1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
   4 * Copyright (C) 2019-2020 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 <net/mac80211.h>
  14#include "rate.h"
  15#include "sta_info.h"
  16#include "rc80211_minstrel_ht.h"
  17
  18#define AVG_AMPDU_SIZE	16
  19#define AVG_PKT_SIZE	1200
  20
  21#define SAMPLE_SWITCH_THR	100
  22
  23/* Number of bits for an average sized packet */
  24#define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3)
  25
  26/* Number of symbols for a packet with (bps) bits per symbol */
  27#define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
  28
  29/* Transmission time (nanoseconds) for a packet containing (syms) symbols */
  30#define MCS_SYMBOL_TIME(sgi, syms)					\
  31	(sgi ?								\
  32	  ((syms) * 18000 + 4000) / 5 :	/* syms * 3.6 us */		\
  33	  ((syms) * 1000) << 2		/* syms * 4 us */		\
  34	)
  35
  36/* Transmit duration for the raw data part of an average sized packet */
  37#define MCS_DURATION(streams, sgi, bps) \
  38	(MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE)
  39
  40#define BW_20			0
  41#define BW_40			1
  42#define BW_80			2
  43
  44/*
  45 * Define group sort order: HT40 -> SGI -> #streams
  46 */
  47#define GROUP_IDX(_streams, _sgi, _ht40)	\
  48	MINSTREL_HT_GROUP_0 +			\
  49	MINSTREL_MAX_STREAMS * 2 * _ht40 +	\
  50	MINSTREL_MAX_STREAMS * _sgi +	\
  51	_streams - 1
  52
  53#define _MAX(a, b) (((a)>(b))?(a):(b))
  54
  55#define GROUP_SHIFT(duration)						\
  56	_MAX(0, 16 - __builtin_clz(duration))
  57
  58/* MCS rate information for an MCS group */
  59#define __MCS_GROUP(_streams, _sgi, _ht40, _s)				\
  60	[GROUP_IDX(_streams, _sgi, _ht40)] = {				\
  61	.streams = _streams,						\
  62	.shift = _s,							\
  63	.bw = _ht40,							\
  64	.flags =							\
  65		IEEE80211_TX_RC_MCS |					\
  66		(_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) |			\
  67		(_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0),		\
  68	.duration = {							\
  69		MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26) >> _s,	\
  70		MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52) >> _s,	\
  71		MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78) >> _s,	\
  72		MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104) >> _s,	\
  73		MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156) >> _s,	\
  74		MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208) >> _s,	\
  75		MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234) >> _s,	\
  76		MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) >> _s	\
  77	}								\
  78}
  79
  80#define MCS_GROUP_SHIFT(_streams, _sgi, _ht40)				\
  81	GROUP_SHIFT(MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26))
  82
  83#define MCS_GROUP(_streams, _sgi, _ht40)				\
  84	__MCS_GROUP(_streams, _sgi, _ht40,				\
  85		    MCS_GROUP_SHIFT(_streams, _sgi, _ht40))
  86
  87#define VHT_GROUP_IDX(_streams, _sgi, _bw)				\
  88	(MINSTREL_VHT_GROUP_0 +						\
  89	 MINSTREL_MAX_STREAMS * 2 * (_bw) +				\
  90	 MINSTREL_MAX_STREAMS * (_sgi) +				\
  91	 (_streams) - 1)
  92
  93#define BW2VBPS(_bw, r3, r2, r1)					\
  94	(_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
  95
  96#define __VHT_GROUP(_streams, _sgi, _bw, _s)				\
  97	[VHT_GROUP_IDX(_streams, _sgi, _bw)] = {			\
  98	.streams = _streams,						\
  99	.shift = _s,							\
 100	.bw = _bw,							\
 101	.flags =							\
 102		IEEE80211_TX_RC_VHT_MCS |				\
 103		(_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) |			\
 104		(_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH :		\
 105		 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0),	\
 106	.duration = {							\
 107		MCS_DURATION(_streams, _sgi,				\
 108			     BW2VBPS(_bw,  117,  54,  26)) >> _s,	\
 109		MCS_DURATION(_streams, _sgi,				\
 110			     BW2VBPS(_bw,  234, 108,  52)) >> _s,	\
 111		MCS_DURATION(_streams, _sgi,				\
 112			     BW2VBPS(_bw,  351, 162,  78)) >> _s,	\
 113		MCS_DURATION(_streams, _sgi,				\
 114			     BW2VBPS(_bw,  468, 216, 104)) >> _s,	\
 115		MCS_DURATION(_streams, _sgi,				\
 116			     BW2VBPS(_bw,  702, 324, 156)) >> _s,	\
 117		MCS_DURATION(_streams, _sgi,				\
 118			     BW2VBPS(_bw,  936, 432, 208)) >> _s,	\
 119		MCS_DURATION(_streams, _sgi,				\
 120			     BW2VBPS(_bw, 1053, 486, 234)) >> _s,	\
 121		MCS_DURATION(_streams, _sgi,				\
 122			     BW2VBPS(_bw, 1170, 540, 260)) >> _s,	\
 123		MCS_DURATION(_streams, _sgi,				\
 124			     BW2VBPS(_bw, 1404, 648, 312)) >> _s,	\
 125		MCS_DURATION(_streams, _sgi,				\
 126			     BW2VBPS(_bw, 1560, 720, 346)) >> _s	\
 127	}								\
 128}
 129
 130#define VHT_GROUP_SHIFT(_streams, _sgi, _bw)				\
 131	GROUP_SHIFT(MCS_DURATION(_streams, _sgi,			\
 132				 BW2VBPS(_bw,  117,  54,  26)))
 133
 134#define VHT_GROUP(_streams, _sgi, _bw)					\
 135	__VHT_GROUP(_streams, _sgi, _bw,				\
 136		    VHT_GROUP_SHIFT(_streams, _sgi, _bw))
 137
 138#define CCK_DURATION(_bitrate, _short)			\
 139	(1000 * (10 /* SIFS */ +			\
 140	 (_short ? 72 + 24 : 144 + 48) +		\
 141	 (8 * (AVG_PKT_SIZE + 4) * 10) / (_bitrate)))
 142
 143#define CCK_DURATION_LIST(_short, _s)			\
 144	CCK_DURATION(10, _short) >> _s,			\
 145	CCK_DURATION(20, _short) >> _s,			\
 146	CCK_DURATION(55, _short) >> _s,			\
 147	CCK_DURATION(110, _short) >> _s
 
 
 
 
 148
 149#define __CCK_GROUP(_s)					\
 150	[MINSTREL_CCK_GROUP] = {			\
 151		.streams = 1,				\
 152		.flags = 0,				\
 153		.shift = _s,				\
 154		.duration = {				\
 155			CCK_DURATION_LIST(false, _s),	\
 156			CCK_DURATION_LIST(true, _s)	\
 157		}					\
 158	}
 159
 160#define CCK_GROUP_SHIFT					\
 161	GROUP_SHIFT(CCK_DURATION(10, false))
 162
 163#define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT)
 164
 165#define OFDM_DURATION(_bitrate)				\
 166	(1000 * (16 /* SIFS + signal ext */ +		\
 167	 16 /* T_PREAMBLE */ +				\
 168	 4 /* T_SIGNAL */ +				\
 169	 4 * (((16 + 80 * (AVG_PKT_SIZE + 4) + 6) /	\
 170	      ((_bitrate) * 4)))))
 171
 172#define OFDM_DURATION_LIST(_s)				\
 173	OFDM_DURATION(60) >> _s,			\
 174	OFDM_DURATION(90) >> _s,			\
 175	OFDM_DURATION(120) >> _s,			\
 176	OFDM_DURATION(180) >> _s,			\
 177	OFDM_DURATION(240) >> _s,			\
 178	OFDM_DURATION(360) >> _s,			\
 179	OFDM_DURATION(480) >> _s,			\
 180	OFDM_DURATION(540) >> _s
 181
 182#define __OFDM_GROUP(_s)				\
 183	[MINSTREL_OFDM_GROUP] = {			\
 184		.streams = 1,				\
 185		.flags = 0,				\
 186		.shift = _s,				\
 187		.duration = {				\
 188			OFDM_DURATION_LIST(_s),		\
 
 189		}					\
 190	}
 191
 192#define OFDM_GROUP_SHIFT				\
 193	GROUP_SHIFT(OFDM_DURATION(60))
 194
 195#define OFDM_GROUP __OFDM_GROUP(OFDM_GROUP_SHIFT)
 196
 197
 198static bool minstrel_vht_only = true;
 199module_param(minstrel_vht_only, bool, 0644);
 200MODULE_PARM_DESC(minstrel_vht_only,
 201		 "Use only VHT rates when VHT is supported by sta.");
 
 202
 203/*
 204 * To enable sufficiently targeted rate sampling, MCS rates are divided into
 205 * groups, based on the number of streams and flags (HT40, SGI) that they
 206 * use.
 207 *
 208 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
 209 * BW -> SGI -> #streams
 210 */
 211const struct mcs_group minstrel_mcs_groups[] = {
 212	MCS_GROUP(1, 0, BW_20),
 213	MCS_GROUP(2, 0, BW_20),
 
 214	MCS_GROUP(3, 0, BW_20),
 215	MCS_GROUP(4, 0, BW_20),
 216
 217	MCS_GROUP(1, 1, BW_20),
 218	MCS_GROUP(2, 1, BW_20),
 
 219	MCS_GROUP(3, 1, BW_20),
 220	MCS_GROUP(4, 1, BW_20),
 221
 222	MCS_GROUP(1, 0, BW_40),
 223	MCS_GROUP(2, 0, BW_40),
 
 224	MCS_GROUP(3, 0, BW_40),
 225	MCS_GROUP(4, 0, BW_40),
 226
 227	MCS_GROUP(1, 1, BW_40),
 228	MCS_GROUP(2, 1, BW_40),
 
 229	MCS_GROUP(3, 1, BW_40),
 230	MCS_GROUP(4, 1, BW_40),
 231
 232	CCK_GROUP,
 233	OFDM_GROUP,
 234
 
 235	VHT_GROUP(1, 0, BW_20),
 236	VHT_GROUP(2, 0, BW_20),
 
 237	VHT_GROUP(3, 0, BW_20),
 238	VHT_GROUP(4, 0, BW_20),
 239
 240	VHT_GROUP(1, 1, BW_20),
 241	VHT_GROUP(2, 1, BW_20),
 
 242	VHT_GROUP(3, 1, BW_20),
 243	VHT_GROUP(4, 1, BW_20),
 244
 245	VHT_GROUP(1, 0, BW_40),
 246	VHT_GROUP(2, 0, BW_40),
 
 247	VHT_GROUP(3, 0, BW_40),
 248	VHT_GROUP(4, 0, BW_40),
 249
 250	VHT_GROUP(1, 1, BW_40),
 251	VHT_GROUP(2, 1, BW_40),
 
 252	VHT_GROUP(3, 1, BW_40),
 253	VHT_GROUP(4, 1, BW_40),
 254
 255	VHT_GROUP(1, 0, BW_80),
 256	VHT_GROUP(2, 0, BW_80),
 
 257	VHT_GROUP(3, 0, BW_80),
 258	VHT_GROUP(4, 0, BW_80),
 259
 260	VHT_GROUP(1, 1, BW_80),
 261	VHT_GROUP(2, 1, BW_80),
 
 262	VHT_GROUP(3, 1, BW_80),
 263	VHT_GROUP(4, 1, BW_80),
 
 264};
 265
 266const s16 minstrel_cck_bitrates[4] = { 10, 20, 55, 110 };
 267const s16 minstrel_ofdm_bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
 268static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
 269static const u8 minstrel_sample_seq[] = {
 270	MINSTREL_SAMPLE_TYPE_INC,
 271	MINSTREL_SAMPLE_TYPE_JUMP,
 272	MINSTREL_SAMPLE_TYPE_INC,
 273	MINSTREL_SAMPLE_TYPE_JUMP,
 274	MINSTREL_SAMPLE_TYPE_INC,
 275	MINSTREL_SAMPLE_TYPE_SLOW,
 276};
 277
 278static void
 279minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
 280
 281/*
 282 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
 283 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
 284 *
 285 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
 286 */
 287static u16
 288minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
 289{
 290	u16 mask = 0;
 291
 292	if (bw == BW_20) {
 293		if (nss != 3 && nss != 6)
 294			mask = BIT(9);
 295	} else if (bw == BW_80) {
 296		if (nss == 3 || nss == 7)
 297			mask = BIT(6);
 298		else if (nss == 6)
 299			mask = BIT(9);
 300	} else {
 301		WARN_ON(bw != BW_40);
 302	}
 303
 304	switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
 305	case IEEE80211_VHT_MCS_SUPPORT_0_7:
 306		mask |= 0x300;
 307		break;
 308	case IEEE80211_VHT_MCS_SUPPORT_0_8:
 309		mask |= 0x200;
 310		break;
 311	case IEEE80211_VHT_MCS_SUPPORT_0_9:
 312		break;
 313	default:
 314		mask = 0x3ff;
 315	}
 316
 317	return 0x3ff & ~mask;
 318}
 319
 320static bool
 321minstrel_ht_is_legacy_group(int group)
 322{
 323	return group == MINSTREL_CCK_GROUP ||
 324	       group == MINSTREL_OFDM_GROUP;
 325}
 326
 327/*
 328 * Look up an MCS group index based on mac80211 rate information
 329 */
 330static int
 331minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
 332{
 333	return GROUP_IDX((rate->idx / 8) + 1,
 334			 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
 335			 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
 336}
 337
 338static int
 339minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
 340{
 341	return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
 342			     !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
 343			     !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
 344			     2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
 345}
 346
 347static struct minstrel_rate_stats *
 348minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 349		      struct ieee80211_tx_rate *rate)
 350{
 351	int group, idx;
 352
 353	if (rate->flags & IEEE80211_TX_RC_MCS) {
 354		group = minstrel_ht_get_group_idx(rate);
 355		idx = rate->idx % 8;
 356		goto out;
 357	}
 358
 359	if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
 360		group = minstrel_vht_get_group_idx(rate);
 361		idx = ieee80211_rate_get_vht_mcs(rate);
 362		goto out;
 363	}
 364
 365	group = MINSTREL_CCK_GROUP;
 366	for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) {
 367		if (rate->idx != mp->cck_rates[idx])
 368			continue;
 369
 370		/* short preamble */
 371		if ((mi->supported[group] & BIT(idx + 4)) &&
 372		    (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
 373			idx += 4;
 374		goto out;
 375	}
 376
 377	group = MINSTREL_OFDM_GROUP;
 378	for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++)
 379		if (rate->idx == mp->ofdm_rates[mi->band][idx])
 380			goto out;
 381
 382	idx = 0;
 383out:
 384	return &mi->groups[group].rates[idx];
 385}
 386
 387static inline struct minstrel_rate_stats *
 388minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
 389{
 390	return &mi->groups[MI_RATE_GROUP(index)].rates[MI_RATE_IDX(index)];
 391}
 392
 393static inline int minstrel_get_duration(int index)
 394{
 395	const struct mcs_group *group = &minstrel_mcs_groups[MI_RATE_GROUP(index)];
 396	unsigned int duration = group->duration[MI_RATE_IDX(index)];
 397
 398	return duration << group->shift;
 399}
 400
 401static unsigned int
 402minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi)
 403{
 404	int duration;
 405
 406	if (mi->avg_ampdu_len)
 407		return MINSTREL_TRUNC(mi->avg_ampdu_len);
 408
 409	if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(mi->max_tp_rate[0])))
 410		return 1;
 411
 412	duration = minstrel_get_duration(mi->max_tp_rate[0]);
 413
 414	if (duration > 400 * 1000)
 415		return 2;
 416
 417	if (duration > 250 * 1000)
 418		return 4;
 419
 420	if (duration > 150 * 1000)
 421		return 8;
 422
 423	return 16;
 424}
 425
 426/*
 427 * Return current throughput based on the average A-MPDU length, taking into
 428 * account the expected number of retransmissions and their expected length
 429 */
 430int
 431minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
 432		       int prob_avg)
 433{
 434	unsigned int nsecs = 0, overhead = mi->overhead;
 435	unsigned int ampdu_len = 1;
 436
 437	/* do not account throughput if success prob is below 10% */
 438	if (prob_avg < MINSTREL_FRAC(10, 100))
 439		return 0;
 440
 441	if (minstrel_ht_is_legacy_group(group))
 442		overhead = mi->overhead_legacy;
 443	else
 444		ampdu_len = minstrel_ht_avg_ampdu_len(mi);
 445
 446	nsecs = 1000 * overhead / ampdu_len;
 447	nsecs += minstrel_mcs_groups[group].duration[rate] <<
 448		 minstrel_mcs_groups[group].shift;
 449
 450	/*
 451	 * For the throughput calculation, limit the probability value to 90% to
 452	 * account for collision related packet error rate fluctuation
 453	 * (prob is scaled - see MINSTREL_FRAC above)
 454	 */
 455	if (prob_avg > MINSTREL_FRAC(90, 100))
 456		prob_avg = MINSTREL_FRAC(90, 100);
 457
 458	return MINSTREL_TRUNC(100 * ((prob_avg * 1000000) / nsecs));
 
 459}
 460
 461/*
 462 * Find & sort topmost throughput rates
 463 *
 464 * If multiple rates provide equal throughput the sorting is based on their
 465 * current success probability. Higher success probability is preferred among
 466 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
 467 */
 468static void
 469minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
 470			       u16 *tp_list)
 471{
 472	int cur_group, cur_idx, cur_tp_avg, cur_prob;
 473	int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
 474	int j = MAX_THR_RATES;
 475
 476	cur_group = MI_RATE_GROUP(index);
 477	cur_idx = MI_RATE_IDX(index);
 478	cur_prob = mi->groups[cur_group].rates[cur_idx].prob_avg;
 479	cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
 480
 481	do {
 482		tmp_group = MI_RATE_GROUP(tp_list[j - 1]);
 483		tmp_idx = MI_RATE_IDX(tp_list[j - 1]);
 484		tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
 485		tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
 486						    tmp_prob);
 487		if (cur_tp_avg < tmp_tp_avg ||
 488		    (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
 489			break;
 490		j--;
 491	} while (j > 0);
 492
 493	if (j < MAX_THR_RATES - 1) {
 494		memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
 495		       (MAX_THR_RATES - (j + 1))));
 496	}
 497	if (j < MAX_THR_RATES)
 498		tp_list[j] = index;
 499}
 500
 501/*
 502 * Find and set the topmost probability rate per sta and per group
 503 */
 504static void
 505minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 *dest, u16 index)
 506{
 507	struct minstrel_mcs_group_data *mg;
 508	struct minstrel_rate_stats *mrs;
 509	int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
 510	int max_tp_group, max_tp_idx, max_tp_prob;
 511	int cur_tp_avg, cur_group, cur_idx;
 512	int max_gpr_group, max_gpr_idx;
 513	int max_gpr_tp_avg, max_gpr_prob;
 514
 515	cur_group = MI_RATE_GROUP(index);
 516	cur_idx = MI_RATE_IDX(index);
 517	mg = &mi->groups[cur_group];
 518	mrs = &mg->rates[cur_idx];
 519
 520	tmp_group = MI_RATE_GROUP(*dest);
 521	tmp_idx = MI_RATE_IDX(*dest);
 522	tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
 523	tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
 524
 525	/* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
 526	 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
 527	max_tp_group = MI_RATE_GROUP(mi->max_tp_rate[0]);
 528	max_tp_idx = MI_RATE_IDX(mi->max_tp_rate[0]);
 529	max_tp_prob = mi->groups[max_tp_group].rates[max_tp_idx].prob_avg;
 530
 531	if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index)) &&
 532	    !minstrel_ht_is_legacy_group(max_tp_group))
 533		return;
 534
 535	/* skip rates faster than max tp rate with lower prob */
 536	if (minstrel_get_duration(mi->max_tp_rate[0]) > minstrel_get_duration(index) &&
 537	    mrs->prob_avg < max_tp_prob)
 538		return;
 539
 540	max_gpr_group = MI_RATE_GROUP(mg->max_group_prob_rate);
 541	max_gpr_idx = MI_RATE_IDX(mg->max_group_prob_rate);
 542	max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_avg;
 543
 544	if (mrs->prob_avg > MINSTREL_FRAC(75, 100)) {
 545		cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
 546						    mrs->prob_avg);
 547		if (cur_tp_avg > tmp_tp_avg)
 548			*dest = index;
 549
 550		max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
 551							max_gpr_idx,
 552							max_gpr_prob);
 553		if (cur_tp_avg > max_gpr_tp_avg)
 554			mg->max_group_prob_rate = index;
 555	} else {
 556		if (mrs->prob_avg > tmp_prob)
 557			*dest = index;
 558		if (mrs->prob_avg > max_gpr_prob)
 559			mg->max_group_prob_rate = index;
 560	}
 561}
 562
 563
 564/*
 565 * Assign new rate set per sta and use CCK rates only if the fastest
 566 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
 567 * rate sets where MCS and CCK rates are mixed, because CCK rates can
 568 * not use aggregation.
 569 */
 570static void
 571minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
 572				 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
 573				 u16 tmp_legacy_tp_rate[MAX_THR_RATES])
 574{
 575	unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
 576	int i;
 577
 578	tmp_group = MI_RATE_GROUP(tmp_legacy_tp_rate[0]);
 579	tmp_idx = MI_RATE_IDX(tmp_legacy_tp_rate[0]);
 580	tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
 581	tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
 582
 583	tmp_group = MI_RATE_GROUP(tmp_mcs_tp_rate[0]);
 584	tmp_idx = MI_RATE_IDX(tmp_mcs_tp_rate[0]);
 585	tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
 586	tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
 587
 588	if (tmp_cck_tp > tmp_mcs_tp) {
 589		for(i = 0; i < MAX_THR_RATES; i++) {
 590			minstrel_ht_sort_best_tp_rates(mi, tmp_legacy_tp_rate[i],
 591						       tmp_mcs_tp_rate);
 592		}
 593	}
 594
 595}
 596
 597/*
 598 * Try to increase robustness of max_prob rate by decrease number of
 599 * streams if possible.
 600 */
 601static inline void
 602minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
 603{
 604	struct minstrel_mcs_group_data *mg;
 605	int tmp_max_streams, group, tmp_idx, tmp_prob;
 606	int tmp_tp = 0;
 607
 608	if (!mi->sta->ht_cap.ht_supported)
 609		return;
 610
 611	group = MI_RATE_GROUP(mi->max_tp_rate[0]);
 612	tmp_max_streams = minstrel_mcs_groups[group].streams;
 613	for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
 614		mg = &mi->groups[group];
 615		if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
 616			continue;
 617
 618		tmp_idx = MI_RATE_IDX(mg->max_group_prob_rate);
 619		tmp_prob = mi->groups[group].rates[tmp_idx].prob_avg;
 620
 621		if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
 622		   (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
 623				mi->max_prob_rate = mg->max_group_prob_rate;
 624				tmp_tp = minstrel_ht_get_tp_avg(mi, group,
 625								tmp_idx,
 626								tmp_prob);
 627		}
 628	}
 629}
 630
 631static u16
 632__minstrel_ht_get_sample_rate(struct minstrel_ht_sta *mi,
 633			      enum minstrel_sample_type type)
 634{
 635	u16 *rates = mi->sample[type].sample_rates;
 636	u16 cur;
 637	int i;
 638
 639	for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) {
 640		if (!rates[i])
 641			continue;
 642
 643		cur = rates[i];
 644		rates[i] = 0;
 645		return cur;
 646	}
 647
 648	return 0;
 649}
 650
 651static inline int
 652minstrel_ewma(int old, int new, int weight)
 653{
 654	int diff, incr;
 655
 656	diff = new - old;
 657	incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
 658
 659	return old + incr;
 660}
 661
 662static inline int minstrel_filter_avg_add(u16 *prev_1, u16 *prev_2, s32 in)
 663{
 664	s32 out_1 = *prev_1;
 665	s32 out_2 = *prev_2;
 666	s32 val;
 667
 668	if (!in)
 669		in += 1;
 670
 671	if (!out_1) {
 672		val = out_1 = in;
 673		goto out;
 674	}
 675
 676	val = MINSTREL_AVG_COEFF1 * in;
 677	val += MINSTREL_AVG_COEFF2 * out_1;
 678	val += MINSTREL_AVG_COEFF3 * out_2;
 679	val >>= MINSTREL_SCALE;
 680
 681	if (val > 1 << MINSTREL_SCALE)
 682		val = 1 << MINSTREL_SCALE;
 683	if (val < 0)
 684		val = 1;
 685
 686out:
 687	*prev_2 = out_1;
 688	*prev_1 = val;
 689
 690	return val;
 691}
 692
 693/*
 694* Recalculate statistics and counters of a given rate
 695*/
 696static void
 697minstrel_ht_calc_rate_stats(struct minstrel_priv *mp,
 698			    struct minstrel_rate_stats *mrs)
 699{
 700	unsigned int cur_prob;
 701
 702	if (unlikely(mrs->attempts > 0)) {
 703		cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts);
 704		minstrel_filter_avg_add(&mrs->prob_avg,
 705					&mrs->prob_avg_1, cur_prob);
 706		mrs->att_hist += mrs->attempts;
 707		mrs->succ_hist += mrs->success;
 708	}
 709
 710	mrs->last_success = mrs->success;
 711	mrs->last_attempts = mrs->attempts;
 712	mrs->success = 0;
 713	mrs->attempts = 0;
 714}
 715
 716static bool
 717minstrel_ht_find_sample_rate(struct minstrel_ht_sta *mi, int type, int idx)
 718{
 719	int i;
 720
 721	for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) {
 722		u16 cur = mi->sample[type].sample_rates[i];
 723
 724		if (cur == idx)
 725			return true;
 726
 727		if (!cur)
 728			break;
 729	}
 730
 731	return false;
 732}
 733
 734static int
 735minstrel_ht_move_sample_rates(struct minstrel_ht_sta *mi, int type,
 736			      u32 fast_rate_dur, u32 slow_rate_dur)
 737{
 738	u16 *rates = mi->sample[type].sample_rates;
 739	int i, j;
 740
 741	for (i = 0, j = 0; i < MINSTREL_SAMPLE_RATES; i++) {
 742		u32 duration;
 743		bool valid = false;
 744		u16 cur;
 745
 746		cur = rates[i];
 747		if (!cur)
 748			continue;
 749
 750		duration = minstrel_get_duration(cur);
 751		switch (type) {
 752		case MINSTREL_SAMPLE_TYPE_SLOW:
 753			valid = duration > fast_rate_dur &&
 754				duration < slow_rate_dur;
 755			break;
 756		case MINSTREL_SAMPLE_TYPE_INC:
 757		case MINSTREL_SAMPLE_TYPE_JUMP:
 758			valid = duration < fast_rate_dur;
 759			break;
 760		default:
 761			valid = false;
 762			break;
 763		}
 764
 765		if (!valid) {
 766			rates[i] = 0;
 767			continue;
 768		}
 769
 770		if (i == j)
 771			continue;
 772
 773		rates[j++] = cur;
 774		rates[i] = 0;
 775	}
 776
 777	return j;
 778}
 779
 780static int
 781minstrel_ht_group_min_rate_offset(struct minstrel_ht_sta *mi, int group,
 782				  u32 max_duration)
 783{
 784	u16 supported = mi->supported[group];
 785	int i;
 786
 787	for (i = 0; i < MCS_GROUP_RATES && supported; i++, supported >>= 1) {
 788		if (!(supported & BIT(0)))
 789			continue;
 790
 791		if (minstrel_get_duration(MI_RATE(group, i)) >= max_duration)
 792			continue;
 793
 794		return i;
 795	}
 796
 797	return -1;
 798}
 799
 800/*
 801 * Incremental update rates:
 802 * Flip through groups and pick the first group rate that is faster than the
 803 * highest currently selected rate
 804 */
 805static u16
 806minstrel_ht_next_inc_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur)
 807{
 808	u8 type = MINSTREL_SAMPLE_TYPE_INC;
 809	int i, index = 0;
 810	u8 group;
 811
 812	group = mi->sample[type].sample_group;
 813	for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
 814		group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups);
 815
 816		index = minstrel_ht_group_min_rate_offset(mi, group,
 817							  fast_rate_dur);
 818		if (index < 0)
 819			continue;
 820
 821		index = MI_RATE(group, index & 0xf);
 822		if (!minstrel_ht_find_sample_rate(mi, type, index))
 823			goto out;
 824	}
 825	index = 0;
 826
 827out:
 828	mi->sample[type].sample_group = group;
 829
 830	return index;
 831}
 832
 833static int
 834minstrel_ht_next_group_sample_rate(struct minstrel_ht_sta *mi, int group,
 835				   u16 supported, int offset)
 836{
 837	struct minstrel_mcs_group_data *mg = &mi->groups[group];
 838	u16 idx;
 839	int i;
 840
 841	for (i = 0; i < MCS_GROUP_RATES; i++) {
 842		idx = sample_table[mg->column][mg->index];
 843		if (++mg->index >= MCS_GROUP_RATES) {
 844			mg->index = 0;
 845			if (++mg->column >= ARRAY_SIZE(sample_table))
 846				mg->column = 0;
 847		}
 848
 849		if (idx < offset)
 850			continue;
 851
 852		if (!(supported & BIT(idx)))
 853			continue;
 854
 855		return MI_RATE(group, idx);
 856	}
 857
 858	return -1;
 859}
 860
 861/*
 862 * Jump rates:
 863 * Sample random rates, use those that are faster than the highest
 864 * currently selected rate. Rates between the fastest and the slowest
 865 * get sorted into the slow sample bucket, but only if it has room
 866 */
 867static u16
 868minstrel_ht_next_jump_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur,
 869			   u32 slow_rate_dur, int *slow_rate_ofs)
 870{
 871	struct minstrel_rate_stats *mrs;
 872	u32 max_duration = slow_rate_dur;
 873	int i, index, offset;
 874	u16 *slow_rates;
 875	u16 supported;
 876	u32 duration;
 877	u8 group;
 878
 879	if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
 880		max_duration = fast_rate_dur;
 881
 882	slow_rates = mi->sample[MINSTREL_SAMPLE_TYPE_SLOW].sample_rates;
 883	group = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group;
 884	for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
 885		u8 type;
 886
 887		group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups);
 888
 889		supported = mi->supported[group];
 890		if (!supported)
 891			continue;
 892
 893		offset = minstrel_ht_group_min_rate_offset(mi, group,
 894							   max_duration);
 895		if (offset < 0)
 896			continue;
 897
 898		index = minstrel_ht_next_group_sample_rate(mi, group, supported,
 899							   offset);
 900		if (index < 0)
 901			continue;
 902
 903		duration = minstrel_get_duration(index);
 904		if (duration < fast_rate_dur)
 905			type = MINSTREL_SAMPLE_TYPE_JUMP;
 906		else
 907			type = MINSTREL_SAMPLE_TYPE_SLOW;
 908
 909		if (minstrel_ht_find_sample_rate(mi, type, index))
 910			continue;
 911
 912		if (type == MINSTREL_SAMPLE_TYPE_JUMP)
 913			goto found;
 914
 915		if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
 916			continue;
 917
 918		if (duration >= slow_rate_dur)
 919			continue;
 920
 921		/* skip slow rates with high success probability */
 922		mrs = minstrel_get_ratestats(mi, index);
 923		if (mrs->prob_avg > MINSTREL_FRAC(95, 100))
 924			continue;
 925
 926		slow_rates[(*slow_rate_ofs)++] = index;
 927		if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
 928			max_duration = fast_rate_dur;
 929	}
 930	index = 0;
 931
 932found:
 933	mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group = group;
 934
 935	return index;
 936}
 937
 938static void
 939minstrel_ht_refill_sample_rates(struct minstrel_ht_sta *mi)
 940{
 941	u32 prob_dur = minstrel_get_duration(mi->max_prob_rate);
 942	u32 tp_dur = minstrel_get_duration(mi->max_tp_rate[0]);
 943	u32 tp2_dur = minstrel_get_duration(mi->max_tp_rate[1]);
 944	u32 fast_rate_dur = min(min(tp_dur, tp2_dur), prob_dur);
 945	u32 slow_rate_dur = max(max(tp_dur, tp2_dur), prob_dur);
 946	u16 *rates;
 947	int i, j;
 948
 949	rates = mi->sample[MINSTREL_SAMPLE_TYPE_INC].sample_rates;
 950	i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_INC,
 951					  fast_rate_dur, slow_rate_dur);
 952	while (i < MINSTREL_SAMPLE_RATES) {
 953		rates[i] = minstrel_ht_next_inc_rate(mi, tp_dur);
 954		if (!rates[i])
 955			break;
 956
 957		i++;
 958	}
 959
 960	rates = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_rates;
 961	i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_JUMP,
 962					  fast_rate_dur, slow_rate_dur);
 963	j = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_SLOW,
 964					  fast_rate_dur, slow_rate_dur);
 965	while (i < MINSTREL_SAMPLE_RATES) {
 966		rates[i] = minstrel_ht_next_jump_rate(mi, fast_rate_dur,
 967						      slow_rate_dur, &j);
 968		if (!rates[i])
 969			break;
 970
 971		i++;
 972	}
 973
 974	for (i = 0; i < ARRAY_SIZE(mi->sample); i++)
 975		memcpy(mi->sample[i].cur_sample_rates, mi->sample[i].sample_rates,
 976		       sizeof(mi->sample[i].cur_sample_rates));
 977}
 978
 979
 980/*
 981 * Update rate statistics and select new primary rates
 982 *
 983 * Rules for rate selection:
 984 *  - max_prob_rate must use only one stream, as a tradeoff between delivery
 985 *    probability and throughput during strong fluctuations
 986 *  - as long as the max prob rate has a probability of more than 75%, pick
 987 *    higher throughput rates, even if the probablity is a bit lower
 988 */
 989static void
 990minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
 991{
 992	struct minstrel_mcs_group_data *mg;
 993	struct minstrel_rate_stats *mrs;
 994	int group, i, j, cur_prob;
 995	u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
 996	u16 tmp_legacy_tp_rate[MAX_THR_RATES], tmp_max_prob_rate;
 997	u16 index;
 998	bool ht_supported = mi->sta->ht_cap.ht_supported;
 999
1000	if (mi->ampdu_packets > 0) {
1001		if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN))
1002			mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
1003				MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets),
1004					      EWMA_LEVEL);
1005		else
1006			mi->avg_ampdu_len = 0;
1007		mi->ampdu_len = 0;
1008		mi->ampdu_packets = 0;
1009	}
1010
1011	if (mi->supported[MINSTREL_CCK_GROUP])
1012		group = MINSTREL_CCK_GROUP;
1013	else if (mi->supported[MINSTREL_OFDM_GROUP])
1014		group = MINSTREL_OFDM_GROUP;
1015	else
1016		group = 0;
1017
1018	index = MI_RATE(group, 0);
1019	for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++)
1020		tmp_legacy_tp_rate[j] = index;
1021
1022	if (mi->supported[MINSTREL_VHT_GROUP_0])
1023		group = MINSTREL_VHT_GROUP_0;
1024	else if (ht_supported)
1025		group = MINSTREL_HT_GROUP_0;
1026	else if (mi->supported[MINSTREL_CCK_GROUP])
1027		group = MINSTREL_CCK_GROUP;
1028	else
1029		group = MINSTREL_OFDM_GROUP;
1030
1031	index = MI_RATE(group, 0);
1032	tmp_max_prob_rate = index;
1033	for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++)
1034		tmp_mcs_tp_rate[j] = index;
 
1035
1036	/* Find best rate sets within all MCS groups*/
1037	for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
1038		u16 *tp_rate = tmp_mcs_tp_rate;
1039		u16 last_prob = 0;
1040
1041		mg = &mi->groups[group];
1042		if (!mi->supported[group])
1043			continue;
1044
 
 
1045		/* (re)Initialize group rate indexes */
1046		for(j = 0; j < MAX_THR_RATES; j++)
1047			tmp_group_tp_rate[j] = MI_RATE(group, 0);
1048
1049		if (group == MINSTREL_CCK_GROUP && ht_supported)
1050			tp_rate = tmp_legacy_tp_rate;
1051
1052		for (i = MCS_GROUP_RATES - 1; i >= 0; i--) {
1053			if (!(mi->supported[group] & BIT(i)))
1054				continue;
1055
1056			index = MI_RATE(group, i);
1057
1058			mrs = &mg->rates[i];
1059			mrs->retry_updated = false;
1060			minstrel_ht_calc_rate_stats(mp, mrs);
1061
1062			if (mrs->att_hist)
1063				last_prob = max(last_prob, mrs->prob_avg);
1064			else
1065				mrs->prob_avg = max(last_prob, mrs->prob_avg);
1066			cur_prob = mrs->prob_avg;
1067
1068			if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
1069				continue;
1070
1071			/* Find max throughput rate set */
1072			minstrel_ht_sort_best_tp_rates(mi, index, tp_rate);
 
 
 
 
 
 
1073
1074			/* Find max throughput rate set within a group */
1075			minstrel_ht_sort_best_tp_rates(mi, index,
1076						       tmp_group_tp_rate);
 
 
 
1077		}
1078
1079		memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
1080		       sizeof(mg->max_group_tp_rate));
1081	}
1082
1083	/* Assign new rate set per sta */
1084	minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate,
1085					 tmp_legacy_tp_rate);
1086	memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
1087
1088	for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
1089		if (!mi->supported[group])
1090			continue;
1091
1092		mg = &mi->groups[group];
1093		mg->max_group_prob_rate = MI_RATE(group, 0);
1094
1095		for (i = 0; i < MCS_GROUP_RATES; i++) {
1096			if (!(mi->supported[group] & BIT(i)))
1097				continue;
1098
1099			index = MI_RATE(group, i);
1100
1101			/* Find max probability rate per group and global */
1102			minstrel_ht_set_best_prob_rate(mi, &tmp_max_prob_rate,
1103						       index);
1104		}
1105	}
1106
1107	mi->max_prob_rate = tmp_max_prob_rate;
1108
1109	/* Try to increase robustness of max_prob_rate*/
1110	minstrel_ht_prob_rate_reduce_streams(mi);
1111	minstrel_ht_refill_sample_rates(mi);
 
 
1112
1113#ifdef CONFIG_MAC80211_DEBUGFS
1114	/* use fixed index if set */
1115	if (mp->fixed_rate_idx != -1) {
1116		for (i = 0; i < 4; i++)
1117			mi->max_tp_rate[i] = mp->fixed_rate_idx;
1118		mi->max_prob_rate = mp->fixed_rate_idx;
1119	}
1120#endif
1121
1122	/* Reset update timer */
1123	mi->last_stats_update = jiffies;
1124	mi->sample_time = jiffies;
1125}
1126
1127static bool
1128minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1129			 struct ieee80211_tx_rate *rate)
1130{
1131	int i;
1132
1133	if (rate->idx < 0)
1134		return false;
1135
1136	if (!rate->count)
1137		return false;
1138
1139	if (rate->flags & IEEE80211_TX_RC_MCS ||
1140	    rate->flags & IEEE80211_TX_RC_VHT_MCS)
1141		return true;
1142
1143	for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++)
1144		if (rate->idx == mp->cck_rates[i])
1145			return true;
1146
1147	for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++)
1148		if (rate->idx == mp->ofdm_rates[mi->band][i])
1149			return true;
 
 
 
 
 
 
 
 
 
 
 
1150
1151	return false;
 
 
 
 
 
 
1152}
1153
1154static void
1155minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
1156{
1157	int group, orig_group;
1158
1159	orig_group = group = MI_RATE_GROUP(*idx);
1160	while (group > 0) {
1161		group--;
1162
1163		if (!mi->supported[group])
1164			continue;
1165
1166		if (minstrel_mcs_groups[group].streams >
1167		    minstrel_mcs_groups[orig_group].streams)
1168			continue;
1169
1170		if (primary)
1171			*idx = mi->groups[group].max_group_tp_rate[0];
1172		else
1173			*idx = mi->groups[group].max_group_tp_rate[1];
1174		break;
1175	}
1176}
1177
1178static void
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1179minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
1180                      void *priv_sta, struct ieee80211_tx_status *st)
 
1181{
1182	struct ieee80211_tx_info *info = st->info;
1183	struct minstrel_ht_sta *mi = priv_sta;
1184	struct ieee80211_tx_rate *ar = info->status.rates;
1185	struct minstrel_rate_stats *rate, *rate2;
1186	struct minstrel_priv *mp = priv;
1187	u32 update_interval = mp->update_interval;
1188	bool last, update = false;
1189	int i;
1190
1191	/* Ignore packet that was sent with noAck flag */
1192	if (info->flags & IEEE80211_TX_CTL_NO_ACK)
1193		return;
1194
1195	/* This packet was aggregated but doesn't carry status info */
1196	if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
1197	    !(info->flags & IEEE80211_TX_STAT_AMPDU))
1198		return;
1199
1200	if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
1201		info->status.ampdu_ack_len =
1202			(info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
1203		info->status.ampdu_len = 1;
1204	}
1205
1206	/* wraparound */
1207	if (mi->total_packets >= ~0 - info->status.ampdu_len) {
1208		mi->total_packets = 0;
1209		mi->sample_packets = 0;
 
 
 
1210	}
1211
1212	mi->total_packets += info->status.ampdu_len;
1213	if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
1214		mi->sample_packets += info->status.ampdu_len;
1215
1216	mi->ampdu_packets++;
1217	mi->ampdu_len += info->status.ampdu_len;
1218
1219	last = !minstrel_ht_txstat_valid(mp, mi, &ar[0]);
1220	for (i = 0; !last; i++) {
1221		last = (i == IEEE80211_TX_MAX_RATES - 1) ||
1222		       !minstrel_ht_txstat_valid(mp, mi, &ar[i + 1]);
1223
1224		rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
 
1225		if (last)
1226			rate->success += info->status.ampdu_ack_len;
1227
1228		rate->attempts += ar[i].count * info->status.ampdu_len;
1229	}
1230
1231	if (mp->hw->max_rates > 1) {
1232		/*
1233		 * check for sudden death of spatial multiplexing,
1234		 * downgrade to a lower number of streams if necessary.
1235		 */
1236		rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
1237		if (rate->attempts > 30 &&
1238		    rate->success < rate->attempts / 4) {
1239			minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
1240			update = true;
1241		}
1242
1243		rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
1244		if (rate2->attempts > 30 &&
1245		    rate2->success < rate2->attempts / 4) {
1246			minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
1247			update = true;
1248		}
1249	}
1250
1251	if (time_after(jiffies, mi->last_stats_update + update_interval)) {
 
1252		update = true;
1253		minstrel_ht_update_stats(mp, mi);
1254	}
1255
1256	if (update)
1257		minstrel_ht_update_rates(mp, mi);
1258}
1259
1260static void
1261minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1262                         int index)
1263{
1264	struct minstrel_rate_stats *mrs;
 
1265	unsigned int tx_time, tx_time_rtscts, tx_time_data;
1266	unsigned int cw = mp->cw_min;
1267	unsigned int ctime = 0;
1268	unsigned int t_slot = 9; /* FIXME */
1269	unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi);
1270	unsigned int overhead = 0, overhead_rtscts = 0;
1271
1272	mrs = minstrel_get_ratestats(mi, index);
1273	if (mrs->prob_avg < MINSTREL_FRAC(1, 10)) {
1274		mrs->retry_count = 1;
1275		mrs->retry_count_rtscts = 1;
1276		return;
1277	}
1278
1279	mrs->retry_count = 2;
1280	mrs->retry_count_rtscts = 2;
1281	mrs->retry_updated = true;
1282
1283	tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;
 
1284
1285	/* Contention time for first 2 tries */
1286	ctime = (t_slot * cw) >> 1;
1287	cw = min((cw << 1) | 1, mp->cw_max);
1288	ctime += (t_slot * cw) >> 1;
1289	cw = min((cw << 1) | 1, mp->cw_max);
1290
1291	if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index))) {
1292		overhead = mi->overhead_legacy;
1293		overhead_rtscts = mi->overhead_legacy_rtscts;
1294	} else {
1295		overhead = mi->overhead;
1296		overhead_rtscts = mi->overhead_rtscts;
1297	}
1298
1299	/* Total TX time for data and Contention after first 2 tries */
1300	tx_time = ctime + 2 * (overhead + tx_time_data);
1301	tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
1302
1303	/* See how many more tries we can fit inside segment size */
1304	do {
1305		/* Contention time for this try */
1306		ctime = (t_slot * cw) >> 1;
1307		cw = min((cw << 1) | 1, mp->cw_max);
1308
1309		/* Total TX time after this try */
1310		tx_time += ctime + overhead + tx_time_data;
1311		tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
1312
1313		if (tx_time_rtscts < mp->segment_size)
1314			mrs->retry_count_rtscts++;
1315	} while ((tx_time < mp->segment_size) &&
1316	         (++mrs->retry_count < mp->max_retry));
1317}
1318
1319
1320static void
1321minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1322                     struct ieee80211_sta_rates *ratetbl, int offset, int index)
1323{
1324	int group_idx = MI_RATE_GROUP(index);
1325	const struct mcs_group *group = &minstrel_mcs_groups[group_idx];
1326	struct minstrel_rate_stats *mrs;
1327	u8 idx;
1328	u16 flags = group->flags;
1329
1330	mrs = minstrel_get_ratestats(mi, index);
1331	if (!mrs->retry_updated)
1332		minstrel_calc_retransmit(mp, mi, index);
1333
1334	if (mrs->prob_avg < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
1335		ratetbl->rate[offset].count = 2;
1336		ratetbl->rate[offset].count_rts = 2;
1337		ratetbl->rate[offset].count_cts = 2;
1338	} else {
1339		ratetbl->rate[offset].count = mrs->retry_count;
1340		ratetbl->rate[offset].count_cts = mrs->retry_count;
1341		ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
1342	}
1343
1344	index = MI_RATE_IDX(index);
1345	if (group_idx == MINSTREL_CCK_GROUP)
1346		idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
1347	else if (group_idx == MINSTREL_OFDM_GROUP)
1348		idx = mp->ofdm_rates[mi->band][index %
1349					       ARRAY_SIZE(mp->ofdm_rates[0])];
1350	else if (flags & IEEE80211_TX_RC_VHT_MCS)
1351		idx = ((group->streams - 1) << 4) |
1352		      (index & 0xF);
1353	else
1354		idx = index + (group->streams - 1) * 8;
1355
1356	/* enable RTS/CTS if needed:
1357	 *  - if station is in dynamic SMPS (and streams > 1)
1358	 *  - for fallback rates, to increase chances of getting through
1359	 */
1360	if (offset > 0 ||
1361	    (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC &&
1362	     group->streams > 1)) {
1363		ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
1364		flags |= IEEE80211_TX_RC_USE_RTS_CTS;
1365	}
1366
1367	ratetbl->rate[offset].idx = idx;
1368	ratetbl->rate[offset].flags = flags;
1369}
1370
1371static inline int
1372minstrel_ht_get_prob_avg(struct minstrel_ht_sta *mi, int rate)
1373{
1374	int group = MI_RATE_GROUP(rate);
1375	rate = MI_RATE_IDX(rate);
1376	return mi->groups[group].rates[rate].prob_avg;
1377}
1378
1379static int
1380minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
1381{
1382	int group = MI_RATE_GROUP(mi->max_prob_rate);
1383	const struct mcs_group *g = &minstrel_mcs_groups[group];
1384	int rate = MI_RATE_IDX(mi->max_prob_rate);
1385	unsigned int duration;
1386
1387	/* Disable A-MSDU if max_prob_rate is bad */
1388	if (mi->groups[group].rates[rate].prob_avg < MINSTREL_FRAC(50, 100))
1389		return 1;
1390
1391	duration = g->duration[rate];
1392	duration <<= g->shift;
1393
1394	/* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
1395	if (duration > MCS_DURATION(1, 0, 52))
1396		return 500;
1397
1398	/*
1399	 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
1400	 * data packet size
1401	 */
1402	if (duration > MCS_DURATION(1, 0, 104))
1403		return 1600;
1404
1405	/*
1406	 * If the rate is slower than single-stream MCS7, or if the max throughput
1407	 * rate success probability is less than 75%, limit A-MSDU to twice the usual
1408	 * data packet size
1409	 */
1410	if (duration > MCS_DURATION(1, 0, 260) ||
1411	    (minstrel_ht_get_prob_avg(mi, mi->max_tp_rate[0]) <
1412	     MINSTREL_FRAC(75, 100)))
1413		return 3200;
1414
1415	/*
1416	 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
1417	 * Since aggregation sessions are started/stopped without txq flush, use
1418	 * the limit here to avoid the complexity of having to de-aggregate
1419	 * packets in the queue.
1420	 */
1421	if (!mi->sta->vht_cap.vht_supported)
1422		return IEEE80211_MAX_MPDU_LEN_HT_BA;
1423
1424	/* unlimited */
1425	return 0;
1426}
1427
1428static void
1429minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1430{
1431	struct ieee80211_sta_rates *rates;
1432	int i = 0;
1433
1434	rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
1435	if (!rates)
1436		return;
1437
1438	/* Start with max_tp_rate[0] */
1439	minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
1440
1441	if (mp->hw->max_rates >= 3) {
1442		/* At least 3 tx rates supported, use max_tp_rate[1] next */
1443		minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
1444	}
1445
1446	if (mp->hw->max_rates >= 2) {
 
 
1447		minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
1448	}
1449
1450	mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
1451	rates->rate[i].idx = -1;
1452	rate_control_set_rates(mp->hw, mi->sta, rates);
1453}
1454
1455static u16
1456minstrel_ht_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1457{
1458	u8 seq;
 
 
1459
1460	if (mp->hw->max_rates > 1) {
1461		seq = mi->sample_seq;
1462		mi->sample_seq = (seq + 1) % ARRAY_SIZE(minstrel_sample_seq);
1463		seq = minstrel_sample_seq[seq];
1464	} else {
1465		seq = MINSTREL_SAMPLE_TYPE_INC;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1466	}
 
1467
1468	return __minstrel_ht_get_sample_rate(mi, seq);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1469}
1470
1471static void
1472minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1473                     struct ieee80211_tx_rate_control *txrc)
1474{
1475	const struct mcs_group *sample_group;
1476	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1477	struct ieee80211_tx_rate *rate = &info->status.rates[0];
1478	struct minstrel_ht_sta *mi = priv_sta;
 
1479	struct minstrel_priv *mp = priv;
1480	u16 sample_idx;
 
 
 
 
 
 
 
 
 
 
1481
1482	info->flags |= mi->tx_flags;
 
1483
1484#ifdef CONFIG_MAC80211_DEBUGFS
1485	if (mp->fixed_rate_idx != -1)
1486		return;
1487#endif
1488
1489	/* Don't use EAPOL frames for sampling on non-mrr hw */
1490	if (mp->hw->max_rates == 1 &&
1491	    (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1492		return;
1493
1494	if (time_is_after_jiffies(mi->sample_time))
1495		return;
1496
1497	mi->sample_time = jiffies + MINSTREL_SAMPLE_INTERVAL;
1498	sample_idx = minstrel_ht_get_sample_rate(mp, mi);
1499	if (!sample_idx)
1500		return;
1501
1502	sample_group = &minstrel_mcs_groups[MI_RATE_GROUP(sample_idx)];
1503	sample_idx = MI_RATE_IDX(sample_idx);
 
 
 
1504
1505	if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
1506	    (sample_idx >= 4) != txrc->short_preamble)
1507		return;
1508
 
1509	info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1510	rate->count = 1;
1511
1512	if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
1513		int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1514		rate->idx = mp->cck_rates[idx];
1515	} else if (sample_group == &minstrel_mcs_groups[MINSTREL_OFDM_GROUP]) {
1516		int idx = sample_idx % ARRAY_SIZE(mp->ofdm_rates[0]);
1517		rate->idx = mp->ofdm_rates[mi->band][idx];
1518	} else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1519		ieee80211_rate_set_vht(rate, MI_RATE_IDX(sample_idx),
1520				       sample_group->streams);
1521	} else {
1522		rate->idx = sample_idx + (sample_group->streams - 1) * 8;
 
1523	}
1524
1525	rate->flags = sample_group->flags;
1526}
1527
1528static void
1529minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1530		       struct ieee80211_supported_band *sband,
1531		       struct ieee80211_sta *sta)
1532{
1533	int i;
1534
1535	if (sband->band != NL80211_BAND_2GHZ)
1536		return;
1537
1538	if (sta->ht_cap.ht_supported &&
1539	    !ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1540		return;
1541
 
 
1542	for (i = 0; i < 4; i++) {
1543		if (mp->cck_rates[i] == 0xff ||
1544		    !rate_supported(sta, sband->band, mp->cck_rates[i]))
1545			continue;
1546
1547		mi->supported[MINSTREL_CCK_GROUP] |= BIT(i);
1548		if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1549			mi->supported[MINSTREL_CCK_GROUP] |= BIT(i + 4);
1550	}
1551}
1552
1553static void
1554minstrel_ht_update_ofdm(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1555			struct ieee80211_supported_band *sband,
1556			struct ieee80211_sta *sta)
1557{
1558	const u8 *rates;
1559	int i;
1560
1561	if (sta->ht_cap.ht_supported)
1562		return;
1563
1564	rates = mp->ofdm_rates[sband->band];
1565	for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++) {
1566		if (rates[i] == 0xff ||
1567		    !rate_supported(sta, sband->band, rates[i]))
1568			continue;
1569
1570		mi->supported[MINSTREL_OFDM_GROUP] |= BIT(i);
1571	}
1572}
1573
1574static void
1575minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1576			struct cfg80211_chan_def *chandef,
1577			struct ieee80211_sta *sta, void *priv_sta)
1578{
1579	struct minstrel_priv *mp = priv;
1580	struct minstrel_ht_sta *mi = priv_sta;
 
1581	struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1582	u16 ht_cap = sta->ht_cap.cap;
1583	struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1584	const struct ieee80211_rate *ctl_rate;
1585	bool ldpc, erp;
1586	int use_vht;
1587	int n_supported = 0;
1588	int ack_dur;
1589	int stbc;
1590	int i;
1591
 
 
 
 
1592	BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1593
 
1594	if (vht_cap->vht_supported)
1595		use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1596	else
1597		use_vht = 0;
 
1598
 
1599	memset(mi, 0, sizeof(*mi));
1600
1601	mi->sta = sta;
1602	mi->band = sband->band;
1603	mi->last_stats_update = jiffies;
1604
1605	ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1606	mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1607	mi->overhead += ack_dur;
1608	mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1609
1610	ctl_rate = &sband->bitrates[rate_lowest_index(sband, sta)];
1611	erp = ctl_rate->flags & IEEE80211_RATE_ERP_G;
1612	ack_dur = ieee80211_frame_duration(sband->band, 10,
1613					   ctl_rate->bitrate, erp, 1,
1614					   ieee80211_chandef_get_shift(chandef));
1615	mi->overhead_legacy = ack_dur;
1616	mi->overhead_legacy_rtscts = mi->overhead_legacy + 2 * ack_dur;
1617
1618	mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1619
 
 
 
 
 
 
 
 
 
 
 
1620	if (!use_vht) {
1621		stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
1622			IEEE80211_HT_CAP_RX_STBC_SHIFT;
 
1623
1624		ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING;
1625	} else {
1626		stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >>
1627			IEEE80211_VHT_CAP_RXSTBC_SHIFT;
1628
1629		ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC;
1630	}
1631
1632	mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1633	if (ldpc)
1634		mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1635
1636	for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1637		u32 gflags = minstrel_mcs_groups[i].flags;
1638		int bw, nss;
1639
1640		mi->supported[i] = 0;
1641		if (minstrel_ht_is_legacy_group(i))
 
1642			continue;
 
1643
1644		if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1645			if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1646				if (!(ht_cap & IEEE80211_HT_CAP_SGI_40))
1647					continue;
1648			} else {
1649				if (!(ht_cap & IEEE80211_HT_CAP_SGI_20))
1650					continue;
1651			}
1652		}
1653
1654		if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1655		    sta->bandwidth < IEEE80211_STA_RX_BW_40)
1656			continue;
1657
1658		nss = minstrel_mcs_groups[i].streams;
1659
1660		/* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1661		if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1662			continue;
1663
1664		/* HT rate */
1665		if (gflags & IEEE80211_TX_RC_MCS) {
 
1666			if (use_vht && minstrel_vht_only)
1667				continue;
1668
1669			mi->supported[i] = mcs->rx_mask[nss - 1];
1670			if (mi->supported[i])
1671				n_supported++;
1672			continue;
1673		}
1674
1675		/* VHT rate */
1676		if (!vht_cap->vht_supported ||
1677		    WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1678		    WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1679			continue;
1680
1681		if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1682			if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1683			    ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1684			     !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1685				continue;
1686			}
1687		}
1688
1689		if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1690			bw = BW_40;
1691		else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1692			bw = BW_80;
1693		else
1694			bw = BW_20;
1695
1696		mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1697				vht_cap->vht_mcs.tx_mcs_map);
1698
1699		if (mi->supported[i])
1700			n_supported++;
1701	}
1702
1703	minstrel_ht_update_cck(mp, mi, sband, sta);
1704	minstrel_ht_update_ofdm(mp, mi, sband, sta);
1705
1706	/* create an initial rate table with the lowest supported rates */
1707	minstrel_ht_update_stats(mp, mi);
1708	minstrel_ht_update_rates(mp, mi);
 
 
 
 
 
 
 
 
 
 
1709}
1710
1711static void
1712minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1713		      struct cfg80211_chan_def *chandef,
1714                      struct ieee80211_sta *sta, void *priv_sta)
1715{
1716	minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1717}
1718
1719static void
1720minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1721			struct cfg80211_chan_def *chandef,
1722                        struct ieee80211_sta *sta, void *priv_sta,
1723                        u32 changed)
1724{
1725	minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1726}
1727
1728static void *
1729minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1730{
1731	struct ieee80211_supported_band *sband;
1732	struct minstrel_ht_sta *mi;
1733	struct minstrel_priv *mp = priv;
1734	struct ieee80211_hw *hw = mp->hw;
1735	int max_rates = 0;
1736	int i;
1737
1738	for (i = 0; i < NUM_NL80211_BANDS; i++) {
1739		sband = hw->wiphy->bands[i];
1740		if (sband && sband->n_bitrates > max_rates)
1741			max_rates = sband->n_bitrates;
1742	}
1743
1744	return kzalloc(sizeof(*mi), gfp);
1745}
1746
1747static void
1748minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1749{
1750	kfree(priv_sta);
1751}
1752
1753static void
1754minstrel_ht_fill_rate_array(u8 *dest, struct ieee80211_supported_band *sband,
1755			    const s16 *bitrates, int n_rates, u32 rate_flags)
1756{
1757	int i, j;
1758
1759	for (i = 0; i < sband->n_bitrates; i++) {
1760		struct ieee80211_rate *rate = &sband->bitrates[i];
1761
1762		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1763			continue;
1764
1765		for (j = 0; j < n_rates; j++) {
1766			if (rate->bitrate != bitrates[j])
1767				continue;
1768
1769			dest[j] = i;
1770			break;
1771		}
1772	}
1773}
1774
1775static void
1776minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
1777{
1778	static const s16 bitrates[4] = { 10, 20, 55, 110 };
1779	struct ieee80211_supported_band *sband;
1780	u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1781
1782	memset(mp->cck_rates, 0xff, sizeof(mp->cck_rates));
1783	sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
1784	if (!sband)
1785		return;
1786
1787	BUILD_BUG_ON(ARRAY_SIZE(mp->cck_rates) != ARRAY_SIZE(bitrates));
1788	minstrel_ht_fill_rate_array(mp->cck_rates, sband,
1789				    minstrel_cck_bitrates,
1790				    ARRAY_SIZE(minstrel_cck_bitrates),
1791				    rate_flags);
 
 
 
 
 
 
 
 
 
 
1792}
1793
1794static void
1795minstrel_ht_init_ofdm_rates(struct minstrel_priv *mp, enum nl80211_band band)
1796{
1797	static const s16 bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
1798	struct ieee80211_supported_band *sband;
1799	u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1800
1801	memset(mp->ofdm_rates[band], 0xff, sizeof(mp->ofdm_rates[band]));
1802	sband = mp->hw->wiphy->bands[band];
1803	if (!sband)
1804		return;
1805
1806	BUILD_BUG_ON(ARRAY_SIZE(mp->ofdm_rates[band]) != ARRAY_SIZE(bitrates));
1807	minstrel_ht_fill_rate_array(mp->ofdm_rates[band], sband,
1808				    minstrel_ofdm_bitrates,
1809				    ARRAY_SIZE(minstrel_ofdm_bitrates),
1810				    rate_flags);
1811}
1812
1813static void *
1814minstrel_ht_alloc(struct ieee80211_hw *hw)
1815{
1816	struct minstrel_priv *mp;
1817	int i;
1818
1819	mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
1820	if (!mp)
1821		return NULL;
1822
1823	/* contention window settings
1824	 * Just an approximation. Using the per-queue values would complicate
1825	 * the calculations and is probably unnecessary */
1826	mp->cw_min = 15;
1827	mp->cw_max = 1023;
1828
1829	/* maximum time that the hw is allowed to stay in one MRR segment */
1830	mp->segment_size = 6000;
1831
1832	if (hw->max_rate_tries > 0)
1833		mp->max_retry = hw->max_rate_tries;
1834	else
1835		/* safe default, does not necessarily have to match hw properties */
1836		mp->max_retry = 7;
1837
1838	if (hw->max_rates >= 4)
1839		mp->has_mrr = true;
1840
1841	mp->hw = hw;
1842	mp->update_interval = HZ / 20;
1843
1844	minstrel_ht_init_cck_rates(mp);
1845	for (i = 0; i < ARRAY_SIZE(mp->hw->wiphy->bands); i++)
1846	    minstrel_ht_init_ofdm_rates(mp, i);
1847
1848	return mp;
1849}
1850
1851#ifdef CONFIG_MAC80211_DEBUGFS
1852static void minstrel_ht_add_debugfs(struct ieee80211_hw *hw, void *priv,
1853				    struct dentry *debugfsdir)
1854{
1855	struct minstrel_priv *mp = priv;
1856
1857	mp->fixed_rate_idx = (u32) -1;
1858	debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
1859			   &mp->fixed_rate_idx);
1860}
1861#endif
1862
1863static void
1864minstrel_ht_free(void *priv)
1865{
1866	kfree(priv);
1867}
1868
1869static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1870{
1871	struct minstrel_ht_sta *mi = priv_sta;
 
1872	int i, j, prob, tp_avg;
1873
1874	i = MI_RATE_GROUP(mi->max_tp_rate[0]);
1875	j = MI_RATE_IDX(mi->max_tp_rate[0]);
1876	prob = mi->groups[i].rates[j].prob_avg;
 
 
 
1877
1878	/* convert tp_avg from pkt per second in kbps */
1879	tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1880	tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1881
1882	return tp_avg;
1883}
1884
1885static const struct rate_control_ops mac80211_minstrel_ht = {
1886	.name = "minstrel_ht",
1887	.capa = RATE_CTRL_CAPA_AMPDU_TRIGGER,
1888	.tx_status_ext = minstrel_ht_tx_status,
1889	.get_rate = minstrel_ht_get_rate,
1890	.rate_init = minstrel_ht_rate_init,
1891	.rate_update = minstrel_ht_rate_update,
1892	.alloc_sta = minstrel_ht_alloc_sta,
1893	.free_sta = minstrel_ht_free_sta,
1894	.alloc = minstrel_ht_alloc,
1895	.free = minstrel_ht_free,
1896#ifdef CONFIG_MAC80211_DEBUGFS
1897	.add_debugfs = minstrel_ht_add_debugfs,
1898	.add_sta_debugfs = minstrel_ht_add_sta_debugfs,
 
1899#endif
1900	.get_expected_throughput = minstrel_ht_get_expected_throughput,
1901};
1902
1903
1904static void __init init_sample_table(void)
1905{
1906	int col, i, new_idx;
1907	u8 rnd[MCS_GROUP_RATES];
1908
1909	memset(sample_table, 0xff, sizeof(sample_table));
1910	for (col = 0; col < SAMPLE_COLUMNS; col++) {
1911		prandom_bytes(rnd, sizeof(rnd));
1912		for (i = 0; i < MCS_GROUP_RATES; i++) {
1913			new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1914			while (sample_table[col][new_idx] != 0xff)
1915				new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1916
1917			sample_table[col][new_idx] = i;
1918		}
1919	}
1920}
1921
1922int __init
1923rc80211_minstrel_init(void)
1924{
1925	init_sample_table();
1926	return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1927}
1928
1929void
1930rc80211_minstrel_exit(void)
1931{
1932	ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1933}