net/mac80211/chan.c

   1 /*
   2  * mac80211 - channel management
   3  */
   4
   5 #include <linux/nl80211.h>
   6 #include <linux/export.h>
   7 #include <linux/rtnetlink.h>
   8 #include <net/cfg80211.h>
   9 #include "ieee80211_i.h"
  10 #include "driver-ops.h"
  11
  12 static enum nl80211_chan_width ieee80211_get_sta_bw(struct ieee80211_sta *sta)
  13 {
  14         switch (sta->bandwidth) {
  15         case IEEE80211_STA_RX_BW_20:
  16                 if (sta->ht_cap.ht_supported)
  17                         return NL80211_CHAN_WIDTH_20;
  18                 else
  19                         return NL80211_CHAN_WIDTH_20_NOHT;
  20         case IEEE80211_STA_RX_BW_40:
  21                 return NL80211_CHAN_WIDTH_40;
  22         case IEEE80211_STA_RX_BW_80:
  23                 return NL80211_CHAN_WIDTH_80;
  24         case IEEE80211_STA_RX_BW_160:
  25                 /*
  26                  * This applied for both 160 and 80+80. since we use
  27                  * the returned value to consider degradation of
  28                  * ctx->conf.min_def, we have to make sure to take
  29                  * the bigger one (NL80211_CHAN_WIDTH_160).
  30                  * Otherwise we might try degrading even when not
  31                  * needed, as the max required sta_bw returned (80+80)
  32                  * might be smaller than the configured bw (160).
  33                  */
  34                 return NL80211_CHAN_WIDTH_160;
  35         default:
  36                 WARN_ON(1);
  37                 return NL80211_CHAN_WIDTH_20;
  38         }
  39 }
  40
  41 static enum nl80211_chan_width
  42 ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata)
  43 {
  44         enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
  45         struct sta_info *sta;
  46
  47         rcu_read_lock();
  48         list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
  49                 if (sdata != sta->sdata &&
  50                     !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
  51                         continue;
  52
  53                 if (!sta->uploaded)
  54                         continue;
  55
  56                 max_bw = max(max_bw, ieee80211_get_sta_bw(&sta->sta));
  57         }
  58         rcu_read_unlock();
  59
  60         return max_bw;
  61 }
  62
  63 static enum nl80211_chan_width
  64 ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
  65                                       struct ieee80211_chanctx_conf *conf)
  66 {
  67         struct ieee80211_sub_if_data *sdata;
  68         enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
  69
  70         rcu_read_lock();
  71         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
  72                 struct ieee80211_vif *vif = &sdata->vif;
  73                 enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
  74
  75                 if (!ieee80211_sdata_running(sdata))
  76                         continue;
  77
  78                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
  79                         continue;
  80
  81                 switch (vif->type) {
  82                 case NL80211_IFTYPE_AP:
  83                 case NL80211_IFTYPE_AP_VLAN:
  84                         width = ieee80211_get_max_required_bw(sdata);
  85                         break;
  86                 case NL80211_IFTYPE_P2P_DEVICE:
  87                         continue;
  88                 case NL80211_IFTYPE_STATION:
  89                 case NL80211_IFTYPE_ADHOC:
  90                 case NL80211_IFTYPE_WDS:
  91                 case NL80211_IFTYPE_MESH_POINT:
  92                         width = vif->bss_conf.chandef.width;
  93                         break;
  94                 case NL80211_IFTYPE_UNSPECIFIED:
  95                 case NUM_NL80211_IFTYPES:
  96                 case NL80211_IFTYPE_MONITOR:
  97                 case NL80211_IFTYPE_P2P_CLIENT:
  98                 case NL80211_IFTYPE_P2P_GO:
  99                         WARN_ON_ONCE(1);
 100                 }
 101                 max_bw = max(max_bw, width);
 102         }
 103         rcu_read_unlock();
 104
 105         return max_bw;
 106 }
 107
 108 /*
 109  * recalc the min required chan width of the channel context, which is
 110  * the max of min required widths of all the interfaces bound to this
 111  * channel context.
 112  */
 113 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
 114                                       struct ieee80211_chanctx *ctx)
 115 {
 116         enum nl80211_chan_width max_bw;
 117         struct cfg80211_chan_def min_def;
 118
 119         lockdep_assert_held(&local->chanctx_mtx);
 120
 121         /* don't optimize 5MHz, 10MHz, and radar_enabled confs */
 122         if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
 123             ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
 124             ctx->conf.radar_enabled) {
 125                 ctx->conf.min_def = ctx->conf.def;
 126                 return;
 127         }
 128
 129         max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
 130
 131         /* downgrade chandef up to max_bw */
 132         min_def = ctx->conf.def;
 133         while (min_def.width > max_bw)
 134                 ieee80211_chandef_downgrade(&min_def);
 135
 136         if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
 137                 return;
 138
 139         ctx->conf.min_def = min_def;
 140         if (!ctx->driver_present)
 141                 return;
 142
 143         drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_MIN_WIDTH);
 144 }
 145
 146 static void ieee80211_change_chanctx(struct ieee80211_local *local,
 147                                      struct ieee80211_chanctx *ctx,
 148                                      const struct cfg80211_chan_def *chandef)
 149 {
 150         if (cfg80211_chandef_identical(&ctx->conf.def, chandef))
 151                 return;
 152
 153         WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
 154
 155         ctx->conf.def = *chandef;
 156         drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
 157         ieee80211_recalc_chanctx_min_def(local, ctx);
 158
 159         if (!local->use_chanctx) {
 160                 local->_oper_chandef = *chandef;
 161                 ieee80211_hw_config(local, 0);
 162         }
 163 }
 164
 165 static struct ieee80211_chanctx *
 166 ieee80211_find_chanctx(struct ieee80211_local *local,
 167                        const struct cfg80211_chan_def *chandef,
 168                        enum ieee80211_chanctx_mode mode)
 169 {
 170         struct ieee80211_chanctx *ctx;
 171
 172         lockdep_assert_held(&local->chanctx_mtx);
 173
 174         if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
 175                 return NULL;
 176
 177         list_for_each_entry(ctx, &local->chanctx_list, list) {
 178                 const struct cfg80211_chan_def *compat;
 179
 180                 if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
 181                         continue;
 182
 183                 compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
 184                 if (!compat)
 185                         continue;
 186
 187                 ieee80211_change_chanctx(local, ctx, compat);
 188
 189                 return ctx;
 190         }
 191
 192         return NULL;
 193 }
 194
 195 static bool ieee80211_is_radar_required(struct ieee80211_local *local)
 196 {
 197         struct ieee80211_sub_if_data *sdata;
 198
 199         rcu_read_lock();
 200         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 201                 if (sdata->radar_required) {
 202                         rcu_read_unlock();
 203                         return true;
 204                 }
 205         }
 206         rcu_read_unlock();
 207
 208         return false;
 209 }
 210
 211 static struct ieee80211_chanctx *
 212 ieee80211_new_chanctx(struct ieee80211_local *local,
 213                       const struct cfg80211_chan_def *chandef,
 214                       enum ieee80211_chanctx_mode mode)
 215 {
 216         struct ieee80211_chanctx *ctx;
 217         u32 changed;
 218         int err;
 219
 220         lockdep_assert_held(&local->chanctx_mtx);
 221
 222         ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
 223         if (!ctx)
 224                 return ERR_PTR(-ENOMEM);
 225
 226         ctx->conf.def = *chandef;
 227         ctx->conf.rx_chains_static = 1;
 228         ctx->conf.rx_chains_dynamic = 1;
 229         ctx->mode = mode;
 230         ctx->conf.radar_enabled = ieee80211_is_radar_required(local);
 231         ieee80211_recalc_chanctx_min_def(local, ctx);
 232         if (!local->use_chanctx)
 233                 local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
 234
 235         /* we hold the mutex to prevent idle from changing */
 236         lockdep_assert_held(&local->mtx);
 237         /* turn idle off *before* setting channel -- some drivers need that */
 238         changed = ieee80211_idle_off(local);
 239         if (changed)
 240                 ieee80211_hw_config(local, changed);
 241
 242         if (!local->use_chanctx) {
 243                 local->_oper_chandef = *chandef;
 244                 ieee80211_hw_config(local, 0);
 245         } else {
 246                 err = drv_add_chanctx(local, ctx);
 247                 if (err) {
 248                         kfree(ctx);
 249                         ieee80211_recalc_idle(local);
 250                         return ERR_PTR(err);
 251                 }
 252         }
 253
 254         /* and keep the mutex held until the new chanctx is on the list */
 255         list_add_rcu(&ctx->list, &local->chanctx_list);
 256
 257         return ctx;
 258 }
 259
 260 static void ieee80211_free_chanctx(struct ieee80211_local *local,
 261                                    struct ieee80211_chanctx *ctx)
 262 {
 263         bool check_single_channel = false;
 264         lockdep_assert_held(&local->chanctx_mtx);
 265
 266         WARN_ON_ONCE(ctx->refcount != 0);
 267
 268         if (!local->use_chanctx) {
 269                 struct cfg80211_chan_def *chandef = &local->_oper_chandef;
 270                 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 271                 chandef->center_freq1 = chandef->chan->center_freq;
 272                 chandef->center_freq2 = 0;
 273
 274                 /* NOTE: Disabling radar is only valid here for
 275                  * single channel context. To be sure, check it ...
 276                  */
 277                 if (local->hw.conf.radar_enabled)
 278                         check_single_channel = true;
 279                 local->hw.conf.radar_enabled = false;
 280
 281                 ieee80211_hw_config(local, 0);
 282         } else {
 283                 drv_remove_chanctx(local, ctx);
 284         }
 285
 286         list_del_rcu(&ctx->list);
 287         kfree_rcu(ctx, rcu_head);
 288
 289         /* throw a warning if this wasn't the only channel context. */
 290         WARN_ON(check_single_channel && !list_empty(&local->chanctx_list));
 291
 292         ieee80211_recalc_idle(local);
 293 }
 294
 295 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 296                                         struct ieee80211_chanctx *ctx)
 297 {
 298         struct ieee80211_local *local = sdata->local;
 299         int ret;
 300
 301         lockdep_assert_held(&local->chanctx_mtx);
 302
 303         ret = drv_assign_vif_chanctx(local, sdata, ctx);
 304         if (ret)
 305                 return ret;
 306
 307         rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
 308         ctx->refcount++;
 309
 310         ieee80211_recalc_txpower(sdata);
 311         ieee80211_recalc_chanctx_min_def(local, ctx);
 312         sdata->vif.bss_conf.idle = false;
 313
 314         if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
 315             sdata->vif.type != NL80211_IFTYPE_MONITOR)
 316                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
 317
 318         return 0;
 319 }
 320
 321 static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
 322                                               struct ieee80211_chanctx *ctx)
 323 {
 324         struct ieee80211_chanctx_conf *conf = &ctx->conf;
 325         struct ieee80211_sub_if_data *sdata;
 326         const struct cfg80211_chan_def *compat = NULL;
 327
 328         lockdep_assert_held(&local->chanctx_mtx);
 329
 330         rcu_read_lock();
 331         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 332
 333                 if (!ieee80211_sdata_running(sdata))
 334                         continue;
 335                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 336                         continue;
 337
 338                 if (!compat)
 339                         compat = &sdata->vif.bss_conf.chandef;
 340
 341                 compat = cfg80211_chandef_compatible(
 342                                 &sdata->vif.bss_conf.chandef, compat);
 343                 if (!compat)
 344                         break;
 345         }
 346         rcu_read_unlock();
 347
 348         if (WARN_ON_ONCE(!compat))
 349                 return;
 350
 351         ieee80211_change_chanctx(local, ctx, compat);
 352 }
 353
 354 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
 355                                            struct ieee80211_chanctx *chanctx)
 356 {
 357         bool radar_enabled;
 358
 359         lockdep_assert_held(&local->chanctx_mtx);
 360         /* for setting local->radar_detect_enabled */
 361         lockdep_assert_held(&local->mtx);
 362
 363         radar_enabled = ieee80211_is_radar_required(local);
 364
 365         if (radar_enabled == chanctx->conf.radar_enabled)
 366                 return;
 367
 368         chanctx->conf.radar_enabled = radar_enabled;
 369         local->radar_detect_enabled = chanctx->conf.radar_enabled;
 370
 371         if (!local->use_chanctx) {
 372                 local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
 373                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 374         }
 375
 376         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
 377 }
 378
 379 static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 380                                            struct ieee80211_chanctx *ctx)
 381 {
 382         struct ieee80211_local *local = sdata->local;
 383
 384         lockdep_assert_held(&local->chanctx_mtx);
 385
 386         ctx->refcount--;
 387         rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);
 388
 389         sdata->vif.bss_conf.idle = true;
 390
 391         if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
 392             sdata->vif.type != NL80211_IFTYPE_MONITOR)
 393                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
 394
 395         drv_unassign_vif_chanctx(local, sdata, ctx);
 396
 397         if (ctx->refcount > 0) {
 398                 ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
 399                 ieee80211_recalc_smps_chanctx(local, ctx);
 400                 ieee80211_recalc_radar_chanctx(local, ctx);
 401                 ieee80211_recalc_chanctx_min_def(local, ctx);
 402         }
 403 }
 404
 405 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 406 {
 407         struct ieee80211_local *local = sdata->local;
 408         struct ieee80211_chanctx_conf *conf;
 409         struct ieee80211_chanctx *ctx;
 410
 411         lockdep_assert_held(&local->chanctx_mtx);
 412
 413         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 414                                          lockdep_is_held(&local->chanctx_mtx));
 415         if (!conf)
 416                 return;
 417
 418         ctx = container_of(conf, struct ieee80211_chanctx, conf);
 419
 420         ieee80211_unassign_vif_chanctx(sdata, ctx);
 421         if (ctx->refcount == 0)
 422                 ieee80211_free_chanctx(local, ctx);
 423 }
 424
 425 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
 426                                    struct ieee80211_chanctx *chanctx)
 427 {
 428         struct ieee80211_sub_if_data *sdata;
 429         u8 rx_chains_static, rx_chains_dynamic;
 430
 431         lockdep_assert_held(&local->chanctx_mtx);
 432
 433         rx_chains_static = 1;
 434         rx_chains_dynamic = 1;
 435
 436         rcu_read_lock();
 437         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 438                 u8 needed_static, needed_dynamic;
 439
 440                 if (!ieee80211_sdata_running(sdata))
 441                         continue;
 442
 443                 if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
 444                                                 &chanctx->conf)
 445                         continue;
 446
 447                 switch (sdata->vif.type) {
 448                 case NL80211_IFTYPE_P2P_DEVICE:
 449                         continue;
 450                 case NL80211_IFTYPE_STATION:
 451                         if (!sdata->u.mgd.associated)
 452                                 continue;
 453                         break;
 454                 case NL80211_IFTYPE_AP_VLAN:
 455                         continue;
 456                 case NL80211_IFTYPE_AP:
 457                 case NL80211_IFTYPE_ADHOC:
 458                 case NL80211_IFTYPE_WDS:
 459                 case NL80211_IFTYPE_MESH_POINT:
 460                         break;
 461                 default:
 462                         WARN_ON_ONCE(1);
 463                 }
 464
 465                 switch (sdata->smps_mode) {
 466                 default:
 467                         WARN_ONCE(1, "Invalid SMPS mode %d\n",
 468                                   sdata->smps_mode);
 469                         /* fall through */
 470                 case IEEE80211_SMPS_OFF:
 471                         needed_static = sdata->needed_rx_chains;
 472                         needed_dynamic = sdata->needed_rx_chains;
 473                         break;
 474                 case IEEE80211_SMPS_DYNAMIC:
 475                         needed_static = 1;
 476                         needed_dynamic = sdata->needed_rx_chains;
 477                         break;
 478                 case IEEE80211_SMPS_STATIC:
 479                         needed_static = 1;
 480                         needed_dynamic = 1;
 481                         break;
 482                 }
 483
 484                 rx_chains_static = max(rx_chains_static, needed_static);
 485                 rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
 486         }
 487         rcu_read_unlock();
 488
 489         if (!local->use_chanctx) {
 490                 if (rx_chains_static > 1)
 491                         local->smps_mode = IEEE80211_SMPS_OFF;
 492                 else if (rx_chains_dynamic > 1)
 493                         local->smps_mode = IEEE80211_SMPS_DYNAMIC;
 494                 else
 495                         local->smps_mode = IEEE80211_SMPS_STATIC;
 496                 ieee80211_hw_config(local, 0);
 497         }
 498
 499         if (rx_chains_static == chanctx->conf.rx_chains_static &&
 500             rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
 501                 return;
 502
 503         chanctx->conf.rx_chains_static = rx_chains_static;
 504         chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
 505         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
 506 }
 507
 508 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 509                               const struct cfg80211_chan_def *chandef,
 510                               enum ieee80211_chanctx_mode mode)
 511 {
 512         struct ieee80211_local *local = sdata->local;
 513         struct ieee80211_chanctx *ctx;
 514         int ret;
 515
 516         lockdep_assert_held(&local->mtx);
 517
 518         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
 519
 520         mutex_lock(&local->chanctx_mtx);
 521         __ieee80211_vif_release_channel(sdata);
 522
 523         ctx = ieee80211_find_chanctx(local, chandef, mode);
 524         if (!ctx)
 525                 ctx = ieee80211_new_chanctx(local, chandef, mode);
 526         if (IS_ERR(ctx)) {
 527                 ret = PTR_ERR(ctx);
 528                 goto out;
 529         }
 530
 531         sdata->vif.bss_conf.chandef = *chandef;
 532
 533         ret = ieee80211_assign_vif_chanctx(sdata, ctx);
 534         if (ret) {
 535                 /* if assign fails refcount stays the same */
 536                 if (ctx->refcount == 0)
 537                         ieee80211_free_chanctx(local, ctx);
 538                 goto out;
 539         }
 540
 541         ieee80211_recalc_smps_chanctx(local, ctx);
 542         ieee80211_recalc_radar_chanctx(local, ctx);
 543  out:
 544         mutex_unlock(&local->chanctx_mtx);
 545         return ret;
 546 }
 547
 548 int ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata,
 549                                  u32 *changed)
 550 {
 551         struct ieee80211_local *local = sdata->local;
 552         struct ieee80211_chanctx_conf *conf;
 553         struct ieee80211_chanctx *ctx;
 554         const struct cfg80211_chan_def *chandef = &sdata->csa_chandef;
 555         int ret;
 556         u32 chanctx_changed = 0;
 557
 558         lockdep_assert_held(&local->mtx);
 559
 560         /* should never be called if not performing a channel switch. */
 561         if (WARN_ON(!sdata->vif.csa_active))
 562                 return -EINVAL;
 563
 564         if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
 565                                      IEEE80211_CHAN_DISABLED))
 566                 return -EINVAL;
 567
 568         mutex_lock(&local->chanctx_mtx);
 569         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 570                                          lockdep_is_held(&local->chanctx_mtx));
 571         if (!conf) {
 572                 ret = -EINVAL;
 573                 goto out;
 574         }
 575
 576         ctx = container_of(conf, struct ieee80211_chanctx, conf);
 577         if (ctx->refcount != 1) {
 578                 ret = -EINVAL;
 579                 goto out;
 580         }
 581
 582         if (sdata->vif.bss_conf.chandef.width != chandef->width) {
 583                 chanctx_changed = IEEE80211_CHANCTX_CHANGE_WIDTH;
 584                 *changed |= BSS_CHANGED_BANDWIDTH;
 585         }
 586
 587         sdata->vif.bss_conf.chandef = *chandef;
 588         ctx->conf.def = *chandef;
 589
 590         chanctx_changed |= IEEE80211_CHANCTX_CHANGE_CHANNEL;
 591         drv_change_chanctx(local, ctx, chanctx_changed);
 592
 593         ieee80211_recalc_chanctx_chantype(local, ctx);
 594         ieee80211_recalc_smps_chanctx(local, ctx);
 595         ieee80211_recalc_radar_chanctx(local, ctx);
 596         ieee80211_recalc_chanctx_min_def(local, ctx);
 597
 598         ret = 0;
 599  out:
 600         mutex_unlock(&local->chanctx_mtx);
 601         return ret;
 602 }
 603
 604 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
 605                                    const struct cfg80211_chan_def *chandef,
 606                                    u32 *changed)
 607 {
 608         struct ieee80211_local *local = sdata->local;
 609         struct ieee80211_chanctx_conf *conf;
 610         struct ieee80211_chanctx *ctx;
 611         int ret;
 612
 613         if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
 614                                      IEEE80211_CHAN_DISABLED))
 615                 return -EINVAL;
 616
 617         mutex_lock(&local->chanctx_mtx);
 618         if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
 619                 ret = 0;
 620                 goto out;
 621         }
 622
 623         if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
 624             sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
 625                 ret = -EINVAL;
 626                 goto out;
 627         }
 628
 629         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 630                                          lockdep_is_held(&local->chanctx_mtx));
 631         if (!conf) {
 632                 ret = -EINVAL;
 633                 goto out;
 634         }
 635
 636         ctx = container_of(conf, struct ieee80211_chanctx, conf);
 637         if (!cfg80211_chandef_compatible(&conf->def, chandef)) {
 638                 ret = -EINVAL;
 639                 goto out;
 640         }
 641
 642         sdata->vif.bss_conf.chandef = *chandef;
 643
 644         ieee80211_recalc_chanctx_chantype(local, ctx);
 645
 646         *changed |= BSS_CHANGED_BANDWIDTH;
 647         ret = 0;
 648  out:
 649         mutex_unlock(&local->chanctx_mtx);
 650         return ret;
 651 }
 652
 653 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 654 {
 655         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
 656
 657         lockdep_assert_held(&sdata->local->mtx);
 658
 659         mutex_lock(&sdata->local->chanctx_mtx);
 660         __ieee80211_vif_release_channel(sdata);
 661         mutex_unlock(&sdata->local->chanctx_mtx);
 662 }
 663
 664 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
 665 {
 666         struct ieee80211_local *local = sdata->local;
 667         struct ieee80211_sub_if_data *ap;
 668         struct ieee80211_chanctx_conf *conf;
 669
 670         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
 671                 return;
 672
 673         ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
 674
 675         mutex_lock(&local->chanctx_mtx);
 676
 677         conf = rcu_dereference_protected(ap->vif.chanctx_conf,
 678                                          lockdep_is_held(&local->chanctx_mtx));
 679         rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
 680         mutex_unlock(&local->chanctx_mtx);
 681 }
 682
 683 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 684                                          bool clear)
 685 {
 686         struct ieee80211_local *local = sdata->local;
 687         struct ieee80211_sub_if_data *vlan;
 688         struct ieee80211_chanctx_conf *conf;
 689
 690         ASSERT_RTNL();
 691
 692         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
 693                 return;
 694
 695         mutex_lock(&local->chanctx_mtx);
 696
 697         /*
 698          * Check that conf exists, even when clearing this function
 699          * must be called with the AP's channel context still there
 700          * as it would otherwise cause VLANs to have an invalid
 701          * channel context pointer for a while, possibly pointing
 702          * to a channel context that has already been freed.
 703          */
 704         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 705                                 lockdep_is_held(&local->chanctx_mtx));
 706         WARN_ON(!conf);
 707
 708         if (clear)
 709                 conf = NULL;
 710
 711         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 712                 rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
 713
 714         mutex_unlock(&local->chanctx_mtx);
 715 }
 716
 717 void ieee80211_iter_chan_contexts_atomic(
 718         struct ieee80211_hw *hw,
 719         void (*iter)(struct ieee80211_hw *hw,
 720                      struct ieee80211_chanctx_conf *chanctx_conf,
 721                      void *data),
 722         void *iter_data)
 723 {
 724         struct ieee80211_local *local = hw_to_local(hw);
 725         struct ieee80211_chanctx *ctx;
 726
 727         rcu_read_lock();
 728         list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
 729                 if (ctx->driver_present)
 730                         iter(hw, &ctx->conf, iter_data);
 731         rcu_read_unlock();
 732 }
 733 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);