net/mac80211/rate.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2002-2005, Instant802 Networks, Inc.
   4  * Copyright 2005-2006, Devicescape Software, Inc.
   5  * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
   6  * Copyright 2017       Intel Deutschland GmbH
   7  * Copyright (C) 2019, 2022-2024 Intel Corporation
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/rtnetlink.h>
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include "rate.h"
  15 #include "ieee80211_i.h"
  16 #include "debugfs.h"
  17
  18 struct rate_control_alg {
  19         struct list_head list;
  20         const struct rate_control_ops *ops;
  21 };
  22
  23 static LIST_HEAD(rate_ctrl_algs);
  24 static DEFINE_MUTEX(rate_ctrl_mutex);
  25
  26 static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
  27 module_param(ieee80211_default_rc_algo, charp, 0644);
  28 MODULE_PARM_DESC(ieee80211_default_rc_algo,
  29                  "Default rate control algorithm for mac80211 to use");
  30
  31 void rate_control_rate_init(struct sta_info *sta)
  32 {
  33         struct ieee80211_local *local = sta->sdata->local;
  34         struct rate_control_ref *ref = sta->rate_ctrl;
  35         struct ieee80211_sta *ista = &sta->sta;
  36         void *priv_sta = sta->rate_ctrl_priv;
  37         struct ieee80211_supported_band *sband;
  38         struct ieee80211_chanctx_conf *chanctx_conf;
  39
  40         ieee80211_sta_init_nss(&sta->deflink);
  41
  42         if (!ref)
  43                 return;
  44
  45         rcu_read_lock();
  46
  47         chanctx_conf = rcu_dereference(sta->sdata->vif.bss_conf.chanctx_conf);
  48         if (WARN_ON(!chanctx_conf)) {
  49                 rcu_read_unlock();
  50                 return;
  51         }
  52
  53         sband = local->hw.wiphy->bands[chanctx_conf->def.chan->band];
  54
  55         /* TODO: check for minstrel_s1g ? */
  56         if (sband->band == NL80211_BAND_S1GHZ) {
  57                 ieee80211_s1g_sta_rate_init(sta);
  58                 rcu_read_unlock();
  59                 return;
  60         }
  61
  62         spin_lock_bh(&sta->rate_ctrl_lock);
  63         ref->ops->rate_init(ref->priv, sband, &chanctx_conf->def, ista,
  64                             priv_sta);
  65         spin_unlock_bh(&sta->rate_ctrl_lock);
  66         rcu_read_unlock();
  67         set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
  68 }
  69
  70 void rate_control_tx_status(struct ieee80211_local *local,
  71                             struct ieee80211_tx_status *st)
  72 {
  73         struct rate_control_ref *ref = local->rate_ctrl;
  74         struct sta_info *sta = container_of(st->sta, struct sta_info, sta);
  75         void *priv_sta = sta->rate_ctrl_priv;
  76         struct ieee80211_supported_band *sband;
  77
  78         if (!ref || !test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
  79                 return;
  80
  81         sband = local->hw.wiphy->bands[st->info->band];
  82
  83         spin_lock_bh(&sta->rate_ctrl_lock);
  84         if (ref->ops->tx_status_ext)
  85                 ref->ops->tx_status_ext(ref->priv, sband, priv_sta, st);
  86         else if (st->skb)
  87                 ref->ops->tx_status(ref->priv, sband, st->sta, priv_sta, st->skb);
  88         else
  89                 WARN_ON_ONCE(1);
  90
  91         spin_unlock_bh(&sta->rate_ctrl_lock);
  92 }
  93
  94 void rate_control_rate_update(struct ieee80211_local *local,
  95                               struct ieee80211_supported_band *sband,
  96                               struct sta_info *sta, unsigned int link_id,
  97                               u32 changed)
  98 {
  99         struct rate_control_ref *ref = local->rate_ctrl;
 100         struct ieee80211_sta *ista = &sta->sta;
 101         void *priv_sta = sta->rate_ctrl_priv;
 102         struct ieee80211_chanctx_conf *chanctx_conf;
 103
 104         WARN_ON(link_id != 0);
 105
 106         if (ref && ref->ops->rate_update) {
 107                 rcu_read_lock();
 108
 109                 chanctx_conf = rcu_dereference(sta->sdata->vif.bss_conf.chanctx_conf);
 110                 if (WARN_ON(!chanctx_conf)) {
 111                         rcu_read_unlock();
 112                         return;
 113                 }
 114
 115                 spin_lock_bh(&sta->rate_ctrl_lock);
 116                 ref->ops->rate_update(ref->priv, sband, &chanctx_conf->def,
 117                                       ista, priv_sta, changed);
 118                 spin_unlock_bh(&sta->rate_ctrl_lock);
 119                 rcu_read_unlock();
 120         }
 121
 122         if (sta->uploaded)
 123                 drv_sta_rc_update(local, sta->sdata, &sta->sta, changed);
 124 }
 125
 126 int ieee80211_rate_control_register(const struct rate_control_ops *ops)
 127 {
 128         struct rate_control_alg *alg;
 129
 130         if (!ops->name)
 131                 return -EINVAL;
 132
 133         mutex_lock(&rate_ctrl_mutex);
 134         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 135                 if (!strcmp(alg->ops->name, ops->name)) {
 136                         /* don't register an algorithm twice */
 137                         WARN_ON(1);
 138                         mutex_unlock(&rate_ctrl_mutex);
 139                         return -EALREADY;
 140                 }
 141         }
 142
 143         alg = kzalloc(sizeof(*alg), GFP_KERNEL);
 144         if (alg == NULL) {
 145                 mutex_unlock(&rate_ctrl_mutex);
 146                 return -ENOMEM;
 147         }
 148         alg->ops = ops;
 149
 150         list_add_tail(&alg->list, &rate_ctrl_algs);
 151         mutex_unlock(&rate_ctrl_mutex);
 152
 153         return 0;
 154 }
 155 EXPORT_SYMBOL(ieee80211_rate_control_register);
 156
 157 void ieee80211_rate_control_unregister(const struct rate_control_ops *ops)
 158 {
 159         struct rate_control_alg *alg;
 160
 161         mutex_lock(&rate_ctrl_mutex);
 162         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 163                 if (alg->ops == ops) {
 164                         list_del(&alg->list);
 165                         kfree(alg);
 166                         break;
 167                 }
 168         }
 169         mutex_unlock(&rate_ctrl_mutex);
 170 }
 171 EXPORT_SYMBOL(ieee80211_rate_control_unregister);
 172
 173 static const struct rate_control_ops *
 174 ieee80211_try_rate_control_ops_get(const char *name)
 175 {
 176         struct rate_control_alg *alg;
 177         const struct rate_control_ops *ops = NULL;
 178
 179         if (!name)
 180                 return NULL;
 181
 182         mutex_lock(&rate_ctrl_mutex);
 183         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 184                 if (!strcmp(alg->ops->name, name)) {
 185                         ops = alg->ops;
 186                         break;
 187                 }
 188         }
 189         mutex_unlock(&rate_ctrl_mutex);
 190         return ops;
 191 }
 192
 193 /* Get the rate control algorithm. */
 194 static const struct rate_control_ops *
 195 ieee80211_rate_control_ops_get(const char *name)
 196 {
 197         const struct rate_control_ops *ops;
 198         const char *alg_name;
 199
 200         kernel_param_lock(THIS_MODULE);
 201         if (!name)
 202                 alg_name = ieee80211_default_rc_algo;
 203         else
 204                 alg_name = name;
 205
 206         ops = ieee80211_try_rate_control_ops_get(alg_name);
 207         if (!ops && name)
 208                 /* try default if specific alg requested but not found */
 209                 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
 210
 211         /* Note: check for > 0 is intentional to avoid clang warning */
 212         if (!ops && (strlen(CONFIG_MAC80211_RC_DEFAULT) > 0))
 213                 /* try built-in one if specific alg requested but not found */
 214                 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
 215
 216         kernel_param_unlock(THIS_MODULE);
 217
 218         return ops;
 219 }
 220
 221 #ifdef CONFIG_MAC80211_DEBUGFS
 222 static ssize_t rcname_read(struct file *file, char __user *userbuf,
 223                            size_t count, loff_t *ppos)
 224 {
 225         struct rate_control_ref *ref = file->private_data;
 226         int len = strlen(ref->ops->name);
 227
 228         return simple_read_from_buffer(userbuf, count, ppos,
 229                                        ref->ops->name, len);
 230 }
 231
 232 const struct file_operations rcname_ops = {
 233         .read = rcname_read,
 234         .open = simple_open,
 235         .llseek = default_llseek,
 236 };
 237 #endif
 238
 239 static struct rate_control_ref *
 240 rate_control_alloc(const char *name, struct ieee80211_local *local)
 241 {
 242         struct rate_control_ref *ref;
 243
 244         ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
 245         if (!ref)
 246                 return NULL;
 247         ref->ops = ieee80211_rate_control_ops_get(name);
 248         if (!ref->ops)
 249                 goto free;
 250
 251         ref->priv = ref->ops->alloc(&local->hw);
 252         if (!ref->priv)
 253                 goto free;
 254         return ref;
 255
 256 free:
 257         kfree(ref);
 258         return NULL;
 259 }
 260
 261 static void rate_control_free(struct ieee80211_local *local,
 262                               struct rate_control_ref *ctrl_ref)
 263 {
 264         ctrl_ref->ops->free(ctrl_ref->priv);
 265
 266 #ifdef CONFIG_MAC80211_DEBUGFS
 267         debugfs_remove_recursive(local->debugfs.rcdir);
 268         local->debugfs.rcdir = NULL;
 269 #endif
 270
 271         kfree(ctrl_ref);
 272 }
 273
 274 void ieee80211_check_rate_mask(struct ieee80211_link_data *link)
 275 {
 276         struct ieee80211_sub_if_data *sdata = link->sdata;
 277         struct ieee80211_local *local = sdata->local;
 278         struct ieee80211_supported_band *sband;
 279         u32 user_mask, basic_rates = link->conf->basic_rates;
 280         enum nl80211_band band;
 281
 282         if (WARN_ON(!link->conf->chanreq.oper.chan))
 283                 return;
 284
 285         band = link->conf->chanreq.oper.chan->band;
 286         if (band == NL80211_BAND_S1GHZ) {
 287                 /* TODO */
 288                 return;
 289         }
 290
 291         if (WARN_ON_ONCE(!basic_rates))
 292                 return;
 293
 294         user_mask = sdata->rc_rateidx_mask[band];
 295         sband = local->hw.wiphy->bands[band];
 296
 297         if (user_mask & basic_rates)
 298                 return;
 299
 300         sdata_dbg(sdata,
 301                   "no overlap between basic rates (0x%x) and user mask (0x%x on band %d) - clearing the latter",
 302                   basic_rates, user_mask, band);
 303         sdata->rc_rateidx_mask[band] = (1 << sband->n_bitrates) - 1;
 304 }
 305
 306 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
 307 {
 308         struct sk_buff *skb = txrc->skb;
 309         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 310
 311         return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
 312                                IEEE80211_TX_CTL_USE_MINRATE)) ||
 313                 !ieee80211_is_tx_data(skb);
 314 }
 315
 316 static void rc_send_low_basicrate(struct ieee80211_tx_rate *rate,
 317                                   u32 basic_rates,
 318                                   struct ieee80211_supported_band *sband)
 319 {
 320         u8 i;
 321
 322         if (sband->band == NL80211_BAND_S1GHZ) {
 323                 /* TODO */
 324                 rate->flags |= IEEE80211_TX_RC_S1G_MCS;
 325                 rate->idx = 0;
 326                 return;
 327         }
 328
 329         if (basic_rates == 0)
 330                 return; /* assume basic rates unknown and accept rate */
 331         if (rate->idx < 0)
 332                 return;
 333         if (basic_rates & (1 << rate->idx))
 334                 return; /* selected rate is a basic rate */
 335
 336         for (i = rate->idx + 1; i <= sband->n_bitrates; i++) {
 337                 if (basic_rates & (1 << i)) {
 338                         rate->idx = i;
 339                         return;
 340                 }
 341         }
 342
 343         /* could not find a basic rate; use original selection */
 344 }
 345
 346 static void __rate_control_send_low(struct ieee80211_hw *hw,
 347                                     struct ieee80211_supported_band *sband,
 348                                     struct ieee80211_sta *sta,
 349                                     struct ieee80211_tx_info *info,
 350                                     u32 rate_mask)
 351 {
 352         int i;
 353         u32 rate_flags =
 354                 ieee80211_chandef_rate_flags(&hw->conf.chandef);
 355
 356         if (sband->band == NL80211_BAND_S1GHZ) {
 357                 info->control.rates[0].flags |= IEEE80211_TX_RC_S1G_MCS;
 358                 info->control.rates[0].idx = 0;
 359                 return;
 360         }
 361
 362         if ((sband->band == NL80211_BAND_2GHZ) &&
 363             (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
 364                 rate_flags |= IEEE80211_RATE_ERP_G;
 365
 366         info->control.rates[0].idx = 0;
 367         for (i = 0; i < sband->n_bitrates; i++) {
 368                 if (!(rate_mask & BIT(i)))
 369                         continue;
 370
 371                 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
 372                         continue;
 373
 374                 if (!rate_supported(sta, sband->band, i))
 375                         continue;
 376
 377                 info->control.rates[0].idx = i;
 378                 break;
 379         }
 380         WARN_ONCE(i == sband->n_bitrates,
 381                   "no supported rates for sta %pM (0x%x, band %d) in rate_mask 0x%x with flags 0x%x\n",
 382                   sta ? sta->addr : NULL,
 383                   sta ? sta->deflink.supp_rates[sband->band] : -1,
 384                   sband->band,
 385                   rate_mask, rate_flags);
 386
 387         info->control.rates[0].count =
 388                 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
 389                 1 : hw->max_rate_tries;
 390
 391         info->control.skip_table = 1;
 392 }
 393
 394
 395 static bool rate_control_send_low(struct ieee80211_sta *pubsta,
 396                                   struct ieee80211_tx_rate_control *txrc)
 397 {
 398         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 399         struct ieee80211_supported_band *sband = txrc->sband;
 400         struct sta_info *sta;
 401         int mcast_rate;
 402         bool use_basicrate = false;
 403
 404         if (!pubsta || rc_no_data_or_no_ack_use_min(txrc)) {
 405                 __rate_control_send_low(txrc->hw, sband, pubsta, info,
 406                                         txrc->rate_idx_mask);
 407
 408                 if (!pubsta && txrc->bss) {
 409                         mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
 410                         if (mcast_rate > 0) {
 411                                 info->control.rates[0].idx = mcast_rate - 1;
 412                                 return true;
 413                         }
 414                         use_basicrate = true;
 415                 } else if (pubsta) {
 416                         sta = container_of(pubsta, struct sta_info, sta);
 417                         if (ieee80211_vif_is_mesh(&sta->sdata->vif))
 418                                 use_basicrate = true;
 419                 }
 420
 421                 if (use_basicrate)
 422                         rc_send_low_basicrate(&info->control.rates[0],
 423                                               txrc->bss_conf->basic_rates,
 424                                               sband);
 425
 426                 return true;
 427         }
 428         return false;
 429 }
 430
 431 static bool rate_idx_match_legacy_mask(s8 *rate_idx, int n_bitrates, u32 mask)
 432 {
 433         int j;
 434
 435         /* See whether the selected rate or anything below it is allowed. */
 436         for (j = *rate_idx; j >= 0; j--) {
 437                 if (mask & (1 << j)) {
 438                         /* Okay, found a suitable rate. Use it. */
 439                         *rate_idx = j;
 440                         return true;
 441                 }
 442         }
 443
 444         /* Try to find a higher rate that would be allowed */
 445         for (j = *rate_idx + 1; j < n_bitrates; j++) {
 446                 if (mask & (1 << j)) {
 447                         /* Okay, found a suitable rate. Use it. */
 448                         *rate_idx = j;
 449                         return true;
 450                 }
 451         }
 452         return false;
 453 }
 454
 455 static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
 456 {
 457         int i, j;
 458         int ridx, rbit;
 459
 460         ridx = *rate_idx / 8;
 461         rbit = *rate_idx % 8;
 462
 463         /* sanity check */
 464         if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
 465                 return false;
 466
 467         /* See whether the selected rate or anything below it is allowed. */
 468         for (i = ridx; i >= 0; i--) {
 469                 for (j = rbit; j >= 0; j--)
 470                         if (mcs_mask[i] & BIT(j)) {
 471                                 *rate_idx = i * 8 + j;
 472                                 return true;
 473                         }
 474                 rbit = 7;
 475         }
 476
 477         /* Try to find a higher rate that would be allowed */
 478         ridx = (*rate_idx + 1) / 8;
 479         rbit = (*rate_idx + 1) % 8;
 480
 481         for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
 482                 for (j = rbit; j < 8; j++)
 483                         if (mcs_mask[i] & BIT(j)) {
 484                                 *rate_idx = i * 8 + j;
 485                                 return true;
 486                         }
 487                 rbit = 0;
 488         }
 489         return false;
 490 }
 491
 492 static bool rate_idx_match_vht_mcs_mask(s8 *rate_idx, u16 *vht_mask)
 493 {
 494         int i, j;
 495         int ridx, rbit;
 496
 497         ridx = *rate_idx >> 4;
 498         rbit = *rate_idx & 0xf;
 499
 500         if (ridx < 0 || ridx >= NL80211_VHT_NSS_MAX)
 501                 return false;
 502
 503         /* See whether the selected rate or anything below it is allowed. */
 504         for (i = ridx; i >= 0; i--) {
 505                 for (j = rbit; j >= 0; j--) {
 506                         if (vht_mask[i] & BIT(j)) {
 507                                 *rate_idx = (i << 4) | j;
 508                                 return true;
 509                         }
 510                 }
 511                 rbit = 15;
 512         }
 513
 514         /* Try to find a higher rate that would be allowed */
 515         ridx = (*rate_idx + 1) >> 4;
 516         rbit = (*rate_idx + 1) & 0xf;
 517
 518         for (i = ridx; i < NL80211_VHT_NSS_MAX; i++) {
 519                 for (j = rbit; j < 16; j++) {
 520                         if (vht_mask[i] & BIT(j)) {
 521                                 *rate_idx = (i << 4) | j;
 522                                 return true;
 523                         }
 524                 }
 525                 rbit = 0;
 526         }
 527         return false;
 528 }
 529
 530 static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
 531                                 struct ieee80211_supported_band *sband,
 532                                 enum nl80211_chan_width chan_width,
 533                                 u32 mask,
 534                                 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 535                                 u16 vht_mask[NL80211_VHT_NSS_MAX])
 536 {
 537         if (*rate_flags & IEEE80211_TX_RC_VHT_MCS) {
 538                 /* handle VHT rates */
 539                 if (rate_idx_match_vht_mcs_mask(rate_idx, vht_mask))
 540                         return;
 541
 542                 *rate_idx = 0;
 543                 /* keep protection flags */
 544                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 545                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 546                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 547
 548                 *rate_flags |= IEEE80211_TX_RC_MCS;
 549                 if (chan_width == NL80211_CHAN_WIDTH_40)
 550                         *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 551
 552                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 553                         return;
 554
 555                 /* also try the legacy rates. */
 556                 *rate_flags &= ~(IEEE80211_TX_RC_MCS |
 557                                  IEEE80211_TX_RC_40_MHZ_WIDTH);
 558                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 559                                                mask))
 560                         return;
 561         } else if (*rate_flags & IEEE80211_TX_RC_MCS) {
 562                 /* handle HT rates */
 563                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 564                         return;
 565
 566                 /* also try the legacy rates. */
 567                 *rate_idx = 0;
 568                 /* keep protection flags */
 569                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 570                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 571                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 572                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 573                                                mask))
 574                         return;
 575         } else {
 576                 /* handle legacy rates */
 577                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 578                                                mask))
 579                         return;
 580
 581                 /* if HT BSS, and we handle a data frame, also try HT rates */
 582                 switch (chan_width) {
 583                 case NL80211_CHAN_WIDTH_20_NOHT:
 584                 case NL80211_CHAN_WIDTH_5:
 585                 case NL80211_CHAN_WIDTH_10:
 586                         return;
 587                 default:
 588                         break;
 589                 }
 590
 591                 *rate_idx = 0;
 592                 /* keep protection flags */
 593                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 594                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 595                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 596
 597                 *rate_flags |= IEEE80211_TX_RC_MCS;
 598
 599                 if (chan_width == NL80211_CHAN_WIDTH_40)
 600                         *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 601
 602                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 603                         return;
 604         }
 605
 606         /*
 607          * Uh.. No suitable rate exists. This should not really happen with
 608          * sane TX rate mask configurations. However, should someone manage to
 609          * configure supported rates and TX rate mask in incompatible way,
 610          * allow the frame to be transmitted with whatever the rate control
 611          * selected.
 612          */
 613 }
 614
 615 static void rate_fixup_ratelist(struct ieee80211_vif *vif,
 616                                 struct ieee80211_supported_band *sband,
 617                                 struct ieee80211_tx_info *info,
 618                                 struct ieee80211_tx_rate *rates,
 619                                 int max_rates)
 620 {
 621         struct ieee80211_rate *rate;
 622         bool inval = false;
 623         int i;
 624
 625         /*
 626          * Set up the RTS/CTS rate as the fastest basic rate
 627          * that is not faster than the data rate unless there
 628          * is no basic rate slower than the data rate, in which
 629          * case we pick the slowest basic rate
 630          *
 631          * XXX: Should this check all retry rates?
 632          */
 633         if (!(rates[0].flags &
 634               (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))) {
 635                 u32 basic_rates = vif->bss_conf.basic_rates;
 636                 s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
 637
 638                 rate = &sband->bitrates[rates[0].idx];
 639
 640                 for (i = 0; i < sband->n_bitrates; i++) {
 641                         /* must be a basic rate */
 642                         if (!(basic_rates & BIT(i)))
 643                                 continue;
 644                         /* must not be faster than the data rate */
 645                         if (sband->bitrates[i].bitrate > rate->bitrate)
 646                                 continue;
 647                         /* maximum */
 648                         if (sband->bitrates[baserate].bitrate <
 649                              sband->bitrates[i].bitrate)
 650                                 baserate = i;
 651                 }
 652
 653                 info->control.rts_cts_rate_idx = baserate;
 654         }
 655
 656         for (i = 0; i < max_rates; i++) {
 657                 /*
 658                  * make sure there's no valid rate following
 659                  * an invalid one, just in case drivers don't
 660                  * take the API seriously to stop at -1.
 661                  */
 662                 if (inval) {
 663                         rates[i].idx = -1;
 664                         continue;
 665                 }
 666                 if (rates[i].idx < 0) {
 667                         inval = true;
 668                         continue;
 669                 }
 670
 671                 /*
 672                  * For now assume MCS is already set up correctly, this
 673                  * needs to be fixed.
 674                  */
 675                 if (rates[i].flags & IEEE80211_TX_RC_MCS) {
 676                         WARN_ON(rates[i].idx > 76);
 677
 678                         if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 679                             info->control.use_cts_prot)
 680                                 rates[i].flags |=
 681                                         IEEE80211_TX_RC_USE_CTS_PROTECT;
 682                         continue;
 683                 }
 684
 685                 if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
 686                         WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
 687                         continue;
 688                 }
 689
 690                 /* set up RTS protection if desired */
 691                 if (info->control.use_rts) {
 692                         rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
 693                         info->control.use_cts_prot = false;
 694                 }
 695
 696                 /* RC is busted */
 697                 if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
 698                         rates[i].idx = -1;
 699                         continue;
 700                 }
 701
 702                 rate = &sband->bitrates[rates[i].idx];
 703
 704                 /* set up short preamble */
 705                 if (info->control.short_preamble &&
 706                     rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
 707                         rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
 708
 709                 /* set up G protection */
 710                 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 711                     info->control.use_cts_prot &&
 712                     rate->flags & IEEE80211_RATE_ERP_G)
 713                         rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
 714         }
 715 }
 716
 717
 718 static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
 719                                         struct ieee80211_tx_info *info,
 720                                         struct ieee80211_tx_rate *rates,
 721                                         int max_rates)
 722 {
 723         struct ieee80211_sta_rates *ratetbl = NULL;
 724         int i;
 725
 726         if (sta && !info->control.skip_table)
 727                 ratetbl = rcu_dereference(sta->rates);
 728
 729         /* Fill remaining rate slots with data from the sta rate table. */
 730         max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
 731         for (i = 0; i < max_rates; i++) {
 732                 if (i < ARRAY_SIZE(info->control.rates) &&
 733                     info->control.rates[i].idx >= 0 &&
 734                     info->control.rates[i].count) {
 735                         if (rates != info->control.rates)
 736                                 rates[i] = info->control.rates[i];
 737                 } else if (ratetbl) {
 738                         rates[i].idx = ratetbl->rate[i].idx;
 739                         rates[i].flags = ratetbl->rate[i].flags;
 740                         if (info->control.use_rts)
 741                                 rates[i].count = ratetbl->rate[i].count_rts;
 742                         else if (info->control.use_cts_prot)
 743                                 rates[i].count = ratetbl->rate[i].count_cts;
 744                         else
 745                                 rates[i].count = ratetbl->rate[i].count;
 746                 } else {
 747                         rates[i].idx = -1;
 748                         rates[i].count = 0;
 749                 }
 750
 751                 if (rates[i].idx < 0 || !rates[i].count)
 752                         break;
 753         }
 754 }
 755
 756 static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
 757                                   struct ieee80211_supported_band *sband,
 758                                   struct ieee80211_sta *sta, u32 *mask,
 759                                   u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 760                                   u16 vht_mask[NL80211_VHT_NSS_MAX])
 761 {
 762         u32 i, flags;
 763
 764         *mask = sdata->rc_rateidx_mask[sband->band];
 765         flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chanreq.oper);
 766         for (i = 0; i < sband->n_bitrates; i++) {
 767                 if ((flags & sband->bitrates[i].flags) != flags)
 768                         *mask &= ~BIT(i);
 769         }
 770
 771         if (*mask == (1 << sband->n_bitrates) - 1 &&
 772             !sdata->rc_has_mcs_mask[sband->band] &&
 773             !sdata->rc_has_vht_mcs_mask[sband->band])
 774                 return false;
 775
 776         if (sdata->rc_has_mcs_mask[sband->band])
 777                 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
 778                        IEEE80211_HT_MCS_MASK_LEN);
 779         else
 780                 memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
 781
 782         if (sdata->rc_has_vht_mcs_mask[sband->band])
 783                 memcpy(vht_mask, sdata->rc_rateidx_vht_mcs_mask[sband->band],
 784                        sizeof(u16) * NL80211_VHT_NSS_MAX);
 785         else
 786                 memset(vht_mask, 0xff, sizeof(u16) * NL80211_VHT_NSS_MAX);
 787
 788         if (sta) {
 789                 __le16 sta_vht_cap;
 790                 u16 sta_vht_mask[NL80211_VHT_NSS_MAX];
 791
 792                 /* Filter out rates that the STA does not support */
 793                 *mask &= sta->deflink.supp_rates[sband->band];
 794                 for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++)
 795                         mcs_mask[i] &= sta->deflink.ht_cap.mcs.rx_mask[i];
 796
 797                 sta_vht_cap = sta->deflink.vht_cap.vht_mcs.rx_mcs_map;
 798                 ieee80211_get_vht_mask_from_cap(sta_vht_cap, sta_vht_mask);
 799                 for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
 800                         vht_mask[i] &= sta_vht_mask[i];
 801         }
 802
 803         return true;
 804 }
 805
 806 static void
 807 rate_control_apply_mask_ratetbl(struct sta_info *sta,
 808                                 struct ieee80211_supported_band *sband,
 809                                 struct ieee80211_sta_rates *rates)
 810 {
 811         int i;
 812         u32 mask;
 813         u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 814         u16 vht_mask[NL80211_VHT_NSS_MAX];
 815         enum nl80211_chan_width chan_width;
 816
 817         if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
 818                                    mcs_mask, vht_mask))
 819                 return;
 820
 821         chan_width = sta->sdata->vif.bss_conf.chanreq.oper.width;
 822         for (i = 0; i < IEEE80211_TX_RATE_TABLE_SIZE; i++) {
 823                 if (rates->rate[i].idx < 0)
 824                         break;
 825
 826                 rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
 827                                     sband, chan_width, mask, mcs_mask,
 828                                     vht_mask);
 829         }
 830 }
 831
 832 static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 833                                     struct ieee80211_sta *sta,
 834                                     struct ieee80211_supported_band *sband,
 835                                     struct ieee80211_tx_rate *rates,
 836                                     int max_rates)
 837 {
 838         enum nl80211_chan_width chan_width;
 839         u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 840         u32 mask;
 841         u16 rate_flags, vht_mask[NL80211_VHT_NSS_MAX];
 842         int i;
 843
 844         /*
 845          * Try to enforce the rateidx mask the user wanted. skip this if the
 846          * default mask (allow all rates) is used to save some processing for
 847          * the common case.
 848          */
 849         if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask,
 850                                    vht_mask))
 851                 return;
 852
 853         /*
 854          * Make sure the rate index selected for each TX rate is
 855          * included in the configured mask and change the rate indexes
 856          * if needed.
 857          */
 858         chan_width = sdata->vif.bss_conf.chanreq.oper.width;
 859         for (i = 0; i < max_rates; i++) {
 860                 /* Skip invalid rates */
 861                 if (rates[i].idx < 0)
 862                         break;
 863
 864                 rate_flags = rates[i].flags;
 865                 rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
 866                                     chan_width, mask, mcs_mask, vht_mask);
 867                 rates[i].flags = rate_flags;
 868         }
 869 }
 870
 871 void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
 872                             struct ieee80211_sta *sta,
 873                             struct sk_buff *skb,
 874                             struct ieee80211_tx_rate *dest,
 875                             int max_rates)
 876 {
 877         struct ieee80211_sub_if_data *sdata;
 878         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 879         struct ieee80211_supported_band *sband;
 880         u32 mask = ~0;
 881
 882         rate_control_fill_sta_table(sta, info, dest, max_rates);
 883
 884         if (!vif)
 885                 return;
 886
 887         sdata = vif_to_sdata(vif);
 888         sband = sdata->local->hw.wiphy->bands[info->band];
 889
 890         if (ieee80211_is_tx_data(skb))
 891                 rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
 892
 893         if (!(info->control.flags & IEEE80211_TX_CTRL_DONT_USE_RATE_MASK))
 894                 mask = sdata->rc_rateidx_mask[info->band];
 895
 896         if (dest[0].idx < 0)
 897                 __rate_control_send_low(&sdata->local->hw, sband, sta, info,
 898                                         mask);
 899
 900         if (sta)
 901                 rate_fixup_ratelist(vif, sband, info, dest, max_rates);
 902 }
 903 EXPORT_SYMBOL(ieee80211_get_tx_rates);
 904
 905 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
 906                            struct sta_info *sta,
 907                            struct ieee80211_tx_rate_control *txrc)
 908 {
 909         struct rate_control_ref *ref = sdata->local->rate_ctrl;
 910         void *priv_sta = NULL;
 911         struct ieee80211_sta *ista = NULL;
 912         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 913         int i;
 914
 915         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 916                 info->control.rates[i].idx = -1;
 917                 info->control.rates[i].flags = 0;
 918                 info->control.rates[i].count = 0;
 919         }
 920
 921         if (rate_control_send_low(sta ? &sta->sta : NULL, txrc))
 922                 return;
 923
 924         if (ieee80211_hw_check(&sdata->local->hw, HAS_RATE_CONTROL))
 925                 return;
 926
 927         if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
 928                 ista = &sta->sta;
 929                 priv_sta = sta->rate_ctrl_priv;
 930         }
 931
 932         if (ista) {
 933                 spin_lock_bh(&sta->rate_ctrl_lock);
 934                 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
 935                 spin_unlock_bh(&sta->rate_ctrl_lock);
 936         } else {
 937                 rate_control_send_low(NULL, txrc);
 938         }
 939
 940         if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_RC_TABLE))
 941                 return;
 942
 943         ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
 944                                info->control.rates,
 945                                ARRAY_SIZE(info->control.rates));
 946 }
 947
 948 int rate_control_set_rates(struct ieee80211_hw *hw,
 949                            struct ieee80211_sta *pubsta,
 950                            struct ieee80211_sta_rates *rates)
 951 {
 952         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 953         struct ieee80211_sta_rates *old;
 954         struct ieee80211_supported_band *sband;
 955
 956         sband = ieee80211_get_sband(sta->sdata);
 957         if (!sband)
 958                 return -EINVAL;
 959         rate_control_apply_mask_ratetbl(sta, sband, rates);
 960         /*
 961          * mac80211 guarantees that this function will not be called
 962          * concurrently, so the following RCU access is safe, even without
 963          * extra locking. This can not be checked easily, so we just set
 964          * the condition to true.
 965          */
 966         old = rcu_dereference_protected(pubsta->rates, true);
 967         rcu_assign_pointer(pubsta->rates, rates);
 968         if (old)
 969                 kfree_rcu(old, rcu_head);
 970
 971         if (sta->uploaded)
 972                 drv_sta_rate_tbl_update(hw_to_local(hw), sta->sdata, pubsta);
 973
 974         ieee80211_sta_set_expected_throughput(pubsta, sta_get_expected_throughput(sta));
 975
 976         return 0;
 977 }
 978 EXPORT_SYMBOL(rate_control_set_rates);
 979
 980 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
 981                                  const char *name)
 982 {
 983         struct rate_control_ref *ref;
 984
 985         ASSERT_RTNL();
 986
 987         if (local->open_count)
 988                 return -EBUSY;
 989
 990         if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
 991                 if (WARN_ON(!local->ops->set_rts_threshold))
 992                         return -EINVAL;
 993                 return 0;
 994         }
 995
 996         ref = rate_control_alloc(name, local);
 997         if (!ref) {
 998                 wiphy_warn(local->hw.wiphy,
 999                            "Failed to select rate control algorithm\n");
1000                 return -ENOENT;
1001         }
1002
1003         WARN_ON(local->rate_ctrl);
1004         local->rate_ctrl = ref;
1005
1006         wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
1007                     ref->ops->name);
1008
1009         return 0;
1010 }
1011
1012 void rate_control_deinitialize(struct ieee80211_local *local)
1013 {
1014         struct rate_control_ref *ref;
1015
1016         ref = local->rate_ctrl;
1017
1018         if (!ref)
1019                 return;
1020
1021         local->rate_ctrl = NULL;
1022         rate_control_free(local, ref);
1023 }