| 1 | /* |
| 2 | * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | */ |
| 8 | #include <linux/netdevice.h> |
| 9 | #include <linux/types.h> |
| 10 | #include <linux/skbuff.h> |
| 11 | #include <linux/debugfs.h> |
| 12 | #include <linux/random.h> |
| 13 | #include <linux/moduleparam.h> |
| 14 | #include <linux/ieee80211.h> |
| 15 | #include <net/mac80211.h> |
| 16 | #include "rate.h" |
| 17 | #include "rc80211_minstrel.h" |
| 18 | #include "rc80211_minstrel_ht.h" |
| 19 | |
| 20 | #define AVG_AMPDU_SIZE 16 |
| 21 | #define AVG_PKT_SIZE 1200 |
| 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 | /* MCS rate information for an MCS group */ |
| 54 | #define MCS_GROUP(_streams, _sgi, _ht40) \ |
| 55 | [GROUP_IDX(_streams, _sgi, _ht40)] = { \ |
| 56 | .streams = _streams, \ |
| 57 | .flags = \ |
| 58 | IEEE80211_TX_RC_MCS | \ |
| 59 | (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ |
| 60 | (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ |
| 61 | .duration = { \ |
| 62 | MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \ |
| 63 | MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \ |
| 64 | MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \ |
| 65 | MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \ |
| 66 | MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \ |
| 67 | MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \ |
| 68 | MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \ |
| 69 | MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \ |
| 70 | } \ |
| 71 | } |
| 72 | |
| 73 | #define VHT_GROUP_IDX(_streams, _sgi, _bw) \ |
| 74 | (MINSTREL_VHT_GROUP_0 + \ |
| 75 | MINSTREL_MAX_STREAMS * 2 * (_bw) + \ |
| 76 | MINSTREL_MAX_STREAMS * (_sgi) + \ |
| 77 | (_streams) - 1) |
| 78 | |
| 79 | #define BW2VBPS(_bw, r3, r2, r1) \ |
| 80 | (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1) |
| 81 | |
| 82 | #define VHT_GROUP(_streams, _sgi, _bw) \ |
| 83 | [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \ |
| 84 | .streams = _streams, \ |
| 85 | .flags = \ |
| 86 | IEEE80211_TX_RC_VHT_MCS | \ |
| 87 | (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ |
| 88 | (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \ |
| 89 | _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ |
| 90 | .duration = { \ |
| 91 | MCS_DURATION(_streams, _sgi, \ |
| 92 | BW2VBPS(_bw, 117, 54, 26)), \ |
| 93 | MCS_DURATION(_streams, _sgi, \ |
| 94 | BW2VBPS(_bw, 234, 108, 52)), \ |
| 95 | MCS_DURATION(_streams, _sgi, \ |
| 96 | BW2VBPS(_bw, 351, 162, 78)), \ |
| 97 | MCS_DURATION(_streams, _sgi, \ |
| 98 | BW2VBPS(_bw, 468, 216, 104)), \ |
| 99 | MCS_DURATION(_streams, _sgi, \ |
| 100 | BW2VBPS(_bw, 702, 324, 156)), \ |
| 101 | MCS_DURATION(_streams, _sgi, \ |
| 102 | BW2VBPS(_bw, 936, 432, 208)), \ |
| 103 | MCS_DURATION(_streams, _sgi, \ |
| 104 | BW2VBPS(_bw, 1053, 486, 234)), \ |
| 105 | MCS_DURATION(_streams, _sgi, \ |
| 106 | BW2VBPS(_bw, 1170, 540, 260)), \ |
| 107 | MCS_DURATION(_streams, _sgi, \ |
| 108 | BW2VBPS(_bw, 1404, 648, 312)), \ |
| 109 | MCS_DURATION(_streams, _sgi, \ |
| 110 | BW2VBPS(_bw, 1560, 720, 346)) \ |
| 111 | } \ |
| 112 | } |
| 113 | |
| 114 | #define CCK_DURATION(_bitrate, _short, _len) \ |
| 115 | (1000 * (10 /* SIFS */ + \ |
| 116 | (_short ? 72 + 24 : 144 + 48) + \ |
| 117 | (8 * (_len + 4) * 10) / (_bitrate))) |
| 118 | |
| 119 | #define CCK_ACK_DURATION(_bitrate, _short) \ |
| 120 | (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \ |
| 121 | CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE)) |
| 122 | |
| 123 | #define CCK_DURATION_LIST(_short) \ |
| 124 | CCK_ACK_DURATION(10, _short), \ |
| 125 | CCK_ACK_DURATION(20, _short), \ |
| 126 | CCK_ACK_DURATION(55, _short), \ |
| 127 | CCK_ACK_DURATION(110, _short) |
| 128 | |
| 129 | #define CCK_GROUP \ |
| 130 | [MINSTREL_CCK_GROUP] = { \ |
| 131 | .streams = 0, \ |
| 132 | .flags = 0, \ |
| 133 | .duration = { \ |
| 134 | CCK_DURATION_LIST(false), \ |
| 135 | CCK_DURATION_LIST(true) \ |
| 136 | } \ |
| 137 | } |
| 138 | |
| 139 | #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT |
| 140 | static bool minstrel_vht_only = true; |
| 141 | module_param(minstrel_vht_only, bool, 0644); |
| 142 | MODULE_PARM_DESC(minstrel_vht_only, |
| 143 | "Use only VHT rates when VHT is supported by sta."); |
| 144 | #endif |
| 145 | |
| 146 | /* |
| 147 | * To enable sufficiently targeted rate sampling, MCS rates are divided into |
| 148 | * groups, based on the number of streams and flags (HT40, SGI) that they |
| 149 | * use. |
| 150 | * |
| 151 | * Sortorder has to be fixed for GROUP_IDX macro to be applicable: |
| 152 | * BW -> SGI -> #streams |
| 153 | */ |
| 154 | const struct mcs_group minstrel_mcs_groups[] = { |
| 155 | MCS_GROUP(1, 0, BW_20), |
| 156 | MCS_GROUP(2, 0, BW_20), |
| 157 | #if MINSTREL_MAX_STREAMS >= 3 |
| 158 | MCS_GROUP(3, 0, BW_20), |
| 159 | #endif |
| 160 | |
| 161 | MCS_GROUP(1, 1, BW_20), |
| 162 | MCS_GROUP(2, 1, BW_20), |
| 163 | #if MINSTREL_MAX_STREAMS >= 3 |
| 164 | MCS_GROUP(3, 1, BW_20), |
| 165 | #endif |
| 166 | |
| 167 | MCS_GROUP(1, 0, BW_40), |
| 168 | MCS_GROUP(2, 0, BW_40), |
| 169 | #if MINSTREL_MAX_STREAMS >= 3 |
| 170 | MCS_GROUP(3, 0, BW_40), |
| 171 | #endif |
| 172 | |
| 173 | MCS_GROUP(1, 1, BW_40), |
| 174 | MCS_GROUP(2, 1, BW_40), |
| 175 | #if MINSTREL_MAX_STREAMS >= 3 |
| 176 | MCS_GROUP(3, 1, BW_40), |
| 177 | #endif |
| 178 | |
| 179 | CCK_GROUP, |
| 180 | |
| 181 | #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT |
| 182 | VHT_GROUP(1, 0, BW_20), |
| 183 | VHT_GROUP(2, 0, BW_20), |
| 184 | #if MINSTREL_MAX_STREAMS >= 3 |
| 185 | VHT_GROUP(3, 0, BW_20), |
| 186 | #endif |
| 187 | |
| 188 | VHT_GROUP(1, 1, BW_20), |
| 189 | VHT_GROUP(2, 1, BW_20), |
| 190 | #if MINSTREL_MAX_STREAMS >= 3 |
| 191 | VHT_GROUP(3, 1, BW_20), |
| 192 | #endif |
| 193 | |
| 194 | VHT_GROUP(1, 0, BW_40), |
| 195 | VHT_GROUP(2, 0, BW_40), |
| 196 | #if MINSTREL_MAX_STREAMS >= 3 |
| 197 | VHT_GROUP(3, 0, BW_40), |
| 198 | #endif |
| 199 | |
| 200 | VHT_GROUP(1, 1, BW_40), |
| 201 | VHT_GROUP(2, 1, BW_40), |
| 202 | #if MINSTREL_MAX_STREAMS >= 3 |
| 203 | VHT_GROUP(3, 1, BW_40), |
| 204 | #endif |
| 205 | |
| 206 | VHT_GROUP(1, 0, BW_80), |
| 207 | VHT_GROUP(2, 0, BW_80), |
| 208 | #if MINSTREL_MAX_STREAMS >= 3 |
| 209 | VHT_GROUP(3, 0, BW_80), |
| 210 | #endif |
| 211 | |
| 212 | VHT_GROUP(1, 1, BW_80), |
| 213 | VHT_GROUP(2, 1, BW_80), |
| 214 | #if MINSTREL_MAX_STREAMS >= 3 |
| 215 | VHT_GROUP(3, 1, BW_80), |
| 216 | #endif |
| 217 | #endif |
| 218 | }; |
| 219 | |
| 220 | static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly; |
| 221 | |
| 222 | static void |
| 223 | minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi); |
| 224 | |
| 225 | /* |
| 226 | * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer) |
| 227 | * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1 |
| 228 | * |
| 229 | * Returns the valid mcs map for struct minstrel_mcs_group_data.supported |
| 230 | */ |
| 231 | static u16 |
| 232 | minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map) |
| 233 | { |
| 234 | u16 mask = 0; |
| 235 | |
| 236 | if (bw == BW_20) { |
| 237 | if (nss != 3 && nss != 6) |
| 238 | mask = BIT(9); |
| 239 | } else if (bw == BW_80) { |
| 240 | if (nss == 3 || nss == 7) |
| 241 | mask = BIT(6); |
| 242 | else if (nss == 6) |
| 243 | mask = BIT(9); |
| 244 | } else { |
| 245 | WARN_ON(bw != BW_40); |
| 246 | } |
| 247 | |
| 248 | switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) { |
| 249 | case IEEE80211_VHT_MCS_SUPPORT_0_7: |
| 250 | mask |= 0x300; |
| 251 | break; |
| 252 | case IEEE80211_VHT_MCS_SUPPORT_0_8: |
| 253 | mask |= 0x200; |
| 254 | break; |
| 255 | case IEEE80211_VHT_MCS_SUPPORT_0_9: |
| 256 | break; |
| 257 | default: |
| 258 | mask = 0x3ff; |
| 259 | } |
| 260 | |
| 261 | return 0x3ff & ~mask; |
| 262 | } |
| 263 | |
| 264 | /* |
| 265 | * Look up an MCS group index based on mac80211 rate information |
| 266 | */ |
| 267 | static int |
| 268 | minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate) |
| 269 | { |
| 270 | return GROUP_IDX((rate->idx / 8) + 1, |
| 271 | !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), |
| 272 | !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)); |
| 273 | } |
| 274 | |
| 275 | static int |
| 276 | minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate) |
| 277 | { |
| 278 | return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate), |
| 279 | !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), |
| 280 | !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) + |
| 281 | 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH)); |
| 282 | } |
| 283 | |
| 284 | static struct minstrel_rate_stats * |
| 285 | minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, |
| 286 | struct ieee80211_tx_rate *rate) |
| 287 | { |
| 288 | int group, idx; |
| 289 | |
| 290 | if (rate->flags & IEEE80211_TX_RC_MCS) { |
| 291 | group = minstrel_ht_get_group_idx(rate); |
| 292 | idx = rate->idx % 8; |
| 293 | } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) { |
| 294 | group = minstrel_vht_get_group_idx(rate); |
| 295 | idx = ieee80211_rate_get_vht_mcs(rate); |
| 296 | } else { |
| 297 | group = MINSTREL_CCK_GROUP; |
| 298 | |
| 299 | for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) |
| 300 | if (rate->idx == mp->cck_rates[idx]) |
| 301 | break; |
| 302 | |
| 303 | /* short preamble */ |
| 304 | if (!(mi->groups[group].supported & BIT(idx))) |
| 305 | idx += 4; |
| 306 | } |
| 307 | return &mi->groups[group].rates[idx]; |
| 308 | } |
| 309 | |
| 310 | static inline struct minstrel_rate_stats * |
| 311 | minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index) |
| 312 | { |
| 313 | return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES]; |
| 314 | } |
| 315 | |
| 316 | /* |
| 317 | * Return current throughput based on the average A-MPDU length, taking into |
| 318 | * account the expected number of retransmissions and their expected length |
| 319 | */ |
| 320 | int |
| 321 | minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate, |
| 322 | int prob_ewma) |
| 323 | { |
| 324 | unsigned int nsecs = 0; |
| 325 | |
| 326 | /* do not account throughput if sucess prob is below 10% */ |
| 327 | if (prob_ewma < MINSTREL_FRAC(10, 100)) |
| 328 | return 0; |
| 329 | |
| 330 | if (group != MINSTREL_CCK_GROUP) |
| 331 | nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len); |
| 332 | |
| 333 | nsecs += minstrel_mcs_groups[group].duration[rate]; |
| 334 | |
| 335 | /* |
| 336 | * For the throughput calculation, limit the probability value to 90% to |
| 337 | * account for collision related packet error rate fluctuation |
| 338 | * (prob is scaled - see MINSTREL_FRAC above) |
| 339 | */ |
| 340 | if (prob_ewma > MINSTREL_FRAC(90, 100)) |
| 341 | return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000) |
| 342 | / nsecs)); |
| 343 | else |
| 344 | return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs)); |
| 345 | } |
| 346 | |
| 347 | /* |
| 348 | * Find & sort topmost throughput rates |
| 349 | * |
| 350 | * If multiple rates provide equal throughput the sorting is based on their |
| 351 | * current success probability. Higher success probability is preferred among |
| 352 | * MCS groups, CCK rates do not provide aggregation and are therefore at last. |
| 353 | */ |
| 354 | static void |
| 355 | minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index, |
| 356 | u16 *tp_list) |
| 357 | { |
| 358 | int cur_group, cur_idx, cur_tp_avg, cur_prob; |
| 359 | int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; |
| 360 | int j = MAX_THR_RATES; |
| 361 | |
| 362 | cur_group = index / MCS_GROUP_RATES; |
| 363 | cur_idx = index % MCS_GROUP_RATES; |
| 364 | cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma; |
| 365 | cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob); |
| 366 | |
| 367 | do { |
| 368 | tmp_group = tp_list[j - 1] / MCS_GROUP_RATES; |
| 369 | tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES; |
| 370 | tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; |
| 371 | tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, |
| 372 | tmp_prob); |
| 373 | if (cur_tp_avg < tmp_tp_avg || |
| 374 | (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob)) |
| 375 | break; |
| 376 | j--; |
| 377 | } while (j > 0); |
| 378 | |
| 379 | if (j < MAX_THR_RATES - 1) { |
| 380 | memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) * |
| 381 | (MAX_THR_RATES - (j + 1)))); |
| 382 | } |
| 383 | if (j < MAX_THR_RATES) |
| 384 | tp_list[j] = index; |
| 385 | } |
| 386 | |
| 387 | /* |
| 388 | * Find and set the topmost probability rate per sta and per group |
| 389 | */ |
| 390 | static void |
| 391 | minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index) |
| 392 | { |
| 393 | struct minstrel_mcs_group_data *mg; |
| 394 | struct minstrel_rate_stats *mrs; |
| 395 | int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; |
| 396 | int max_tp_group, cur_tp_avg, cur_group, cur_idx; |
| 397 | int max_gpr_group, max_gpr_idx; |
| 398 | int max_gpr_tp_avg, max_gpr_prob; |
| 399 | |
| 400 | cur_group = index / MCS_GROUP_RATES; |
| 401 | cur_idx = index % MCS_GROUP_RATES; |
| 402 | mg = &mi->groups[index / MCS_GROUP_RATES]; |
| 403 | mrs = &mg->rates[index % MCS_GROUP_RATES]; |
| 404 | |
| 405 | tmp_group = mi->max_prob_rate / MCS_GROUP_RATES; |
| 406 | tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES; |
| 407 | tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; |
| 408 | tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); |
| 409 | |
| 410 | /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from |
| 411 | * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */ |
| 412 | max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES; |
| 413 | if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) && |
| 414 | (max_tp_group != MINSTREL_CCK_GROUP)) |
| 415 | return; |
| 416 | |
| 417 | if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) { |
| 418 | cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, |
| 419 | mrs->prob_ewma); |
| 420 | if (cur_tp_avg > tmp_tp_avg) |
| 421 | mi->max_prob_rate = index; |
| 422 | |
| 423 | max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES; |
| 424 | max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; |
| 425 | max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma; |
| 426 | max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group, |
| 427 | max_gpr_idx, |
| 428 | max_gpr_prob); |
| 429 | if (cur_tp_avg > max_gpr_tp_avg) |
| 430 | mg->max_group_prob_rate = index; |
| 431 | } else { |
| 432 | if (mrs->prob_ewma > tmp_prob) |
| 433 | mi->max_prob_rate = index; |
| 434 | if (mrs->prob_ewma > mg->rates[mg->max_group_prob_rate].prob_ewma) |
| 435 | mg->max_group_prob_rate = index; |
| 436 | } |
| 437 | } |
| 438 | |
| 439 | |
| 440 | /* |
| 441 | * Assign new rate set per sta and use CCK rates only if the fastest |
| 442 | * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted |
| 443 | * rate sets where MCS and CCK rates are mixed, because CCK rates can |
| 444 | * not use aggregation. |
| 445 | */ |
| 446 | static void |
| 447 | minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi, |
| 448 | u16 tmp_mcs_tp_rate[MAX_THR_RATES], |
| 449 | u16 tmp_cck_tp_rate[MAX_THR_RATES]) |
| 450 | { |
| 451 | unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob; |
| 452 | int i; |
| 453 | |
| 454 | tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES; |
| 455 | tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES; |
| 456 | tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; |
| 457 | tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); |
| 458 | |
| 459 | tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES; |
| 460 | tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES; |
| 461 | tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; |
| 462 | tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); |
| 463 | |
| 464 | if (tmp_cck_tp > tmp_mcs_tp) { |
| 465 | for(i = 0; i < MAX_THR_RATES; i++) { |
| 466 | minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i], |
| 467 | tmp_mcs_tp_rate); |
| 468 | } |
| 469 | } |
| 470 | |
| 471 | } |
| 472 | |
| 473 | /* |
| 474 | * Try to increase robustness of max_prob rate by decrease number of |
| 475 | * streams if possible. |
| 476 | */ |
| 477 | static inline void |
| 478 | minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi) |
| 479 | { |
| 480 | struct minstrel_mcs_group_data *mg; |
| 481 | int tmp_max_streams, group, tmp_idx, tmp_prob; |
| 482 | int tmp_tp = 0; |
| 483 | |
| 484 | tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / |
| 485 | MCS_GROUP_RATES].streams; |
| 486 | for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { |
| 487 | mg = &mi->groups[group]; |
| 488 | if (!mg->supported || group == MINSTREL_CCK_GROUP) |
| 489 | continue; |
| 490 | |
| 491 | tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; |
| 492 | tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma; |
| 493 | |
| 494 | if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) && |
| 495 | (minstrel_mcs_groups[group].streams < tmp_max_streams)) { |
| 496 | mi->max_prob_rate = mg->max_group_prob_rate; |
| 497 | tmp_tp = minstrel_ht_get_tp_avg(mi, group, |
| 498 | tmp_idx, |
| 499 | tmp_prob); |
| 500 | } |
| 501 | } |
| 502 | } |
| 503 | |
| 504 | /* |
| 505 | * Update rate statistics and select new primary rates |
| 506 | * |
| 507 | * Rules for rate selection: |
| 508 | * - max_prob_rate must use only one stream, as a tradeoff between delivery |
| 509 | * probability and throughput during strong fluctuations |
| 510 | * - as long as the max prob rate has a probability of more than 75%, pick |
| 511 | * higher throughput rates, even if the probablity is a bit lower |
| 512 | */ |
| 513 | static void |
| 514 | minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) |
| 515 | { |
| 516 | struct minstrel_mcs_group_data *mg; |
| 517 | struct minstrel_rate_stats *mrs; |
| 518 | int group, i, j, cur_prob; |
| 519 | u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES]; |
| 520 | u16 tmp_cck_tp_rate[MAX_THR_RATES], index; |
| 521 | |
| 522 | if (mi->ampdu_packets > 0) { |
| 523 | mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len, |
| 524 | MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL); |
| 525 | mi->ampdu_len = 0; |
| 526 | mi->ampdu_packets = 0; |
| 527 | } |
| 528 | |
| 529 | mi->sample_slow = 0; |
| 530 | mi->sample_count = 0; |
| 531 | |
| 532 | /* Initialize global rate indexes */ |
| 533 | for(j = 0; j < MAX_THR_RATES; j++){ |
| 534 | tmp_mcs_tp_rate[j] = 0; |
| 535 | tmp_cck_tp_rate[j] = 0; |
| 536 | } |
| 537 | |
| 538 | /* Find best rate sets within all MCS groups*/ |
| 539 | for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { |
| 540 | |
| 541 | mg = &mi->groups[group]; |
| 542 | if (!mg->supported) |
| 543 | continue; |
| 544 | |
| 545 | mi->sample_count++; |
| 546 | |
| 547 | /* (re)Initialize group rate indexes */ |
| 548 | for(j = 0; j < MAX_THR_RATES; j++) |
| 549 | tmp_group_tp_rate[j] = group; |
| 550 | |
| 551 | for (i = 0; i < MCS_GROUP_RATES; i++) { |
| 552 | if (!(mg->supported & BIT(i))) |
| 553 | continue; |
| 554 | |
| 555 | index = MCS_GROUP_RATES * group + i; |
| 556 | |
| 557 | mrs = &mg->rates[i]; |
| 558 | mrs->retry_updated = false; |
| 559 | minstrel_calc_rate_stats(mrs); |
| 560 | cur_prob = mrs->prob_ewma; |
| 561 | |
| 562 | if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0) |
| 563 | continue; |
| 564 | |
| 565 | /* Find max throughput rate set */ |
| 566 | if (group != MINSTREL_CCK_GROUP) { |
| 567 | minstrel_ht_sort_best_tp_rates(mi, index, |
| 568 | tmp_mcs_tp_rate); |
| 569 | } else if (group == MINSTREL_CCK_GROUP) { |
| 570 | minstrel_ht_sort_best_tp_rates(mi, index, |
| 571 | tmp_cck_tp_rate); |
| 572 | } |
| 573 | |
| 574 | /* Find max throughput rate set within a group */ |
| 575 | minstrel_ht_sort_best_tp_rates(mi, index, |
| 576 | tmp_group_tp_rate); |
| 577 | |
| 578 | /* Find max probability rate per group and global */ |
| 579 | minstrel_ht_set_best_prob_rate(mi, index); |
| 580 | } |
| 581 | |
| 582 | memcpy(mg->max_group_tp_rate, tmp_group_tp_rate, |
| 583 | sizeof(mg->max_group_tp_rate)); |
| 584 | } |
| 585 | |
| 586 | /* Assign new rate set per sta */ |
| 587 | minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate); |
| 588 | memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate)); |
| 589 | |
| 590 | /* Try to increase robustness of max_prob_rate*/ |
| 591 | minstrel_ht_prob_rate_reduce_streams(mi); |
| 592 | |
| 593 | /* try to sample all available rates during each interval */ |
| 594 | mi->sample_count *= 8; |
| 595 | |
| 596 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 597 | /* use fixed index if set */ |
| 598 | if (mp->fixed_rate_idx != -1) { |
| 599 | for (i = 0; i < 4; i++) |
| 600 | mi->max_tp_rate[i] = mp->fixed_rate_idx; |
| 601 | mi->max_prob_rate = mp->fixed_rate_idx; |
| 602 | } |
| 603 | #endif |
| 604 | |
| 605 | /* Reset update timer */ |
| 606 | mi->last_stats_update = jiffies; |
| 607 | } |
| 608 | |
| 609 | static bool |
| 610 | minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate) |
| 611 | { |
| 612 | if (rate->idx < 0) |
| 613 | return false; |
| 614 | |
| 615 | if (!rate->count) |
| 616 | return false; |
| 617 | |
| 618 | if (rate->flags & IEEE80211_TX_RC_MCS || |
| 619 | rate->flags & IEEE80211_TX_RC_VHT_MCS) |
| 620 | return true; |
| 621 | |
| 622 | return rate->idx == mp->cck_rates[0] || |
| 623 | rate->idx == mp->cck_rates[1] || |
| 624 | rate->idx == mp->cck_rates[2] || |
| 625 | rate->idx == mp->cck_rates[3]; |
| 626 | } |
| 627 | |
| 628 | static void |
| 629 | minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi) |
| 630 | { |
| 631 | struct minstrel_mcs_group_data *mg; |
| 632 | |
| 633 | for (;;) { |
| 634 | mi->sample_group++; |
| 635 | mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups); |
| 636 | mg = &mi->groups[mi->sample_group]; |
| 637 | |
| 638 | if (!mg->supported) |
| 639 | continue; |
| 640 | |
| 641 | if (++mg->index >= MCS_GROUP_RATES) { |
| 642 | mg->index = 0; |
| 643 | if (++mg->column >= ARRAY_SIZE(sample_table)) |
| 644 | mg->column = 0; |
| 645 | } |
| 646 | break; |
| 647 | } |
| 648 | } |
| 649 | |
| 650 | static void |
| 651 | minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary) |
| 652 | { |
| 653 | int group, orig_group; |
| 654 | |
| 655 | orig_group = group = *idx / MCS_GROUP_RATES; |
| 656 | while (group > 0) { |
| 657 | group--; |
| 658 | |
| 659 | if (!mi->groups[group].supported) |
| 660 | continue; |
| 661 | |
| 662 | if (minstrel_mcs_groups[group].streams > |
| 663 | minstrel_mcs_groups[orig_group].streams) |
| 664 | continue; |
| 665 | |
| 666 | if (primary) |
| 667 | *idx = mi->groups[group].max_group_tp_rate[0]; |
| 668 | else |
| 669 | *idx = mi->groups[group].max_group_tp_rate[1]; |
| 670 | break; |
| 671 | } |
| 672 | } |
| 673 | |
| 674 | static void |
| 675 | minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb) |
| 676 | { |
| 677 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; |
| 678 | struct sta_info *sta = container_of(pubsta, struct sta_info, sta); |
| 679 | u16 tid; |
| 680 | |
| 681 | if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO) |
| 682 | return; |
| 683 | |
| 684 | if (unlikely(!ieee80211_is_data_qos(hdr->frame_control))) |
| 685 | return; |
| 686 | |
| 687 | if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE))) |
| 688 | return; |
| 689 | |
| 690 | tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK; |
| 691 | if (likely(sta->ampdu_mlme.tid_tx[tid])) |
| 692 | return; |
| 693 | |
| 694 | ieee80211_start_tx_ba_session(pubsta, tid, 5000); |
| 695 | } |
| 696 | |
| 697 | static void |
| 698 | minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, |
| 699 | struct ieee80211_sta *sta, void *priv_sta, |
| 700 | struct ieee80211_tx_info *info) |
| 701 | { |
| 702 | struct minstrel_ht_sta_priv *msp = priv_sta; |
| 703 | struct minstrel_ht_sta *mi = &msp->ht; |
| 704 | struct ieee80211_tx_rate *ar = info->status.rates; |
| 705 | struct minstrel_rate_stats *rate, *rate2; |
| 706 | struct minstrel_priv *mp = priv; |
| 707 | bool last, update = false; |
| 708 | int i; |
| 709 | |
| 710 | if (!msp->is_ht) |
| 711 | return mac80211_minstrel.tx_status_noskb(priv, sband, sta, |
| 712 | &msp->legacy, info); |
| 713 | |
| 714 | /* This packet was aggregated but doesn't carry status info */ |
| 715 | if ((info->flags & IEEE80211_TX_CTL_AMPDU) && |
| 716 | !(info->flags & IEEE80211_TX_STAT_AMPDU)) |
| 717 | return; |
| 718 | |
| 719 | if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) { |
| 720 | info->status.ampdu_ack_len = |
| 721 | (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0); |
| 722 | info->status.ampdu_len = 1; |
| 723 | } |
| 724 | |
| 725 | mi->ampdu_packets++; |
| 726 | mi->ampdu_len += info->status.ampdu_len; |
| 727 | |
| 728 | if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) { |
| 729 | mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len); |
| 730 | mi->sample_tries = 1; |
| 731 | mi->sample_count--; |
| 732 | } |
| 733 | |
| 734 | if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) |
| 735 | mi->sample_packets += info->status.ampdu_len; |
| 736 | |
| 737 | last = !minstrel_ht_txstat_valid(mp, &ar[0]); |
| 738 | for (i = 0; !last; i++) { |
| 739 | last = (i == IEEE80211_TX_MAX_RATES - 1) || |
| 740 | !minstrel_ht_txstat_valid(mp, &ar[i + 1]); |
| 741 | |
| 742 | rate = minstrel_ht_get_stats(mp, mi, &ar[i]); |
| 743 | |
| 744 | if (last) |
| 745 | rate->success += info->status.ampdu_ack_len; |
| 746 | |
| 747 | rate->attempts += ar[i].count * info->status.ampdu_len; |
| 748 | } |
| 749 | |
| 750 | /* |
| 751 | * check for sudden death of spatial multiplexing, |
| 752 | * downgrade to a lower number of streams if necessary. |
| 753 | */ |
| 754 | rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); |
| 755 | if (rate->attempts > 30 && |
| 756 | MINSTREL_FRAC(rate->success, rate->attempts) < |
| 757 | MINSTREL_FRAC(20, 100)) { |
| 758 | minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true); |
| 759 | update = true; |
| 760 | } |
| 761 | |
| 762 | rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]); |
| 763 | if (rate2->attempts > 30 && |
| 764 | MINSTREL_FRAC(rate2->success, rate2->attempts) < |
| 765 | MINSTREL_FRAC(20, 100)) { |
| 766 | minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false); |
| 767 | update = true; |
| 768 | } |
| 769 | |
| 770 | if (time_after(jiffies, mi->last_stats_update + |
| 771 | (mp->update_interval / 2 * HZ) / 1000)) { |
| 772 | update = true; |
| 773 | minstrel_ht_update_stats(mp, mi); |
| 774 | } |
| 775 | |
| 776 | if (update) |
| 777 | minstrel_ht_update_rates(mp, mi); |
| 778 | } |
| 779 | |
| 780 | static void |
| 781 | minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, |
| 782 | int index) |
| 783 | { |
| 784 | struct minstrel_rate_stats *mrs; |
| 785 | const struct mcs_group *group; |
| 786 | unsigned int tx_time, tx_time_rtscts, tx_time_data; |
| 787 | unsigned int cw = mp->cw_min; |
| 788 | unsigned int ctime = 0; |
| 789 | unsigned int t_slot = 9; /* FIXME */ |
| 790 | unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len); |
| 791 | unsigned int overhead = 0, overhead_rtscts = 0; |
| 792 | |
| 793 | mrs = minstrel_get_ratestats(mi, index); |
| 794 | if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) { |
| 795 | mrs->retry_count = 1; |
| 796 | mrs->retry_count_rtscts = 1; |
| 797 | return; |
| 798 | } |
| 799 | |
| 800 | mrs->retry_count = 2; |
| 801 | mrs->retry_count_rtscts = 2; |
| 802 | mrs->retry_updated = true; |
| 803 | |
| 804 | group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; |
| 805 | tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000; |
| 806 | |
| 807 | /* Contention time for first 2 tries */ |
| 808 | ctime = (t_slot * cw) >> 1; |
| 809 | cw = min((cw << 1) | 1, mp->cw_max); |
| 810 | ctime += (t_slot * cw) >> 1; |
| 811 | cw = min((cw << 1) | 1, mp->cw_max); |
| 812 | |
| 813 | if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) { |
| 814 | overhead = mi->overhead; |
| 815 | overhead_rtscts = mi->overhead_rtscts; |
| 816 | } |
| 817 | |
| 818 | /* Total TX time for data and Contention after first 2 tries */ |
| 819 | tx_time = ctime + 2 * (overhead + tx_time_data); |
| 820 | tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data); |
| 821 | |
| 822 | /* See how many more tries we can fit inside segment size */ |
| 823 | do { |
| 824 | /* Contention time for this try */ |
| 825 | ctime = (t_slot * cw) >> 1; |
| 826 | cw = min((cw << 1) | 1, mp->cw_max); |
| 827 | |
| 828 | /* Total TX time after this try */ |
| 829 | tx_time += ctime + overhead + tx_time_data; |
| 830 | tx_time_rtscts += ctime + overhead_rtscts + tx_time_data; |
| 831 | |
| 832 | if (tx_time_rtscts < mp->segment_size) |
| 833 | mrs->retry_count_rtscts++; |
| 834 | } while ((tx_time < mp->segment_size) && |
| 835 | (++mrs->retry_count < mp->max_retry)); |
| 836 | } |
| 837 | |
| 838 | |
| 839 | static void |
| 840 | minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, |
| 841 | struct ieee80211_sta_rates *ratetbl, int offset, int index) |
| 842 | { |
| 843 | const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; |
| 844 | struct minstrel_rate_stats *mrs; |
| 845 | u8 idx; |
| 846 | u16 flags = group->flags; |
| 847 | |
| 848 | mrs = minstrel_get_ratestats(mi, index); |
| 849 | if (!mrs->retry_updated) |
| 850 | minstrel_calc_retransmit(mp, mi, index); |
| 851 | |
| 852 | if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) { |
| 853 | ratetbl->rate[offset].count = 2; |
| 854 | ratetbl->rate[offset].count_rts = 2; |
| 855 | ratetbl->rate[offset].count_cts = 2; |
| 856 | } else { |
| 857 | ratetbl->rate[offset].count = mrs->retry_count; |
| 858 | ratetbl->rate[offset].count_cts = mrs->retry_count; |
| 859 | ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts; |
| 860 | } |
| 861 | |
| 862 | if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) |
| 863 | idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)]; |
| 864 | else if (flags & IEEE80211_TX_RC_VHT_MCS) |
| 865 | idx = ((group->streams - 1) << 4) | |
| 866 | ((index % MCS_GROUP_RATES) & 0xF); |
| 867 | else |
| 868 | idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8; |
| 869 | |
| 870 | /* enable RTS/CTS if needed: |
| 871 | * - if station is in dynamic SMPS (and streams > 1) |
| 872 | * - for fallback rates, to increase chances of getting through |
| 873 | */ |
| 874 | if (offset > 0 && |
| 875 | (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC && |
| 876 | group->streams > 1)) { |
| 877 | ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts; |
| 878 | flags |= IEEE80211_TX_RC_USE_RTS_CTS; |
| 879 | } |
| 880 | |
| 881 | ratetbl->rate[offset].idx = idx; |
| 882 | ratetbl->rate[offset].flags = flags; |
| 883 | } |
| 884 | |
| 885 | static void |
| 886 | minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) |
| 887 | { |
| 888 | struct ieee80211_sta_rates *rates; |
| 889 | int i = 0; |
| 890 | |
| 891 | rates = kzalloc(sizeof(*rates), GFP_ATOMIC); |
| 892 | if (!rates) |
| 893 | return; |
| 894 | |
| 895 | /* Start with max_tp_rate[0] */ |
| 896 | minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]); |
| 897 | |
| 898 | if (mp->hw->max_rates >= 3) { |
| 899 | /* At least 3 tx rates supported, use max_tp_rate[1] next */ |
| 900 | minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]); |
| 901 | } |
| 902 | |
| 903 | if (mp->hw->max_rates >= 2) { |
| 904 | /* |
| 905 | * At least 2 tx rates supported, use max_prob_rate next */ |
| 906 | minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate); |
| 907 | } |
| 908 | |
| 909 | rates->rate[i].idx = -1; |
| 910 | rate_control_set_rates(mp->hw, mi->sta, rates); |
| 911 | } |
| 912 | |
| 913 | static inline int |
| 914 | minstrel_get_duration(int index) |
| 915 | { |
| 916 | const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; |
| 917 | return group->duration[index % MCS_GROUP_RATES]; |
| 918 | } |
| 919 | |
| 920 | static int |
| 921 | minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) |
| 922 | { |
| 923 | struct minstrel_rate_stats *mrs; |
| 924 | struct minstrel_mcs_group_data *mg; |
| 925 | unsigned int sample_dur, sample_group, cur_max_tp_streams; |
| 926 | int sample_idx = 0; |
| 927 | |
| 928 | if (mi->sample_wait > 0) { |
| 929 | mi->sample_wait--; |
| 930 | return -1; |
| 931 | } |
| 932 | |
| 933 | if (!mi->sample_tries) |
| 934 | return -1; |
| 935 | |
| 936 | sample_group = mi->sample_group; |
| 937 | mg = &mi->groups[sample_group]; |
| 938 | sample_idx = sample_table[mg->column][mg->index]; |
| 939 | minstrel_set_next_sample_idx(mi); |
| 940 | |
| 941 | if (!(mg->supported & BIT(sample_idx))) |
| 942 | return -1; |
| 943 | |
| 944 | mrs = &mg->rates[sample_idx]; |
| 945 | sample_idx += sample_group * MCS_GROUP_RATES; |
| 946 | |
| 947 | /* |
| 948 | * Sampling might add some overhead (RTS, no aggregation) |
| 949 | * to the frame. Hence, don't use sampling for the currently |
| 950 | * used rates. |
| 951 | */ |
| 952 | if (sample_idx == mi->max_tp_rate[0] || |
| 953 | sample_idx == mi->max_tp_rate[1] || |
| 954 | sample_idx == mi->max_prob_rate) |
| 955 | return -1; |
| 956 | |
| 957 | /* |
| 958 | * Do not sample if the probability is already higher than 95% |
| 959 | * to avoid wasting airtime. |
| 960 | */ |
| 961 | if (mrs->prob_ewma > MINSTREL_FRAC(95, 100)) |
| 962 | return -1; |
| 963 | |
| 964 | /* |
| 965 | * Make sure that lower rates get sampled only occasionally, |
| 966 | * if the link is working perfectly. |
| 967 | */ |
| 968 | |
| 969 | cur_max_tp_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / |
| 970 | MCS_GROUP_RATES].streams; |
| 971 | sample_dur = minstrel_get_duration(sample_idx); |
| 972 | if (sample_dur >= minstrel_get_duration(mi->max_tp_rate[1]) && |
| 973 | (cur_max_tp_streams - 1 < |
| 974 | minstrel_mcs_groups[sample_group].streams || |
| 975 | sample_dur >= minstrel_get_duration(mi->max_prob_rate))) { |
| 976 | if (mrs->sample_skipped < 20) |
| 977 | return -1; |
| 978 | |
| 979 | if (mi->sample_slow++ > 2) |
| 980 | return -1; |
| 981 | } |
| 982 | mi->sample_tries--; |
| 983 | |
| 984 | return sample_idx; |
| 985 | } |
| 986 | |
| 987 | static void |
| 988 | minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp, |
| 989 | struct minstrel_ht_sta *mi, bool val) |
| 990 | { |
| 991 | u8 supported = mi->groups[MINSTREL_CCK_GROUP].supported; |
| 992 | |
| 993 | if (!supported || !mi->cck_supported_short) |
| 994 | return; |
| 995 | |
| 996 | if (supported & (mi->cck_supported_short << (val * 4))) |
| 997 | return; |
| 998 | |
| 999 | supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4); |
| 1000 | mi->groups[MINSTREL_CCK_GROUP].supported = supported; |
| 1001 | } |
| 1002 | |
| 1003 | static void |
| 1004 | minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, |
| 1005 | struct ieee80211_tx_rate_control *txrc) |
| 1006 | { |
| 1007 | const struct mcs_group *sample_group; |
| 1008 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); |
| 1009 | struct ieee80211_tx_rate *rate = &info->status.rates[0]; |
| 1010 | struct minstrel_ht_sta_priv *msp = priv_sta; |
| 1011 | struct minstrel_ht_sta *mi = &msp->ht; |
| 1012 | struct minstrel_priv *mp = priv; |
| 1013 | int sample_idx; |
| 1014 | |
| 1015 | if (rate_control_send_low(sta, priv_sta, txrc)) |
| 1016 | return; |
| 1017 | |
| 1018 | if (!msp->is_ht) |
| 1019 | return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc); |
| 1020 | |
| 1021 | if (!(info->flags & IEEE80211_TX_CTL_AMPDU) && |
| 1022 | mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) |
| 1023 | minstrel_aggr_check(sta, txrc->skb); |
| 1024 | |
| 1025 | info->flags |= mi->tx_flags; |
| 1026 | minstrel_ht_check_cck_shortpreamble(mp, mi, txrc->short_preamble); |
| 1027 | |
| 1028 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 1029 | if (mp->fixed_rate_idx != -1) |
| 1030 | return; |
| 1031 | #endif |
| 1032 | |
| 1033 | /* Don't use EAPOL frames for sampling on non-mrr hw */ |
| 1034 | if (mp->hw->max_rates == 1 && |
| 1035 | (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO)) |
| 1036 | sample_idx = -1; |
| 1037 | else |
| 1038 | sample_idx = minstrel_get_sample_rate(mp, mi); |
| 1039 | |
| 1040 | mi->total_packets++; |
| 1041 | |
| 1042 | /* wraparound */ |
| 1043 | if (mi->total_packets == ~0) { |
| 1044 | mi->total_packets = 0; |
| 1045 | mi->sample_packets = 0; |
| 1046 | } |
| 1047 | |
| 1048 | if (sample_idx < 0) |
| 1049 | return; |
| 1050 | |
| 1051 | sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES]; |
| 1052 | info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; |
| 1053 | rate->count = 1; |
| 1054 | |
| 1055 | if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) { |
| 1056 | int idx = sample_idx % ARRAY_SIZE(mp->cck_rates); |
| 1057 | rate->idx = mp->cck_rates[idx]; |
| 1058 | } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) { |
| 1059 | ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES, |
| 1060 | sample_group->streams); |
| 1061 | } else { |
| 1062 | rate->idx = sample_idx % MCS_GROUP_RATES + |
| 1063 | (sample_group->streams - 1) * 8; |
| 1064 | } |
| 1065 | |
| 1066 | rate->flags = sample_group->flags; |
| 1067 | } |
| 1068 | |
| 1069 | static void |
| 1070 | minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, |
| 1071 | struct ieee80211_supported_band *sband, |
| 1072 | struct ieee80211_sta *sta) |
| 1073 | { |
| 1074 | int i; |
| 1075 | |
| 1076 | if (sband->band != IEEE80211_BAND_2GHZ) |
| 1077 | return; |
| 1078 | |
| 1079 | if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES)) |
| 1080 | return; |
| 1081 | |
| 1082 | mi->cck_supported = 0; |
| 1083 | mi->cck_supported_short = 0; |
| 1084 | for (i = 0; i < 4; i++) { |
| 1085 | if (!rate_supported(sta, sband->band, mp->cck_rates[i])) |
| 1086 | continue; |
| 1087 | |
| 1088 | mi->cck_supported |= BIT(i); |
| 1089 | if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE) |
| 1090 | mi->cck_supported_short |= BIT(i); |
| 1091 | } |
| 1092 | |
| 1093 | mi->groups[MINSTREL_CCK_GROUP].supported = mi->cck_supported; |
| 1094 | } |
| 1095 | |
| 1096 | static void |
| 1097 | minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, |
| 1098 | struct cfg80211_chan_def *chandef, |
| 1099 | struct ieee80211_sta *sta, void *priv_sta) |
| 1100 | { |
| 1101 | struct minstrel_priv *mp = priv; |
| 1102 | struct minstrel_ht_sta_priv *msp = priv_sta; |
| 1103 | struct minstrel_ht_sta *mi = &msp->ht; |
| 1104 | struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs; |
| 1105 | u16 sta_cap = sta->ht_cap.cap; |
| 1106 | struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap; |
| 1107 | int use_vht; |
| 1108 | int n_supported = 0; |
| 1109 | int ack_dur; |
| 1110 | int stbc; |
| 1111 | int i; |
| 1112 | |
| 1113 | /* fall back to the old minstrel for legacy stations */ |
| 1114 | if (!sta->ht_cap.ht_supported) |
| 1115 | goto use_legacy; |
| 1116 | |
| 1117 | BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB); |
| 1118 | |
| 1119 | #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT |
| 1120 | if (vht_cap->vht_supported) |
| 1121 | use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0); |
| 1122 | else |
| 1123 | #endif |
| 1124 | use_vht = 0; |
| 1125 | |
| 1126 | msp->is_ht = true; |
| 1127 | memset(mi, 0, sizeof(*mi)); |
| 1128 | |
| 1129 | mi->sta = sta; |
| 1130 | mi->last_stats_update = jiffies; |
| 1131 | |
| 1132 | ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0); |
| 1133 | mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0); |
| 1134 | mi->overhead += ack_dur; |
| 1135 | mi->overhead_rtscts = mi->overhead + 2 * ack_dur; |
| 1136 | |
| 1137 | mi->avg_ampdu_len = MINSTREL_FRAC(1, 1); |
| 1138 | |
| 1139 | /* When using MRR, sample more on the first attempt, without delay */ |
| 1140 | if (mp->has_mrr) { |
| 1141 | mi->sample_count = 16; |
| 1142 | mi->sample_wait = 0; |
| 1143 | } else { |
| 1144 | mi->sample_count = 8; |
| 1145 | mi->sample_wait = 8; |
| 1146 | } |
| 1147 | mi->sample_tries = 4; |
| 1148 | |
| 1149 | /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */ |
| 1150 | if (!use_vht) { |
| 1151 | stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >> |
| 1152 | IEEE80211_HT_CAP_RX_STBC_SHIFT; |
| 1153 | mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT; |
| 1154 | |
| 1155 | if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING) |
| 1156 | mi->tx_flags |= IEEE80211_TX_CTL_LDPC; |
| 1157 | } |
| 1158 | |
| 1159 | for (i = 0; i < ARRAY_SIZE(mi->groups); i++) { |
| 1160 | u32 gflags = minstrel_mcs_groups[i].flags; |
| 1161 | int bw, nss; |
| 1162 | |
| 1163 | mi->groups[i].supported = 0; |
| 1164 | if (i == MINSTREL_CCK_GROUP) { |
| 1165 | minstrel_ht_update_cck(mp, mi, sband, sta); |
| 1166 | continue; |
| 1167 | } |
| 1168 | |
| 1169 | if (gflags & IEEE80211_TX_RC_SHORT_GI) { |
| 1170 | if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) { |
| 1171 | if (!(sta_cap & IEEE80211_HT_CAP_SGI_40)) |
| 1172 | continue; |
| 1173 | } else { |
| 1174 | if (!(sta_cap & IEEE80211_HT_CAP_SGI_20)) |
| 1175 | continue; |
| 1176 | } |
| 1177 | } |
| 1178 | |
| 1179 | if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH && |
| 1180 | sta->bandwidth < IEEE80211_STA_RX_BW_40) |
| 1181 | continue; |
| 1182 | |
| 1183 | nss = minstrel_mcs_groups[i].streams; |
| 1184 | |
| 1185 | /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */ |
| 1186 | if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1) |
| 1187 | continue; |
| 1188 | |
| 1189 | /* HT rate */ |
| 1190 | if (gflags & IEEE80211_TX_RC_MCS) { |
| 1191 | #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT |
| 1192 | if (use_vht && minstrel_vht_only) |
| 1193 | continue; |
| 1194 | #endif |
| 1195 | mi->groups[i].supported = mcs->rx_mask[nss - 1]; |
| 1196 | if (mi->groups[i].supported) |
| 1197 | n_supported++; |
| 1198 | continue; |
| 1199 | } |
| 1200 | |
| 1201 | /* VHT rate */ |
| 1202 | if (!vht_cap->vht_supported || |
| 1203 | WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) || |
| 1204 | WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH)) |
| 1205 | continue; |
| 1206 | |
| 1207 | if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) { |
| 1208 | if (sta->bandwidth < IEEE80211_STA_RX_BW_80 || |
| 1209 | ((gflags & IEEE80211_TX_RC_SHORT_GI) && |
| 1210 | !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) { |
| 1211 | continue; |
| 1212 | } |
| 1213 | } |
| 1214 | |
| 1215 | if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) |
| 1216 | bw = BW_40; |
| 1217 | else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) |
| 1218 | bw = BW_80; |
| 1219 | else |
| 1220 | bw = BW_20; |
| 1221 | |
| 1222 | mi->groups[i].supported = minstrel_get_valid_vht_rates(bw, nss, |
| 1223 | vht_cap->vht_mcs.tx_mcs_map); |
| 1224 | |
| 1225 | if (mi->groups[i].supported) |
| 1226 | n_supported++; |
| 1227 | } |
| 1228 | |
| 1229 | if (!n_supported) |
| 1230 | goto use_legacy; |
| 1231 | |
| 1232 | /* create an initial rate table with the lowest supported rates */ |
| 1233 | minstrel_ht_update_stats(mp, mi); |
| 1234 | minstrel_ht_update_rates(mp, mi); |
| 1235 | |
| 1236 | return; |
| 1237 | |
| 1238 | use_legacy: |
| 1239 | msp->is_ht = false; |
| 1240 | memset(&msp->legacy, 0, sizeof(msp->legacy)); |
| 1241 | msp->legacy.r = msp->ratelist; |
| 1242 | msp->legacy.sample_table = msp->sample_table; |
| 1243 | return mac80211_minstrel.rate_init(priv, sband, chandef, sta, |
| 1244 | &msp->legacy); |
| 1245 | } |
| 1246 | |
| 1247 | static void |
| 1248 | minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband, |
| 1249 | struct cfg80211_chan_def *chandef, |
| 1250 | struct ieee80211_sta *sta, void *priv_sta) |
| 1251 | { |
| 1252 | minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); |
| 1253 | } |
| 1254 | |
| 1255 | static void |
| 1256 | minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband, |
| 1257 | struct cfg80211_chan_def *chandef, |
| 1258 | struct ieee80211_sta *sta, void *priv_sta, |
| 1259 | u32 changed) |
| 1260 | { |
| 1261 | minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); |
| 1262 | } |
| 1263 | |
| 1264 | static void * |
| 1265 | minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) |
| 1266 | { |
| 1267 | struct ieee80211_supported_band *sband; |
| 1268 | struct minstrel_ht_sta_priv *msp; |
| 1269 | struct minstrel_priv *mp = priv; |
| 1270 | struct ieee80211_hw *hw = mp->hw; |
| 1271 | int max_rates = 0; |
| 1272 | int i; |
| 1273 | |
| 1274 | for (i = 0; i < IEEE80211_NUM_BANDS; i++) { |
| 1275 | sband = hw->wiphy->bands[i]; |
| 1276 | if (sband && sband->n_bitrates > max_rates) |
| 1277 | max_rates = sband->n_bitrates; |
| 1278 | } |
| 1279 | |
| 1280 | msp = kzalloc(sizeof(*msp), gfp); |
| 1281 | if (!msp) |
| 1282 | return NULL; |
| 1283 | |
| 1284 | msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp); |
| 1285 | if (!msp->ratelist) |
| 1286 | goto error; |
| 1287 | |
| 1288 | msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp); |
| 1289 | if (!msp->sample_table) |
| 1290 | goto error1; |
| 1291 | |
| 1292 | return msp; |
| 1293 | |
| 1294 | error1: |
| 1295 | kfree(msp->ratelist); |
| 1296 | error: |
| 1297 | kfree(msp); |
| 1298 | return NULL; |
| 1299 | } |
| 1300 | |
| 1301 | static void |
| 1302 | minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) |
| 1303 | { |
| 1304 | struct minstrel_ht_sta_priv *msp = priv_sta; |
| 1305 | |
| 1306 | kfree(msp->sample_table); |
| 1307 | kfree(msp->ratelist); |
| 1308 | kfree(msp); |
| 1309 | } |
| 1310 | |
| 1311 | static void * |
| 1312 | minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) |
| 1313 | { |
| 1314 | return mac80211_minstrel.alloc(hw, debugfsdir); |
| 1315 | } |
| 1316 | |
| 1317 | static void |
| 1318 | minstrel_ht_free(void *priv) |
| 1319 | { |
| 1320 | mac80211_minstrel.free(priv); |
| 1321 | } |
| 1322 | |
| 1323 | static u32 minstrel_ht_get_expected_throughput(void *priv_sta) |
| 1324 | { |
| 1325 | struct minstrel_ht_sta_priv *msp = priv_sta; |
| 1326 | struct minstrel_ht_sta *mi = &msp->ht; |
| 1327 | int i, j, prob, tp_avg; |
| 1328 | |
| 1329 | if (!msp->is_ht) |
| 1330 | return mac80211_minstrel.get_expected_throughput(priv_sta); |
| 1331 | |
| 1332 | i = mi->max_tp_rate[0] / MCS_GROUP_RATES; |
| 1333 | j = mi->max_tp_rate[0] % MCS_GROUP_RATES; |
| 1334 | prob = mi->groups[i].rates[j].prob_ewma; |
| 1335 | |
| 1336 | /* convert tp_avg from pkt per second in kbps */ |
| 1337 | tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * AVG_PKT_SIZE * 8 / 1024; |
| 1338 | |
| 1339 | return tp_avg; |
| 1340 | } |
| 1341 | |
| 1342 | static const struct rate_control_ops mac80211_minstrel_ht = { |
| 1343 | .name = "minstrel_ht", |
| 1344 | .tx_status_noskb = minstrel_ht_tx_status, |
| 1345 | .get_rate = minstrel_ht_get_rate, |
| 1346 | .rate_init = minstrel_ht_rate_init, |
| 1347 | .rate_update = minstrel_ht_rate_update, |
| 1348 | .alloc_sta = minstrel_ht_alloc_sta, |
| 1349 | .free_sta = minstrel_ht_free_sta, |
| 1350 | .alloc = minstrel_ht_alloc, |
| 1351 | .free = minstrel_ht_free, |
| 1352 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 1353 | .add_sta_debugfs = minstrel_ht_add_sta_debugfs, |
| 1354 | .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs, |
| 1355 | #endif |
| 1356 | .get_expected_throughput = minstrel_ht_get_expected_throughput, |
| 1357 | }; |
| 1358 | |
| 1359 | |
| 1360 | static void __init init_sample_table(void) |
| 1361 | { |
| 1362 | int col, i, new_idx; |
| 1363 | u8 rnd[MCS_GROUP_RATES]; |
| 1364 | |
| 1365 | memset(sample_table, 0xff, sizeof(sample_table)); |
| 1366 | for (col = 0; col < SAMPLE_COLUMNS; col++) { |
| 1367 | prandom_bytes(rnd, sizeof(rnd)); |
| 1368 | for (i = 0; i < MCS_GROUP_RATES; i++) { |
| 1369 | new_idx = (i + rnd[i]) % MCS_GROUP_RATES; |
| 1370 | while (sample_table[col][new_idx] != 0xff) |
| 1371 | new_idx = (new_idx + 1) % MCS_GROUP_RATES; |
| 1372 | |
| 1373 | sample_table[col][new_idx] = i; |
| 1374 | } |
| 1375 | } |
| 1376 | } |
| 1377 | |
| 1378 | int __init |
| 1379 | rc80211_minstrel_ht_init(void) |
| 1380 | { |
| 1381 | init_sample_table(); |
| 1382 | return ieee80211_rate_control_register(&mac80211_minstrel_ht); |
| 1383 | } |
| 1384 | |
| 1385 | void |
| 1386 | rc80211_minstrel_ht_exit(void) |
| 1387 | { |
| 1388 | ieee80211_rate_control_unregister(&mac80211_minstrel_ht); |
| 1389 | } |