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/*
43 * AMRR rate control. See:
44 * http://www-sop.inria.fr/rapports/sophia/RR-5208.html
45 * "IEEE 802.11 Rate Adaptation: A Practical Approach" by
46 *    Mathieu Lacage, Hossein Manshaei, Thierry Turletti
47 */
48#include "opt_ath.h"
49#include "opt_inet.h"
50#include "opt_wlan.h"
51
52#include <sys/param.h>
53#include <sys/systm.h>
54#include <sys/sysctl.h>
55#include <sys/kernel.h>
56#include <sys/lock.h>
57#include <sys/mutex.h>
58#include <sys/errno.h>
59
60#include <machine/bus.h>
61#include <machine/resource.h>
62#include <sys/bus.h>
63
64#include <sys/socket.h>
65
66#include <net/if.h>
67#include <net/if_media.h>
68#include <net/if_arp.h>
69
70#include <net80211/ieee80211_var.h>
71
72#include <net/bpf.h>
73
74#ifdef INET
75#include <netinet/in.h>
76#include <netinet/if_ether.h>
77#endif
78
79#include <dev/ath/if_athvar.h>
80#include <dev/ath/ath_rate/amrr/amrr.h>
81#include <dev/ath/ath_hal/ah_desc.h>
82
83static	int ath_rateinterval = 1000;		/* rate ctl interval (ms)  */
84static	int ath_rate_max_success_threshold = 10;
85static	int ath_rate_min_success_threshold = 1;
86
87static void	ath_rate_update(struct ath_softc *, struct ieee80211_node *,
88			int rate);
89static void	ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
90static void	ath_rate_ctl(void *, struct ieee80211_node *);
91
92void
93ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
94{
95	/* NB: assumed to be zero'd by caller */
96}
97
98void
99ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
100{
101}
102
103void
104ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
105	int shortPreamble, size_t frameLen, int tid, int is_aggr,
106	u_int8_t *rix, int *try0, u_int8_t *txrate, int *maxdur,
107	int *maxpktlen)
108{
109	struct amrr_node *amn = ATH_NODE_AMRR(an);
110
111	*rix = amn->amn_tx_rix0;
112	*try0 = amn->amn_tx_try0;
113	if (shortPreamble)
114		*txrate = amn->amn_tx_rate0sp;
115	else
116		*txrate = amn->amn_tx_rate0;
117	maxdur = -1;
118	maxpktlen = -1;
119}
120
121/*
122 * Get the TX rates.
123 *
124 * The short preamble bits aren't set here; the caller should augment
125 * the returned rate with the relevant preamble rate flag.
126 */
127void
128ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
129    uint8_t rix0, int is_aggr, struct ath_rc_series *rc)
130{
131	struct amrr_node *amn = ATH_NODE_AMRR(an);
132
133	rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0;
134
135	rc[0].rix = amn->amn_tx_rate0;
136	rc[1].rix = amn->amn_tx_rate1;
137	rc[2].rix = amn->amn_tx_rate2;
138	rc[3].rix = amn->amn_tx_rate3;
139
140	rc[0].tries = amn->amn_tx_try0;
141	rc[1].tries = amn->amn_tx_try1;
142	rc[2].tries = amn->amn_tx_try2;
143	rc[3].tries = amn->amn_tx_try3;
144}
145
146void
147ath_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
159void
160ath_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 rc_framesize, 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
192void
193ath_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
199void
200ath_rate_update_rx_rssi(struct ath_softc *sc, struct ath_node *an, int rssi)
201{
202}
203
204static void
205node_reset(struct amrr_node *amn)
206{
207	amn->amn_tx_try0_cnt = 0;
208	amn->amn_tx_try1_cnt = 0;
209	amn->amn_tx_try2_cnt = 0;
210	amn->amn_tx_try3_cnt = 0;
211	amn->amn_tx_failure_cnt = 0;
212  	amn->amn_success = 0;
213  	amn->amn_recovery = 0;
214  	amn->amn_success_threshold = ath_rate_min_success_threshold;
215}
216
217/**
218 * The code below assumes that we are dealing with hardware multi rate retry
219 * I have no idea what will happen if you try to use this module with another
220 * type of hardware. Your machine might catch fire or it might work with
221 * horrible performance...
222 */
223static void
224ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
225{
226	struct ath_node *an = ATH_NODE(ni);
227	struct amrr_node *amn = ATH_NODE_AMRR(an);
228	struct ieee80211vap *vap = ni->ni_vap;
229	const HAL_RATE_TABLE *rt = sc->sc_currates;
230	u_int8_t rix;
231
232	KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
233
234	IEEE80211_NOTE(vap, IEEE80211_MSG_RATECTL, ni,
235	    "%s: set xmit rate to %dM", __func__,
236	    ni->ni_rates.rs_nrates > 0 ?
237		(ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
238
239	amn->amn_rix = rate;
240	/*
241	 * Before associating a node has no rate set setup
242	 * so we can't calculate any transmit codes to use.
243	 * This is ok since we should never be sending anything
244	 * but management frames and those always go at the
245	 * lowest hardware rate.
246	 */
247	if (ni->ni_rates.rs_nrates > 0) {
248		ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL;
249		amn->amn_tx_rix0 = sc->sc_rixmap[ni->ni_txrate];
250		amn->amn_tx_rate0 = rt->info[amn->amn_tx_rix0].rateCode;
251		amn->amn_tx_rate0sp = amn->amn_tx_rate0 |
252			rt->info[amn->amn_tx_rix0].shortPreamble;
253		if (sc->sc_mrretry) {
254			amn->amn_tx_try0 = 1;
255			amn->amn_tx_try1 = 1;
256			amn->amn_tx_try2 = 1;
257			amn->amn_tx_try3 = 1;
258			if (--rate >= 0) {
259				rix = sc->sc_rixmap[
260						    ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
261				amn->amn_tx_rate1 = rt->info[rix].rateCode;
262				amn->amn_tx_rate1sp = amn->amn_tx_rate1 |
263					rt->info[rix].shortPreamble;
264			} else {
265				amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
266			}
267			if (--rate >= 0) {
268				rix = sc->sc_rixmap[
269						    ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
270				amn->amn_tx_rate2 = rt->info[rix].rateCode;
271				amn->amn_tx_rate2sp = amn->amn_tx_rate2 |
272					rt->info[rix].shortPreamble;
273			} else {
274				amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
275			}
276			if (rate > 0) {
277				/* NB: only do this if we didn't already do it above */
278				amn->amn_tx_rate3 = rt->info[0].rateCode;
279				amn->amn_tx_rate3sp =
280					amn->amn_tx_rate3 | rt->info[0].shortPreamble;
281			} else {
282				amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
283			}
284		} else {
285			amn->amn_tx_try0 = ATH_TXMAXTRY;
286			/* theorically, these statements are useless because
287			 *  the code which uses them tests for an_tx_try0 == ATH_TXMAXTRY
288			 */
289			amn->amn_tx_try1 = 0;
290			amn->amn_tx_try2 = 0;
291			amn->amn_tx_try3 = 0;
292			amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
293			amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
294			amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
295		}
296	}
297	node_reset(amn);
298
299	amn->amn_interval = ath_rateinterval;
300	if (vap->iv_opmode == IEEE80211_M_STA)
301		amn->amn_interval /= 2;
302	amn->amn_interval = (amn->amn_interval * hz) / 1000;
303}
304
305/*
306 * Set the starting transmit rate for a node.
307 */
308static void
309ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
310{
311#define	RATE(_ix)	(ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
312	const struct ieee80211_txparam *tp = ni->ni_txparms;
313	int srate;
314
315	KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
316	if (tp == NULL || tp->ucastrate == IEEE80211_FIXED_RATE_NONE) {
317		/*
318		 * No fixed rate is requested. For 11b start with
319		 * the highest negotiated rate; otherwise, for 11g
320		 * and 11a, we start "in the middle" at 24Mb or 36Mb.
321		 */
322		srate = ni->ni_rates.rs_nrates - 1;
323		if (sc->sc_curmode != IEEE80211_MODE_11B) {
324			/*
325			 * Scan the negotiated rate set to find the
326			 * closest rate.
327			 */
328			/* NB: the rate set is assumed sorted */
329			for (; srate >= 0 && RATE(srate) > 72; srate--)
330				;
331		}
332	} else {
333		/*
334		 * A fixed rate is to be used; ic_fixed_rate is the
335		 * IEEE code for this rate (sans basic bit).  Convert this
336		 * to the index into the negotiated rate set for
337		 * the node.  We know the rate is there because the
338		 * rate set is checked when the station associates.
339		 */
340		/* NB: the rate set is assumed sorted */
341		srate = ni->ni_rates.rs_nrates - 1;
342		for (; srate >= 0 && RATE(srate) != tp->ucastrate; srate--)
343			;
344	}
345	/*
346	 * The selected rate may not be available due to races
347	 * and mode settings.  Also orphaned nodes created in
348	 * adhoc mode may not have any rate set so this lookup
349	 * can fail.  This is not fatal.
350	 */
351	ath_rate_update(sc, ni, srate < 0 ? 0 : srate);
352#undef RATE
353}
354
355/*
356 * Examine and potentially adjust the transmit rate.
357 */
358static void
359ath_rate_ctl(void *arg, struct ieee80211_node *ni)
360{
361	struct ath_softc *sc = arg;
362	struct amrr_node *amn = ATH_NODE_AMRR(ATH_NODE (ni));
363	int rix;
364
365#define is_success(amn) \
366(amn->amn_tx_try1_cnt  < (amn->amn_tx_try0_cnt/10))
367#define is_enough(amn) \
368(amn->amn_tx_try0_cnt > 10)
369#define is_failure(amn) \
370(amn->amn_tx_try1_cnt > (amn->amn_tx_try0_cnt/3))
371
372	rix = amn->amn_rix;
373
374  	IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
375	    "cnt0: %d cnt1: %d cnt2: %d cnt3: %d -- threshold: %d",
376	    amn->amn_tx_try0_cnt, amn->amn_tx_try1_cnt, amn->amn_tx_try2_cnt,
377	    amn->amn_tx_try3_cnt, amn->amn_success_threshold);
378  	if (is_success (amn) && is_enough (amn)) {
379		amn->amn_success++;
380		if (amn->amn_success == amn->amn_success_threshold &&
381		    rix + 1 < ni->ni_rates.rs_nrates) {
382  			amn->amn_recovery = 1;
383  			amn->amn_success = 0;
384  			rix++;
385			IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
386			    "increase rate to %d", rix);
387  		} else {
388			amn->amn_recovery = 0;
389		}
390  	} else if (is_failure (amn)) {
391  		amn->amn_success = 0;
392		if (rix > 0) {
393  			if (amn->amn_recovery) {
394  				/* recovery failure. */
395  				amn->amn_success_threshold *= 2;
396  				amn->amn_success_threshold = min (amn->amn_success_threshold,
397								  (u_int)ath_rate_max_success_threshold);
398				IEEE80211_NOTE(ni->ni_vap,
399				    IEEE80211_MSG_RATECTL, ni,
400				    "decrease rate recovery thr: %d",
401				    amn->amn_success_threshold);
402  			} else {
403  				/* simple failure. */
404 				amn->amn_success_threshold = ath_rate_min_success_threshold;
405				IEEE80211_NOTE(ni->ni_vap,
406				    IEEE80211_MSG_RATECTL, ni,
407				    "decrease rate normal thr: %d",
408				    amn->amn_success_threshold);
409  			}
410			amn->amn_recovery = 0;
411  			rix--;
412   		} else {
413			amn->amn_recovery = 0;
414		}
415   	}
416	if (is_enough (amn) || rix != amn->amn_rix) {
417		/* reset counters. */
418		amn->amn_tx_try0_cnt = 0;
419		amn->amn_tx_try1_cnt = 0;
420		amn->amn_tx_try2_cnt = 0;
421		amn->amn_tx_try3_cnt = 0;
422		amn->amn_tx_failure_cnt = 0;
423	}
424	if (rix != amn->amn_rix) {
425		ath_rate_update(sc, ni, rix);
426	}
427}
428
429static int
430ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
431    struct ath_rateioctl *re)
432{
433
434	return (EINVAL);
435}
436
437static void
438ath_rate_sysctlattach(struct ath_softc *sc)
439{
440	struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
441	struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
442
443	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
444		"rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
445		"rate control: operation interval (ms)");
446	/* XXX bounds check values */
447	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
448		"max_sucess_threshold", CTLFLAG_RW,
449		&ath_rate_max_success_threshold, 0, "");
450	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
451		"min_sucess_threshold", CTLFLAG_RW,
452		&ath_rate_min_success_threshold, 0, "");
453}
454
455struct ath_ratectrl *
456ath_rate_attach(struct ath_softc *sc)
457{
458	struct amrr_softc *asc;
459
460	asc = malloc(sizeof(struct amrr_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
461	if (asc == NULL)
462		return NULL;
463	asc->arc.arc_space = sizeof(struct amrr_node);
464	ath_rate_sysctlattach(sc);
465
466	return &asc->arc;
467}
468
469void
470ath_rate_detach(struct ath_ratectrl *arc)
471{
472	struct amrr_softc *asc = (struct amrr_softc *) arc;
473
474	free(asc, M_DEVBUF);
475}
476