1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
4 * Copyright (C) 2019-2022 Intel Corporation
5 */
6#include <linux/netdevice.h>
7#include <linux/types.h>
8#include <linux/skbuff.h>
9#include <linux/debugfs.h>
10#include <linux/random.h>
11#include <linux/moduleparam.h>
12#include <linux/ieee80211.h>
13#include <linux/minmax.h>
14#include <net/mac80211.h>
15#include "rate.h"
16#include "sta_info.h"
17#include "rc80211_minstrel_ht.h"
18
19#define AVG_AMPDU_SIZE	16
20#define AVG_PKT_SIZE	1200
21
22/* Number of bits for an average sized packet */
23#define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3)
24
25/* Number of symbols for a packet with (bps) bits per symbol */
26#define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
27
28/* Transmission time (nanoseconds) for a packet containing (syms) symbols */
29#define MCS_SYMBOL_TIME(sgi, syms)					\
30	(sgi ?								\
31	  ((syms) * 18000 + 4000) / 5 :	/* syms * 3.6 us */		\
32	  ((syms) * 1000) << 2		/* syms * 4 us */		\
33	)
34
35/* Transmit duration for the raw data part of an average sized packet */
36#define MCS_DURATION(streams, sgi, bps) \
37	(MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE)
38
39#define BW_20			0
40#define BW_40			1
41#define BW_80			2
42
43/*
44 * Define group sort order: HT40 -> SGI -> #streams
45 */
46#define GROUP_IDX(_streams, _sgi, _ht40)	\
47	MINSTREL_HT_GROUP_0 +			\
48	MINSTREL_MAX_STREAMS * 2 * _ht40 +	\
49	MINSTREL_MAX_STREAMS * _sgi +	\
50	_streams - 1
51
52#define _MAX(a, b) (((a)>(b))?(a):(b))
53
54#define GROUP_SHIFT(duration)						\
55	_MAX(0, 16 - __builtin_clz(duration))
56
57/* MCS rate information for an MCS group */
58#define __MCS_GROUP(_streams, _sgi, _ht40, _s)				\
59	[GROUP_IDX(_streams, _sgi, _ht40)] = {				\
60	.streams = _streams,						\
61	.shift = _s,							\
62	.bw = _ht40,							\
63	.flags =							\
64		IEEE80211_TX_RC_MCS |					\
65		(_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) |			\
66		(_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0),		\
67	.duration = {							\
68		MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26) >> _s,	\
69		MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52) >> _s,	\
70		MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78) >> _s,	\
71		MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104) >> _s,	\
72		MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156) >> _s,	\
73		MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208) >> _s,	\
74		MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234) >> _s,	\
75		MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) >> _s	\
76	}								\
77}
78
79#define MCS_GROUP_SHIFT(_streams, _sgi, _ht40)				\
80	GROUP_SHIFT(MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26))
81
82#define MCS_GROUP(_streams, _sgi, _ht40)				\
83	__MCS_GROUP(_streams, _sgi, _ht40,				\
84		    MCS_GROUP_SHIFT(_streams, _sgi, _ht40))
85
86#define VHT_GROUP_IDX(_streams, _sgi, _bw)				\
87	(MINSTREL_VHT_GROUP_0 +						\
88	 MINSTREL_MAX_STREAMS * 2 * (_bw) +				\
89	 MINSTREL_MAX_STREAMS * (_sgi) +				\
90	 (_streams) - 1)
91
92#define BW2VBPS(_bw, r3, r2, r1)					\
93	(_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
94
95#define __VHT_GROUP(_streams, _sgi, _bw, _s)				\
96	[VHT_GROUP_IDX(_streams, _sgi, _bw)] = {			\
97	.streams = _streams,						\
98	.shift = _s,							\
99	.bw = _bw,							\
100	.flags =							\
101		IEEE80211_TX_RC_VHT_MCS |				\
102		(_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) |			\
103		(_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH :		\
104		 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0),	\
105	.duration = {							\
106		MCS_DURATION(_streams, _sgi,				\
107			     BW2VBPS(_bw,  117,  54,  26)) >> _s,	\
108		MCS_DURATION(_streams, _sgi,				\
109			     BW2VBPS(_bw,  234, 108,  52)) >> _s,	\
110		MCS_DURATION(_streams, _sgi,				\
111			     BW2VBPS(_bw,  351, 162,  78)) >> _s,	\
112		MCS_DURATION(_streams, _sgi,				\
113			     BW2VBPS(_bw,  468, 216, 104)) >> _s,	\
114		MCS_DURATION(_streams, _sgi,				\
115			     BW2VBPS(_bw,  702, 324, 156)) >> _s,	\
116		MCS_DURATION(_streams, _sgi,				\
117			     BW2VBPS(_bw,  936, 432, 208)) >> _s,	\
118		MCS_DURATION(_streams, _sgi,				\
119			     BW2VBPS(_bw, 1053, 486, 234)) >> _s,	\
120		MCS_DURATION(_streams, _sgi,				\
121			     BW2VBPS(_bw, 1170, 540, 260)) >> _s,	\
122		MCS_DURATION(_streams, _sgi,				\
123			     BW2VBPS(_bw, 1404, 648, 312)) >> _s,	\
124		MCS_DURATION(_streams, _sgi,				\
125			     BW2VBPS(_bw, 1560, 720, 346)) >> _s	\
126	}								\
127}
128
129#define VHT_GROUP_SHIFT(_streams, _sgi, _bw)				\
130	GROUP_SHIFT(MCS_DURATION(_streams, _sgi,			\
131				 BW2VBPS(_bw,  117,  54,  26)))
132
133#define VHT_GROUP(_streams, _sgi, _bw)					\
134	__VHT_GROUP(_streams, _sgi, _bw,				\
135		    VHT_GROUP_SHIFT(_streams, _sgi, _bw))
136
137#define CCK_DURATION(_bitrate, _short)			\
138	(1000 * (10 /* SIFS */ +			\
139	 (_short ? 72 + 24 : 144 + 48) +		\
140	 (8 * (AVG_PKT_SIZE + 4) * 10) / (_bitrate)))
141
142#define CCK_DURATION_LIST(_short, _s)			\
143	CCK_DURATION(10, _short) >> _s,			\
144	CCK_DURATION(20, _short) >> _s,			\
145	CCK_DURATION(55, _short) >> _s,			\
146	CCK_DURATION(110, _short) >> _s
147
148#define __CCK_GROUP(_s)					\
149	[MINSTREL_CCK_GROUP] = {			\
150		.streams = 1,				\
151		.flags = 0,				\
152		.shift = _s,				\
153		.duration = {				\
154			CCK_DURATION_LIST(false, _s),	\
155			CCK_DURATION_LIST(true, _s)	\
156		}					\
157	}
158
159#define CCK_GROUP_SHIFT					\
160	GROUP_SHIFT(CCK_DURATION(10, false))
161
162#define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT)
163
164#define OFDM_DURATION(_bitrate)				\
165	(1000 * (16 /* SIFS + signal ext */ +		\
166	 16 /* T_PREAMBLE */ +				\
167	 4 /* T_SIGNAL */ +				\
168	 4 * (((16 + 80 * (AVG_PKT_SIZE + 4) + 6) /	\
169	      ((_bitrate) * 4)))))
170
171#define OFDM_DURATION_LIST(_s)				\
172	OFDM_DURATION(60) >> _s,			\
173	OFDM_DURATION(90) >> _s,			\
174	OFDM_DURATION(120) >> _s,			\
175	OFDM_DURATION(180) >> _s,			\
176	OFDM_DURATION(240) >> _s,			\
177	OFDM_DURATION(360) >> _s,			\
178	OFDM_DURATION(480) >> _s,			\
179	OFDM_DURATION(540) >> _s
180
181#define __OFDM_GROUP(_s)				\
182	[MINSTREL_OFDM_GROUP] = {			\
183		.streams = 1,				\
184		.flags = 0,				\
185		.shift = _s,				\
186		.duration = {				\
187			OFDM_DURATION_LIST(_s),		\
188		}					\
189	}
190
191#define OFDM_GROUP_SHIFT				\
192	GROUP_SHIFT(OFDM_DURATION(60))
193
194#define OFDM_GROUP __OFDM_GROUP(OFDM_GROUP_SHIFT)
195
196
197static bool minstrel_vht_only = true;
198module_param(minstrel_vht_only, bool, 0644);
199MODULE_PARM_DESC(minstrel_vht_only,
200		 "Use only VHT rates when VHT is supported by sta.");
201
202/*
203 * To enable sufficiently targeted rate sampling, MCS rates are divided into
204 * groups, based on the number of streams and flags (HT40, SGI) that they
205 * use.
206 *
207 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
208 * BW -> SGI -> #streams
209 */
210const struct mcs_group minstrel_mcs_groups[] = {
211	MCS_GROUP(1, 0, BW_20),
212	MCS_GROUP(2, 0, BW_20),
213	MCS_GROUP(3, 0, BW_20),
214	MCS_GROUP(4, 0, BW_20),
215
216	MCS_GROUP(1, 1, BW_20),
217	MCS_GROUP(2, 1, BW_20),
218	MCS_GROUP(3, 1, BW_20),
219	MCS_GROUP(4, 1, BW_20),
220
221	MCS_GROUP(1, 0, BW_40),
222	MCS_GROUP(2, 0, BW_40),
223	MCS_GROUP(3, 0, BW_40),
224	MCS_GROUP(4, 0, BW_40),
225
226	MCS_GROUP(1, 1, BW_40),
227	MCS_GROUP(2, 1, BW_40),
228	MCS_GROUP(3, 1, BW_40),
229	MCS_GROUP(4, 1, BW_40),
230
231	CCK_GROUP,
232	OFDM_GROUP,
233
234	VHT_GROUP(1, 0, BW_20),
235	VHT_GROUP(2, 0, BW_20),
236	VHT_GROUP(3, 0, BW_20),
237	VHT_GROUP(4, 0, BW_20),
238
239	VHT_GROUP(1, 1, BW_20),
240	VHT_GROUP(2, 1, BW_20),
241	VHT_GROUP(3, 1, BW_20),
242	VHT_GROUP(4, 1, BW_20),
243
244	VHT_GROUP(1, 0, BW_40),
245	VHT_GROUP(2, 0, BW_40),
246	VHT_GROUP(3, 0, BW_40),
247	VHT_GROUP(4, 0, BW_40),
248
249	VHT_GROUP(1, 1, BW_40),
250	VHT_GROUP(2, 1, BW_40),
251	VHT_GROUP(3, 1, BW_40),
252	VHT_GROUP(4, 1, BW_40),
253
254	VHT_GROUP(1, 0, BW_80),
255	VHT_GROUP(2, 0, BW_80),
256	VHT_GROUP(3, 0, BW_80),
257	VHT_GROUP(4, 0, BW_80),
258
259	VHT_GROUP(1, 1, BW_80),
260	VHT_GROUP(2, 1, BW_80),
261	VHT_GROUP(3, 1, BW_80),
262	VHT_GROUP(4, 1, BW_80),
263};
264
265const s16 minstrel_cck_bitrates[4] = { 10, 20, 55, 110 };
266const s16 minstrel_ofdm_bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
267static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
268static const u8 minstrel_sample_seq[] = {
269	MINSTREL_SAMPLE_TYPE_INC,
270	MINSTREL_SAMPLE_TYPE_JUMP,
271	MINSTREL_SAMPLE_TYPE_INC,
272	MINSTREL_SAMPLE_TYPE_JUMP,
273	MINSTREL_SAMPLE_TYPE_INC,
274	MINSTREL_SAMPLE_TYPE_SLOW,
275};
276
277static void
278minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
279
280/*
281 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
282 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
283 *
284 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
285 */
286static u16
287minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
288{
289	u16 mask = 0;
290
291	if (bw == BW_20) {
292		if (nss != 3 && nss != 6)
293			mask = BIT(9);
294	} else if (bw == BW_80) {
295		if (nss == 3 || nss == 7)
296			mask = BIT(6);
297		else if (nss == 6)
298			mask = BIT(9);
299	} else {
300		WARN_ON(bw != BW_40);
301	}
302
303	switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
304	case IEEE80211_VHT_MCS_SUPPORT_0_7:
305		mask |= 0x300;
306		break;
307	case IEEE80211_VHT_MCS_SUPPORT_0_8:
308		mask |= 0x200;
309		break;
310	case IEEE80211_VHT_MCS_SUPPORT_0_9:
311		break;
312	default:
313		mask = 0x3ff;
314	}
315
316	return 0x3ff & ~mask;
317}
318
319static bool
320minstrel_ht_is_legacy_group(int group)
321{
322	return group == MINSTREL_CCK_GROUP ||
323	       group == MINSTREL_OFDM_GROUP;
324}
325
326/*
327 * Look up an MCS group index based on mac80211 rate information
328 */
329static int
330minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
331{
332	return GROUP_IDX((rate->idx / 8) + 1,
333			 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
334			 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
335}
336
337/*
338 * Look up an MCS group index based on new cfg80211 rate_info.
339 */
340static int
341minstrel_ht_ri_get_group_idx(struct rate_info *rate)
342{
343	return GROUP_IDX((rate->mcs / 8) + 1,
344			 !!(rate->flags & RATE_INFO_FLAGS_SHORT_GI),
345			 !!(rate->bw & RATE_INFO_BW_40));
346}
347
348static int
349minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
350{
351	return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
352			     !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
353			     !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
354			     2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
355}
356
357/*
358 * Look up an MCS group index based on new cfg80211 rate_info.
359 */
360static int
361minstrel_vht_ri_get_group_idx(struct rate_info *rate)
362{
363	return VHT_GROUP_IDX(rate->nss,
364			     !!(rate->flags & RATE_INFO_FLAGS_SHORT_GI),
365			     !!(rate->bw & RATE_INFO_BW_40) +
366			     2*!!(rate->bw & RATE_INFO_BW_80));
367}
368
369static struct minstrel_rate_stats *
370minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
371		      struct ieee80211_tx_rate *rate)
372{
373	int group, idx;
374
375	if (rate->flags & IEEE80211_TX_RC_MCS) {
376		group = minstrel_ht_get_group_idx(rate);
377		idx = rate->idx % 8;
378		goto out;
379	}
380
381	if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
382		group = minstrel_vht_get_group_idx(rate);
383		idx = ieee80211_rate_get_vht_mcs(rate);
384		goto out;
385	}
386
387	group = MINSTREL_CCK_GROUP;
388	for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) {
389		if (!(mi->supported[group] & BIT(idx)))
390			continue;
391
392		if (rate->idx != mp->cck_rates[idx])
393			continue;
394
395		/* short preamble */
396		if ((mi->supported[group] & BIT(idx + 4)) &&
397		    (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
398			idx += 4;
399		goto out;
400	}
401
402	group = MINSTREL_OFDM_GROUP;
403	for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++)
404		if (rate->idx == mp->ofdm_rates[mi->band][idx])
405			goto out;
406
407	idx = 0;
408out:
409	return &mi->groups[group].rates[idx];
410}
411
412/*
413 * Get the minstrel rate statistics for specified STA and rate info.
414 */
415static struct minstrel_rate_stats *
416minstrel_ht_ri_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
417			  struct ieee80211_rate_status *rate_status)
418{
419	int group, idx;
420	struct rate_info *rate = &rate_status->rate_idx;
421
422	if (rate->flags & RATE_INFO_FLAGS_MCS) {
423		group = minstrel_ht_ri_get_group_idx(rate);
424		idx = rate->mcs % 8;
425		goto out;
426	}
427
428	if (rate->flags & RATE_INFO_FLAGS_VHT_MCS) {
429		group = minstrel_vht_ri_get_group_idx(rate);
430		idx = rate->mcs;
431		goto out;
432	}
433
434	group = MINSTREL_CCK_GROUP;
435	for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) {
436		if (rate->legacy != minstrel_cck_bitrates[ mp->cck_rates[idx] ])
437			continue;
438
439		/* short preamble */
440		if ((mi->supported[group] & BIT(idx + 4)) &&
441							mi->use_short_preamble)
442			idx += 4;
443		goto out;
444	}
445
446	group = MINSTREL_OFDM_GROUP;
447	for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++)
448		if (rate->legacy == minstrel_ofdm_bitrates[ mp->ofdm_rates[mi->band][idx] ])
449			goto out;
450
451	idx = 0;
452out:
453	return &mi->groups[group].rates[idx];
454}
455
456static inline struct minstrel_rate_stats *
457minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
458{
459	return &mi->groups[MI_RATE_GROUP(index)].rates[MI_RATE_IDX(index)];
460}
461
462static inline int minstrel_get_duration(int index)
463{
464	const struct mcs_group *group = &minstrel_mcs_groups[MI_RATE_GROUP(index)];
465	unsigned int duration = group->duration[MI_RATE_IDX(index)];
466
467	return duration << group->shift;
468}
469
470static unsigned int
471minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi)
472{
473	int duration;
474
475	if (mi->avg_ampdu_len)
476		return MINSTREL_TRUNC(mi->avg_ampdu_len);
477
478	if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(mi->max_tp_rate[0])))
479		return 1;
480
481	duration = minstrel_get_duration(mi->max_tp_rate[0]);
482
483	if (duration > 400 * 1000)
484		return 2;
485
486	if (duration > 250 * 1000)
487		return 4;
488
489	if (duration > 150 * 1000)
490		return 8;
491
492	return 16;
493}
494
495/*
496 * Return current throughput based on the average A-MPDU length, taking into
497 * account the expected number of retransmissions and their expected length
498 */
499int
500minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
501		       int prob_avg)
502{
503	unsigned int nsecs = 0, overhead = mi->overhead;
504	unsigned int ampdu_len = 1;
505
506	/* do not account throughput if success prob is below 10% */
507	if (prob_avg < MINSTREL_FRAC(10, 100))
508		return 0;
509
510	if (minstrel_ht_is_legacy_group(group))
511		overhead = mi->overhead_legacy;
512	else
513		ampdu_len = minstrel_ht_avg_ampdu_len(mi);
514
515	nsecs = 1000 * overhead / ampdu_len;
516	nsecs += minstrel_mcs_groups[group].duration[rate] <<
517		 minstrel_mcs_groups[group].shift;
518
519	/*
520	 * For the throughput calculation, limit the probability value to 90% to
521	 * account for collision related packet error rate fluctuation
522	 * (prob is scaled - see MINSTREL_FRAC above)
523	 */
524	if (prob_avg > MINSTREL_FRAC(90, 100))
525		prob_avg = MINSTREL_FRAC(90, 100);
526
527	return MINSTREL_TRUNC(100 * ((prob_avg * 1000000) / nsecs));
528}
529
530/*
531 * Find & sort topmost throughput rates
532 *
533 * If multiple rates provide equal throughput the sorting is based on their
534 * current success probability. Higher success probability is preferred among
535 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
536 */
537static void
538minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
539			       u16 *tp_list)
540{
541	int cur_group, cur_idx, cur_tp_avg, cur_prob;
542	int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
543	int j = MAX_THR_RATES;
544
545	cur_group = MI_RATE_GROUP(index);
546	cur_idx = MI_RATE_IDX(index);
547	cur_prob = mi->groups[cur_group].rates[cur_idx].prob_avg;
548	cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
549
550	do {
551		tmp_group = MI_RATE_GROUP(tp_list[j - 1]);
552		tmp_idx = MI_RATE_IDX(tp_list[j - 1]);
553		tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
554		tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
555						    tmp_prob);
556		if (cur_tp_avg < tmp_tp_avg ||
557		    (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
558			break;
559		j--;
560	} while (j > 0);
561
562	if (j < MAX_THR_RATES - 1) {
563		memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
564		       (MAX_THR_RATES - (j + 1))));
565	}
566	if (j < MAX_THR_RATES)
567		tp_list[j] = index;
568}
569
570/*
571 * Find and set the topmost probability rate per sta and per group
572 */
573static void
574minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 *dest, u16 index)
575{
576	struct minstrel_mcs_group_data *mg;
577	struct minstrel_rate_stats *mrs;
578	int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
579	int max_tp_group, max_tp_idx, max_tp_prob;
580	int cur_tp_avg, cur_group, cur_idx;
581	int max_gpr_group, max_gpr_idx;
582	int max_gpr_tp_avg, max_gpr_prob;
583
584	cur_group = MI_RATE_GROUP(index);
585	cur_idx = MI_RATE_IDX(index);
586	mg = &mi->groups[cur_group];
587	mrs = &mg->rates[cur_idx];
588
589	tmp_group = MI_RATE_GROUP(*dest);
590	tmp_idx = MI_RATE_IDX(*dest);
591	tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
592	tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
593
594	/* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
595	 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
596	max_tp_group = MI_RATE_GROUP(mi->max_tp_rate[0]);
597	max_tp_idx = MI_RATE_IDX(mi->max_tp_rate[0]);
598	max_tp_prob = mi->groups[max_tp_group].rates[max_tp_idx].prob_avg;
599
600	if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index)) &&
601	    !minstrel_ht_is_legacy_group(max_tp_group))
602		return;
603
604	/* skip rates faster than max tp rate with lower prob */
605	if (minstrel_get_duration(mi->max_tp_rate[0]) > minstrel_get_duration(index) &&
606	    mrs->prob_avg < max_tp_prob)
607		return;
608
609	max_gpr_group = MI_RATE_GROUP(mg->max_group_prob_rate);
610	max_gpr_idx = MI_RATE_IDX(mg->max_group_prob_rate);
611	max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_avg;
612
613	if (mrs->prob_avg > MINSTREL_FRAC(75, 100)) {
614		cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
615						    mrs->prob_avg);
616		if (cur_tp_avg > tmp_tp_avg)
617			*dest = index;
618
619		max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
620							max_gpr_idx,
621							max_gpr_prob);
622		if (cur_tp_avg > max_gpr_tp_avg)
623			mg->max_group_prob_rate = index;
624	} else {
625		if (mrs->prob_avg > tmp_prob)
626			*dest = index;
627		if (mrs->prob_avg > max_gpr_prob)
628			mg->max_group_prob_rate = index;
629	}
630}
631
632
633/*
634 * Assign new rate set per sta and use CCK rates only if the fastest
635 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
636 * rate sets where MCS and CCK rates are mixed, because CCK rates can
637 * not use aggregation.
638 */
639static void
640minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
641				 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
642				 u16 tmp_legacy_tp_rate[MAX_THR_RATES])
643{
644	unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
645	int i;
646
647	tmp_group = MI_RATE_GROUP(tmp_legacy_tp_rate[0]);
648	tmp_idx = MI_RATE_IDX(tmp_legacy_tp_rate[0]);
649	tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
650	tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
651
652	tmp_group = MI_RATE_GROUP(tmp_mcs_tp_rate[0]);
653	tmp_idx = MI_RATE_IDX(tmp_mcs_tp_rate[0]);
654	tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
655	tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
656
657	if (tmp_cck_tp > tmp_mcs_tp) {
658		for(i = 0; i < MAX_THR_RATES; i++) {
659			minstrel_ht_sort_best_tp_rates(mi, tmp_legacy_tp_rate[i],
660						       tmp_mcs_tp_rate);
661		}
662	}
663
664}
665
666/*
667 * Try to increase robustness of max_prob rate by decrease number of
668 * streams if possible.
669 */
670static inline void
671minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
672{
673	struct minstrel_mcs_group_data *mg;
674	int tmp_max_streams, group, tmp_idx, tmp_prob;
675	int tmp_tp = 0;
676
677	if (!mi->sta->deflink.ht_cap.ht_supported)
678		return;
679
680	group = MI_RATE_GROUP(mi->max_tp_rate[0]);
681	tmp_max_streams = minstrel_mcs_groups[group].streams;
682	for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
683		mg = &mi->groups[group];
684		if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
685			continue;
686
687		tmp_idx = MI_RATE_IDX(mg->max_group_prob_rate);
688		tmp_prob = mi->groups[group].rates[tmp_idx].prob_avg;
689
690		if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
691		   (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
692				mi->max_prob_rate = mg->max_group_prob_rate;
693				tmp_tp = minstrel_ht_get_tp_avg(mi, group,
694								tmp_idx,
695								tmp_prob);
696		}
697	}
698}
699
700static u16
701__minstrel_ht_get_sample_rate(struct minstrel_ht_sta *mi,
702			      enum minstrel_sample_type type)
703{
704	u16 *rates = mi->sample[type].sample_rates;
705	u16 cur;
706	int i;
707
708	for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) {
709		if (!rates[i])
710			continue;
711
712		cur = rates[i];
713		rates[i] = 0;
714		return cur;
715	}
716
717	return 0;
718}
719
720static inline int
721minstrel_ewma(int old, int new, int weight)
722{
723	int diff, incr;
724
725	diff = new - old;
726	incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
727
728	return old + incr;
729}
730
731static inline int minstrel_filter_avg_add(u16 *prev_1, u16 *prev_2, s32 in)
732{
733	s32 out_1 = *prev_1;
734	s32 out_2 = *prev_2;
735	s32 val;
736
737	if (!in)
738		in += 1;
739
740	if (!out_1) {
741		val = out_1 = in;
742		goto out;
743	}
744
745	val = MINSTREL_AVG_COEFF1 * in;
746	val += MINSTREL_AVG_COEFF2 * out_1;
747	val += MINSTREL_AVG_COEFF3 * out_2;
748	val >>= MINSTREL_SCALE;
749
750	if (val > 1 << MINSTREL_SCALE)
751		val = 1 << MINSTREL_SCALE;
752	if (val < 0)
753		val = 1;
754
755out:
756	*prev_2 = out_1;
757	*prev_1 = val;
758
759	return val;
760}
761
762/*
763* Recalculate statistics and counters of a given rate
764*/
765static void
766minstrel_ht_calc_rate_stats(struct minstrel_priv *mp,
767			    struct minstrel_rate_stats *mrs)
768{
769	unsigned int cur_prob;
770
771	if (unlikely(mrs->attempts > 0)) {
772		cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts);
773		minstrel_filter_avg_add(&mrs->prob_avg,
774					&mrs->prob_avg_1, cur_prob);
775		mrs->att_hist += mrs->attempts;
776		mrs->succ_hist += mrs->success;
777	}
778
779	mrs->last_success = mrs->success;
780	mrs->last_attempts = mrs->attempts;
781	mrs->success = 0;
782	mrs->attempts = 0;
783}
784
785static bool
786minstrel_ht_find_sample_rate(struct minstrel_ht_sta *mi, int type, int idx)
787{
788	int i;
789
790	for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) {
791		u16 cur = mi->sample[type].sample_rates[i];
792
793		if (cur == idx)
794			return true;
795
796		if (!cur)
797			break;
798	}
799
800	return false;
801}
802
803static int
804minstrel_ht_move_sample_rates(struct minstrel_ht_sta *mi, int type,
805			      u32 fast_rate_dur, u32 slow_rate_dur)
806{
807	u16 *rates = mi->sample[type].sample_rates;
808	int i, j;
809
810	for (i = 0, j = 0; i < MINSTREL_SAMPLE_RATES; i++) {
811		u32 duration;
812		bool valid = false;
813		u16 cur;
814
815		cur = rates[i];
816		if (!cur)
817			continue;
818
819		duration = minstrel_get_duration(cur);
820		switch (type) {
821		case MINSTREL_SAMPLE_TYPE_SLOW:
822			valid = duration > fast_rate_dur &&
823				duration < slow_rate_dur;
824			break;
825		case MINSTREL_SAMPLE_TYPE_INC:
826		case MINSTREL_SAMPLE_TYPE_JUMP:
827			valid = duration < fast_rate_dur;
828			break;
829		default:
830			valid = false;
831			break;
832		}
833
834		if (!valid) {
835			rates[i] = 0;
836			continue;
837		}
838
839		if (i == j)
840			continue;
841
842		rates[j++] = cur;
843		rates[i] = 0;
844	}
845
846	return j;
847}
848
849static int
850minstrel_ht_group_min_rate_offset(struct minstrel_ht_sta *mi, int group,
851				  u32 max_duration)
852{
853	u16 supported = mi->supported[group];
854	int i;
855
856	for (i = 0; i < MCS_GROUP_RATES && supported; i++, supported >>= 1) {
857		if (!(supported & BIT(0)))
858			continue;
859
860		if (minstrel_get_duration(MI_RATE(group, i)) >= max_duration)
861			continue;
862
863		return i;
864	}
865
866	return -1;
867}
868
869/*
870 * Incremental update rates:
871 * Flip through groups and pick the first group rate that is faster than the
872 * highest currently selected rate
873 */
874static u16
875minstrel_ht_next_inc_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur)
876{
877	u8 type = MINSTREL_SAMPLE_TYPE_INC;
878	int i, index = 0;
879	u8 group;
880
881	group = mi->sample[type].sample_group;
882	for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
883		group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups);
884
885		index = minstrel_ht_group_min_rate_offset(mi, group,
886							  fast_rate_dur);
887		if (index < 0)
888			continue;
889
890		index = MI_RATE(group, index & 0xf);
891		if (!minstrel_ht_find_sample_rate(mi, type, index))
892			goto out;
893	}
894	index = 0;
895
896out:
897	mi->sample[type].sample_group = group;
898
899	return index;
900}
901
902static int
903minstrel_ht_next_group_sample_rate(struct minstrel_ht_sta *mi, int group,
904				   u16 supported, int offset)
905{
906	struct minstrel_mcs_group_data *mg = &mi->groups[group];
907	u16 idx;
908	int i;
909
910	for (i = 0; i < MCS_GROUP_RATES; i++) {
911		idx = sample_table[mg->column][mg->index];
912		if (++mg->index >= MCS_GROUP_RATES) {
913			mg->index = 0;
914			if (++mg->column >= ARRAY_SIZE(sample_table))
915				mg->column = 0;
916		}
917
918		if (idx < offset)
919			continue;
920
921		if (!(supported & BIT(idx)))
922			continue;
923
924		return MI_RATE(group, idx);
925	}
926
927	return -1;
928}
929
930/*
931 * Jump rates:
932 * Sample random rates, use those that are faster than the highest
933 * currently selected rate. Rates between the fastest and the slowest
934 * get sorted into the slow sample bucket, but only if it has room
935 */
936static u16
937minstrel_ht_next_jump_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur,
938			   u32 slow_rate_dur, int *slow_rate_ofs)
939{
940	struct minstrel_rate_stats *mrs;
941	u32 max_duration = slow_rate_dur;
942	int i, index, offset;
943	u16 *slow_rates;
944	u16 supported;
945	u32 duration;
946	u8 group;
947
948	if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
949		max_duration = fast_rate_dur;
950
951	slow_rates = mi->sample[MINSTREL_SAMPLE_TYPE_SLOW].sample_rates;
952	group = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group;
953	for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
954		u8 type;
955
956		group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups);
957
958		supported = mi->supported[group];
959		if (!supported)
960			continue;
961
962		offset = minstrel_ht_group_min_rate_offset(mi, group,
963							   max_duration);
964		if (offset < 0)
965			continue;
966
967		index = minstrel_ht_next_group_sample_rate(mi, group, supported,
968							   offset);
969		if (index < 0)
970			continue;
971
972		duration = minstrel_get_duration(index);
973		if (duration < fast_rate_dur)
974			type = MINSTREL_SAMPLE_TYPE_JUMP;
975		else
976			type = MINSTREL_SAMPLE_TYPE_SLOW;
977
978		if (minstrel_ht_find_sample_rate(mi, type, index))
979			continue;
980
981		if (type == MINSTREL_SAMPLE_TYPE_JUMP)
982			goto found;
983
984		if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
985			continue;
986
987		if (duration >= slow_rate_dur)
988			continue;
989
990		/* skip slow rates with high success probability */
991		mrs = minstrel_get_ratestats(mi, index);
992		if (mrs->prob_avg > MINSTREL_FRAC(95, 100))
993			continue;
994
995		slow_rates[(*slow_rate_ofs)++] = index;
996		if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
997			max_duration = fast_rate_dur;
998	}
999	index = 0;
1000
1001found:
1002	mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group = group;
1003
1004	return index;
1005}
1006
1007static void
1008minstrel_ht_refill_sample_rates(struct minstrel_ht_sta *mi)
1009{
1010	u32 prob_dur = minstrel_get_duration(mi->max_prob_rate);
1011	u32 tp_dur = minstrel_get_duration(mi->max_tp_rate[0]);
1012	u32 tp2_dur = minstrel_get_duration(mi->max_tp_rate[1]);
1013	u32 fast_rate_dur = min(min(tp_dur, tp2_dur), prob_dur);
1014	u32 slow_rate_dur = max(max(tp_dur, tp2_dur), prob_dur);
1015	u16 *rates;
1016	int i, j;
1017
1018	rates = mi->sample[MINSTREL_SAMPLE_TYPE_INC].sample_rates;
1019	i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_INC,
1020					  fast_rate_dur, slow_rate_dur);
1021	while (i < MINSTREL_SAMPLE_RATES) {
1022		rates[i] = minstrel_ht_next_inc_rate(mi, tp_dur);
1023		if (!rates[i])
1024			break;
1025
1026		i++;
1027	}
1028
1029	rates = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_rates;
1030	i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_JUMP,
1031					  fast_rate_dur, slow_rate_dur);
1032	j = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_SLOW,
1033					  fast_rate_dur, slow_rate_dur);
1034	while (i < MINSTREL_SAMPLE_RATES) {
1035		rates[i] = minstrel_ht_next_jump_rate(mi, fast_rate_dur,
1036						      slow_rate_dur, &j);
1037		if (!rates[i])
1038			break;
1039
1040		i++;
1041	}
1042
1043	for (i = 0; i < ARRAY_SIZE(mi->sample); i++)
1044		memcpy(mi->sample[i].cur_sample_rates, mi->sample[i].sample_rates,
1045		       sizeof(mi->sample[i].cur_sample_rates));
1046}
1047
1048
1049/*
1050 * Update rate statistics and select new primary rates
1051 *
1052 * Rules for rate selection:
1053 *  - max_prob_rate must use only one stream, as a tradeoff between delivery
1054 *    probability and throughput during strong fluctuations
1055 *  - as long as the max prob rate has a probability of more than 75%, pick
1056 *    higher throughput rates, even if the probablity is a bit lower
1057 */
1058static void
1059minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1060{
1061	struct minstrel_mcs_group_data *mg;
1062	struct minstrel_rate_stats *mrs;
1063	int group, i, j, cur_prob;
1064	u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
1065	u16 tmp_legacy_tp_rate[MAX_THR_RATES], tmp_max_prob_rate;
1066	u16 index;
1067	bool ht_supported = mi->sta->deflink.ht_cap.ht_supported;
1068
1069	if (mi->ampdu_packets > 0) {
1070		if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN))
1071			mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
1072				MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets),
1073					      EWMA_LEVEL);
1074		else
1075			mi->avg_ampdu_len = 0;
1076		mi->ampdu_len = 0;
1077		mi->ampdu_packets = 0;
1078	}
1079
1080	if (mi->supported[MINSTREL_CCK_GROUP])
1081		group = MINSTREL_CCK_GROUP;
1082	else if (mi->supported[MINSTREL_OFDM_GROUP])
1083		group = MINSTREL_OFDM_GROUP;
1084	else
1085		group = 0;
1086
1087	index = MI_RATE(group, 0);
1088	for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++)
1089		tmp_legacy_tp_rate[j] = index;
1090
1091	if (mi->supported[MINSTREL_VHT_GROUP_0])
1092		group = MINSTREL_VHT_GROUP_0;
1093	else if (ht_supported)
1094		group = MINSTREL_HT_GROUP_0;
1095	else if (mi->supported[MINSTREL_CCK_GROUP])
1096		group = MINSTREL_CCK_GROUP;
1097	else
1098		group = MINSTREL_OFDM_GROUP;
1099
1100	index = MI_RATE(group, 0);
1101	tmp_max_prob_rate = index;
1102	for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++)
1103		tmp_mcs_tp_rate[j] = index;
1104
1105	/* Find best rate sets within all MCS groups*/
1106	for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
1107		u16 *tp_rate = tmp_mcs_tp_rate;
1108		u16 last_prob = 0;
1109
1110		mg = &mi->groups[group];
1111		if (!mi->supported[group])
1112			continue;
1113
1114		/* (re)Initialize group rate indexes */
1115		for(j = 0; j < MAX_THR_RATES; j++)
1116			tmp_group_tp_rate[j] = MI_RATE(group, 0);
1117
1118		if (group == MINSTREL_CCK_GROUP && ht_supported)
1119			tp_rate = tmp_legacy_tp_rate;
1120
1121		for (i = MCS_GROUP_RATES - 1; i >= 0; i--) {
1122			if (!(mi->supported[group] & BIT(i)))
1123				continue;
1124
1125			index = MI_RATE(group, i);
1126
1127			mrs = &mg->rates[i];
1128			mrs->retry_updated = false;
1129			minstrel_ht_calc_rate_stats(mp, mrs);
1130
1131			if (mrs->att_hist)
1132				last_prob = max(last_prob, mrs->prob_avg);
1133			else
1134				mrs->prob_avg = max(last_prob, mrs->prob_avg);
1135			cur_prob = mrs->prob_avg;
1136
1137			if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
1138				continue;
1139
1140			/* Find max throughput rate set */
1141			minstrel_ht_sort_best_tp_rates(mi, index, tp_rate);
1142
1143			/* Find max throughput rate set within a group */
1144			minstrel_ht_sort_best_tp_rates(mi, index,
1145						       tmp_group_tp_rate);
1146		}
1147
1148		memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
1149		       sizeof(mg->max_group_tp_rate));
1150	}
1151
1152	/* Assign new rate set per sta */
1153	minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate,
1154					 tmp_legacy_tp_rate);
1155	memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
1156
1157	for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
1158		if (!mi->supported[group])
1159			continue;
1160
1161		mg = &mi->groups[group];
1162		mg->max_group_prob_rate = MI_RATE(group, 0);
1163
1164		for (i = 0; i < MCS_GROUP_RATES; i++) {
1165			if (!(mi->supported[group] & BIT(i)))
1166				continue;
1167
1168			index = MI_RATE(group, i);
1169
1170			/* Find max probability rate per group and global */
1171			minstrel_ht_set_best_prob_rate(mi, &tmp_max_prob_rate,
1172						       index);
1173		}
1174	}
1175
1176	mi->max_prob_rate = tmp_max_prob_rate;
1177
1178	/* Try to increase robustness of max_prob_rate*/
1179	minstrel_ht_prob_rate_reduce_streams(mi);
1180	minstrel_ht_refill_sample_rates(mi);
1181
1182#ifdef CONFIG_MAC80211_DEBUGFS
1183	/* use fixed index if set */
1184	if (mp->fixed_rate_idx != -1) {
1185		for (i = 0; i < 4; i++)
1186			mi->max_tp_rate[i] = mp->fixed_rate_idx;
1187		mi->max_prob_rate = mp->fixed_rate_idx;
1188	}
1189#endif
1190
1191	/* Reset update timer */
1192	mi->last_stats_update = jiffies;
1193	mi->sample_time = jiffies;
1194}
1195
1196static bool
1197minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1198			 struct ieee80211_tx_rate *rate)
1199{
1200	int i;
1201
1202	if (rate->idx < 0)
1203		return false;
1204
1205	if (!rate->count)
1206		return false;
1207
1208	if (rate->flags & IEEE80211_TX_RC_MCS ||
1209	    rate->flags & IEEE80211_TX_RC_VHT_MCS)
1210		return true;
1211
1212	for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++)
1213		if (rate->idx == mp->cck_rates[i])
1214			return true;
1215
1216	for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++)
1217		if (rate->idx == mp->ofdm_rates[mi->band][i])
1218			return true;
1219
1220	return false;
1221}
1222
1223/*
1224 * Check whether rate_status contains valid information.
1225 */
1226static bool
1227minstrel_ht_ri_txstat_valid(struct minstrel_priv *mp,
1228			    struct minstrel_ht_sta *mi,
1229			    struct ieee80211_rate_status *rate_status)
1230{
1231	int i;
1232
1233	if (!rate_status)
1234		return false;
1235	if (!rate_status->try_count)
1236		return false;
1237
1238	if (rate_status->rate_idx.flags & RATE_INFO_FLAGS_MCS ||
1239	    rate_status->rate_idx.flags & RATE_INFO_FLAGS_VHT_MCS)
1240		return true;
1241
1242	for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++) {
1243		if (rate_status->rate_idx.legacy ==
1244		    minstrel_cck_bitrates[ mp->cck_rates[i] ])
1245			return true;
1246	}
1247
1248	for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates); i++) {
1249		if (rate_status->rate_idx.legacy ==
1250		    minstrel_ofdm_bitrates[ mp->ofdm_rates[mi->band][i] ])
1251			return true;
1252	}
1253
1254	return false;
1255}
1256
1257static void
1258minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
1259{
1260	int group, orig_group;
1261
1262	orig_group = group = MI_RATE_GROUP(*idx);
1263	while (group > 0) {
1264		group--;
1265
1266		if (!mi->supported[group])
1267			continue;
1268
1269		if (minstrel_mcs_groups[group].streams >
1270		    minstrel_mcs_groups[orig_group].streams)
1271			continue;
1272
1273		if (primary)
1274			*idx = mi->groups[group].max_group_tp_rate[0];
1275		else
1276			*idx = mi->groups[group].max_group_tp_rate[1];
1277		break;
1278	}
1279}
1280
1281static void
1282minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
1283                      void *priv_sta, struct ieee80211_tx_status *st)
1284{
1285	struct ieee80211_tx_info *info = st->info;
1286	struct minstrel_ht_sta *mi = priv_sta;
1287	struct ieee80211_tx_rate *ar = info->status.rates;
1288	struct minstrel_rate_stats *rate, *rate2;
1289	struct minstrel_priv *mp = priv;
1290	u32 update_interval = mp->update_interval;
1291	bool last, update = false;
1292	int i;
1293
1294	/* Ignore packet that was sent with noAck flag */
1295	if (info->flags & IEEE80211_TX_CTL_NO_ACK)
1296		return;
1297
1298	/* This packet was aggregated but doesn't carry status info */
1299	if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
1300	    !(info->flags & IEEE80211_TX_STAT_AMPDU))
1301		return;
1302
1303	if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
1304		info->status.ampdu_ack_len =
1305			(info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
1306		info->status.ampdu_len = 1;
1307	}
1308
1309	/* wraparound */
1310	if (mi->total_packets >= ~0 - info->status.ampdu_len) {
1311		mi->total_packets = 0;
1312		mi->sample_packets = 0;
1313	}
1314
1315	mi->total_packets += info->status.ampdu_len;
1316	if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
1317		mi->sample_packets += info->status.ampdu_len;
1318
1319	mi->ampdu_packets++;
1320	mi->ampdu_len += info->status.ampdu_len;
1321
1322	if (st->rates && st->n_rates) {
1323		last = !minstrel_ht_ri_txstat_valid(mp, mi, &(st->rates[0]));
1324		for (i = 0; !last; i++) {
1325			last = (i == st->n_rates - 1) ||
1326				!minstrel_ht_ri_txstat_valid(mp, mi,
1327							&(st->rates[i + 1]));
1328
1329			rate = minstrel_ht_ri_get_stats(mp, mi,
1330							&(st->rates[i]));
1331
1332			if (last)
1333				rate->success += info->status.ampdu_ack_len;
1334
1335			rate->attempts += st->rates[i].try_count *
1336					  info->status.ampdu_len;
1337		}
1338	} else {
1339		last = !minstrel_ht_txstat_valid(mp, mi, &ar[0]);
1340		for (i = 0; !last; i++) {
1341			last = (i == IEEE80211_TX_MAX_RATES - 1) ||
1342				!minstrel_ht_txstat_valid(mp, mi, &ar[i + 1]);
1343
1344			rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
1345			if (last)
1346				rate->success += info->status.ampdu_ack_len;
1347
1348			rate->attempts += ar[i].count * info->status.ampdu_len;
1349		}
1350	}
1351
1352	if (mp->hw->max_rates > 1) {
1353		/*
1354		 * check for sudden death of spatial multiplexing,
1355		 * downgrade to a lower number of streams if necessary.
1356		 */
1357		rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
1358		if (rate->attempts > 30 &&
1359		    rate->success < rate->attempts / 4) {
1360			minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
1361			update = true;
1362		}
1363
1364		rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
1365		if (rate2->attempts > 30 &&
1366		    rate2->success < rate2->attempts / 4) {
1367			minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
1368			update = true;
1369		}
1370	}
1371
1372	if (time_after(jiffies, mi->last_stats_update + update_interval)) {
1373		update = true;
1374		minstrel_ht_update_stats(mp, mi);
1375	}
1376
1377	if (update)
1378		minstrel_ht_update_rates(mp, mi);
1379}
1380
1381static void
1382minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1383                         int index)
1384{
1385	struct minstrel_rate_stats *mrs;
1386	unsigned int tx_time, tx_time_rtscts, tx_time_data;
1387	unsigned int cw = mp->cw_min;
1388	unsigned int ctime = 0;
1389	unsigned int t_slot = 9; /* FIXME */
1390	unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi);
1391	unsigned int overhead = 0, overhead_rtscts = 0;
1392
1393	mrs = minstrel_get_ratestats(mi, index);
1394	if (mrs->prob_avg < MINSTREL_FRAC(1, 10)) {
1395		mrs->retry_count = 1;
1396		mrs->retry_count_rtscts = 1;
1397		return;
1398	}
1399
1400	mrs->retry_count = 2;
1401	mrs->retry_count_rtscts = 2;
1402	mrs->retry_updated = true;
1403
1404	tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;
1405
1406	/* Contention time for first 2 tries */
1407	ctime = (t_slot * cw) >> 1;
1408	cw = min((cw << 1) | 1, mp->cw_max);
1409	ctime += (t_slot * cw) >> 1;
1410	cw = min((cw << 1) | 1, mp->cw_max);
1411
1412	if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index))) {
1413		overhead = mi->overhead_legacy;
1414		overhead_rtscts = mi->overhead_legacy_rtscts;
1415	} else {
1416		overhead = mi->overhead;
1417		overhead_rtscts = mi->overhead_rtscts;
1418	}
1419
1420	/* Total TX time for data and Contention after first 2 tries */
1421	tx_time = ctime + 2 * (overhead + tx_time_data);
1422	tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
1423
1424	/* See how many more tries we can fit inside segment size */
1425	do {
1426		/* Contention time for this try */
1427		ctime = (t_slot * cw) >> 1;
1428		cw = min((cw << 1) | 1, mp->cw_max);
1429
1430		/* Total TX time after this try */
1431		tx_time += ctime + overhead + tx_time_data;
1432		tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
1433
1434		if (tx_time_rtscts < mp->segment_size)
1435			mrs->retry_count_rtscts++;
1436	} while ((tx_time < mp->segment_size) &&
1437	         (++mrs->retry_count < mp->max_retry));
1438}
1439
1440
1441static void
1442minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1443                     struct ieee80211_sta_rates *ratetbl, int offset, int index)
1444{
1445	int group_idx = MI_RATE_GROUP(index);
1446	const struct mcs_group *group = &minstrel_mcs_groups[group_idx];
1447	struct minstrel_rate_stats *mrs;
1448	u8 idx;
1449	u16 flags = group->flags;
1450
1451	mrs = minstrel_get_ratestats(mi, index);
1452	if (!mrs->retry_updated)
1453		minstrel_calc_retransmit(mp, mi, index);
1454
1455	if (mrs->prob_avg < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
1456		ratetbl->rate[offset].count = 2;
1457		ratetbl->rate[offset].count_rts = 2;
1458		ratetbl->rate[offset].count_cts = 2;
1459	} else {
1460		ratetbl->rate[offset].count = mrs->retry_count;
1461		ratetbl->rate[offset].count_cts = mrs->retry_count;
1462		ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
1463	}
1464
1465	index = MI_RATE_IDX(index);
1466	if (group_idx == MINSTREL_CCK_GROUP)
1467		idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
1468	else if (group_idx == MINSTREL_OFDM_GROUP)
1469		idx = mp->ofdm_rates[mi->band][index %
1470					       ARRAY_SIZE(mp->ofdm_rates[0])];
1471	else if (flags & IEEE80211_TX_RC_VHT_MCS)
1472		idx = ((group->streams - 1) << 4) |
1473		      (index & 0xF);
1474	else
1475		idx = index + (group->streams - 1) * 8;
1476
1477	/* enable RTS/CTS if needed:
1478	 *  - if station is in dynamic SMPS (and streams > 1)
1479	 *  - for fallback rates, to increase chances of getting through
1480	 */
1481	if (offset > 0 ||
1482	    (mi->sta->deflink.smps_mode == IEEE80211_SMPS_DYNAMIC &&
1483	     group->streams > 1)) {
1484		ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
1485		flags |= IEEE80211_TX_RC_USE_RTS_CTS;
1486	}
1487
1488	ratetbl->rate[offset].idx = idx;
1489	ratetbl->rate[offset].flags = flags;
1490}
1491
1492static inline int
1493minstrel_ht_get_prob_avg(struct minstrel_ht_sta *mi, int rate)
1494{
1495	int group = MI_RATE_GROUP(rate);
1496	rate = MI_RATE_IDX(rate);
1497	return mi->groups[group].rates[rate].prob_avg;
1498}
1499
1500static int
1501minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
1502{
1503	int group = MI_RATE_GROUP(mi->max_prob_rate);
1504	const struct mcs_group *g = &minstrel_mcs_groups[group];
1505	int rate = MI_RATE_IDX(mi->max_prob_rate);
1506	unsigned int duration;
1507
1508	/* Disable A-MSDU if max_prob_rate is bad */
1509	if (mi->groups[group].rates[rate].prob_avg < MINSTREL_FRAC(50, 100))
1510		return 1;
1511
1512	duration = g->duration[rate];
1513	duration <<= g->shift;
1514
1515	/* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
1516	if (duration > MCS_DURATION(1, 0, 52))
1517		return 500;
1518
1519	/*
1520	 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
1521	 * data packet size
1522	 */
1523	if (duration > MCS_DURATION(1, 0, 104))
1524		return 1600;
1525
1526	/*
1527	 * If the rate is slower than single-stream MCS7, or if the max throughput
1528	 * rate success probability is less than 75%, limit A-MSDU to twice the usual
1529	 * data packet size
1530	 */
1531	if (duration > MCS_DURATION(1, 0, 260) ||
1532	    (minstrel_ht_get_prob_avg(mi, mi->max_tp_rate[0]) <
1533	     MINSTREL_FRAC(75, 100)))
1534		return 3200;
1535
1536	/*
1537	 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
1538	 * Since aggregation sessions are started/stopped without txq flush, use
1539	 * the limit here to avoid the complexity of having to de-aggregate
1540	 * packets in the queue.
1541	 */
1542	if (!mi->sta->deflink.vht_cap.vht_supported)
1543		return IEEE80211_MAX_MPDU_LEN_HT_BA;
1544
1545	/* unlimited */
1546	return 0;
1547}
1548
1549static void
1550minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1551{
1552	struct ieee80211_sta_rates *rates;
1553	int i = 0;
1554	int max_rates = min_t(int, mp->hw->max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
1555
1556	rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
1557	if (!rates)
1558		return;
1559
1560	/* Start with max_tp_rate[0] */
1561	minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
1562
1563	/* Fill up remaining, keep one entry for max_probe_rate */
1564	for (; i < (max_rates - 1); i++)
1565		minstrel_ht_set_rate(mp, mi, rates, i, mi->max_tp_rate[i]);
1566
1567	if (i < max_rates)
1568		minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
1569
1570	if (i < IEEE80211_TX_RATE_TABLE_SIZE)
1571		rates->rate[i].idx = -1;
1572
1573	mi->sta->deflink.agg.max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
1574	ieee80211_sta_recalc_aggregates(mi->sta);
1575	rate_control_set_rates(mp->hw, mi->sta, rates);
1576}
1577
1578static u16
1579minstrel_ht_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1580{
1581	u8 seq;
1582
1583	if (mp->hw->max_rates > 1) {
1584		seq = mi->sample_seq;
1585		mi->sample_seq = (seq + 1) % ARRAY_SIZE(minstrel_sample_seq);
1586		seq = minstrel_sample_seq[seq];
1587	} else {
1588		seq = MINSTREL_SAMPLE_TYPE_INC;
1589	}
1590
1591	return __minstrel_ht_get_sample_rate(mi, seq);
1592}
1593
1594static void
1595minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1596                     struct ieee80211_tx_rate_control *txrc)
1597{
1598	const struct mcs_group *sample_group;
1599	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1600	struct ieee80211_tx_rate *rate = &info->status.rates[0];
1601	struct minstrel_ht_sta *mi = priv_sta;
1602	struct minstrel_priv *mp = priv;
1603	u16 sample_idx;
1604
1605	info->flags |= mi->tx_flags;
1606
1607#ifdef CONFIG_MAC80211_DEBUGFS
1608	if (mp->fixed_rate_idx != -1)
1609		return;
1610#endif
1611
1612	/* Don't use EAPOL frames for sampling on non-mrr hw */
1613	if (mp->hw->max_rates == 1 &&
1614	    (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1615		return;
1616
1617	if (time_is_after_jiffies(mi->sample_time))
1618		return;
1619
1620	mi->sample_time = jiffies + MINSTREL_SAMPLE_INTERVAL;
1621	sample_idx = minstrel_ht_get_sample_rate(mp, mi);
1622	if (!sample_idx)
1623		return;
1624
1625	sample_group = &minstrel_mcs_groups[MI_RATE_GROUP(sample_idx)];
1626	sample_idx = MI_RATE_IDX(sample_idx);
1627
1628	if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
1629	    (sample_idx >= 4) != txrc->short_preamble)
1630		return;
1631
1632	info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1633	rate->count = 1;
1634
1635	if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
1636		int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1637		rate->idx = mp->cck_rates[idx];
1638	} else if (sample_group == &minstrel_mcs_groups[MINSTREL_OFDM_GROUP]) {
1639		int idx = sample_idx % ARRAY_SIZE(mp->ofdm_rates[0]);
1640		rate->idx = mp->ofdm_rates[mi->band][idx];
1641	} else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1642		ieee80211_rate_set_vht(rate, MI_RATE_IDX(sample_idx),
1643				       sample_group->streams);
1644	} else {
1645		rate->idx = sample_idx + (sample_group->streams - 1) * 8;
1646	}
1647
1648	rate->flags = sample_group->flags;
1649}
1650
1651static void
1652minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1653		       struct ieee80211_supported_band *sband,
1654		       struct ieee80211_sta *sta)
1655{
1656	int i;
1657
1658	if (sband->band != NL80211_BAND_2GHZ)
1659		return;
1660
1661	if (sta->deflink.ht_cap.ht_supported &&
1662	    !ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1663		return;
1664
1665	for (i = 0; i < 4; i++) {
1666		if (mp->cck_rates[i] == 0xff ||
1667		    !rate_supported(sta, sband->band, mp->cck_rates[i]))
1668			continue;
1669
1670		mi->supported[MINSTREL_CCK_GROUP] |= BIT(i);
1671		if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1672			mi->supported[MINSTREL_CCK_GROUP] |= BIT(i + 4);
1673	}
1674}
1675
1676static void
1677minstrel_ht_update_ofdm(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1678			struct ieee80211_supported_band *sband,
1679			struct ieee80211_sta *sta)
1680{
1681	const u8 *rates;
1682	int i;
1683
1684	if (sta->deflink.ht_cap.ht_supported)
1685		return;
1686
1687	rates = mp->ofdm_rates[sband->band];
1688	for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++) {
1689		if (rates[i] == 0xff ||
1690		    !rate_supported(sta, sband->band, rates[i]))
1691			continue;
1692
1693		mi->supported[MINSTREL_OFDM_GROUP] |= BIT(i);
1694	}
1695}
1696
1697static void
1698minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1699			struct cfg80211_chan_def *chandef,
1700			struct ieee80211_sta *sta, void *priv_sta)
1701{
1702	struct minstrel_priv *mp = priv;
1703	struct minstrel_ht_sta *mi = priv_sta;
1704	struct ieee80211_mcs_info *mcs = &sta->deflink.ht_cap.mcs;
1705	u16 ht_cap = sta->deflink.ht_cap.cap;
1706	struct ieee80211_sta_vht_cap *vht_cap = &sta->deflink.vht_cap;
1707	const struct ieee80211_rate *ctl_rate;
1708	struct sta_info *sta_info;
1709	bool ldpc, erp;
1710	int use_vht;
1711	int ack_dur;
1712	int stbc;
1713	int i;
1714
1715	BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1716
1717	if (vht_cap->vht_supported)
1718		use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1719	else
1720		use_vht = 0;
1721
1722	memset(mi, 0, sizeof(*mi));
1723
1724	mi->sta = sta;
1725	mi->band = sband->band;
1726	mi->last_stats_update = jiffies;
1727
1728	ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1);
1729	mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1);
1730	mi->overhead += ack_dur;
1731	mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1732
1733	ctl_rate = &sband->bitrates[rate_lowest_index(sband, sta)];
1734	erp = ctl_rate->flags & IEEE80211_RATE_ERP_G;
1735	ack_dur = ieee80211_frame_duration(sband->band, 10,
1736					   ctl_rate->bitrate, erp, 1);
1737	mi->overhead_legacy = ack_dur;
1738	mi->overhead_legacy_rtscts = mi->overhead_legacy + 2 * ack_dur;
1739
1740	mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1741
1742	if (!use_vht) {
1743		stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
1744			IEEE80211_HT_CAP_RX_STBC_SHIFT;
1745
1746		ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING;
1747	} else {
1748		stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >>
1749			IEEE80211_VHT_CAP_RXSTBC_SHIFT;
1750
1751		ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC;
1752	}
1753
1754	mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1755	if (ldpc)
1756		mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1757
1758	for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1759		u32 gflags = minstrel_mcs_groups[i].flags;
1760		int bw, nss;
1761
1762		mi->supported[i] = 0;
1763		if (minstrel_ht_is_legacy_group(i))
1764			continue;
1765
1766		if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1767			if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1768				if (!(ht_cap & IEEE80211_HT_CAP_SGI_40))
1769					continue;
1770			} else {
1771				if (!(ht_cap & IEEE80211_HT_CAP_SGI_20))
1772					continue;
1773			}
1774		}
1775
1776		if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1777		    sta->deflink.bandwidth < IEEE80211_STA_RX_BW_40)
1778			continue;
1779
1780		nss = minstrel_mcs_groups[i].streams;
1781
1782		/* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1783		if (sta->deflink.smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1784			continue;
1785
1786		/* HT rate */
1787		if (gflags & IEEE80211_TX_RC_MCS) {
1788			if (use_vht && minstrel_vht_only)
1789				continue;
1790
1791			mi->supported[i] = mcs->rx_mask[nss - 1];
1792			continue;
1793		}
1794
1795		/* VHT rate */
1796		if (!vht_cap->vht_supported ||
1797		    WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1798		    WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1799			continue;
1800
1801		if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1802			if (sta->deflink.bandwidth < IEEE80211_STA_RX_BW_80 ||
1803			    ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1804			     !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1805				continue;
1806			}
1807		}
1808
1809		if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1810			bw = BW_40;
1811		else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1812			bw = BW_80;
1813		else
1814			bw = BW_20;
1815
1816		mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1817				vht_cap->vht_mcs.tx_mcs_map);
1818	}
1819
1820	sta_info = container_of(sta, struct sta_info, sta);
1821	mi->use_short_preamble = test_sta_flag(sta_info, WLAN_STA_SHORT_PREAMBLE) &&
1822				 sta_info->sdata->vif.bss_conf.use_short_preamble;
1823
1824	minstrel_ht_update_cck(mp, mi, sband, sta);
1825	minstrel_ht_update_ofdm(mp, mi, sband, sta);
1826
1827	/* create an initial rate table with the lowest supported rates */
1828	minstrel_ht_update_stats(mp, mi);
1829	minstrel_ht_update_rates(mp, mi);
1830}
1831
1832static void
1833minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1834		      struct cfg80211_chan_def *chandef,
1835                      struct ieee80211_sta *sta, void *priv_sta)
1836{
1837	minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1838}
1839
1840static void
1841minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1842			struct cfg80211_chan_def *chandef,
1843                        struct ieee80211_sta *sta, void *priv_sta,
1844                        u32 changed)
1845{
1846	minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1847}
1848
1849static void *
1850minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1851{
1852	struct ieee80211_supported_band *sband;
1853	struct minstrel_ht_sta *mi;
1854	struct minstrel_priv *mp = priv;
1855	struct ieee80211_hw *hw = mp->hw;
1856	int max_rates = 0;
1857	int i;
1858
1859	for (i = 0; i < NUM_NL80211_BANDS; i++) {
1860		sband = hw->wiphy->bands[i];
1861		if (sband && sband->n_bitrates > max_rates)
1862			max_rates = sband->n_bitrates;
1863	}
1864
1865	return kzalloc(sizeof(*mi), gfp);
1866}
1867
1868static void
1869minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1870{
1871	kfree(priv_sta);
1872}
1873
1874static void
1875minstrel_ht_fill_rate_array(u8 *dest, struct ieee80211_supported_band *sband,
1876			    const s16 *bitrates, int n_rates, u32 rate_flags)
1877{
1878	int i, j;
1879
1880	for (i = 0; i < sband->n_bitrates; i++) {
1881		struct ieee80211_rate *rate = &sband->bitrates[i];
1882
1883		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1884			continue;
1885
1886		for (j = 0; j < n_rates; j++) {
1887			if (rate->bitrate != bitrates[j])
1888				continue;
1889
1890			dest[j] = i;
1891			break;
1892		}
1893	}
1894}
1895
1896static void
1897minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
1898{
1899	static const s16 bitrates[4] = { 10, 20, 55, 110 };
1900	struct ieee80211_supported_band *sband;
1901	u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1902
1903	memset(mp->cck_rates, 0xff, sizeof(mp->cck_rates));
1904	sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
1905	if (!sband)
1906		return;
1907
1908	BUILD_BUG_ON(ARRAY_SIZE(mp->cck_rates) != ARRAY_SIZE(bitrates));
1909	minstrel_ht_fill_rate_array(mp->cck_rates, sband,
1910				    minstrel_cck_bitrates,
1911				    ARRAY_SIZE(minstrel_cck_bitrates),
1912				    rate_flags);
1913}
1914
1915static void
1916minstrel_ht_init_ofdm_rates(struct minstrel_priv *mp, enum nl80211_band band)
1917{
1918	static const s16 bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
1919	struct ieee80211_supported_band *sband;
1920	u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1921
1922	memset(mp->ofdm_rates[band], 0xff, sizeof(mp->ofdm_rates[band]));
1923	sband = mp->hw->wiphy->bands[band];
1924	if (!sband)
1925		return;
1926
1927	BUILD_BUG_ON(ARRAY_SIZE(mp->ofdm_rates[band]) != ARRAY_SIZE(bitrates));
1928	minstrel_ht_fill_rate_array(mp->ofdm_rates[band], sband,
1929				    minstrel_ofdm_bitrates,
1930				    ARRAY_SIZE(minstrel_ofdm_bitrates),
1931				    rate_flags);
1932}
1933
1934static void *
1935minstrel_ht_alloc(struct ieee80211_hw *hw)
1936{
1937	struct minstrel_priv *mp;
1938	int i;
1939
1940	mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
1941	if (!mp)
1942		return NULL;
1943
1944	/* contention window settings
1945	 * Just an approximation. Using the per-queue values would complicate
1946	 * the calculations and is probably unnecessary */
1947	mp->cw_min = 15;
1948	mp->cw_max = 1023;
1949
1950	/* maximum time that the hw is allowed to stay in one MRR segment */
1951	mp->segment_size = 6000;
1952
1953	if (hw->max_rate_tries > 0)
1954		mp->max_retry = hw->max_rate_tries;
1955	else
1956		/* safe default, does not necessarily have to match hw properties */
1957		mp->max_retry = 7;
1958
1959	mp->hw = hw;
1960	mp->update_interval = HZ / 20;
1961
1962	minstrel_ht_init_cck_rates(mp);
1963	for (i = 0; i < ARRAY_SIZE(mp->hw->wiphy->bands); i++)
1964	    minstrel_ht_init_ofdm_rates(mp, i);
1965
1966	return mp;
1967}
1968
1969#ifdef CONFIG_MAC80211_DEBUGFS
1970static void minstrel_ht_add_debugfs(struct ieee80211_hw *hw, void *priv,
1971				    struct dentry *debugfsdir)
1972{
1973	struct minstrel_priv *mp = priv;
1974
1975	mp->fixed_rate_idx = (u32) -1;
1976	debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
1977			   &mp->fixed_rate_idx);
1978}
1979#endif
1980
1981static void
1982minstrel_ht_free(void *priv)
1983{
1984	kfree(priv);
1985}
1986
1987static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1988{
1989	struct minstrel_ht_sta *mi = priv_sta;
1990	int i, j, prob, tp_avg;
1991
1992	i = MI_RATE_GROUP(mi->max_tp_rate[0]);
1993	j = MI_RATE_IDX(mi->max_tp_rate[0]);
1994	prob = mi->groups[i].rates[j].prob_avg;
1995
1996	/* convert tp_avg from pkt per second in kbps */
1997	tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1998	tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1999
2000	return tp_avg;
2001}
2002
2003static const struct rate_control_ops mac80211_minstrel_ht = {
2004	.name = "minstrel_ht",
2005	.capa = RATE_CTRL_CAPA_AMPDU_TRIGGER,
2006	.tx_status_ext = minstrel_ht_tx_status,
2007	.get_rate = minstrel_ht_get_rate,
2008	.rate_init = minstrel_ht_rate_init,
2009	.rate_update = minstrel_ht_rate_update,
2010	.alloc_sta = minstrel_ht_alloc_sta,
2011	.free_sta = minstrel_ht_free_sta,
2012	.alloc = minstrel_ht_alloc,
2013	.free = minstrel_ht_free,
2014#ifdef CONFIG_MAC80211_DEBUGFS
2015	.add_debugfs = minstrel_ht_add_debugfs,
2016	.add_sta_debugfs = minstrel_ht_add_sta_debugfs,
2017#endif
2018	.get_expected_throughput = minstrel_ht_get_expected_throughput,
2019};
2020
2021
2022static void __init init_sample_table(void)
2023{
2024	int col, i, new_idx;
2025	u8 rnd[MCS_GROUP_RATES];
2026
2027	memset(sample_table, 0xff, sizeof(sample_table));
2028	for (col = 0; col < SAMPLE_COLUMNS; col++) {
2029		get_random_bytes(rnd, sizeof(rnd));
2030		for (i = 0; i < MCS_GROUP_RATES; i++) {
2031			new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
2032			while (sample_table[col][new_idx] != 0xff)
2033				new_idx = (new_idx + 1) % MCS_GROUP_RATES;
2034
2035			sample_table[col][new_idx] = i;
2036		}
2037	}
2038}
2039
2040int __init
2041rc80211_minstrel_init(void)
2042{
2043	init_sample_table();
2044	return ieee80211_rate_control_register(&mac80211_minstrel_ht);
2045}
2046
2047void
2048rc80211_minstrel_exit(void)
2049{
2050	ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
2051}
2052