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: releng/12.0/sys/dev/ath/ath_rate/amrr/amrr.c 326255 2017-11-27 14:52:40Z pfg $");
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
85static	int ath_rateinterval = 1000;		/* rate ctl interval (ms)  */
86static	int ath_rate_max_success_threshold = 10;
87static	int ath_rate_min_success_threshold = 1;
88
89static void	ath_rate_update(struct ath_softc *, struct ieee80211_node *,
90			int rate);
91static void	ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
92static void	ath_rate_ctl(void *, struct ieee80211_node *);
93
94void
95ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
96{
97	/* NB: assumed to be zero'd by caller */
98}
99
100void
101ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
102{
103}
104
105void
106ath_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 */
129void
130ath_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
148void
149ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
150	struct ath_desc *ds, int shortPreamble, u_int8_t rix)
151{
152	struct amrr_node *amn = ATH_NODE_AMRR(an);
153
154	ath_hal_setupxtxdesc(sc->sc_ah, ds
155		, amn->amn_tx_rate1sp, amn->amn_tx_try1	/* series 1 */
156		, amn->amn_tx_rate2sp, amn->amn_tx_try2	/* series 2 */
157		, amn->amn_tx_rate3sp, amn->amn_tx_try3	/* series 3 */
158	);
159}
160
161void
162ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
163	const struct ath_rc_series *rc, const struct ath_tx_status *ts,
164	int frame_size, int rc_framesize, int nframes, int nbad)
165{
166	struct amrr_node *amn = ATH_NODE_AMRR(an);
167	int sr = ts->ts_shortretry;
168	int lr = ts->ts_longretry;
169	int retry_count = sr + lr;
170
171	amn->amn_tx_try0_cnt++;
172	if (retry_count == 1) {
173		amn->amn_tx_try1_cnt++;
174	} else if (retry_count == 2) {
175		amn->amn_tx_try1_cnt++;
176		amn->amn_tx_try2_cnt++;
177	} else if (retry_count == 3) {
178		amn->amn_tx_try1_cnt++;
179		amn->amn_tx_try2_cnt++;
180		amn->amn_tx_try3_cnt++;
181	} else if (retry_count > 3) {
182		amn->amn_tx_try1_cnt++;
183		amn->amn_tx_try2_cnt++;
184		amn->amn_tx_try3_cnt++;
185		amn->amn_tx_failure_cnt++;
186	}
187	if (amn->amn_interval != 0 &&
188	    ticks - amn->amn_ticks > amn->amn_interval) {
189		ath_rate_ctl(sc, &an->an_node);
190		amn->amn_ticks = ticks;
191	}
192}
193
194void
195ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
196{
197	if (isnew)
198		ath_rate_ctl_start(sc, &an->an_node);
199}
200
201void
202ath_rate_update_rx_rssi(struct ath_softc *sc, struct ath_node *an, int rssi)
203{
204}
205
206static void
207node_reset(struct amrr_node *amn)
208{
209	amn->amn_tx_try0_cnt = 0;
210	amn->amn_tx_try1_cnt = 0;
211	amn->amn_tx_try2_cnt = 0;
212	amn->amn_tx_try3_cnt = 0;
213	amn->amn_tx_failure_cnt = 0;
214  	amn->amn_success = 0;
215  	amn->amn_recovery = 0;
216  	amn->amn_success_threshold = ath_rate_min_success_threshold;
217}
218
219/**
220 * The code below assumes that we are dealing with hardware multi rate retry
221 * I have no idea what will happen if you try to use this module with another
222 * type of hardware. Your machine might catch fire or it might work with
223 * horrible performance...
224 */
225static void
226ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
227{
228	struct ath_node *an = ATH_NODE(ni);
229	struct amrr_node *amn = ATH_NODE_AMRR(an);
230	struct ieee80211vap *vap = ni->ni_vap;
231	const HAL_RATE_TABLE *rt = sc->sc_currates;
232	u_int8_t rix;
233
234	KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
235
236	IEEE80211_NOTE(vap, IEEE80211_MSG_RATECTL, ni,
237	    "%s: set xmit rate to %dM", __func__,
238	    ni->ni_rates.rs_nrates > 0 ?
239		(ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
240
241	amn->amn_rix = rate;
242	/*
243	 * Before associating a node has no rate set setup
244	 * so we can't calculate any transmit codes to use.
245	 * This is ok since we should never be sending anything
246	 * but management frames and those always go at the
247	 * lowest hardware rate.
248	 */
249	if (ni->ni_rates.rs_nrates > 0) {
250		ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL;
251		amn->amn_tx_rix0 = sc->sc_rixmap[ni->ni_txrate];
252		amn->amn_tx_rate0 = rt->info[amn->amn_tx_rix0].rateCode;
253		amn->amn_tx_rate0sp = amn->amn_tx_rate0 |
254			rt->info[amn->amn_tx_rix0].shortPreamble;
255		if (sc->sc_mrretry) {
256			amn->amn_tx_try0 = 1;
257			amn->amn_tx_try1 = 1;
258			amn->amn_tx_try2 = 1;
259			amn->amn_tx_try3 = 1;
260			if (--rate >= 0) {
261				rix = sc->sc_rixmap[
262						    ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
263				amn->amn_tx_rate1 = rt->info[rix].rateCode;
264				amn->amn_tx_rate1sp = amn->amn_tx_rate1 |
265					rt->info[rix].shortPreamble;
266			} else {
267				amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
268			}
269			if (--rate >= 0) {
270				rix = sc->sc_rixmap[
271						    ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
272				amn->amn_tx_rate2 = rt->info[rix].rateCode;
273				amn->amn_tx_rate2sp = amn->amn_tx_rate2 |
274					rt->info[rix].shortPreamble;
275			} else {
276				amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
277			}
278			if (rate > 0) {
279				/* NB: only do this if we didn't already do it above */
280				amn->amn_tx_rate3 = rt->info[0].rateCode;
281				amn->amn_tx_rate3sp =
282					amn->amn_tx_rate3 | rt->info[0].shortPreamble;
283			} else {
284				amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
285			}
286		} else {
287			amn->amn_tx_try0 = ATH_TXMAXTRY;
288			/* theorically, these statements are useless because
289			 *  the code which uses them tests for an_tx_try0 == ATH_TXMAXTRY
290			 */
291			amn->amn_tx_try1 = 0;
292			amn->amn_tx_try2 = 0;
293			amn->amn_tx_try3 = 0;
294			amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
295			amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
296			amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
297		}
298	}
299	node_reset(amn);
300
301	amn->amn_interval = ath_rateinterval;
302	if (vap->iv_opmode == IEEE80211_M_STA)
303		amn->amn_interval /= 2;
304	amn->amn_interval = (amn->amn_interval * hz) / 1000;
305}
306
307/*
308 * Set the starting transmit rate for a node.
309 */
310static void
311ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
312{
313#define	RATE(_ix)	(ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
314	const struct ieee80211_txparam *tp = ni->ni_txparms;
315	int srate;
316
317	KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
318	if (tp == NULL || tp->ucastrate == IEEE80211_FIXED_RATE_NONE) {
319		/*
320		 * No fixed rate is requested. For 11b start with
321		 * the highest negotiated rate; otherwise, for 11g
322		 * and 11a, we start "in the middle" at 24Mb or 36Mb.
323		 */
324		srate = ni->ni_rates.rs_nrates - 1;
325		if (sc->sc_curmode != IEEE80211_MODE_11B) {
326			/*
327			 * Scan the negotiated rate set to find the
328			 * closest rate.
329			 */
330			/* NB: the rate set is assumed sorted */
331			for (; srate >= 0 && RATE(srate) > 72; srate--)
332				;
333		}
334	} else {
335		/*
336		 * A fixed rate is to be used; ic_fixed_rate is the
337		 * IEEE code for this rate (sans basic bit).  Convert this
338		 * to the index into the negotiated rate set for
339		 * the node.  We know the rate is there because the
340		 * rate set is checked when the station associates.
341		 */
342		/* NB: the rate set is assumed sorted */
343		srate = ni->ni_rates.rs_nrates - 1;
344		for (; srate >= 0 && RATE(srate) != tp->ucastrate; srate--)
345			;
346	}
347	/*
348	 * The selected rate may not be available due to races
349	 * and mode settings.  Also orphaned nodes created in
350	 * adhoc mode may not have any rate set so this lookup
351	 * can fail.  This is not fatal.
352	 */
353	ath_rate_update(sc, ni, srate < 0 ? 0 : srate);
354#undef RATE
355}
356
357/*
358 * Examine and potentially adjust the transmit rate.
359 */
360static void
361ath_rate_ctl(void *arg, struct ieee80211_node *ni)
362{
363	struct ath_softc *sc = arg;
364	struct amrr_node *amn = ATH_NODE_AMRR(ATH_NODE (ni));
365	int rix;
366
367#define is_success(amn) \
368(amn->amn_tx_try1_cnt  < (amn->amn_tx_try0_cnt/10))
369#define is_enough(amn) \
370(amn->amn_tx_try0_cnt > 10)
371#define is_failure(amn) \
372(amn->amn_tx_try1_cnt > (amn->amn_tx_try0_cnt/3))
373
374	rix = amn->amn_rix;
375
376  	IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
377	    "cnt0: %d cnt1: %d cnt2: %d cnt3: %d -- threshold: %d",
378	    amn->amn_tx_try0_cnt, amn->amn_tx_try1_cnt, amn->amn_tx_try2_cnt,
379	    amn->amn_tx_try3_cnt, amn->amn_success_threshold);
380  	if (is_success (amn) && is_enough (amn)) {
381		amn->amn_success++;
382		if (amn->amn_success == amn->amn_success_threshold &&
383		    rix + 1 < ni->ni_rates.rs_nrates) {
384  			amn->amn_recovery = 1;
385  			amn->amn_success = 0;
386  			rix++;
387			IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
388			    "increase rate to %d", rix);
389  		} else {
390			amn->amn_recovery = 0;
391		}
392  	} else if (is_failure (amn)) {
393  		amn->amn_success = 0;
394		if (rix > 0) {
395  			if (amn->amn_recovery) {
396  				/* recovery failure. */
397  				amn->amn_success_threshold *= 2;
398  				amn->amn_success_threshold = min (amn->amn_success_threshold,
399								  (u_int)ath_rate_max_success_threshold);
400				IEEE80211_NOTE(ni->ni_vap,
401				    IEEE80211_MSG_RATECTL, ni,
402				    "decrease rate recovery thr: %d",
403				    amn->amn_success_threshold);
404  			} else {
405  				/* simple failure. */
406 				amn->amn_success_threshold = ath_rate_min_success_threshold;
407				IEEE80211_NOTE(ni->ni_vap,
408				    IEEE80211_MSG_RATECTL, ni,
409				    "decrease rate normal thr: %d",
410				    amn->amn_success_threshold);
411  			}
412			amn->amn_recovery = 0;
413  			rix--;
414   		} else {
415			amn->amn_recovery = 0;
416		}
417   	}
418	if (is_enough (amn) || rix != amn->amn_rix) {
419		/* reset counters. */
420		amn->amn_tx_try0_cnt = 0;
421		amn->amn_tx_try1_cnt = 0;
422		amn->amn_tx_try2_cnt = 0;
423		amn->amn_tx_try3_cnt = 0;
424		amn->amn_tx_failure_cnt = 0;
425	}
426	if (rix != amn->amn_rix) {
427		ath_rate_update(sc, ni, rix);
428	}
429}
430
431static int
432ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
433    struct ath_rateioctl *re)
434{
435
436	return (EINVAL);
437}
438
439static void
440ath_rate_sysctlattach(struct ath_softc *sc)
441{
442	struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
443	struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
444
445	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
446		"rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
447		"rate control: operation interval (ms)");
448	/* XXX bounds check values */
449	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
450		"max_sucess_threshold", CTLFLAG_RW,
451		&ath_rate_max_success_threshold, 0, "");
452	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
453		"min_sucess_threshold", CTLFLAG_RW,
454		&ath_rate_min_success_threshold, 0, "");
455}
456
457struct ath_ratectrl *
458ath_rate_attach(struct ath_softc *sc)
459{
460	struct amrr_softc *asc;
461
462	asc = malloc(sizeof(struct amrr_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
463	if (asc == NULL)
464		return NULL;
465	asc->arc.arc_space = sizeof(struct amrr_node);
466	ath_rate_sysctlattach(sc);
467
468	return &asc->arc;
469}
470
471void
472ath_rate_detach(struct ath_ratectrl *arc)
473{
474	struct amrr_softc *asc = (struct amrr_softc *) arc;
475
476	free(asc, M_DEVBUF);
477}
478