rc80211_minstrel_ht.c

   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 probability 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)
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		for (j = 0; j < n_rates; j++) {
1884			if (rate->bitrate != bitrates[j])
1885				continue;
1886
1887			dest[j] = i;
1888			break;
1889		}
1890	}
1891}
1892
1893static void
1894minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
1895{
1896	static const s16 bitrates[4] = { 10, 20, 55, 110 };
1897	struct ieee80211_supported_band *sband;
1898
1899	memset(mp->cck_rates, 0xff, sizeof(mp->cck_rates));
1900	sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
1901	if (!sband)
1902		return;
1903
1904	BUILD_BUG_ON(ARRAY_SIZE(mp->cck_rates) != ARRAY_SIZE(bitrates));
1905	minstrel_ht_fill_rate_array(mp->cck_rates, sband,
1906				    minstrel_cck_bitrates,
1907				    ARRAY_SIZE(minstrel_cck_bitrates));
1908}
1909
1910static void
1911minstrel_ht_init_ofdm_rates(struct minstrel_priv *mp, enum nl80211_band band)
1912{
1913	static const s16 bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
1914	struct ieee80211_supported_band *sband;
1915
1916	memset(mp->ofdm_rates[band], 0xff, sizeof(mp->ofdm_rates[band]));
1917	sband = mp->hw->wiphy->bands[band];
1918	if (!sband)
1919		return;
1920
1921	BUILD_BUG_ON(ARRAY_SIZE(mp->ofdm_rates[band]) != ARRAY_SIZE(bitrates));
1922	minstrel_ht_fill_rate_array(mp->ofdm_rates[band], sband,
1923				    minstrel_ofdm_bitrates,
1924				    ARRAY_SIZE(minstrel_ofdm_bitrates));
1925}
1926
1927static void *
1928minstrel_ht_alloc(struct ieee80211_hw *hw)
1929{
1930	struct minstrel_priv *mp;
1931	int i;
1932
1933	mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
1934	if (!mp)
1935		return NULL;
1936
1937	/* contention window settings
1938	 * Just an approximation. Using the per-queue values would complicate
1939	 * the calculations and is probably unnecessary */
1940	mp->cw_min = 15;
1941	mp->cw_max = 1023;
1942
1943	/* maximum time that the hw is allowed to stay in one MRR segment */
1944	mp->segment_size = 6000;
1945
1946	if (hw->max_rate_tries > 0)
1947		mp->max_retry = hw->max_rate_tries;
1948	else
1949		/* safe default, does not necessarily have to match hw properties */
1950		mp->max_retry = 7;
1951
1952	mp->hw = hw;
1953	mp->update_interval = HZ / 20;
1954
1955	minstrel_ht_init_cck_rates(mp);
1956	for (i = 0; i < ARRAY_SIZE(mp->hw->wiphy->bands); i++)
1957	    minstrel_ht_init_ofdm_rates(mp, i);
1958
1959	return mp;
1960}
1961
1962#ifdef CONFIG_MAC80211_DEBUGFS
1963static void minstrel_ht_add_debugfs(struct ieee80211_hw *hw, void *priv,
1964				    struct dentry *debugfsdir)
1965{
1966	struct minstrel_priv *mp = priv;
1967
1968	mp->fixed_rate_idx = (u32) -1;
1969	debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
1970			   &mp->fixed_rate_idx);
1971}
1972#endif
1973
1974static void
1975minstrel_ht_free(void *priv)
1976{
1977	kfree(priv);
1978}
1979
1980static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1981{
1982	struct minstrel_ht_sta *mi = priv_sta;
1983	int i, j, prob, tp_avg;
1984
1985	i = MI_RATE_GROUP(mi->max_tp_rate[0]);
1986	j = MI_RATE_IDX(mi->max_tp_rate[0]);
1987	prob = mi->groups[i].rates[j].prob_avg;
1988
1989	/* convert tp_avg from pkt per second in kbps */
1990	tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1991	tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1992
1993	return tp_avg;
1994}
1995
1996static const struct rate_control_ops mac80211_minstrel_ht = {
1997	.name = "minstrel_ht",
1998	.capa = RATE_CTRL_CAPA_AMPDU_TRIGGER,
1999	.tx_status_ext = minstrel_ht_tx_status,
2000	.get_rate = minstrel_ht_get_rate,
2001	.rate_init = minstrel_ht_rate_init,
2002	.rate_update = minstrel_ht_rate_update,
2003	.alloc_sta = minstrel_ht_alloc_sta,
2004	.free_sta = minstrel_ht_free_sta,
2005	.alloc = minstrel_ht_alloc,
2006	.free = minstrel_ht_free,
2007#ifdef CONFIG_MAC80211_DEBUGFS
2008	.add_debugfs = minstrel_ht_add_debugfs,
2009	.add_sta_debugfs = minstrel_ht_add_sta_debugfs,
2010#endif
2011	.get_expected_throughput = minstrel_ht_get_expected_throughput,
2012};
2013
2014
2015static void __init init_sample_table(void)
2016{
2017	int col, i, new_idx;
2018	u8 rnd[MCS_GROUP_RATES];
2019
2020	memset(sample_table, 0xff, sizeof(sample_table));
2021	for (col = 0; col < SAMPLE_COLUMNS; col++) {
2022		get_random_bytes(rnd, sizeof(rnd));
2023		for (i = 0; i < MCS_GROUP_RATES; i++) {
2024			new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
2025			while (sample_table[col][new_idx] != 0xff)
2026				new_idx = (new_idx + 1) % MCS_GROUP_RATES;
2027
2028			sample_table[col][new_idx] = i;
2029		}
2030	}
2031}
2032
2033int __init
2034rc80211_minstrel_init(void)
2035{
2036	init_sample_table();
2037	return ieee80211_rate_control_register(&mac80211_minstrel_ht);
2038}
2039
2040void
2041rc80211_minstrel_exit(void)
2042{
2043	ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
2044}