_success_threshold &&
377 		    rix + 1 < ni->ni_rates.rs_nrates) {
378   			amn->amn_recovery = 1;
379   			amn->amn_success = 0;
380   			rix++;
381 			IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
382 			    "increase rate to %d", rix);
383   		} else {
384 			amn->amn_recovery = 0;
385 		}
386   	} else if (is_failure (amn)) {
387   		amn->amn_success = 0;
388 		if (rix > 0) {
389   			if (amn->amn_recovery) {
390   				/* recovery failure. */
391   				amn->amn_success_threshold *= 2;
392   				amn->amn_success_threshold = min (amn->amn_success_threshold,
393 								  (u_int)ath_rate_max_success_threshold);
394 				IEEE80211_NOTE(ni->ni_vap,
395 				    IEEE80211_MSG_RATECTL, ni,
396 				    "decrease rate recovery thr: %d",
397 				    amn->amn_success_threshold);
398   			} else {
399   				/* simple failure. */
400  				amn->amn_success_threshold = ath_rate_min_success_threshold;
401 				IEEE80211_NOTE(ni->ni_vap,
402 				    IEEE80211_MSG_RATECTL, ni,
403 				    "decrease rate normal thr: %d",
404 				    amn->amn_success_threshold);
405   			}
406 			amn->amn_recovery = 0;
407   			rix--;
408    		} else {
409 			amn->amn_recovery = 0;
410 		}
411 
412    	}
413 	if (is_enough (amn) || rix != amn->amn_rix) {
414 		/* reset counters. */
415 		amn->amn_tx_try0_cnt = 0;
416 		amn->amn_tx_try1_cnt = 0;
417 		amn->amn_tx_try2_cnt = 0;
418 		amn->amn_tx_try3_cnt = 0;
419 		amn->amn_tx_failure_cnt = 0;
420 	}
421 	if (rix != amn->amn_rix) {
422 		ath_rate_update(sc, ni, rix);
423 	}
424 }
425 
426 static int
427 ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
428     struct ath_rateioctl *re)
429 {
430 
431 	return (EINVAL);
432 }
433 
434 static void
435 ath_rate_sysctlattach(struct ath_softc *sc)
436 {
437 	struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
438 	struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
439 
440 	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
441 		"rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
442 		"rate control: operation interval (ms)");
443 	/* XXX bounds check values */
444 	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
445 		"max_sucess_threshold", CTLFLAG_RW,
446 		&ath_rate_max_success_threshold, 0, "");
447 	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
448 		"min_sucess_threshold", CTLFLAG_RW,
449 		&ath_rate_min_success_threshold, 0, "");
450 }
451 
452 struct ath_ratectrl *
453 ath_rate_attach(struct ath_softc *sc)
454 {
455 	struct amrr_softc *asc;
456 
457 	asc = malloc(sizeof(struct amrr_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
458 	if (asc == NULL)
459 		return NULL;
460 	asc->arc.arc_space = sizeof(struct amrr_node);
461 	ath_rate_sysctlattach(sc);
462 
463 	return &asc->arc;
464 }
465 
466 void
467 ath_rate_detach(struct ath_ratectrl *arc)
468 {
469 	struct amrr_softc *asc = (struct amrr_softc *) arc;
470 
471 	free(asc, M_DEVBUF);
472 }
473