net/mac80211/rate.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/rtnetlink.h>
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include "rate.h"
  16 #include "ieee80211_i.h"
  17 #include "debugfs.h"
  18
  19 struct rate_control_alg {
  20         struct list_head list;
  21         const struct rate_control_ops *ops;
  22 };
  23
  24 static LIST_HEAD(rate_ctrl_algs);
  25 static DEFINE_MUTEX(rate_ctrl_mutex);
  26
  27 static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
  28 module_param(ieee80211_default_rc_algo, charp, 0644);
  29 MODULE_PARM_DESC(ieee80211_default_rc_algo,
  30                  "Default rate control algorithm for mac80211 to use");
  31
  32 void rate_control_rate_init(struct sta_info *sta)
  33 {
  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_set_rx_nss(sta);
  42
  43         ieee80211_recalc_min_chandef(sta->sdata);
  44
  45         if (!ref)
  46                 return;
  47
  48         rcu_read_lock();
  49
  50         chanctx_conf = rcu_dereference(sta->sdata->vif.chanctx_conf);
  51         if (WARN_ON(!chanctx_conf)) {
  52                 rcu_read_unlock();
  53                 return;
  54         }
  55
  56         sband = local->hw.wiphy->bands[chanctx_conf->def.chan->band];
  57
  58         spin_lock_bh(&sta->rate_ctrl_lock);
  59         ref->ops->rate_init(ref->priv, sband, &chanctx_conf->def, ista,
  60                             priv_sta);
  61         spin_unlock_bh(&sta->rate_ctrl_lock);
  62         rcu_read_unlock();
  63         set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
  64 }
  65
  66 void rate_control_rate_update(struct ieee80211_local *local,
  67                                     struct ieee80211_supported_band *sband,
  68                                     struct sta_info *sta, u32 changed)
  69 {
  70         struct rate_control_ref *ref = local->rate_ctrl;
  71         struct ieee80211_sta *ista = &sta->sta;
  72         void *priv_sta = sta->rate_ctrl_priv;
  73         struct ieee80211_chanctx_conf *chanctx_conf;
  74
  75         if (ref && ref->ops->rate_update) {
  76                 rcu_read_lock();
  77
  78                 chanctx_conf = rcu_dereference(sta->sdata->vif.chanctx_conf);
  79                 if (WARN_ON(!chanctx_conf)) {
  80                         rcu_read_unlock();
  81                         return;
  82                 }
  83
  84                 spin_lock_bh(&sta->rate_ctrl_lock);
  85                 ref->ops->rate_update(ref->priv, sband, &chanctx_conf->def,
  86                                       ista, priv_sta, changed);
  87                 spin_unlock_bh(&sta->rate_ctrl_lock);
  88                 rcu_read_unlock();
  89         }
  90         drv_sta_rc_update(local, sta->sdata, &sta->sta, changed);
  91 }
  92
  93 int ieee80211_rate_control_register(const struct rate_control_ops *ops)
  94 {
  95         struct rate_control_alg *alg;
  96
  97         if (!ops->name)
  98                 return -EINVAL;
  99
 100         mutex_lock(&rate_ctrl_mutex);
 101         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 102                 if (!strcmp(alg->ops->name, ops->name)) {
 103                         /* don't register an algorithm twice */
 104                         WARN_ON(1);
 105                         mutex_unlock(&rate_ctrl_mutex);
 106                         return -EALREADY;
 107                 }
 108         }
 109
 110         alg = kzalloc(sizeof(*alg), GFP_KERNEL);
 111         if (alg == NULL) {
 112                 mutex_unlock(&rate_ctrl_mutex);
 113                 return -ENOMEM;
 114         }
 115         alg->ops = ops;
 116
 117         list_add_tail(&alg->list, &rate_ctrl_algs);
 118         mutex_unlock(&rate_ctrl_mutex);
 119
 120         return 0;
 121 }
 122 EXPORT_SYMBOL(ieee80211_rate_control_register);
 123
 124 void ieee80211_rate_control_unregister(const struct rate_control_ops *ops)
 125 {
 126         struct rate_control_alg *alg;
 127
 128         mutex_lock(&rate_ctrl_mutex);
 129         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 130                 if (alg->ops == ops) {
 131                         list_del(&alg->list);
 132                         kfree(alg);
 133                         break;
 134                 }
 135         }
 136         mutex_unlock(&rate_ctrl_mutex);
 137 }
 138 EXPORT_SYMBOL(ieee80211_rate_control_unregister);
 139
 140 static const struct rate_control_ops *
 141 ieee80211_try_rate_control_ops_get(const char *name)
 142 {
 143         struct rate_control_alg *alg;
 144         const struct rate_control_ops *ops = NULL;
 145
 146         if (!name)
 147                 return NULL;
 148
 149         mutex_lock(&rate_ctrl_mutex);
 150         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 151                 if (!strcmp(alg->ops->name, name)) {
 152                         ops = alg->ops;
 153                         break;
 154                 }
 155         }
 156         mutex_unlock(&rate_ctrl_mutex);
 157         return ops;
 158 }
 159
 160 /* Get the rate control algorithm. */
 161 static const struct rate_control_ops *
 162 ieee80211_rate_control_ops_get(const char *name)
 163 {
 164         const struct rate_control_ops *ops;
 165         const char *alg_name;
 166
 167         kernel_param_lock(THIS_MODULE);
 168         if (!name)
 169                 alg_name = ieee80211_default_rc_algo;
 170         else
 171                 alg_name = name;
 172
 173         ops = ieee80211_try_rate_control_ops_get(alg_name);
 174         if (!ops && name)
 175                 /* try default if specific alg requested but not found */
 176                 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
 177
 178         /* try built-in one if specific alg requested but not found */
 179         if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
 180                 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
 181         kernel_param_unlock(THIS_MODULE);
 182
 183         return ops;
 184 }
 185
 186 #ifdef CONFIG_MAC80211_DEBUGFS
 187 static ssize_t rcname_read(struct file *file, char __user *userbuf,
 188                            size_t count, loff_t *ppos)
 189 {
 190         struct rate_control_ref *ref = file->private_data;
 191         int len = strlen(ref->ops->name);
 192
 193         return simple_read_from_buffer(userbuf, count, ppos,
 194                                        ref->ops->name, len);
 195 }
 196
 197 static const struct file_operations rcname_ops = {
 198         .read = rcname_read,
 199         .open = simple_open,
 200         .llseek = default_llseek,
 201 };
 202 #endif
 203
 204 static struct rate_control_ref *rate_control_alloc(const char *name,
 205                                             struct ieee80211_local *local)
 206 {
 207         struct dentry *debugfsdir = NULL;
 208         struct rate_control_ref *ref;
 209
 210         ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
 211         if (!ref)
 212                 return NULL;
 213         ref->local = local;
 214         ref->ops = ieee80211_rate_control_ops_get(name);
 215         if (!ref->ops)
 216                 goto free;
 217
 218 #ifdef CONFIG_MAC80211_DEBUGFS
 219         debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
 220         local->debugfs.rcdir = debugfsdir;
 221         debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
 222 #endif
 223
 224         ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
 225         if (!ref->priv)
 226                 goto free;
 227         return ref;
 228
 229 free:
 230         kfree(ref);
 231         return NULL;
 232 }
 233
 234 static void rate_control_free(struct rate_control_ref *ctrl_ref)
 235 {
 236         ctrl_ref->ops->free(ctrl_ref->priv);
 237
 238 #ifdef CONFIG_MAC80211_DEBUGFS
 239         debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
 240         ctrl_ref->local->debugfs.rcdir = NULL;
 241 #endif
 242
 243         kfree(ctrl_ref);
 244 }
 245
 246 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
 247 {
 248         struct sk_buff *skb = txrc->skb;
 249         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 250         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 251         __le16 fc;
 252
 253         fc = hdr->frame_control;
 254
 255         return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
 256                                IEEE80211_TX_CTL_USE_MINRATE)) ||
 257                 !ieee80211_is_data(fc);
 258 }
 259
 260 static void rc_send_low_basicrate(s8 *idx, u32 basic_rates,
 261                                   struct ieee80211_supported_band *sband)
 262 {
 263         u8 i;
 264
 265         if (basic_rates == 0)
 266                 return; /* assume basic rates unknown and accept rate */
 267         if (*idx < 0)
 268                 return;
 269         if (basic_rates & (1 << *idx))
 270                 return; /* selected rate is a basic rate */
 271
 272         for (i = *idx + 1; i <= sband->n_bitrates; i++) {
 273                 if (basic_rates & (1 << i)) {
 274                         *idx = i;
 275                         return;
 276                 }
 277         }
 278
 279         /* could not find a basic rate; use original selection */
 280 }
 281
 282 static void __rate_control_send_low(struct ieee80211_hw *hw,
 283                                     struct ieee80211_supported_band *sband,
 284                                     struct ieee80211_sta *sta,
 285                                     struct ieee80211_tx_info *info,
 286                                     u32 rate_mask)
 287 {
 288         int i;
 289         u32 rate_flags =
 290                 ieee80211_chandef_rate_flags(&hw->conf.chandef);
 291
 292         if ((sband->band == NL80211_BAND_2GHZ) &&
 293             (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
 294                 rate_flags |= IEEE80211_RATE_ERP_G;
 295
 296         info->control.rates[0].idx = 0;
 297         for (i = 0; i < sband->n_bitrates; i++) {
 298                 if (!(rate_mask & BIT(i)))
 299                         continue;
 300
 301                 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
 302                         continue;
 303
 304                 if (!rate_supported(sta, sband->band, i))
 305                         continue;
 306
 307                 info->control.rates[0].idx = i;
 308                 break;
 309         }
 310         WARN_ONCE(i == sband->n_bitrates,
 311                   "no supported rates (0x%x) in rate_mask 0x%x with flags 0x%x\n",
 312                   sta ? sta->supp_rates[sband->band] : -1,
 313                   rate_mask, rate_flags);
 314
 315         info->control.rates[0].count =
 316                 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
 317                 1 : hw->max_rate_tries;
 318
 319         info->control.skip_table = 1;
 320 }
 321
 322
 323 bool rate_control_send_low(struct ieee80211_sta *pubsta,
 324                            void *priv_sta,
 325                            struct ieee80211_tx_rate_control *txrc)
 326 {
 327         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 328         struct ieee80211_supported_band *sband = txrc->sband;
 329         struct sta_info *sta;
 330         int mcast_rate;
 331         bool use_basicrate = false;
 332
 333         if (!pubsta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
 334                 __rate_control_send_low(txrc->hw, sband, pubsta, info,
 335                                         txrc->rate_idx_mask);
 336
 337                 if (!pubsta && txrc->bss) {
 338                         mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
 339                         if (mcast_rate > 0) {
 340                                 info->control.rates[0].idx = mcast_rate - 1;
 341                                 return true;
 342                         }
 343                         use_basicrate = true;
 344                 } else if (pubsta) {
 345                         sta = container_of(pubsta, struct sta_info, sta);
 346                         if (ieee80211_vif_is_mesh(&sta->sdata->vif))
 347                                 use_basicrate = true;
 348                 }
 349
 350                 if (use_basicrate)
 351                         rc_send_low_basicrate(&info->control.rates[0].idx,
 352                                               txrc->bss_conf->basic_rates,
 353                                               sband);
 354
 355                 return true;
 356         }
 357         return false;
 358 }
 359 EXPORT_SYMBOL(rate_control_send_low);
 360
 361 static bool rate_idx_match_legacy_mask(s8 *rate_idx, int n_bitrates, u32 mask)
 362 {
 363         int j;
 364
 365         /* See whether the selected rate or anything below it is allowed. */
 366         for (j = *rate_idx; j >= 0; j--) {
 367                 if (mask & (1 << j)) {
 368                         /* Okay, found a suitable rate. Use it. */
 369                         *rate_idx = j;
 370                         return true;
 371                 }
 372         }
 373
 374         /* Try to find a higher rate that would be allowed */
 375         for (j = *rate_idx + 1; j < n_bitrates; j++) {
 376                 if (mask & (1 << j)) {
 377                         /* Okay, found a suitable rate. Use it. */
 378                         *rate_idx = j;
 379                         return true;
 380                 }
 381         }
 382         return false;
 383 }
 384
 385 static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
 386 {
 387         int i, j;
 388         int ridx, rbit;
 389
 390         ridx = *rate_idx / 8;
 391         rbit = *rate_idx % 8;
 392
 393         /* sanity check */
 394         if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
 395                 return false;
 396
 397         /* See whether the selected rate or anything below it is allowed. */
 398         for (i = ridx; i >= 0; i--) {
 399                 for (j = rbit; j >= 0; j--)
 400                         if (mcs_mask[i] & BIT(j)) {
 401                                 *rate_idx = i * 8 + j;
 402                                 return true;
 403                         }
 404                 rbit = 7;
 405         }
 406
 407         /* Try to find a higher rate that would be allowed */
 408         ridx = (*rate_idx + 1) / 8;
 409         rbit = (*rate_idx + 1) % 8;
 410
 411         for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
 412                 for (j = rbit; j < 8; j++)
 413                         if (mcs_mask[i] & BIT(j)) {
 414                                 *rate_idx = i * 8 + j;
 415                                 return true;
 416                         }
 417                 rbit = 0;
 418         }
 419         return false;
 420 }
 421
 422 static bool rate_idx_match_vht_mcs_mask(s8 *rate_idx, u16 *vht_mask)
 423 {
 424         int i, j;
 425         int ridx, rbit;
 426
 427         ridx = *rate_idx >> 4;
 428         rbit = *rate_idx & 0xf;
 429
 430         if (ridx < 0 || ridx >= NL80211_VHT_NSS_MAX)
 431                 return false;
 432
 433         /* See whether the selected rate or anything below it is allowed. */
 434         for (i = ridx; i >= 0; i--) {
 435                 for (j = rbit; j >= 0; j--) {
 436                         if (vht_mask[i] & BIT(j)) {
 437                                 *rate_idx = (i << 4) | j;
 438                                 return true;
 439                         }
 440                 }
 441                 rbit = 15;
 442         }
 443
 444         /* Try to find a higher rate that would be allowed */
 445         ridx = (*rate_idx + 1) >> 4;
 446         rbit = (*rate_idx + 1) & 0xf;
 447
 448         for (i = ridx; i < NL80211_VHT_NSS_MAX; i++) {
 449                 for (j = rbit; j < 16; j++) {
 450                         if (vht_mask[i] & BIT(j)) {
 451                                 *rate_idx = (i << 4) | j;
 452                                 return true;
 453                         }
 454                 }
 455                 rbit = 0;
 456         }
 457         return false;
 458 }
 459
 460 static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
 461                                 struct ieee80211_supported_band *sband,
 462                                 enum nl80211_chan_width chan_width,
 463                                 u32 mask,
 464                                 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 465                                 u16 vht_mask[NL80211_VHT_NSS_MAX])
 466 {
 467         if (*rate_flags & IEEE80211_TX_RC_VHT_MCS) {
 468                 /* handle VHT rates */
 469                 if (rate_idx_match_vht_mcs_mask(rate_idx, vht_mask))
 470                         return;
 471
 472                 *rate_idx = 0;
 473                 /* keep protection flags */
 474                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 475                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 476                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 477
 478                 *rate_flags |= IEEE80211_TX_RC_MCS;
 479                 if (chan_width == NL80211_CHAN_WIDTH_40)
 480                         *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 481
 482                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 483                         return;
 484
 485                 /* also try the legacy rates. */
 486                 *rate_flags &= ~(IEEE80211_TX_RC_MCS |
 487                                  IEEE80211_TX_RC_40_MHZ_WIDTH);
 488                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 489                                                mask))
 490                         return;
 491         } else if (*rate_flags & IEEE80211_TX_RC_MCS) {
 492                 /* handle HT rates */
 493                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 494                         return;
 495
 496                 /* also try the legacy rates. */
 497                 *rate_idx = 0;
 498                 /* keep protection flags */
 499                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 500                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 501                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 502                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 503                                                mask))
 504                         return;
 505         } else {
 506                 /* handle legacy rates */
 507                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 508                                                mask))
 509                         return;
 510
 511                 /* if HT BSS, and we handle a data frame, also try HT rates */
 512                 switch (chan_width) {
 513                 case NL80211_CHAN_WIDTH_20_NOHT:
 514                 case NL80211_CHAN_WIDTH_5:
 515                 case NL80211_CHAN_WIDTH_10:
 516                         return;
 517                 default:
 518                         break;
 519                 }
 520
 521                 *rate_idx = 0;
 522                 /* keep protection flags */
 523                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 524                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 525                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 526
 527                 *rate_flags |= IEEE80211_TX_RC_MCS;
 528
 529                 if (chan_width == NL80211_CHAN_WIDTH_40)
 530                         *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 531
 532                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 533                         return;
 534         }
 535
 536         /*
 537          * Uh.. No suitable rate exists. This should not really happen with
 538          * sane TX rate mask configurations. However, should someone manage to
 539          * configure supported rates and TX rate mask in incompatible way,
 540          * allow the frame to be transmitted with whatever the rate control
 541          * selected.
 542          */
 543 }
 544
 545 static void rate_fixup_ratelist(struct ieee80211_vif *vif,
 546                                 struct ieee80211_supported_band *sband,
 547                                 struct ieee80211_tx_info *info,
 548                                 struct ieee80211_tx_rate *rates,
 549                                 int max_rates)
 550 {
 551         struct ieee80211_rate *rate;
 552         bool inval = false;
 553         int i;
 554
 555         /*
 556          * Set up the RTS/CTS rate as the fastest basic rate
 557          * that is not faster than the data rate unless there
 558          * is no basic rate slower than the data rate, in which
 559          * case we pick the slowest basic rate
 560          *
 561          * XXX: Should this check all retry rates?
 562          */
 563         if (!(rates[0].flags &
 564               (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))) {
 565                 u32 basic_rates = vif->bss_conf.basic_rates;
 566                 s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
 567
 568                 rate = &sband->bitrates[rates[0].idx];
 569
 570                 for (i = 0; i < sband->n_bitrates; i++) {
 571                         /* must be a basic rate */
 572                         if (!(basic_rates & BIT(i)))
 573                                 continue;
 574                         /* must not be faster than the data rate */
 575                         if (sband->bitrates[i].bitrate > rate->bitrate)
 576                                 continue;
 577                         /* maximum */
 578                         if (sband->bitrates[baserate].bitrate <
 579                              sband->bitrates[i].bitrate)
 580                                 baserate = i;
 581                 }
 582
 583                 info->control.rts_cts_rate_idx = baserate;
 584         }
 585
 586         for (i = 0; i < max_rates; i++) {
 587                 /*
 588                  * make sure there's no valid rate following
 589                  * an invalid one, just in case drivers don't
 590                  * take the API seriously to stop at -1.
 591                  */
 592                 if (inval) {
 593                         rates[i].idx = -1;
 594                         continue;
 595                 }
 596                 if (rates[i].idx < 0) {
 597                         inval = true;
 598                         continue;
 599                 }
 600
 601                 /*
 602                  * For now assume MCS is already set up correctly, this
 603                  * needs to be fixed.
 604                  */
 605                 if (rates[i].flags & IEEE80211_TX_RC_MCS) {
 606                         WARN_ON(rates[i].idx > 76);
 607
 608                         if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 609                             info->control.use_cts_prot)
 610                                 rates[i].flags |=
 611                                         IEEE80211_TX_RC_USE_CTS_PROTECT;
 612                         continue;
 613                 }
 614
 615                 if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
 616                         WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
 617                         continue;
 618                 }
 619
 620                 /* set up RTS protection if desired */
 621                 if (info->control.use_rts) {
 622                         rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
 623                         info->control.use_cts_prot = false;
 624                 }
 625
 626                 /* RC is busted */
 627                 if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
 628                         rates[i].idx = -1;
 629                         continue;
 630                 }
 631
 632                 rate = &sband->bitrates[rates[i].idx];
 633
 634                 /* set up short preamble */
 635                 if (info->control.short_preamble &&
 636                     rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
 637                         rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
 638
 639                 /* set up G protection */
 640                 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 641                     info->control.use_cts_prot &&
 642                     rate->flags & IEEE80211_RATE_ERP_G)
 643                         rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
 644         }
 645 }
 646
 647
 648 static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
 649                                         struct ieee80211_tx_info *info,
 650                                         struct ieee80211_tx_rate *rates,
 651                                         int max_rates)
 652 {
 653         struct ieee80211_sta_rates *ratetbl = NULL;
 654         int i;
 655
 656         if (sta && !info->control.skip_table)
 657                 ratetbl = rcu_dereference(sta->rates);
 658
 659         /* Fill remaining rate slots with data from the sta rate table. */
 660         max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
 661         for (i = 0; i < max_rates; i++) {
 662                 if (i < ARRAY_SIZE(info->control.rates) &&
 663                     info->control.rates[i].idx >= 0 &&
 664                     info->control.rates[i].count) {
 665                         if (rates != info->control.rates)
 666                                 rates[i] = info->control.rates[i];
 667                 } else if (ratetbl) {
 668                         rates[i].idx = ratetbl->rate[i].idx;
 669                         rates[i].flags = ratetbl->rate[i].flags;
 670                         if (info->control.use_rts)
 671                                 rates[i].count = ratetbl->rate[i].count_rts;
 672                         else if (info->control.use_cts_prot)
 673                                 rates[i].count = ratetbl->rate[i].count_cts;
 674                         else
 675                                 rates[i].count = ratetbl->rate[i].count;
 676                 } else {
 677                         rates[i].idx = -1;
 678                         rates[i].count = 0;
 679                 }
 680
 681                 if (rates[i].idx < 0 || !rates[i].count)
 682                         break;
 683         }
 684 }
 685
 686 static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
 687                                   struct ieee80211_supported_band *sband,
 688                                   struct ieee80211_sta *sta, u32 *mask,
 689                                   u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 690                                   u16 vht_mask[NL80211_VHT_NSS_MAX])
 691 {
 692         u32 i, flags;
 693
 694         *mask = sdata->rc_rateidx_mask[sband->band];
 695         flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
 696         for (i = 0; i < sband->n_bitrates; i++) {
 697                 if ((flags & sband->bitrates[i].flags) != flags)
 698                         *mask &= ~BIT(i);
 699         }
 700
 701         if (*mask == (1 << sband->n_bitrates) - 1 &&
 702             !sdata->rc_has_mcs_mask[sband->band] &&
 703             !sdata->rc_has_vht_mcs_mask[sband->band])
 704                 return false;
 705
 706         if (sdata->rc_has_mcs_mask[sband->band])
 707                 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
 708                        IEEE80211_HT_MCS_MASK_LEN);
 709         else
 710                 memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
 711
 712         if (sdata->rc_has_vht_mcs_mask[sband->band])
 713                 memcpy(vht_mask, sdata->rc_rateidx_vht_mcs_mask[sband->band],
 714                        sizeof(u16) * NL80211_VHT_NSS_MAX);
 715         else
 716                 memset(vht_mask, 0xff, sizeof(u16) * NL80211_VHT_NSS_MAX);
 717
 718         if (sta) {
 719                 __le16 sta_vht_cap;
 720                 u16 sta_vht_mask[NL80211_VHT_NSS_MAX];
 721
 722                 /* Filter out rates that the STA does not support */
 723                 *mask &= sta->supp_rates[sband->band];
 724                 for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++)
 725                         mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
 726
 727                 sta_vht_cap = sta->vht_cap.vht_mcs.rx_mcs_map;
 728                 ieee80211_get_vht_mask_from_cap(sta_vht_cap, sta_vht_mask);
 729                 for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
 730                         vht_mask[i] &= sta_vht_mask[i];
 731         }
 732
 733         return true;
 734 }
 735
 736 static void
 737 rate_control_apply_mask_ratetbl(struct sta_info *sta,
 738                                 struct ieee80211_supported_band *sband,
 739                                 struct ieee80211_sta_rates *rates)
 740 {
 741         int i;
 742         u32 mask;
 743         u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 744         u16 vht_mask[NL80211_VHT_NSS_MAX];
 745         enum nl80211_chan_width chan_width;
 746
 747         if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
 748                                    mcs_mask, vht_mask))
 749                 return;
 750
 751         chan_width = sta->sdata->vif.bss_conf.chandef.width;
 752         for (i = 0; i < IEEE80211_TX_RATE_TABLE_SIZE; i++) {
 753                 if (rates->rate[i].idx < 0)
 754                         break;
 755
 756                 rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
 757                                     sband, chan_width, mask, mcs_mask,
 758                                     vht_mask);
 759         }
 760 }
 761
 762 static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 763                                     struct ieee80211_sta *sta,
 764                                     struct ieee80211_supported_band *sband,
 765                                     struct ieee80211_tx_rate *rates,
 766                                     int max_rates)
 767 {
 768         enum nl80211_chan_width chan_width;
 769         u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 770         u32 mask;
 771         u16 rate_flags, vht_mask[NL80211_VHT_NSS_MAX];
 772         int i;
 773
 774         /*
 775          * Try to enforce the rateidx mask the user wanted. skip this if the
 776          * default mask (allow all rates) is used to save some processing for
 777          * the common case.
 778          */
 779         if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask,
 780                                    vht_mask))
 781                 return;
 782
 783         /*
 784          * Make sure the rate index selected for each TX rate is
 785          * included in the configured mask and change the rate indexes
 786          * if needed.
 787          */
 788         chan_width = sdata->vif.bss_conf.chandef.width;
 789         for (i = 0; i < max_rates; i++) {
 790                 /* Skip invalid rates */
 791                 if (rates[i].idx < 0)
 792                         break;
 793
 794                 rate_flags = rates[i].flags;
 795                 rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
 796                                     chan_width, mask, mcs_mask, vht_mask);
 797                 rates[i].flags = rate_flags;
 798         }
 799 }
 800
 801 void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
 802                             struct ieee80211_sta *sta,
 803                             struct sk_buff *skb,
 804                             struct ieee80211_tx_rate *dest,
 805                             int max_rates)
 806 {
 807         struct ieee80211_sub_if_data *sdata;
 808         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 809         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 810         struct ieee80211_supported_band *sband;
 811
 812         rate_control_fill_sta_table(sta, info, dest, max_rates);
 813
 814         if (!vif)
 815                 return;
 816
 817         sdata = vif_to_sdata(vif);
 818         sband = sdata->local->hw.wiphy->bands[info->band];
 819
 820         if (ieee80211_is_data(hdr->frame_control))
 821                 rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
 822
 823         if (dest[0].idx < 0)
 824                 __rate_control_send_low(&sdata->local->hw, sband, sta, info,
 825                                         sdata->rc_rateidx_mask[info->band]);
 826
 827         if (sta)
 828                 rate_fixup_ratelist(vif, sband, info, dest, max_rates);
 829 }
 830 EXPORT_SYMBOL(ieee80211_get_tx_rates);
 831
 832 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
 833                            struct sta_info *sta,
 834                            struct ieee80211_tx_rate_control *txrc)
 835 {
 836         struct rate_control_ref *ref = sdata->local->rate_ctrl;
 837         void *priv_sta = NULL;
 838         struct ieee80211_sta *ista = NULL;
 839         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 840         int i;
 841
 842         if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
 843                 ista = &sta->sta;
 844                 priv_sta = sta->rate_ctrl_priv;
 845         }
 846
 847         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 848                 info->control.rates[i].idx = -1;
 849                 info->control.rates[i].flags = 0;
 850                 info->control.rates[i].count = 0;
 851         }
 852
 853         if (ieee80211_hw_check(&sdata->local->hw, HAS_RATE_CONTROL))
 854                 return;
 855
 856         if (ista) {
 857                 spin_lock_bh(&sta->rate_ctrl_lock);
 858                 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
 859                 spin_unlock_bh(&sta->rate_ctrl_lock);
 860         } else {
 861                 ref->ops->get_rate(ref->priv, NULL, NULL, txrc);
 862         }
 863
 864         if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_RC_TABLE))
 865                 return;
 866
 867         ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
 868                                info->control.rates,
 869                                ARRAY_SIZE(info->control.rates));
 870 }
 871
 872 int rate_control_set_rates(struct ieee80211_hw *hw,
 873                            struct ieee80211_sta *pubsta,
 874                            struct ieee80211_sta_rates *rates)
 875 {
 876         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 877         struct ieee80211_sta_rates *old;
 878         struct ieee80211_supported_band *sband;
 879
 880         sband = hw->wiphy->bands[ieee80211_get_sdata_band(sta->sdata)];
 881         rate_control_apply_mask_ratetbl(sta, sband, rates);
 882         /*
 883          * mac80211 guarantees that this function will not be called
 884          * concurrently, so the following RCU access is safe, even without
 885          * extra locking. This can not be checked easily, so we just set
 886          * the condition to true.
 887          */
 888         old = rcu_dereference_protected(pubsta->rates, true);
 889         rcu_assign_pointer(pubsta->rates, rates);
 890         if (old)
 891                 kfree_rcu(old, rcu_head);
 892
 893         drv_sta_rate_tbl_update(hw_to_local(hw), sta->sdata, pubsta);
 894
 895         return 0;
 896 }
 897 EXPORT_SYMBOL(rate_control_set_rates);
 898
 899 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
 900                                  const char *name)
 901 {
 902         struct rate_control_ref *ref;
 903
 904         ASSERT_RTNL();
 905
 906         if (local->open_count)
 907                 return -EBUSY;
 908
 909         if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
 910                 if (WARN_ON(!local->ops->set_rts_threshold))
 911                         return -EINVAL;
 912                 return 0;
 913         }
 914
 915         ref = rate_control_alloc(name, local);
 916         if (!ref) {
 917                 wiphy_warn(local->hw.wiphy,
 918                            "Failed to select rate control algorithm\n");
 919                 return -ENOENT;
 920         }
 921
 922         WARN_ON(local->rate_ctrl);
 923         local->rate_ctrl = ref;
 924
 925         wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
 926                     ref->ops->name);
 927
 928         return 0;
 929 }
 930
 931 void rate_control_deinitialize(struct ieee80211_local *local)
 932 {
 933         struct rate_control_ref *ref;
 934
 935         ref = local->rate_ctrl;
 936
 937         if (!ref)
 938                 return;
 939
 940         local->rate_ctrl = NULL;
 941         rate_control_free(ref);
 942 }
 943