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
 104         /* use the configured bandwidth in case of monitor interface */
 105         sdata = rcu_dereference(local->monitor_sdata);
 106         if (sdata && rcu_access_pointer(sdata->vif.chanctx_conf) == conf)
 107                 max_bw = max(max_bw, conf->def.width);
 108
 109         rcu_read_unlock();
 110
 111         return max_bw;
 112 }
 113
 114 /*
 115  * recalc the min required chan width of the channel context, which is
 116  * the max of min required widths of all the interfaces bound to this
 117  * channel context.
 118  */
 119 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
 120                                       struct ieee80211_chanctx *ctx)
 121 {
 122         enum nl80211_chan_width max_bw;
 123         struct cfg80211_chan_def min_def;
 124
 125         lockdep_assert_held(&local->chanctx_mtx);
 126
 127         /* don't optimize 5MHz, 10MHz, and radar_enabled confs */
 128         if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
 129             ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
 130             ctx->conf.radar_enabled) {
 131                 ctx->conf.min_def = ctx->conf.def;
 132                 return;
 133         }
 134
 135         max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
 136
 137         /* downgrade chandef up to max_bw */
 138         min_def = ctx->conf.def;
 139         while (min_def.width > max_bw)
 140                 ieee80211_chandef_downgrade(&min_def);
 141
 142         if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
 143                 return;
 144
 145         ctx->conf.min_def = min_def;
 146         if (!ctx->driver_present)
 147                 return;
 148
 149         drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_MIN_WIDTH);
 150 }
 151
 152 static void ieee80211_change_chanctx(struct ieee80211_local *local,
 153                                      struct ieee80211_chanctx *ctx,
 154                                      const struct cfg80211_chan_def *chandef)
 155 {
 156         if (cfg80211_chandef_identical(&ctx->conf.def, chandef))
 157                 return;
 158
 159         WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
 160
 161         ctx->conf.def = *chandef;
 162         drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
 163         ieee80211_recalc_chanctx_min_def(local, ctx);
 164
 165         if (!local->use_chanctx) {
 166                 local->_oper_chandef = *chandef;
 167                 ieee80211_hw_config(local, 0);
 168         }
 169 }
 170
 171 static struct ieee80211_chanctx *
 172 ieee80211_find_chanctx(struct ieee80211_local *local,
 173                        const struct cfg80211_chan_def *chandef,
 174                        enum ieee80211_chanctx_mode mode)
 175 {
 176         struct ieee80211_chanctx *ctx;
 177
 178         lockdep_assert_held(&local->chanctx_mtx);
 179
 180         if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
 181                 return NULL;
 182
 183         list_for_each_entry(ctx, &local->chanctx_list, list) {
 184                 const struct cfg80211_chan_def *compat;
 185
 186                 if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
 187                         continue;
 188
 189                 compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
 190                 if (!compat)
 191                         continue;
 192
 193                 ieee80211_change_chanctx(local, ctx, compat);
 194
 195                 return ctx;
 196         }
 197
 198         return NULL;
 199 }
 200
 201 static bool ieee80211_is_radar_required(struct ieee80211_local *local)
 202 {
 203         struct ieee80211_sub_if_data *sdata;
 204
 205         lockdep_assert_held(&local->mtx);
 206
 207         rcu_read_lock();
 208         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 209                 if (sdata->radar_required) {
 210                         rcu_read_unlock();
 211                         return true;
 212                 }
 213         }
 214         rcu_read_unlock();
 215
 216         return false;
 217 }
 218
 219 static struct ieee80211_chanctx *
 220 ieee80211_new_chanctx(struct ieee80211_local *local,
 221                       const struct cfg80211_chan_def *chandef,
 222                       enum ieee80211_chanctx_mode mode)
 223 {
 224         struct ieee80211_chanctx *ctx;
 225         u32 changed;
 226         int err;
 227
 228         lockdep_assert_held(&local->chanctx_mtx);
 229
 230         ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
 231         if (!ctx)
 232                 return ERR_PTR(-ENOMEM);
 233
 234         ctx->conf.def = *chandef;
 235         ctx->conf.rx_chains_static = 1;
 236         ctx->conf.rx_chains_dynamic = 1;
 237         ctx->mode = mode;
 238         ctx->conf.radar_enabled = ieee80211_is_radar_required(local);
 239         ieee80211_recalc_chanctx_min_def(local, ctx);
 240         if (!local->use_chanctx)
 241                 local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
 242
 243         /* we hold the mutex to prevent idle from changing */
 244         lockdep_assert_held(&local->mtx);
 245         /* turn idle off *before* setting channel -- some drivers need that */
 246         changed = ieee80211_idle_off(local);
 247         if (changed)
 248                 ieee80211_hw_config(local, changed);
 249
 250         if (!local->use_chanctx) {
 251                 local->_oper_chandef = *chandef;
 252                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 253         } else {
 254                 err = drv_add_chanctx(local, ctx);
 255                 if (err) {
 256                         kfree(ctx);
 257                         ieee80211_recalc_idle(local);
 258                         return ERR_PTR(err);
 259                 }
 260         }
 261
 262         /* and keep the mutex held until the new chanctx is on the list */
 263         list_add_rcu(&ctx->list, &local->chanctx_list);
 264
 265         return ctx;
 266 }
 267
 268 static void ieee80211_free_chanctx(struct ieee80211_local *local,
 269                                    struct ieee80211_chanctx *ctx)
 270 {
 271         bool check_single_channel = false;
 272         lockdep_assert_held(&local->chanctx_mtx);
 273
 274         WARN_ON_ONCE(ctx->refcount != 0);
 275
 276         if (!local->use_chanctx) {
 277                 struct cfg80211_chan_def *chandef = &local->_oper_chandef;
 278                 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 279                 chandef->center_freq1 = chandef->chan->center_freq;
 280                 chandef->center_freq2 = 0;
 281
 282                 /* NOTE: Disabling radar is only valid here for
 283                  * single channel context. To be sure, check it ...
 284                  */
 285                 if (local->hw.conf.radar_enabled)
 286                         check_single_channel = true;
 287                 local->hw.conf.radar_enabled = false;
 288
 289                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 290         } else {
 291                 drv_remove_chanctx(local, ctx);
 292         }
 293
 294         list_del_rcu(&ctx->list);
 295         kfree_rcu(ctx, rcu_head);
 296
 297         /* throw a warning if this wasn't the only channel context. */
 298         WARN_ON(check_single_channel && !list_empty(&local->chanctx_list));
 299
 300         ieee80211_recalc_idle(local);
 301 }
 302
 303 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 304                                         struct ieee80211_chanctx *ctx)
 305 {
 306         struct ieee80211_local *local = sdata->local;
 307         int ret;
 308
 309         lockdep_assert_held(&local->chanctx_mtx);
 310
 311         ret = drv_assign_vif_chanctx(local, sdata, ctx);
 312         if (ret)
 313                 return ret;
 314
 315         rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
 316         ctx->refcount++;
 317
 318         ieee80211_recalc_txpower(sdata);
 319         ieee80211_recalc_chanctx_min_def(local, ctx);
 320         sdata->vif.bss_conf.idle = false;
 321
 322         if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
 323             sdata->vif.type != NL80211_IFTYPE_MONITOR)
 324                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
 325
 326         return 0;
 327 }
 328
 329 static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
 330                                               struct ieee80211_chanctx *ctx)
 331 {
 332         struct ieee80211_chanctx_conf *conf = &ctx->conf;
 333         struct ieee80211_sub_if_data *sdata;
 334         const struct cfg80211_chan_def *compat = NULL;
 335
 336         lockdep_assert_held(&local->chanctx_mtx);
 337
 338         rcu_read_lock();
 339         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 340
 341                 if (!ieee80211_sdata_running(sdata))
 342                         continue;
 343                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 344                         continue;
 345
 346                 if (!compat)
 347                         compat = &sdata->vif.bss_conf.chandef;
 348
 349                 compat = cfg80211_chandef_compatible(
 350                                 &sdata->vif.bss_conf.chandef, compat);
 351                 if (!compat)
 352                         break;
 353         }
 354         rcu_read_unlock();
 355
 356         if (WARN_ON_ONCE(!compat))
 357                 return;
 358
 359         ieee80211_change_chanctx(local, ctx, compat);
 360 }
 361
 362 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
 363                                            struct ieee80211_chanctx *chanctx)
 364 {
 365         bool radar_enabled;
 366
 367         lockdep_assert_held(&local->chanctx_mtx);
 368         /* for setting local->radar_detect_enabled */
 369         lockdep_assert_held(&local->mtx);
 370
 371         radar_enabled = ieee80211_is_radar_required(local);
 372
 373         if (radar_enabled == chanctx->conf.radar_enabled)
 374                 return;
 375
 376         chanctx->conf.radar_enabled = radar_enabled;
 377         local->radar_detect_enabled = chanctx->conf.radar_enabled;
 378
 379         if (!local->use_chanctx) {
 380                 local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
 381                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 382         }
 383
 384         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
 385 }
 386
 387 static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 388                                            struct ieee80211_chanctx *ctx)
 389 {
 390         struct ieee80211_local *local = sdata->local;
 391
 392         lockdep_assert_held(&local->chanctx_mtx);
 393
 394         ctx->refcount--;
 395         rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);
 396
 397         sdata->vif.bss_conf.idle = true;
 398
 399         if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
 400             sdata->vif.type != NL80211_IFTYPE_MONITOR)
 401                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
 402
 403         drv_unassign_vif_chanctx(local, sdata, ctx);
 404
 405         if (ctx->refcount > 0) {
 406                 ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
 407                 ieee80211_recalc_smps_chanctx(local, ctx);
 408                 ieee80211_recalc_radar_chanctx(local, ctx);
 409                 ieee80211_recalc_chanctx_min_def(local, ctx);
 410         }
 411 }
 412
 413 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 414 {
 415         struct ieee80211_local *local = sdata->local;
 416         struct ieee80211_chanctx_conf *conf;
 417         struct ieee80211_chanctx *ctx;
 418
 419         lockdep_assert_held(&local->chanctx_mtx);
 420
 421         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 422                                          lockdep_is_held(&local->chanctx_mtx));
 423         if (!conf)
 424                 return;
 425
 426         ctx = container_of(conf, struct ieee80211_chanctx, conf);
 427
 428         ieee80211_unassign_vif_chanctx(sdata, ctx);
 429         if (ctx->refcount == 0)
 430                 ieee80211_free_chanctx(local, ctx);
 431 }
 432
 433 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
 434                                    struct ieee80211_chanctx *chanctx)
 435 {
 436         struct ieee80211_sub_if_data *sdata;
 437         u8 rx_chains_static, rx_chains_dynamic;
 438
 439         lockdep_assert_held(&local->chanctx_mtx);
 440
 441         rx_chains_static = 1;
 442         rx_chains_dynamic = 1;
 443
 444         rcu_read_lock();
 445         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 446                 u8 needed_static, needed_dynamic;
 447
 448                 if (!ieee80211_sdata_running(sdata))
 449                         continue;
 450
 451                 if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
 452                                                 &chanctx->conf)
 453                         continue;
 454
 455                 switch (sdata->vif.type) {
 456                 case NL80211_IFTYPE_P2P_DEVICE:
 457                         continue;
 458                 case NL80211_IFTYPE_STATION:
 459                         if (!sdata->u.mgd.associated)
 460                                 continue;
 461                         break;
 462                 case NL80211_IFTYPE_AP_VLAN:
 463                         continue;
 464                 case NL80211_IFTYPE_AP:
 465                 case NL80211_IFTYPE_ADHOC:
 466                 case NL80211_IFTYPE_WDS:
 467                 case NL80211_IFTYPE_MESH_POINT:
 468                         break;
 469                 default:
 470                         WARN_ON_ONCE(1);
 471                 }
 472
 473                 switch (sdata->smps_mode) {
 474                 default:
 475                         WARN_ONCE(1, "Invalid SMPS mode %d\n",
 476                                   sdata->smps_mode);
 477                         /* fall through */
 478                 case IEEE80211_SMPS_OFF:
 479                         needed_static = sdata->needed_rx_chains;
 480                         needed_dynamic = sdata->needed_rx_chains;
 481                         break;
 482                 case IEEE80211_SMPS_DYNAMIC:
 483                         needed_static = 1;
 484                         needed_dynamic = sdata->needed_rx_chains;
 485                         break;
 486                 case IEEE80211_SMPS_STATIC:
 487                         needed_static = 1;
 488                         needed_dynamic = 1;
 489                         break;
 490                 }
 491
 492                 rx_chains_static = max(rx_chains_static, needed_static);
 493                 rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
 494         }
 495
 496         /* Disable SMPS for the monitor interface */
 497         sdata = rcu_dereference(local->monitor_sdata);
 498         if (sdata &&
 499             rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
 500                 rx_chains_dynamic = rx_chains_static = local->rx_chains;
 501
 502         rcu_read_unlock();
 503
 504         if (!local->use_chanctx) {
 505                 if (rx_chains_static > 1)
 506                         local->smps_mode = IEEE80211_SMPS_OFF;
 507                 else if (rx_chains_dynamic > 1)
 508                         local->smps_mode = IEEE80211_SMPS_DYNAMIC;
 509                 else
 510                         local->smps_mode = IEEE80211_SMPS_STATIC;
 511                 ieee80211_hw_config(local, 0);
 512         }
 513
 514         if (rx_chains_static == chanctx->conf.rx_chains_static &&
 515             rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
 516                 return;
 517
 518         chanctx->conf.rx_chains_static = rx_chains_static;
 519         chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
 520         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
 521 }
 522
 523 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 524                               const struct cfg80211_chan_def *chandef,
 525                               enum ieee80211_chanctx_mode mode)
 526 {
 527         struct ieee80211_local *local = sdata->local;
 528         struct ieee80211_chanctx *ctx;
 529         int ret;
 530
 531         lockdep_assert_held(&local->mtx);
 532
 533         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
 534
 535         mutex_lock(&local->chanctx_mtx);
 536         __ieee80211_vif_release_channel(sdata);
 537
 538         ctx = ieee80211_find_chanctx(local, chandef, mode);
 539         if (!ctx)
 540                 ctx = ieee80211_new_chanctx(local, chandef, mode);
 541         if (IS_ERR(ctx)) {
 542                 ret = PTR_ERR(ctx);
 543                 goto out;
 544         }
 545
 546         sdata->vif.bss_conf.chandef = *chandef;
 547
 548         ret = ieee80211_assign_vif_chanctx(sdata, ctx);
 549         if (ret) {
 550                 /* if assign fails refcount stays the same */
 551                 if (ctx->refcount == 0)
 552                         ieee80211_free_chanctx(local, ctx);
 553                 goto out;
 554         }
 555
 556         ieee80211_recalc_smps_chanctx(local, ctx);
 557         ieee80211_recalc_radar_chanctx(local, ctx);
 558  out:
 559         mutex_unlock(&local->chanctx_mtx);
 560         return ret;
 561 }
 562
 563 int ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata,
 564                                  u32 *changed)
 565 {
 566         struct ieee80211_local *local = sdata->local;
 567         struct ieee80211_chanctx_conf *conf;
 568         struct ieee80211_chanctx *ctx;
 569         const struct cfg80211_chan_def *chandef = &sdata->csa_chandef;
 570         int ret;
 571         u32 chanctx_changed = 0;
 572
 573         lockdep_assert_held(&local->mtx);
 574
 575         /* should never be called if not performing a channel switch. */
 576         if (WARN_ON(!sdata->vif.csa_active))
 577                 return -EINVAL;
 578
 579         if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
 580                                      IEEE80211_CHAN_DISABLED))
 581                 return -EINVAL;
 582
 583         mutex_lock(&local->chanctx_mtx);
 584         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 585                                          lockdep_is_held(&local->chanctx_mtx));
 586         if (!conf) {
 587                 ret = -EINVAL;
 588                 goto out;
 589         }
 590
 591         ctx = container_of(conf, struct ieee80211_chanctx, conf);
 592         if (ctx->refcount != 1) {
 593                 ret = -EINVAL;
 594                 goto out;
 595         }
 596
 597         if (sdata->vif.bss_conf.chandef.width != chandef->width) {
 598                 chanctx_changed = IEEE80211_CHANCTX_CHANGE_WIDTH;
 599                 *changed |= BSS_CHANGED_BANDWIDTH;
 600         }
 601
 602         sdata->vif.bss_conf.chandef = *chandef;
 603         ctx->conf.def = *chandef;
 604
 605         chanctx_changed |= IEEE80211_CHANCTX_CHANGE_CHANNEL;
 606         drv_change_chanctx(local, ctx, chanctx_changed);
 607
 608         ieee80211_recalc_chanctx_chantype(local, ctx);
 609         ieee80211_recalc_smps_chanctx(local, ctx);
 610         ieee80211_recalc_radar_chanctx(local, ctx);
 611         ieee80211_recalc_chanctx_min_def(local, ctx);
 612
 613         ret = 0;
 614  out:
 615         mutex_unlock(&local->chanctx_mtx);
 616         return ret;
 617 }
 618
 619 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
 620                                    const struct cfg80211_chan_def *chandef,
 621                                    u32 *changed)
 622 {
 623         struct ieee80211_local *local = sdata->local;
 624         struct ieee80211_chanctx_conf *conf;
 625         struct ieee80211_chanctx *ctx;
 626         int ret;
 627
 628         if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
 629                                      IEEE80211_CHAN_DISABLED))
 630                 return -EINVAL;
 631
 632         mutex_lock(&local->chanctx_mtx);
 633         if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
 634                 ret = 0;
 635                 goto out;
 636         }
 637
 638         if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
 639             sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
 640                 ret = -EINVAL;
 641                 goto out;
 642         }
 643
 644         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 645                                          lockdep_is_held(&local->chanctx_mtx));
 646         if (!conf) {
 647                 ret = -EINVAL;
 648                 goto out;
 649         }
 650
 651         ctx = container_of(conf, struct ieee80211_chanctx, conf);
 652         if (!cfg80211_chandef_compatible(&conf->def, chandef)) {
 653                 ret = -EINVAL;
 654                 goto out;
 655         }
 656
 657         sdata->vif.bss_conf.chandef = *chandef;
 658
 659         ieee80211_recalc_chanctx_chantype(local, ctx);
 660
 661         *changed |= BSS_CHANGED_BANDWIDTH;
 662         ret = 0;
 663  out:
 664         mutex_unlock(&local->chanctx_mtx);
 665         return ret;
 666 }
 667
 668 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 669 {
 670         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
 671
 672         lockdep_assert_held(&sdata->local->mtx);
 673
 674         mutex_lock(&sdata->local->chanctx_mtx);
 675         __ieee80211_vif_release_channel(sdata);
 676         mutex_unlock(&sdata->local->chanctx_mtx);
 677 }
 678
 679 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
 680 {
 681         struct ieee80211_local *local = sdata->local;
 682         struct ieee80211_sub_if_data *ap;
 683         struct ieee80211_chanctx_conf *conf;
 684
 685         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
 686                 return;
 687
 688         ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
 689
 690         mutex_lock(&local->chanctx_mtx);
 691
 692         conf = rcu_dereference_protected(ap->vif.chanctx_conf,
 693                                          lockdep_is_held(&local->chanctx_mtx));
 694         rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
 695         mutex_unlock(&local->chanctx_mtx);
 696 }
 697
 698 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 699                                          bool clear)
 700 {
 701         struct ieee80211_local *local = sdata->local;
 702         struct ieee80211_sub_if_data *vlan;
 703         struct ieee80211_chanctx_conf *conf;
 704
 705         ASSERT_RTNL();
 706
 707         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
 708                 return;
 709
 710         mutex_lock(&local->chanctx_mtx);
 711
 712         /*
 713          * Check that conf exists, even when clearing this function
 714          * must be called with the AP's channel context still there
 715          * as it would otherwise cause VLANs to have an invalid
 716          * channel context pointer for a while, possibly pointing
 717          * to a channel context that has already been freed.
 718          */
 719         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 720                                 lockdep_is_held(&local->chanctx_mtx));
 721         WARN_ON(!conf);
 722
 723         if (clear)
 724                 conf = NULL;
 725
 726         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 727                 rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
 728
 729         mutex_unlock(&local->chanctx_mtx);
 730 }
 731
 732 void ieee80211_iter_chan_contexts_atomic(
 733         struct ieee80211_hw *hw,
 734         void (*iter)(struct ieee80211_hw *hw,
 735                      struct ieee80211_chanctx_conf *chanctx_conf,
 736                      void *data),
 737         void *iter_data)
 738 {
 739         struct ieee80211_local *local = hw_to_local(hw);
 740         struct ieee80211_chanctx *ctx;
 741
 742         rcu_read_lock();
 743         list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
 744                 if (ctx->driver_present)
 745                         iter(hw, &ctx->conf, iter_data);
 746         rcu_read_unlock();
 747 }
 748 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);