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 link_sta_info *link_sta)
  32 {
  33         struct sta_info *sta = link_sta->sta;
  34         struct ieee80211_local *local = sta->sdata->local;
  35         struct rate_control_ref *ref = sta->rate_ctrl;
  36         struct ieee80211_sta *ista = &sta->sta;
  37         void *priv_sta = sta->rate_ctrl_priv;
  38         struct ieee80211_supported_band *sband;
  39         struct ieee80211_chanctx_conf *chanctx_conf;
  40
  41         ieee80211_sta_init_nss(link_sta);
  42
  43         if (!ref)
  44                 return;
  45
  46         /* SW rate control isn't supported with MLO right now */
  47         if (WARN_ON(ieee80211_vif_is_mld(&sta->sdata->vif)))
  48                 return;
  49
  50         rcu_read_lock();
  51
  52         chanctx_conf = rcu_dereference(sta->sdata->vif.bss_conf.chanctx_conf);
  53         if (WARN_ON(!chanctx_conf)) {
  54                 rcu_read_unlock();
  55                 return;
  56         }
  57
  58         sband = local->hw.wiphy->bands[chanctx_conf->def.chan->band];
  59
  60         /* TODO: check for minstrel_s1g ? */
  61         if (sband->band == NL80211_BAND_S1GHZ) {
  62                 ieee80211_s1g_sta_rate_init(sta);
  63                 rcu_read_unlock();
  64                 return;
  65         }
  66
  67         spin_lock_bh(&sta->rate_ctrl_lock);
  68         ref->ops->rate_init(ref->priv, sband, &chanctx_conf->def, ista,
  69                             priv_sta);
  70         spin_unlock_bh(&sta->rate_ctrl_lock);
  71         rcu_read_unlock();
  72         set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
  73 }
  74
  75 void rate_control_rate_init_all_links(struct sta_info *sta)
  76 {
  77         int link_id;
  78
  79         for (link_id = 0; link_id < ARRAY_SIZE(sta->link); link_id++) {
  80                 struct link_sta_info *link_sta;
  81
  82                 link_sta = sdata_dereference(sta->link[link_id], sta->sdata);
  83                 if (!link_sta)
  84                         continue;
  85
  86                 rate_control_rate_init(link_sta);
  87         }
  88 }
  89
  90 void rate_control_tx_status(struct ieee80211_local *local,
  91                             struct ieee80211_tx_status *st)
  92 {
  93         struct rate_control_ref *ref = local->rate_ctrl;
  94         struct sta_info *sta = container_of(st->sta, struct sta_info, sta);
  95         void *priv_sta = sta->rate_ctrl_priv;
  96         struct ieee80211_supported_band *sband;
  97
  98         if (!ref || !test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
  99                 return;
 100
 101         sband = local->hw.wiphy->bands[st->info->band];
 102
 103         spin_lock_bh(&sta->rate_ctrl_lock);
 104         if (ref->ops->tx_status_ext)
 105                 ref->ops->tx_status_ext(ref->priv, sband, priv_sta, st);
 106         else if (st->skb)
 107                 ref->ops->tx_status(ref->priv, sband, st->sta, priv_sta, st->skb);
 108         else
 109                 WARN_ON_ONCE(1);
 110
 111         spin_unlock_bh(&sta->rate_ctrl_lock);
 112 }
 113
 114 void rate_control_rate_update(struct ieee80211_local *local,
 115                               struct ieee80211_supported_band *sband,
 116                               struct link_sta_info *link_sta,
 117                               u32 changed)
 118 {
 119         struct rate_control_ref *ref = local->rate_ctrl;
 120         struct sta_info *sta = link_sta->sta;
 121         struct ieee80211_sta *ista = &sta->sta;
 122         void *priv_sta = sta->rate_ctrl_priv;
 123         struct ieee80211_chanctx_conf *chanctx_conf;
 124
 125         if (ref && ref->ops->rate_update) {
 126                 rcu_read_lock();
 127
 128                 chanctx_conf = rcu_dereference(sta->sdata->vif.bss_conf.chanctx_conf);
 129                 if (WARN_ON(!chanctx_conf)) {
 130                         rcu_read_unlock();
 131                         return;
 132                 }
 133
 134                 spin_lock_bh(&sta->rate_ctrl_lock);
 135                 ref->ops->rate_update(ref->priv, sband, &chanctx_conf->def,
 136                                       ista, priv_sta, changed);
 137                 spin_unlock_bh(&sta->rate_ctrl_lock);
 138                 rcu_read_unlock();
 139         }
 140
 141         if (sta->uploaded)
 142                 drv_link_sta_rc_update(local, sta->sdata, link_sta->pub,
 143                                        changed);
 144 }
 145
 146 int ieee80211_rate_control_register(const struct rate_control_ops *ops)
 147 {
 148         struct rate_control_alg *alg;
 149
 150         if (!ops->name)
 151                 return -EINVAL;
 152
 153         mutex_lock(&rate_ctrl_mutex);
 154         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 155                 if (!strcmp(alg->ops->name, ops->name)) {
 156                         /* don't register an algorithm twice */
 157                         WARN_ON(1);
 158                         mutex_unlock(&rate_ctrl_mutex);
 159                         return -EALREADY;
 160                 }
 161         }
 162
 163         alg = kzalloc(sizeof(*alg), GFP_KERNEL);
 164         if (alg == NULL) {
 165                 mutex_unlock(&rate_ctrl_mutex);
 166                 return -ENOMEM;
 167         }
 168         alg->ops = ops;
 169
 170         list_add_tail(&alg->list, &rate_ctrl_algs);
 171         mutex_unlock(&rate_ctrl_mutex);
 172
 173         return 0;
 174 }
 175 EXPORT_SYMBOL(ieee80211_rate_control_register);
 176
 177 void ieee80211_rate_control_unregister(const struct rate_control_ops *ops)
 178 {
 179         struct rate_control_alg *alg;
 180
 181         mutex_lock(&rate_ctrl_mutex);
 182         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 183                 if (alg->ops == ops) {
 184                         list_del(&alg->list);
 185                         kfree(alg);
 186                         break;
 187                 }
 188         }
 189         mutex_unlock(&rate_ctrl_mutex);
 190 }
 191 EXPORT_SYMBOL(ieee80211_rate_control_unregister);
 192
 193 static const struct rate_control_ops *
 194 ieee80211_try_rate_control_ops_get(const char *name)
 195 {
 196         struct rate_control_alg *alg;
 197         const struct rate_control_ops *ops = NULL;
 198
 199         if (!name)
 200                 return NULL;
 201
 202         mutex_lock(&rate_ctrl_mutex);
 203         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 204                 if (!strcmp(alg->ops->name, name)) {
 205                         ops = alg->ops;
 206                         break;
 207                 }
 208         }
 209         mutex_unlock(&rate_ctrl_mutex);
 210         return ops;
 211 }
 212
 213 /* Get the rate control algorithm. */
 214 static const struct rate_control_ops *
 215 ieee80211_rate_control_ops_get(const char *name)
 216 {
 217         const struct rate_control_ops *ops;
 218         const char *alg_name;
 219
 220         kernel_param_lock(THIS_MODULE);
 221         if (!name)
 222                 alg_name = ieee80211_default_rc_algo;
 223         else
 224                 alg_name = name;
 225
 226         ops = ieee80211_try_rate_control_ops_get(alg_name);
 227         if (!ops && name)
 228                 /* try default if specific alg requested but not found */
 229                 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
 230
 231         /* Note: check for > 0 is intentional to avoid clang warning */
 232         if (!ops && (strlen(CONFIG_MAC80211_RC_DEFAULT) > 0))
 233                 /* try built-in one if specific alg requested but not found */
 234                 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
 235
 236         kernel_param_unlock(THIS_MODULE);
 237
 238         return ops;
 239 }
 240
 241 #ifdef CONFIG_MAC80211_DEBUGFS
 242 static ssize_t rcname_read(struct file *file, char __user *userbuf,
 243                            size_t count, loff_t *ppos)
 244 {
 245         struct rate_control_ref *ref = file->private_data;
 246         int len = strlen(ref->ops->name);
 247
 248         return simple_read_from_buffer(userbuf, count, ppos,
 249                                        ref->ops->name, len);
 250 }
 251
 252 const struct debugfs_short_fops rcname_ops = {
 253         .read = rcname_read,
 254         .llseek = default_llseek,
 255 };
 256 #endif
 257
 258 static struct rate_control_ref *
 259 rate_control_alloc(const char *name, struct ieee80211_local *local)
 260 {
 261         struct rate_control_ref *ref;
 262
 263         ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
 264         if (!ref)
 265                 return NULL;
 266         ref->ops = ieee80211_rate_control_ops_get(name);
 267         if (!ref->ops)
 268                 goto free;
 269
 270         ref->priv = ref->ops->alloc(&local->hw);
 271         if (!ref->priv)
 272                 goto free;
 273         return ref;
 274
 275 free:
 276         kfree(ref);
 277         return NULL;
 278 }
 279
 280 static void rate_control_free(struct ieee80211_local *local,
 281                               struct rate_control_ref *ctrl_ref)
 282 {
 283         ctrl_ref->ops->free(ctrl_ref->priv);
 284
 285 #ifdef CONFIG_MAC80211_DEBUGFS
 286         debugfs_remove_recursive(local->debugfs.rcdir);
 287         local->debugfs.rcdir = NULL;
 288 #endif
 289
 290         kfree(ctrl_ref);
 291 }
 292
 293 void ieee80211_check_rate_mask(struct ieee80211_link_data *link)
 294 {
 295         struct ieee80211_sub_if_data *sdata = link->sdata;
 296         struct ieee80211_local *local = sdata->local;
 297         struct ieee80211_supported_band *sband;
 298         u32 user_mask, basic_rates = link->conf->basic_rates;
 299         enum nl80211_band band;
 300
 301         if (WARN_ON(!link->conf->chanreq.oper.chan))
 302                 return;
 303
 304         band = link->conf->chanreq.oper.chan->band;
 305         if (band == NL80211_BAND_S1GHZ) {
 306                 /* TODO */
 307                 return;
 308         }
 309
 310         if (WARN_ON_ONCE(!basic_rates))
 311                 return;
 312
 313         user_mask = sdata->rc_rateidx_mask[band];
 314         sband = local->hw.wiphy->bands[band];
 315
 316         if (user_mask & basic_rates)
 317                 return;
 318
 319         sdata_dbg(sdata,
 320                   "no overlap between basic rates (0x%x) and user mask (0x%x on band %d) - clearing the latter",
 321                   basic_rates, user_mask, band);
 322         sdata->rc_rateidx_mask[band] = (1 << sband->n_bitrates) - 1;
 323 }
 324
 325 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
 326 {
 327         struct sk_buff *skb = txrc->skb;
 328         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 329
 330         return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
 331                                IEEE80211_TX_CTL_USE_MINRATE)) ||
 332                 !ieee80211_is_tx_data(skb);
 333 }
 334
 335 static void rc_send_low_basicrate(struct ieee80211_tx_rate *rate,
 336                                   u32 basic_rates,
 337                                   struct ieee80211_supported_band *sband)
 338 {
 339         u8 i;
 340
 341         if (sband->band == NL80211_BAND_S1GHZ) {
 342                 /* TODO */
 343                 rate->flags |= IEEE80211_TX_RC_S1G_MCS;
 344                 rate->idx = 0;
 345                 return;
 346         }
 347
 348         if (basic_rates == 0)
 349                 return; /* assume basic rates unknown and accept rate */
 350         if (rate->idx < 0)
 351                 return;
 352         if (basic_rates & (1 << rate->idx))
 353                 return; /* selected rate is a basic rate */
 354
 355         for (i = rate->idx + 1; i <= sband->n_bitrates; i++) {
 356                 if (basic_rates & (1 << i)) {
 357                         rate->idx = i;
 358                         return;
 359                 }
 360         }
 361
 362         /* could not find a basic rate; use original selection */
 363 }
 364
 365 static void __rate_control_send_low(struct ieee80211_hw *hw,
 366                                     struct ieee80211_supported_band *sband,
 367                                     struct ieee80211_sta *sta,
 368                                     struct ieee80211_tx_info *info,
 369                                     u32 rate_mask)
 370 {
 371         int i;
 372         u32 rate_flags =
 373                 ieee80211_chandef_rate_flags(&hw->conf.chandef);
 374
 375         if (sband->band == NL80211_BAND_S1GHZ) {
 376                 info->control.rates[0].flags |= IEEE80211_TX_RC_S1G_MCS;
 377                 info->control.rates[0].idx = 0;
 378                 return;
 379         }
 380
 381         if ((sband->band == NL80211_BAND_2GHZ) &&
 382             (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
 383                 rate_flags |= IEEE80211_RATE_ERP_G;
 384
 385         info->control.rates[0].idx = 0;
 386         for (i = 0; i < sband->n_bitrates; i++) {
 387                 if (!(rate_mask & BIT(i)))
 388                         continue;
 389
 390                 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
 391                         continue;
 392
 393                 if (!rate_supported(sta, sband->band, i))
 394                         continue;
 395
 396                 info->control.rates[0].idx = i;
 397                 break;
 398         }
 399         WARN_ONCE(i == sband->n_bitrates,
 400                   "no supported rates for sta %pM (0x%x, band %d) in rate_mask 0x%x with flags 0x%x\n",
 401                   sta ? sta->addr : NULL,
 402                   sta ? sta->deflink.supp_rates[sband->band] : -1,
 403                   sband->band,
 404                   rate_mask, rate_flags);
 405
 406         info->control.rates[0].count =
 407                 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
 408                 1 : hw->max_rate_tries;
 409
 410         info->control.skip_table = 1;
 411 }
 412
 413
 414 static bool rate_control_send_low(struct ieee80211_sta *pubsta,
 415                                   struct ieee80211_tx_rate_control *txrc)
 416 {
 417         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 418         struct ieee80211_supported_band *sband = txrc->sband;
 419         struct sta_info *sta;
 420         int mcast_rate;
 421         bool use_basicrate = false;
 422
 423         if (!pubsta || rc_no_data_or_no_ack_use_min(txrc)) {
 424                 __rate_control_send_low(txrc->hw, sband, pubsta, info,
 425                                         txrc->rate_idx_mask);
 426
 427                 if (!pubsta && txrc->bss) {
 428                         mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
 429                         if (mcast_rate > 0) {
 430                                 info->control.rates[0].idx = mcast_rate - 1;
 431                                 return true;
 432                         }
 433                         use_basicrate = true;
 434                 } else if (pubsta) {
 435                         sta = container_of(pubsta, struct sta_info, sta);
 436                         if (ieee80211_vif_is_mesh(&sta->sdata->vif))
 437                                 use_basicrate = true;
 438                 }
 439
 440                 if (use_basicrate)
 441                         rc_send_low_basicrate(&info->control.rates[0],
 442                                               txrc->bss_conf->basic_rates,
 443                                               sband);
 444
 445                 return true;
 446         }
 447         return false;
 448 }
 449
 450 static bool rate_idx_match_legacy_mask(s8 *rate_idx, int n_bitrates, u32 mask)
 451 {
 452         int j;
 453
 454         /* See whether the selected rate or anything below it is allowed. */
 455         for (j = *rate_idx; j >= 0; j--) {
 456                 if (mask & (1 << j)) {
 457                         /* Okay, found a suitable rate. Use it. */
 458                         *rate_idx = j;
 459                         return true;
 460                 }
 461         }
 462
 463         /* Try to find a higher rate that would be allowed */
 464         for (j = *rate_idx + 1; j < n_bitrates; j++) {
 465                 if (mask & (1 << j)) {
 466                         /* Okay, found a suitable rate. Use it. */
 467                         *rate_idx = j;
 468                         return true;
 469                 }
 470         }
 471         return false;
 472 }
 473
 474 static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
 475 {
 476         int i, j;
 477         int ridx, rbit;
 478
 479         ridx = *rate_idx / 8;
 480         rbit = *rate_idx % 8;
 481
 482         /* sanity check */
 483         if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
 484                 return false;
 485
 486         /* See whether the selected rate or anything below it is allowed. */
 487         for (i = ridx; i >= 0; i--) {
 488                 for (j = rbit; j >= 0; j--)
 489                         if (mcs_mask[i] & BIT(j)) {
 490                                 *rate_idx = i * 8 + j;
 491                                 return true;
 492                         }
 493                 rbit = 7;
 494         }
 495
 496         /* Try to find a higher rate that would be allowed */
 497         ridx = (*rate_idx + 1) / 8;
 498         rbit = (*rate_idx + 1) % 8;
 499
 500         for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
 501                 for (j = rbit; j < 8; j++)
 502                         if (mcs_mask[i] & BIT(j)) {
 503                                 *rate_idx = i * 8 + j;
 504                                 return true;
 505                         }
 506                 rbit = 0;
 507         }
 508         return false;
 509 }
 510
 511 static bool rate_idx_match_vht_mcs_mask(s8 *rate_idx, u16 *vht_mask)
 512 {
 513         int i, j;
 514         int ridx, rbit;
 515
 516         ridx = *rate_idx >> 4;
 517         rbit = *rate_idx & 0xf;
 518
 519         if (ridx < 0 || ridx >= NL80211_VHT_NSS_MAX)
 520                 return false;
 521
 522         /* See whether the selected rate or anything below it is allowed. */
 523         for (i = ridx; i >= 0; i--) {
 524                 for (j = rbit; j >= 0; j--) {
 525                         if (vht_mask[i] & BIT(j)) {
 526                                 *rate_idx = (i << 4) | j;
 527                                 return true;
 528                         }
 529                 }
 530                 rbit = 15;
 531         }
 532
 533         /* Try to find a higher rate that would be allowed */
 534         ridx = (*rate_idx + 1) >> 4;
 535         rbit = (*rate_idx + 1) & 0xf;
 536
 537         for (i = ridx; i < NL80211_VHT_NSS_MAX; i++) {
 538                 for (j = rbit; j < 16; j++) {
 539                         if (vht_mask[i] & BIT(j)) {
 540                                 *rate_idx = (i << 4) | j;
 541                                 return true;
 542                         }
 543                 }
 544                 rbit = 0;
 545         }
 546         return false;
 547 }
 548
 549 static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
 550                                 struct ieee80211_supported_band *sband,
 551                                 enum nl80211_chan_width chan_width,
 552                                 u32 mask,
 553                                 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 554                                 u16 vht_mask[NL80211_VHT_NSS_MAX])
 555 {
 556         if (*rate_flags & IEEE80211_TX_RC_VHT_MCS) {
 557                 /* handle VHT rates */
 558                 if (rate_idx_match_vht_mcs_mask(rate_idx, vht_mask))
 559                         return;
 560
 561                 *rate_idx = 0;
 562                 /* keep protection flags */
 563                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 564                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 565                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 566
 567                 *rate_flags |= IEEE80211_TX_RC_MCS;
 568                 if (chan_width == NL80211_CHAN_WIDTH_40)
 569                         *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 570
 571                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 572                         return;
 573
 574                 /* also try the legacy rates. */
 575                 *rate_flags &= ~(IEEE80211_TX_RC_MCS |
 576                                  IEEE80211_TX_RC_40_MHZ_WIDTH);
 577                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 578                                                mask))
 579                         return;
 580         } else if (*rate_flags & IEEE80211_TX_RC_MCS) {
 581                 /* handle HT rates */
 582                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 583                         return;
 584
 585                 /* also try the legacy rates. */
 586                 *rate_idx = 0;
 587                 /* keep protection flags */
 588                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 589                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 590                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 591                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 592                                                mask))
 593                         return;
 594         } else {
 595                 /* handle legacy rates */
 596                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 597                                                mask))
 598                         return;
 599
 600                 /* if HT BSS, and we handle a data frame, also try HT rates */
 601                 switch (chan_width) {
 602                 case NL80211_CHAN_WIDTH_20_NOHT:
 603                 case NL80211_CHAN_WIDTH_5:
 604                 case NL80211_CHAN_WIDTH_10:
 605                         return;
 606                 default:
 607                         break;
 608                 }
 609
 610                 *rate_idx = 0;
 611                 /* keep protection flags */
 612                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 613                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 614                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 615
 616                 *rate_flags |= IEEE80211_TX_RC_MCS;
 617
 618                 if (chan_width == NL80211_CHAN_WIDTH_40)
 619                         *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 620
 621                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 622                         return;
 623         }
 624
 625         /*
 626          * Uh.. No suitable rate exists. This should not really happen with
 627          * sane TX rate mask configurations. However, should someone manage to
 628          * configure supported rates and TX rate mask in incompatible way,
 629          * allow the frame to be transmitted with whatever the rate control
 630          * selected.
 631          */
 632 }
 633
 634 static void rate_fixup_ratelist(struct ieee80211_vif *vif,
 635                                 struct ieee80211_supported_band *sband,
 636                                 struct ieee80211_tx_info *info,
 637                                 struct ieee80211_tx_rate *rates,
 638                                 int max_rates)
 639 {
 640         struct ieee80211_rate *rate;
 641         bool inval = false;
 642         int i;
 643
 644         /*
 645          * Set up the RTS/CTS rate as the fastest basic rate
 646          * that is not faster than the data rate unless there
 647          * is no basic rate slower than the data rate, in which
 648          * case we pick the slowest basic rate
 649          *
 650          * XXX: Should this check all retry rates?
 651          */
 652         if (!(rates[0].flags &
 653               (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))) {
 654                 u32 basic_rates = vif->bss_conf.basic_rates;
 655                 s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
 656
 657                 rate = &sband->bitrates[rates[0].idx];
 658
 659                 for (i = 0; i < sband->n_bitrates; i++) {
 660                         /* must be a basic rate */
 661                         if (!(basic_rates & BIT(i)))
 662                                 continue;
 663                         /* must not be faster than the data rate */
 664                         if (sband->bitrates[i].bitrate > rate->bitrate)
 665                                 continue;
 666                         /* maximum */
 667                         if (sband->bitrates[baserate].bitrate <
 668                              sband->bitrates[i].bitrate)
 669                                 baserate = i;
 670                 }
 671
 672                 info->control.rts_cts_rate_idx = baserate;
 673         }
 674
 675         for (i = 0; i < max_rates; i++) {
 676                 /*
 677                  * make sure there's no valid rate following
 678                  * an invalid one, just in case drivers don't
 679                  * take the API seriously to stop at -1.
 680                  */
 681                 if (inval) {
 682                         rates[i].idx = -1;
 683                         continue;
 684                 }
 685                 if (rates[i].idx < 0) {
 686                         inval = true;
 687                         continue;
 688                 }
 689
 690                 /*
 691                  * For now assume MCS is already set up correctly, this
 692                  * needs to be fixed.
 693                  */
 694                 if (rates[i].flags & IEEE80211_TX_RC_MCS) {
 695                         WARN_ON(rates[i].idx > 76);
 696
 697                         if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 698                             info->control.use_cts_prot)
 699                                 rates[i].flags |=
 700                                         IEEE80211_TX_RC_USE_CTS_PROTECT;
 701                         continue;
 702                 }
 703
 704                 if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
 705                         WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
 706                         continue;
 707                 }
 708
 709                 /* set up RTS protection if desired */
 710                 if (info->control.use_rts) {
 711                         rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
 712                         info->control.use_cts_prot = false;
 713                 }
 714
 715                 /* RC is busted */
 716                 if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
 717                         rates[i].idx = -1;
 718                         continue;
 719                 }
 720
 721                 rate = &sband->bitrates[rates[i].idx];
 722
 723                 /* set up short preamble */
 724                 if (info->control.short_preamble &&
 725                     rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
 726                         rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
 727
 728                 /* set up G protection */
 729                 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 730                     info->control.use_cts_prot &&
 731                     rate->flags & IEEE80211_RATE_ERP_G)
 732                         rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
 733         }
 734 }
 735
 736
 737 static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
 738                                         struct ieee80211_tx_info *info,
 739                                         struct ieee80211_tx_rate *rates,
 740                                         int max_rates)
 741 {
 742         struct ieee80211_sta_rates *ratetbl = NULL;
 743         int i;
 744
 745         if (sta && !info->control.skip_table)
 746                 ratetbl = rcu_dereference(sta->rates);
 747
 748         /* Fill remaining rate slots with data from the sta rate table. */
 749         max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
 750         for (i = 0; i < max_rates; i++) {
 751                 if (i < ARRAY_SIZE(info->control.rates) &&
 752                     info->control.rates[i].idx >= 0 &&
 753                     info->control.rates[i].count) {
 754                         if (rates != info->control.rates)
 755                                 rates[i] = info->control.rates[i];
 756                 } else if (ratetbl) {
 757                         rates[i].idx = ratetbl->rate[i].idx;
 758                         rates[i].flags = ratetbl->rate[i].flags;
 759                         if (info->control.use_rts)
 760                                 rates[i].count = ratetbl->rate[i].count_rts;
 761                         else if (info->control.use_cts_prot)
 762                                 rates[i].count = ratetbl->rate[i].count_cts;
 763                         else
 764                                 rates[i].count = ratetbl->rate[i].count;
 765                 } else {
 766                         rates[i].idx = -1;
 767                         rates[i].count = 0;
 768                 }
 769
 770                 if (rates[i].idx < 0 || !rates[i].count)
 771                         break;
 772         }
 773 }
 774
 775 static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
 776                                   struct ieee80211_supported_band *sband,
 777                                   struct ieee80211_sta *sta, u32 *mask,
 778                                   u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 779                                   u16 vht_mask[NL80211_VHT_NSS_MAX])
 780 {
 781         u32 i, flags;
 782
 783         *mask = sdata->rc_rateidx_mask[sband->band];
 784         flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chanreq.oper);
 785         for (i = 0; i < sband->n_bitrates; i++) {
 786                 if ((flags & sband->bitrates[i].flags) != flags)
 787                         *mask &= ~BIT(i);
 788         }
 789
 790         if (*mask == (1 << sband->n_bitrates) - 1 &&
 791             !sdata->rc_has_mcs_mask[sband->band] &&
 792             !sdata->rc_has_vht_mcs_mask[sband->band])
 793                 return false;
 794
 795         if (sdata->rc_has_mcs_mask[sband->band])
 796                 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
 797                        IEEE80211_HT_MCS_MASK_LEN);
 798         else
 799                 memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
 800
 801         if (sdata->rc_has_vht_mcs_mask[sband->band])
 802                 memcpy(vht_mask, sdata->rc_rateidx_vht_mcs_mask[sband->band],
 803                        sizeof(u16) * NL80211_VHT_NSS_MAX);
 804         else
 805                 memset(vht_mask, 0xff, sizeof(u16) * NL80211_VHT_NSS_MAX);
 806
 807         if (sta) {
 808                 __le16 sta_vht_cap;
 809                 u16 sta_vht_mask[NL80211_VHT_NSS_MAX];
 810
 811                 /* Filter out rates that the STA does not support */
 812                 *mask &= sta->deflink.supp_rates[sband->band];
 813                 for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++)
 814                         mcs_mask[i] &= sta->deflink.ht_cap.mcs.rx_mask[i];
 815
 816                 sta_vht_cap = sta->deflink.vht_cap.vht_mcs.rx_mcs_map;
 817                 ieee80211_get_vht_mask_from_cap(sta_vht_cap, sta_vht_mask);
 818                 for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
 819                         vht_mask[i] &= sta_vht_mask[i];
 820         }
 821
 822         return true;
 823 }
 824
 825 static void
 826 rate_control_apply_mask_ratetbl(struct sta_info *sta,
 827                                 struct ieee80211_supported_band *sband,
 828                                 struct ieee80211_sta_rates *rates)
 829 {
 830         int i;
 831         u32 mask;
 832         u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 833         u16 vht_mask[NL80211_VHT_NSS_MAX];
 834         enum nl80211_chan_width chan_width;
 835
 836         if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
 837                                    mcs_mask, vht_mask))
 838                 return;
 839
 840         chan_width = sta->sdata->vif.bss_conf.chanreq.oper.width;
 841         for (i = 0; i < IEEE80211_TX_RATE_TABLE_SIZE; i++) {
 842                 if (rates->rate[i].idx < 0)
 843                         break;
 844
 845                 rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
 846                                     sband, chan_width, mask, mcs_mask,
 847                                     vht_mask);
 848         }
 849 }
 850
 851 static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 852                                     struct ieee80211_sta *sta,
 853                                     struct ieee80211_supported_band *sband,
 854                                     struct ieee80211_tx_rate *rates,
 855                                     int max_rates)
 856 {
 857         enum nl80211_chan_width chan_width;
 858         u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 859         u32 mask;
 860         u16 rate_flags, vht_mask[NL80211_VHT_NSS_MAX];
 861         int i;
 862
 863         /*
 864          * Try to enforce the rateidx mask the user wanted. skip this if the
 865          * default mask (allow all rates) is used to save some processing for
 866          * the common case.
 867          */
 868         if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask,
 869                                    vht_mask))
 870                 return;
 871
 872         /*
 873          * Make sure the rate index selected for each TX rate is
 874          * included in the configured mask and change the rate indexes
 875          * if needed.
 876          */
 877         chan_width = sdata->vif.bss_conf.chanreq.oper.width;
 878         for (i = 0; i < max_rates; i++) {
 879                 /* Skip invalid rates */
 880                 if (rates[i].idx < 0)
 881                         break;
 882
 883                 rate_flags = rates[i].flags;
 884                 rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
 885                                     chan_width, mask, mcs_mask, vht_mask);
 886                 rates[i].flags = rate_flags;
 887         }
 888 }
 889
 890 void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
 891                             struct ieee80211_sta *sta,
 892                             struct sk_buff *skb,
 893                             struct ieee80211_tx_rate *dest,
 894                             int max_rates)
 895 {
 896         struct ieee80211_sub_if_data *sdata;
 897         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 898         struct ieee80211_supported_band *sband;
 899         u32 mask = ~0;
 900
 901         rate_control_fill_sta_table(sta, info, dest, max_rates);
 902
 903         if (!vif)
 904                 return;
 905
 906         sdata = vif_to_sdata(vif);
 907         sband = sdata->local->hw.wiphy->bands[info->band];
 908
 909         if (ieee80211_is_tx_data(skb))
 910                 rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
 911
 912         if (!(info->control.flags & IEEE80211_TX_CTRL_DONT_USE_RATE_MASK))
 913                 mask = sdata->rc_rateidx_mask[info->band];
 914
 915         if (dest[0].idx < 0)
 916                 __rate_control_send_low(&sdata->local->hw, sband, sta, info,
 917                                         mask);
 918
 919         if (sta)
 920                 rate_fixup_ratelist(vif, sband, info, dest, max_rates);
 921 }
 922 EXPORT_SYMBOL(ieee80211_get_tx_rates);
 923
 924 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
 925                            struct sta_info *sta,
 926                            struct ieee80211_tx_rate_control *txrc)
 927 {
 928         struct rate_control_ref *ref = sdata->local->rate_ctrl;
 929         void *priv_sta = NULL;
 930         struct ieee80211_sta *ista = NULL;
 931         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 932         int i;
 933
 934         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 935                 info->control.rates[i].idx = -1;
 936                 info->control.rates[i].flags = 0;
 937                 info->control.rates[i].count = 0;
 938         }
 939
 940         if (rate_control_send_low(sta ? &sta->sta : NULL, txrc))
 941                 return;
 942
 943         if (ieee80211_hw_check(&sdata->local->hw, HAS_RATE_CONTROL))
 944                 return;
 945
 946         if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
 947                 ista = &sta->sta;
 948                 priv_sta = sta->rate_ctrl_priv;
 949         }
 950
 951         if (ista) {
 952                 spin_lock_bh(&sta->rate_ctrl_lock);
 953                 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
 954                 spin_unlock_bh(&sta->rate_ctrl_lock);
 955         } else {
 956                 rate_control_send_low(NULL, txrc);
 957         }
 958
 959         if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_RC_TABLE))
 960                 return;
 961
 962         ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
 963                                info->control.rates,
 964                                ARRAY_SIZE(info->control.rates));
 965 }
 966
 967 int rate_control_set_rates(struct ieee80211_hw *hw,
 968                            struct ieee80211_sta *pubsta,
 969                            struct ieee80211_sta_rates *rates)
 970 {
 971         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 972         struct ieee80211_sta_rates *old;
 973         struct ieee80211_supported_band *sband;
 974
 975         sband = ieee80211_get_sband(sta->sdata);
 976         if (!sband)
 977                 return -EINVAL;
 978         rate_control_apply_mask_ratetbl(sta, sband, rates);
 979         /*
 980          * mac80211 guarantees that this function will not be called
 981          * concurrently, so the following RCU access is safe, even without
 982          * extra locking. This can not be checked easily, so we just set
 983          * the condition to true.
 984          */
 985         old = rcu_dereference_protected(pubsta->rates, true);
 986         rcu_assign_pointer(pubsta->rates, rates);
 987         if (old)
 988                 kfree_rcu(old, rcu_head);
 989
 990         if (sta->uploaded)
 991                 drv_sta_rate_tbl_update(hw_to_local(hw), sta->sdata, pubsta);
 992
 993         ieee80211_sta_set_expected_throughput(pubsta, sta_get_expected_throughput(sta));
 994
 995         return 0;
 996 }
 997 EXPORT_SYMBOL(rate_control_set_rates);
 998
 999 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
1000                                  const char *name)
1001 {
1002         struct rate_control_ref *ref;
1003
1004         ASSERT_RTNL();
1005
1006         if (local->open_count)
1007                 return -EBUSY;
1008
1009         if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
1010                 if (WARN_ON(!local->ops->set_rts_threshold))
1011                         return -EINVAL;
1012                 return 0;
1013         }
1014
1015         ref = rate_control_alloc(name, local);
1016         if (!ref) {
1017                 wiphy_warn(local->hw.wiphy,
1018                            "Failed to select rate control algorithm\n");
1019                 return -ENOENT;
1020         }
1021
1022         WARN_ON(local->rate_ctrl);
1023         local->rate_ctrl = ref;
1024
1025         wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
1026                     ref->ops->name);
1027
1028         return 0;
1029 }
1030
1031 void rate_control_deinitialize(struct ieee80211_local *local)
1032 {
1033         struct rate_control_ref *ref;
1034
1035         ref = local->rate_ctrl;
1036
1037         if (!ref)
1038                 return;
1039
1040         local->rate_ctrl = NULL;
1041         rate_control_free(local, ref);
1042 }