1/*-
2 * Copyright (c) 2004 INRIA
3 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer,
11 *    without modification.
12 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
13 *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
14 *    redistribution must be conditioned upon including a substantially
15 *    similar Disclaimer requirement for further binary redistribution.
16 * 3. Neither the names of the above-listed copyright holders nor the names
17 *    of any contributors may be used to endorse or promote products derived
18 *    from this software without specific prior written permission.
19 *
20 * Alternatively, this software may be distributed under the terms of the
21 * GNU General Public License ("GPL") version 2 as published by the Free
22 * Software Foundation.
23 *
24 * NO WARRANTY
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
28 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
29 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
30 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
33 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
35 * THE POSSIBILITY OF SUCH DAMAGES.
36 *
37 */
38
39#include <sys/cdefs.h>
40__FBSDID("$FreeBSD$");
41
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,
106	u_int8_t *rix, int *try0, u_int8_t *txrate)
107{
108	struct amrr_node *amn = ATH_NODE_AMRR(an);
109
110	*rix = amn->amn_tx_rix0;
111	*try0 = amn->amn_tx_try0;
112	if (shortPreamble)
113		*txrate = amn->amn_tx_rate0sp;
114	else
115		*txrate = amn->amn_tx_rate0;
116}
117
118/*
119 * Get the TX rates.
120 *
121 * The short preamble bits aren't set here; the caller should augment
122 * the returned rate with the relevant preamble rate flag.
123 */
124void
125ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
126    uint8_t rix0, struct ath_rc_series *rc)
127{
128	struct amrr_node *amn = ATH_NODE_AMRR(an);
129
130	rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0;
131
132	rc[0].rix = amn->amn_tx_rate0;
133	rc[1].rix = amn->amn_tx_rate1;
134	rc[2].rix = amn->amn_tx_rate2;
135	rc[3].rix = amn->amn_tx_rate3;
136
137	rc[0].tries = amn->amn_tx_try0;
138	rc[1].tries = amn->amn_tx_try1;
139	rc[2].tries = amn->amn_tx_try2;
140	rc[3].tries = amn->amn_tx_try3;
141}
142
143
144void
145ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
146	struct ath_desc *ds, int shortPreamble, u_int8_t rix)
147{
148	struct amrr_node *amn = ATH_NODE_AMRR(an);
149
150	ath_hal_setupxtxdesc(sc->sc_ah, ds
151		, amn->amn_tx_rate1sp, amn->amn_tx_try1	/* series 1 */
152		, amn->amn_tx_rate2sp, amn->amn_tx_try2	/* series 2 */
153		, amn->amn_tx_rate3sp, amn->amn_tx_try3	/* series 3 */
154	);
155}
156
157void
158ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
159	const struct ath_rc_series *rc, const struct ath_tx_status *ts,
160	int frame_size, int nframes, int nbad)
161{
162	struct amrr_node *amn = ATH_NODE_AMRR(an);
163	int sr = ts->ts_shortretry;
164	int lr = ts->ts_longretry;
165	int retry_count = sr + lr;
166
167	amn->amn_tx_try0_cnt++;
168	if (retry_count == 1) {
169		amn->amn_tx_try1_cnt++;
170	} else if (retry_count == 2) {
171		amn->amn_tx_try1_cnt++;
172		amn->amn_tx_try2_cnt++;
173	} else if (retry_count == 3) {
174		amn->amn_tx_try1_cnt++;
175		amn->amn_tx_try2_cnt++;
176		amn->amn_tx_try3_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		amn->amn_tx_failure_cnt++;
182	}
183	if (amn->amn_interval != 0 &&
184	    ticks - amn->amn_ticks > amn->amn_interval) {
185		ath_rate_ctl(sc, &an->an_node);
186		amn->amn_ticks = ticks;
187	}
188}
189
190void
191ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
192{
193	if (isnew)
194		ath_rate_ctl_start(sc, &an->an_node);
195}
196
197static void
198node_reset(struct amrr_node *amn)
199{
200	amn->amn_tx_try0_cnt = 0;
201	amn->amn_tx_try1_cnt = 0;
202	amn->amn_tx_try2_cnt = 0;
203	amn->amn_tx_try3_cnt = 0;
204	amn->amn_tx_failure_cnt = 0;
205  	amn->amn_success = 0;
206  	amn->amn_recovery = 0;
207  	amn->amn_success_threshold = ath_rate_min_success_threshold;
208}
209
210
211/**
212 * The code below assumes that we are dealing with hardware multi rate retry
213 * I have no idea what will happen if you try to use this module with another
214 * type of hardware. Your machine might catch fire or it might work with
215 * horrible performance...
216 */
217static void
218ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
219{
220	struct ath_node *an = ATH_NODE(ni);
221	struct amrr_node *amn = ATH_NODE_AMRR(an);
222	struct ieee80211vap *vap = ni->ni_vap;
223	const HAL_RATE_TABLE *rt = sc->sc_currates;
224	u_int8_t rix;
225
226	KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
227
228	IEEE80211_NOTE(vap, IEEE80211_MSG_RATECTL, ni,
229	    "%s: set xmit rate to %dM", __func__,
230	    ni->ni_rates.rs_nrates > 0 ?
231		(ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
232
233	amn->amn_rix = rate;
234	/*
235	 * Before associating a node has no rate set setup
236	 * so we can't calculate any transmit codes to use.
237	 * This is ok since we should never be sending anything
238	 * but management frames and those always go at the
239	 * lowest hardware rate.
240	 */
241	if (ni->ni_rates.rs_nrates > 0) {
242		ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL;
243		amn->amn_tx_rix0 = sc->sc_rixmap[ni->ni_txrate];
244		amn->amn_tx_rate0 = rt->info[amn->amn_tx_rix0].rateCode;
245		amn->amn_tx_rate0sp = amn->amn_tx_rate0 |
246			rt->info[amn->amn_tx_rix0].shortPreamble;
247		if (sc->sc_mrretry) {
248			amn->amn_tx_try0 = 1;
249			amn->amn_tx_try1 = 1;
250			amn->amn_tx_try2 = 1;
251			amn->amn_tx_try3 = 1;
252			if (--rate >= 0) {
253				rix = sc->sc_rixmap[
254						    ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
255				amn->amn_tx_rate1 = rt->info[rix].rateCode;
256				amn->amn_tx_rate1sp = amn->amn_tx_rate1 |
257					rt->info[rix].shortPreamble;
258			} else {
259				amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
260			}
261			if (--rate >= 0) {
262				rix = sc->sc_rixmap[
263						    ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
264				amn->amn_tx_rate2 = rt->info[rix].rateCode;
265				amn->amn_tx_rate2sp = amn->amn_tx_rate2 |
266					rt->info[rix].shortPreamble;
267			} else {
268				amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
269			}
270			if (rate > 0) {
271				/* NB: only do this if we didn't already do it above */
272				amn->amn_tx_rate3 = rt->info[0].rateCode;
273				amn->amn_tx_rate3sp =
274					amn->amn_tx_rate3 | rt->info[0].shortPreamble;
275			} else {
276				amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
277			}
278		} else {
279			amn->amn_tx_try0 = ATH_TXMAXTRY;
280			/* theorically, these statements are useless because
281			 *  the code which uses them tests for an_tx_try0 == ATH_TXMAXTRY
282			 */
283			amn->amn_tx_try1 = 0;
284			amn->amn_tx_try2 = 0;
285			amn->amn_tx_try3 = 0;
286			amn->amn_tx_rate1 = amn->amn_tx_rate1sp = 0;
287			amn->amn_tx_rate2 = amn->amn_tx_rate2sp = 0;
288			amn->amn_tx_rate3 = amn->amn_tx_rate3sp = 0;
289		}
290	}
291	node_reset(amn);
292
293	amn->amn_interval = ath_rateinterval;
294	if (vap->iv_opmode == IEEE80211_M_STA)
295		amn->amn_interval /= 2;
296	amn->amn_interval = (amn->amn_interval * hz) / 1000;
297}
298
299/*
300 * Set the starting transmit rate for a node.
301 */
302static void
303ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
304{
305#define	RATE(_ix)	(ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
306	const struct ieee80211_txparam *tp = ni->ni_txparms;
307	int srate;
308
309	KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
310	if (tp == NULL || tp->ucastrate == IEEE80211_FIXED_RATE_NONE) {
311		/*
312		 * No fixed rate is requested. For 11b start with
313		 * the highest negotiated rate; otherwise, for 11g
314		 * and 11a, we start "in the middle" at 24Mb or 36Mb.
315		 */
316		srate = ni->ni_rates.rs_nrates - 1;
317		if (sc->sc_curmode != IEEE80211_MODE_11B) {
318			/*
319			 * Scan the negotiated rate set to find the
320			 * closest rate.
321			 */
322			/* NB: the rate set is assumed sorted */
323			for (; srate >= 0 && RATE(srate) > 72; srate--)
324				;
325		}
326	} else {
327		/*
328		 * A fixed rate is to be used; ic_fixed_rate is the
329		 * IEEE code for this rate (sans basic bit).  Convert this
330		 * to the index into the negotiated rate set for
331		 * the node.  We know the rate is there because the
332		 * rate set is checked when the station associates.
333		 */
334		/* NB: the rate set is assumed sorted */
335		srate = ni->ni_rates.rs_nrates - 1;
336		for (; srate >= 0 && RATE(srate) != tp->ucastrate; srate--)
337			;
338	}
339	/*
340	 * The selected rate may not be available due to races
341	 * and mode settings.  Also orphaned nodes created in
342	 * adhoc mode may not have any rate set so this lookup
343	 * can fail.  This is not fatal.
344	 */
345	ath_rate_update(sc, ni, srate < 0 ? 0 : srate);
346#undef RATE
347}
348
349/*
350 * Examine and potentially adjust the transmit rate.
351 */
352static void
353ath_rate_ctl(void *arg, struct ieee80211_node *ni)
354{
355	struct ath_softc *sc = arg;
356	struct amrr_node *amn = ATH_NODE_AMRR(ATH_NODE (ni));
357	int rix;
358
359#define is_success(amn) \
360(amn->amn_tx_try1_cnt  < (amn->amn_tx_try0_cnt/10))
361#define is_enough(amn) \
362(amn->amn_tx_try0_cnt > 10)
363#define is_failure(amn) \
364(amn->amn_tx_try1_cnt > (amn->amn_tx_try0_cnt/3))
365
366	rix = amn->amn_rix;
367
368  	IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
369	    "cnt0: %d cnt1: %d cnt2: %d cnt3: %d -- threshold: %d",
370	    amn->amn_tx_try0_cnt, amn->amn_tx_try1_cnt, amn->amn_tx_try2_cnt,
371	    amn->amn_tx_try3_cnt, amn->amn_success_threshold);
372  	if (is_success (amn) && is_enough (amn)) {
373		amn->amn_success++;
374		if (amn->amn_success == amn->amn_success_threshold &&
375		    rix + 1 < ni->ni_rates.rs_nrates) {
376  			amn->amn_recovery = 1;
377  			amn->amn_success = 0;
378  			rix++;
379			IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
380			    "increase rate to %d", rix);
381  		} else {
382			amn->amn_recovery = 0;
383		}
384  	} else if (is_failure (amn)) {
385  		amn->amn_success = 0;
386		if (rix > 0) {
387  			if (amn->amn_recovery) {
388  				/* recovery failure. */
389  				amn->amn_success_threshold *= 2;
390  				amn->amn_success_threshold = min (amn->amn_success_threshold,
391								  (u_int)ath_rate_max_success_threshold);
392				IEEE80211_NOTE(ni->ni_vap,
393				    IEEE80211_MSG_RATECTL, ni,
394				    "decrease rate recovery thr: %d",
395				    amn->amn_success_threshold);
396  			} else {
397  				/* simple failure. */
398 				amn->amn_success_threshold = ath_rate_min_success_threshold;
399				IEEE80211_NOTE(ni->ni_vap,
400				    IEEE80211_MSG_RATECTL, ni,
401				    "decrease rate normal thr: %d",
402				    amn->amn_success_threshold);
403  			}
404			amn->amn_recovery = 0;
405  			rix--;
406   		} else {
407			amn->amn_recovery = 0;
408		}
409
410   	}
411	if (is_enough (amn) || rix != amn->amn_rix) {
412		/* reset counters. */
413		amn->amn_tx_try0_cnt = 0;
414		amn->amn_tx_try1_cnt = 0;
415		amn->amn_tx_try2_cnt = 0;
416		amn->amn_tx_try3_cnt = 0;
417		amn->amn_tx_failure_cnt = 0;
418	}
419	if (rix != amn->amn_rix) {
420		ath_rate_update(sc, ni, rix);
421	}
422}
423
424static int
425ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
426    struct ath_rateioctl *re)
427{
428
429	return (EINVAL);
430}
431
432static void
433ath_rate_sysctlattach(struct ath_softc *sc)
434{
435	struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
436	struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
437
438	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
439		"rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
440		"rate control: operation interval (ms)");
441	/* XXX bounds check values */
442	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
443		"max_sucess_threshold", CTLFLAG_RW,
444		&ath_rate_max_success_threshold, 0, "");
445	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
446		"min_sucess_threshold", CTLFLAG_RW,
447		&ath_rate_min_success_threshold, 0, "");
448}
449
450struct ath_ratectrl *
451ath_rate_attach(struct ath_softc *sc)
452{
453	struct amrr_softc *asc;
454
455	asc = malloc(sizeof(struct amrr_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
456	if (asc == NULL)
457		return NULL;
458	asc->arc.arc_space = sizeof(struct amrr_node);
459	ath_rate_sysctlattach(sc);
460
461	return &asc->arc;
462}
463
464void
465ath_rate_detach(struct ath_ratectrl *arc)
466{
467	struct amrr_softc *asc = (struct amrr_softc *) arc;
468
469	free(asc, M_DEVBUF);
470}
471