net/mac80211/chan.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * mac80211 - channel management
   4  * Copyright 2020 - 2021 Intel Corporation
   5  */
   6
   7 #include <linux/nl80211.h>
   8 #include <linux/export.h>
   9 #include <linux/rtnetlink.h>
  10 #include <net/cfg80211.h>
  11 #include "ieee80211_i.h"
  12 #include "driver-ops.h"
  13 #include "rate.h"
  14
  15 static int ieee80211_chanctx_num_assigned(struct ieee80211_local *local,
  16                                           struct ieee80211_chanctx *ctx)
  17 {
  18         struct ieee80211_sub_if_data *sdata;
  19         int num = 0;
  20
  21         lockdep_assert_held(&local->chanctx_mtx);
  22
  23         list_for_each_entry(sdata, &ctx->assigned_vifs, assigned_chanctx_list)
  24                 num++;
  25
  26         return num;
  27 }
  28
  29 static int ieee80211_chanctx_num_reserved(struct ieee80211_local *local,
  30                                           struct ieee80211_chanctx *ctx)
  31 {
  32         struct ieee80211_sub_if_data *sdata;
  33         int num = 0;
  34
  35         lockdep_assert_held(&local->chanctx_mtx);
  36
  37         list_for_each_entry(sdata, &ctx->reserved_vifs, reserved_chanctx_list)
  38                 num++;
  39
  40         return num;
  41 }
  42
  43 int ieee80211_chanctx_refcount(struct ieee80211_local *local,
  44                                struct ieee80211_chanctx *ctx)
  45 {
  46         return ieee80211_chanctx_num_assigned(local, ctx) +
  47                ieee80211_chanctx_num_reserved(local, ctx);
  48 }
  49
  50 static int ieee80211_num_chanctx(struct ieee80211_local *local)
  51 {
  52         struct ieee80211_chanctx *ctx;
  53         int num = 0;
  54
  55         lockdep_assert_held(&local->chanctx_mtx);
  56
  57         list_for_each_entry(ctx, &local->chanctx_list, list)
  58                 num++;
  59
  60         return num;
  61 }
  62
  63 static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local)
  64 {
  65         lockdep_assert_held(&local->chanctx_mtx);
  66         return ieee80211_num_chanctx(local) < ieee80211_max_num_channels(local);
  67 }
  68
  69 static struct ieee80211_chanctx *
  70 ieee80211_vif_get_chanctx(struct ieee80211_sub_if_data *sdata)
  71 {
  72         struct ieee80211_local *local __maybe_unused = sdata->local;
  73         struct ieee80211_chanctx_conf *conf;
  74
  75         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
  76                                          lockdep_is_held(&local->chanctx_mtx));
  77         if (!conf)
  78                 return NULL;
  79
  80         return container_of(conf, struct ieee80211_chanctx, conf);
  81 }
  82
  83 static const struct cfg80211_chan_def *
  84 ieee80211_chanctx_reserved_chandef(struct ieee80211_local *local,
  85                                    struct ieee80211_chanctx *ctx,
  86                                    const struct cfg80211_chan_def *compat)
  87 {
  88         struct ieee80211_sub_if_data *sdata;
  89
  90         lockdep_assert_held(&local->chanctx_mtx);
  91
  92         list_for_each_entry(sdata, &ctx->reserved_vifs,
  93                             reserved_chanctx_list) {
  94                 if (!compat)
  95                         compat = &sdata->reserved_chandef;
  96
  97                 compat = cfg80211_chandef_compatible(&sdata->reserved_chandef,
  98                                                      compat);
  99                 if (!compat)
 100                         break;
 101         }
 102
 103         return compat;
 104 }
 105
 106 static const struct cfg80211_chan_def *
 107 ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local,
 108                                        struct ieee80211_chanctx *ctx,
 109                                        const struct cfg80211_chan_def *compat)
 110 {
 111         struct ieee80211_sub_if_data *sdata;
 112
 113         lockdep_assert_held(&local->chanctx_mtx);
 114
 115         list_for_each_entry(sdata, &ctx->assigned_vifs,
 116                             assigned_chanctx_list) {
 117                 if (sdata->reserved_chanctx != NULL)
 118                         continue;
 119
 120                 if (!compat)
 121                         compat = &sdata->vif.bss_conf.chandef;
 122
 123                 compat = cfg80211_chandef_compatible(
 124                                 &sdata->vif.bss_conf.chandef, compat);
 125                 if (!compat)
 126                         break;
 127         }
 128
 129         return compat;
 130 }
 131
 132 static const struct cfg80211_chan_def *
 133 ieee80211_chanctx_combined_chandef(struct ieee80211_local *local,
 134                                    struct ieee80211_chanctx *ctx,
 135                                    const struct cfg80211_chan_def *compat)
 136 {
 137         lockdep_assert_held(&local->chanctx_mtx);
 138
 139         compat = ieee80211_chanctx_reserved_chandef(local, ctx, compat);
 140         if (!compat)
 141                 return NULL;
 142
 143         compat = ieee80211_chanctx_non_reserved_chandef(local, ctx, compat);
 144         if (!compat)
 145                 return NULL;
 146
 147         return compat;
 148 }
 149
 150 static bool
 151 ieee80211_chanctx_can_reserve_chandef(struct ieee80211_local *local,
 152                                       struct ieee80211_chanctx *ctx,
 153                                       const struct cfg80211_chan_def *def)
 154 {
 155         lockdep_assert_held(&local->chanctx_mtx);
 156
 157         if (ieee80211_chanctx_combined_chandef(local, ctx, def))
 158                 return true;
 159
 160         if (!list_empty(&ctx->reserved_vifs) &&
 161             ieee80211_chanctx_reserved_chandef(local, ctx, def))
 162                 return true;
 163
 164         return false;
 165 }
 166
 167 static struct ieee80211_chanctx *
 168 ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
 169                                    const struct cfg80211_chan_def *chandef,
 170                                    enum ieee80211_chanctx_mode mode)
 171 {
 172         struct ieee80211_chanctx *ctx;
 173
 174         lockdep_assert_held(&local->chanctx_mtx);
 175
 176         if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
 177                 return NULL;
 178
 179         list_for_each_entry(ctx, &local->chanctx_list, list) {
 180                 if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
 181                         continue;
 182
 183                 if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
 184                         continue;
 185
 186                 if (!ieee80211_chanctx_can_reserve_chandef(local, ctx,
 187                                                            chandef))
 188                         continue;
 189
 190                 return ctx;
 191         }
 192
 193         return NULL;
 194 }
 195
 196 static enum nl80211_chan_width ieee80211_get_sta_bw(struct sta_info *sta)
 197 {
 198         enum ieee80211_sta_rx_bandwidth width = ieee80211_sta_cap_rx_bw(sta);
 199
 200         switch (width) {
 201         case IEEE80211_STA_RX_BW_20:
 202                 if (sta->sta.ht_cap.ht_supported)
 203                         return NL80211_CHAN_WIDTH_20;
 204                 else
 205                         return NL80211_CHAN_WIDTH_20_NOHT;
 206         case IEEE80211_STA_RX_BW_40:
 207                 return NL80211_CHAN_WIDTH_40;
 208         case IEEE80211_STA_RX_BW_80:
 209                 return NL80211_CHAN_WIDTH_80;
 210         case IEEE80211_STA_RX_BW_160:
 211                 /*
 212                  * This applied for both 160 and 80+80. since we use
 213                  * the returned value to consider degradation of
 214                  * ctx->conf.min_def, we have to make sure to take
 215                  * the bigger one (NL80211_CHAN_WIDTH_160).
 216                  * Otherwise we might try degrading even when not
 217                  * needed, as the max required sta_bw returned (80+80)
 218                  * might be smaller than the configured bw (160).
 219                  */
 220                 return NL80211_CHAN_WIDTH_160;
 221         default:
 222                 WARN_ON(1);
 223                 return NL80211_CHAN_WIDTH_20;
 224         }
 225 }
 226
 227 static enum nl80211_chan_width
 228 ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata)
 229 {
 230         enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
 231         struct sta_info *sta;
 232
 233         rcu_read_lock();
 234         list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
 235                 if (sdata != sta->sdata &&
 236                     !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
 237                         continue;
 238
 239                 max_bw = max(max_bw, ieee80211_get_sta_bw(sta));
 240         }
 241         rcu_read_unlock();
 242
 243         return max_bw;
 244 }
 245
 246 static enum nl80211_chan_width
 247 ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
 248                                       struct ieee80211_chanctx_conf *conf)
 249 {
 250         struct ieee80211_sub_if_data *sdata;
 251         enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
 252
 253         rcu_read_lock();
 254         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 255                 struct ieee80211_vif *vif = &sdata->vif;
 256                 enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
 257
 258                 if (!ieee80211_sdata_running(sdata))
 259                         continue;
 260
 261                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 262                         continue;
 263
 264                 switch (vif->type) {
 265                 case NL80211_IFTYPE_AP:
 266                 case NL80211_IFTYPE_AP_VLAN:
 267                         width = ieee80211_get_max_required_bw(sdata);
 268                         break;
 269                 case NL80211_IFTYPE_STATION:
 270                         /*
 271                          * The ap's sta->bandwidth is not set yet at this
 272                          * point, so take the width from the chandef, but
 273                          * account also for TDLS peers
 274                          */
 275                         width = max(vif->bss_conf.chandef.width,
 276                                     ieee80211_get_max_required_bw(sdata));
 277                         break;
 278                 case NL80211_IFTYPE_P2P_DEVICE:
 279                 case NL80211_IFTYPE_NAN:
 280                         continue;
 281                 case NL80211_IFTYPE_ADHOC:
 282                 case NL80211_IFTYPE_MESH_POINT:
 283                 case NL80211_IFTYPE_OCB:
 284                         width = vif->bss_conf.chandef.width;
 285                         break;
 286                 case NL80211_IFTYPE_WDS:
 287                 case NL80211_IFTYPE_UNSPECIFIED:
 288                 case NUM_NL80211_IFTYPES:
 289                 case NL80211_IFTYPE_MONITOR:
 290                 case NL80211_IFTYPE_P2P_CLIENT:
 291                 case NL80211_IFTYPE_P2P_GO:
 292                         WARN_ON_ONCE(1);
 293                 }
 294                 max_bw = max(max_bw, width);
 295         }
 296
 297         /* use the configured bandwidth in case of monitor interface */
 298         sdata = rcu_dereference(local->monitor_sdata);
 299         if (sdata && rcu_access_pointer(sdata->vif.chanctx_conf) == conf)
 300                 max_bw = max(max_bw, conf->def.width);
 301
 302         rcu_read_unlock();
 303
 304         return max_bw;
 305 }
 306
 307 /*
 308  * recalc the min required chan width of the channel context, which is
 309  * the max of min required widths of all the interfaces bound to this
 310  * channel context.
 311  */
 312 static u32 _ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
 313                                              struct ieee80211_chanctx *ctx)
 314 {
 315         enum nl80211_chan_width max_bw;
 316         struct cfg80211_chan_def min_def;
 317
 318         lockdep_assert_held(&local->chanctx_mtx);
 319
 320         /* don't optimize non-20MHz based and radar_enabled confs */
 321         if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
 322             ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
 323             ctx->conf.def.width == NL80211_CHAN_WIDTH_1 ||
 324             ctx->conf.def.width == NL80211_CHAN_WIDTH_2 ||
 325             ctx->conf.def.width == NL80211_CHAN_WIDTH_4 ||
 326             ctx->conf.def.width == NL80211_CHAN_WIDTH_8 ||
 327             ctx->conf.def.width == NL80211_CHAN_WIDTH_16 ||
 328             ctx->conf.radar_enabled) {
 329                 ctx->conf.min_def = ctx->conf.def;
 330                 return 0;
 331         }
 332
 333         max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
 334
 335         /* downgrade chandef up to max_bw */
 336         min_def = ctx->conf.def;
 337         while (min_def.width > max_bw)
 338                 ieee80211_chandef_downgrade(&min_def);
 339
 340         if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
 341                 return 0;
 342
 343         ctx->conf.min_def = min_def;
 344         if (!ctx->driver_present)
 345                 return 0;
 346
 347         return IEEE80211_CHANCTX_CHANGE_MIN_WIDTH;
 348 }
 349
 350 /* calling this function is assuming that station vif is updated to
 351  * lates changes by calling ieee80211_vif_update_chandef
 352  */
 353 static void ieee80211_chan_bw_change(struct ieee80211_local *local,
 354                                      struct ieee80211_chanctx *ctx,
 355                                      bool narrowed)
 356 {
 357         struct sta_info *sta;
 358         struct ieee80211_supported_band *sband =
 359                 local->hw.wiphy->bands[ctx->conf.def.chan->band];
 360
 361         rcu_read_lock();
 362         list_for_each_entry_rcu(sta, &local->sta_list,
 363                                 list) {
 364                 enum ieee80211_sta_rx_bandwidth new_sta_bw;
 365
 366                 if (!ieee80211_sdata_running(sta->sdata))
 367                         continue;
 368
 369                 if (rcu_access_pointer(sta->sdata->vif.chanctx_conf) !=
 370                     &ctx->conf)
 371                         continue;
 372
 373                 new_sta_bw = ieee80211_sta_cur_vht_bw(sta);
 374
 375                 /* nothing change */
 376                 if (new_sta_bw == sta->sta.bandwidth)
 377                         continue;
 378
 379                 /* vif changed to narrow BW and narrow BW for station wasn't
 380                  * requested or vise versa */
 381                 if ((new_sta_bw < sta->sta.bandwidth) == !narrowed)
 382                         continue;
 383
 384                 sta->sta.bandwidth = new_sta_bw;
 385                 rate_control_rate_update(local, sband, sta,
 386                                          IEEE80211_RC_BW_CHANGED);
 387         }
 388         rcu_read_unlock();
 389 }
 390
 391 /*
 392  * recalc the min required chan width of the channel context, which is
 393  * the max of min required widths of all the interfaces bound to this
 394  * channel context.
 395  */
 396 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
 397                                       struct ieee80211_chanctx *ctx)
 398 {
 399         u32 changed = _ieee80211_recalc_chanctx_min_def(local, ctx);
 400
 401         if (!changed)
 402                 return;
 403
 404         /* check is BW narrowed */
 405         ieee80211_chan_bw_change(local, ctx, true);
 406
 407         drv_change_chanctx(local, ctx, changed);
 408
 409         /* check is BW wider */
 410         ieee80211_chan_bw_change(local, ctx, false);
 411 }
 412
 413 static void ieee80211_change_chanctx(struct ieee80211_local *local,
 414                                      struct ieee80211_chanctx *ctx,
 415                                      struct ieee80211_chanctx *old_ctx,
 416                                      const struct cfg80211_chan_def *chandef)
 417 {
 418         u32 changed;
 419
 420         /* expected to handle only 20/40/80/160 channel widths */
 421         switch (chandef->width) {
 422         case NL80211_CHAN_WIDTH_20_NOHT:
 423         case NL80211_CHAN_WIDTH_20:
 424         case NL80211_CHAN_WIDTH_40:
 425         case NL80211_CHAN_WIDTH_80:
 426         case NL80211_CHAN_WIDTH_80P80:
 427         case NL80211_CHAN_WIDTH_160:
 428                 break;
 429         default:
 430                 WARN_ON(1);
 431         }
 432
 433         /* Check maybe BW narrowed - we do this _before_ calling recalc_chanctx_min_def
 434          * due to maybe not returning from it, e.g in case new context was added
 435          * first time with all parameters up to date.
 436          */
 437         ieee80211_chan_bw_change(local, old_ctx, true);
 438
 439         if (cfg80211_chandef_identical(&ctx->conf.def, chandef)) {
 440                 ieee80211_recalc_chanctx_min_def(local, ctx);
 441                 return;
 442         }
 443
 444         WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
 445
 446         ctx->conf.def = *chandef;
 447
 448         /* check if min chanctx also changed */
 449         changed = IEEE80211_CHANCTX_CHANGE_WIDTH |
 450                   _ieee80211_recalc_chanctx_min_def(local, ctx);
 451         drv_change_chanctx(local, ctx, changed);
 452
 453         if (!local->use_chanctx) {
 454                 local->_oper_chandef = *chandef;
 455                 ieee80211_hw_config(local, 0);
 456         }
 457
 458         /* check is BW wider */
 459         ieee80211_chan_bw_change(local, old_ctx, false);
 460 }
 461
 462 static struct ieee80211_chanctx *
 463 ieee80211_find_chanctx(struct ieee80211_local *local,
 464                        const struct cfg80211_chan_def *chandef,
 465                        enum ieee80211_chanctx_mode mode)
 466 {
 467         struct ieee80211_chanctx *ctx;
 468
 469         lockdep_assert_held(&local->chanctx_mtx);
 470
 471         if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
 472                 return NULL;
 473
 474         list_for_each_entry(ctx, &local->chanctx_list, list) {
 475                 const struct cfg80211_chan_def *compat;
 476
 477                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
 478                         continue;
 479
 480                 if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
 481                         continue;
 482
 483                 compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
 484                 if (!compat)
 485                         continue;
 486
 487                 compat = ieee80211_chanctx_reserved_chandef(local, ctx,
 488                                                             compat);
 489                 if (!compat)
 490                         continue;
 491
 492                 ieee80211_change_chanctx(local, ctx, ctx, compat);
 493
 494                 return ctx;
 495         }
 496
 497         return NULL;
 498 }
 499
 500 bool ieee80211_is_radar_required(struct ieee80211_local *local)
 501 {
 502         struct ieee80211_sub_if_data *sdata;
 503
 504         lockdep_assert_held(&local->mtx);
 505
 506         rcu_read_lock();
 507         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 508                 if (sdata->radar_required) {
 509                         rcu_read_unlock();
 510                         return true;
 511                 }
 512         }
 513         rcu_read_unlock();
 514
 515         return false;
 516 }
 517
 518 static bool
 519 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
 520                                  struct ieee80211_chanctx *ctx)
 521 {
 522         struct ieee80211_chanctx_conf *conf = &ctx->conf;
 523         struct ieee80211_sub_if_data *sdata;
 524         bool required = false;
 525
 526         lockdep_assert_held(&local->chanctx_mtx);
 527         lockdep_assert_held(&local->mtx);
 528
 529         rcu_read_lock();
 530         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 531                 if (!ieee80211_sdata_running(sdata))
 532                         continue;
 533                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 534                         continue;
 535                 if (!sdata->radar_required)
 536                         continue;
 537
 538                 required = true;
 539                 break;
 540         }
 541         rcu_read_unlock();
 542
 543         return required;
 544 }
 545
 546 static struct ieee80211_chanctx *
 547 ieee80211_alloc_chanctx(struct ieee80211_local *local,
 548                         const struct cfg80211_chan_def *chandef,
 549                         enum ieee80211_chanctx_mode mode)
 550 {
 551         struct ieee80211_chanctx *ctx;
 552
 553         lockdep_assert_held(&local->chanctx_mtx);
 554
 555         ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
 556         if (!ctx)
 557                 return NULL;
 558
 559         INIT_LIST_HEAD(&ctx->assigned_vifs);
 560         INIT_LIST_HEAD(&ctx->reserved_vifs);
 561         ctx->conf.def = *chandef;
 562         ctx->conf.rx_chains_static = 1;
 563         ctx->conf.rx_chains_dynamic = 1;
 564         ctx->mode = mode;
 565         ctx->conf.radar_enabled = false;
 566         ieee80211_recalc_chanctx_min_def(local, ctx);
 567
 568         return ctx;
 569 }
 570
 571 static int ieee80211_add_chanctx(struct ieee80211_local *local,
 572                                  struct ieee80211_chanctx *ctx)
 573 {
 574         u32 changed;
 575         int err;
 576
 577         lockdep_assert_held(&local->mtx);
 578         lockdep_assert_held(&local->chanctx_mtx);
 579
 580         if (!local->use_chanctx)
 581                 local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
 582
 583         /* turn idle off *before* setting channel -- some drivers need that */
 584         changed = ieee80211_idle_off(local);
 585         if (changed)
 586                 ieee80211_hw_config(local, changed);
 587
 588         if (!local->use_chanctx) {
 589                 local->_oper_chandef = ctx->conf.def;
 590                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 591         } else {
 592                 err = drv_add_chanctx(local, ctx);
 593                 if (err) {
 594                         ieee80211_recalc_idle(local);
 595                         return err;
 596                 }
 597         }
 598
 599         return 0;
 600 }
 601
 602 static struct ieee80211_chanctx *
 603 ieee80211_new_chanctx(struct ieee80211_local *local,
 604                       const struct cfg80211_chan_def *chandef,
 605                       enum ieee80211_chanctx_mode mode)
 606 {
 607         struct ieee80211_chanctx *ctx;
 608         int err;
 609
 610         lockdep_assert_held(&local->mtx);
 611         lockdep_assert_held(&local->chanctx_mtx);
 612
 613         ctx = ieee80211_alloc_chanctx(local, chandef, mode);
 614         if (!ctx)
 615                 return ERR_PTR(-ENOMEM);
 616
 617         err = ieee80211_add_chanctx(local, ctx);
 618         if (err) {
 619                 kfree(ctx);
 620                 return ERR_PTR(err);
 621         }
 622
 623         list_add_rcu(&ctx->list, &local->chanctx_list);
 624         return ctx;
 625 }
 626
 627 static void ieee80211_del_chanctx(struct ieee80211_local *local,
 628                                   struct ieee80211_chanctx *ctx)
 629 {
 630         lockdep_assert_held(&local->chanctx_mtx);
 631
 632         if (!local->use_chanctx) {
 633                 struct cfg80211_chan_def *chandef = &local->_oper_chandef;
 634                 /* S1G doesn't have 20MHz, so get the correct width for the
 635                  * current channel.
 636                  */
 637                 if (chandef->chan->band == NL80211_BAND_S1GHZ)
 638                         chandef->width =
 639                                 ieee80211_s1g_channel_width(chandef->chan);
 640                 else
 641                         chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 642                 chandef->center_freq1 = chandef->chan->center_freq;
 643                 chandef->freq1_offset = chandef->chan->freq_offset;
 644                 chandef->center_freq2 = 0;
 645
 646                 /* NOTE: Disabling radar is only valid here for
 647                  * single channel context. To be sure, check it ...
 648                  */
 649                 WARN_ON(local->hw.conf.radar_enabled &&
 650                         !list_empty(&local->chanctx_list));
 651
 652                 local->hw.conf.radar_enabled = false;
 653
 654                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 655         } else {
 656                 drv_remove_chanctx(local, ctx);
 657         }
 658
 659         ieee80211_recalc_idle(local);
 660 }
 661
 662 static void ieee80211_free_chanctx(struct ieee80211_local *local,
 663                                    struct ieee80211_chanctx *ctx)
 664 {
 665         lockdep_assert_held(&local->chanctx_mtx);
 666
 667         WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
 668
 669         list_del_rcu(&ctx->list);
 670         ieee80211_del_chanctx(local, ctx);
 671         kfree_rcu(ctx, rcu_head);
 672 }
 673
 674 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
 675                                        struct ieee80211_chanctx *ctx)
 676 {
 677         struct ieee80211_chanctx_conf *conf = &ctx->conf;
 678         struct ieee80211_sub_if_data *sdata;
 679         const struct cfg80211_chan_def *compat = NULL;
 680         struct sta_info *sta;
 681
 682         lockdep_assert_held(&local->chanctx_mtx);
 683
 684         rcu_read_lock();
 685         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 686
 687                 if (!ieee80211_sdata_running(sdata))
 688                         continue;
 689                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 690                         continue;
 691                 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 692                         continue;
 693
 694                 if (!compat)
 695                         compat = &sdata->vif.bss_conf.chandef;
 696
 697                 compat = cfg80211_chandef_compatible(
 698                                 &sdata->vif.bss_conf.chandef, compat);
 699                 if (WARN_ON_ONCE(!compat))
 700                         break;
 701         }
 702
 703         /* TDLS peers can sometimes affect the chandef width */
 704         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 705                 if (!sta->uploaded ||
 706                     !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
 707                     !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
 708                     !sta->tdls_chandef.chan)
 709                         continue;
 710
 711                 compat = cfg80211_chandef_compatible(&sta->tdls_chandef,
 712                                                      compat);
 713                 if (WARN_ON_ONCE(!compat))
 714                         break;
 715         }
 716         rcu_read_unlock();
 717
 718         if (!compat)
 719                 return;
 720
 721         ieee80211_change_chanctx(local, ctx, ctx, compat);
 722 }
 723
 724 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
 725                                            struct ieee80211_chanctx *chanctx)
 726 {
 727         bool radar_enabled;
 728
 729         lockdep_assert_held(&local->chanctx_mtx);
 730         /* for ieee80211_is_radar_required */
 731         lockdep_assert_held(&local->mtx);
 732
 733         radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
 734
 735         if (radar_enabled == chanctx->conf.radar_enabled)
 736                 return;
 737
 738         chanctx->conf.radar_enabled = radar_enabled;
 739
 740         if (!local->use_chanctx) {
 741                 local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
 742                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 743         }
 744
 745         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
 746 }
 747
 748 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 749                                         struct ieee80211_chanctx *new_ctx)
 750 {
 751         struct ieee80211_local *local = sdata->local;
 752         struct ieee80211_chanctx_conf *conf;
 753         struct ieee80211_chanctx *curr_ctx = NULL;
 754         int ret = 0;
 755
 756         if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
 757                 return -ENOTSUPP;
 758
 759         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 760                                          lockdep_is_held(&local->chanctx_mtx));
 761
 762         if (conf) {
 763                 curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
 764
 765                 drv_unassign_vif_chanctx(local, sdata, curr_ctx);
 766                 conf = NULL;
 767                 list_del(&sdata->assigned_chanctx_list);
 768         }
 769
 770         if (new_ctx) {
 771                 ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
 772                 if (ret)
 773                         goto out;
 774
 775                 conf = &new_ctx->conf;
 776                 list_add(&sdata->assigned_chanctx_list,
 777                          &new_ctx->assigned_vifs);
 778         }
 779
 780 out:
 781         rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
 782
 783         sdata->vif.bss_conf.idle = !conf;
 784
 785         if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
 786                 ieee80211_recalc_chanctx_chantype(local, curr_ctx);
 787                 ieee80211_recalc_smps_chanctx(local, curr_ctx);
 788                 ieee80211_recalc_radar_chanctx(local, curr_ctx);
 789                 ieee80211_recalc_chanctx_min_def(local, curr_ctx);
 790         }
 791
 792         if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
 793                 ieee80211_recalc_txpower(sdata, false);
 794                 ieee80211_recalc_chanctx_min_def(local, new_ctx);
 795         }
 796
 797         if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
 798             sdata->vif.type != NL80211_IFTYPE_MONITOR)
 799                 ieee80211_bss_info_change_notify(sdata,
 800                                                  BSS_CHANGED_IDLE);
 801
 802         ieee80211_check_fast_xmit_iface(sdata);
 803
 804         return ret;
 805 }
 806
 807 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
 808                                    struct ieee80211_chanctx *chanctx)
 809 {
 810         struct ieee80211_sub_if_data *sdata;
 811         u8 rx_chains_static, rx_chains_dynamic;
 812
 813         lockdep_assert_held(&local->chanctx_mtx);
 814
 815         rx_chains_static = 1;
 816         rx_chains_dynamic = 1;
 817
 818         rcu_read_lock();
 819         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 820                 u8 needed_static, needed_dynamic;
 821
 822                 if (!ieee80211_sdata_running(sdata))
 823                         continue;
 824
 825                 if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
 826                                                 &chanctx->conf)
 827                         continue;
 828
 829                 switch (sdata->vif.type) {
 830                 case NL80211_IFTYPE_P2P_DEVICE:
 831                 case NL80211_IFTYPE_NAN:
 832                         continue;
 833                 case NL80211_IFTYPE_STATION:
 834                         if (!sdata->u.mgd.associated)
 835                                 continue;
 836                         break;
 837                 case NL80211_IFTYPE_AP_VLAN:
 838                         continue;
 839                 case NL80211_IFTYPE_AP:
 840                 case NL80211_IFTYPE_ADHOC:
 841                 case NL80211_IFTYPE_MESH_POINT:
 842                 case NL80211_IFTYPE_OCB:
 843                         break;
 844                 default:
 845                         WARN_ON_ONCE(1);
 846                 }
 847
 848                 switch (sdata->smps_mode) {
 849                 default:
 850                         WARN_ONCE(1, "Invalid SMPS mode %d\n",
 851                                   sdata->smps_mode);
 852                         fallthrough;
 853                 case IEEE80211_SMPS_OFF:
 854                         needed_static = sdata->needed_rx_chains;
 855                         needed_dynamic = sdata->needed_rx_chains;
 856                         break;
 857                 case IEEE80211_SMPS_DYNAMIC:
 858                         needed_static = 1;
 859                         needed_dynamic = sdata->needed_rx_chains;
 860                         break;
 861                 case IEEE80211_SMPS_STATIC:
 862                         needed_static = 1;
 863                         needed_dynamic = 1;
 864                         break;
 865                 }
 866
 867                 rx_chains_static = max(rx_chains_static, needed_static);
 868                 rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
 869         }
 870
 871         /* Disable SMPS for the monitor interface */
 872         sdata = rcu_dereference(local->monitor_sdata);
 873         if (sdata &&
 874             rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
 875                 rx_chains_dynamic = rx_chains_static = local->rx_chains;
 876
 877         rcu_read_unlock();
 878
 879         if (!local->use_chanctx) {
 880                 if (rx_chains_static > 1)
 881                         local->smps_mode = IEEE80211_SMPS_OFF;
 882                 else if (rx_chains_dynamic > 1)
 883                         local->smps_mode = IEEE80211_SMPS_DYNAMIC;
 884                 else
 885                         local->smps_mode = IEEE80211_SMPS_STATIC;
 886                 ieee80211_hw_config(local, 0);
 887         }
 888
 889         if (rx_chains_static == chanctx->conf.rx_chains_static &&
 890             rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
 891                 return;
 892
 893         chanctx->conf.rx_chains_static = rx_chains_static;
 894         chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
 895         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
 896 }
 897
 898 static void
 899 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 900                                       bool clear)
 901 {
 902         struct ieee80211_local *local __maybe_unused = sdata->local;
 903         struct ieee80211_sub_if_data *vlan;
 904         struct ieee80211_chanctx_conf *conf;
 905
 906         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
 907                 return;
 908
 909         lockdep_assert_held(&local->mtx);
 910
 911         /* Check that conf exists, even when clearing this function
 912          * must be called with the AP's channel context still there
 913          * as it would otherwise cause VLANs to have an invalid
 914          * channel context pointer for a while, possibly pointing
 915          * to a channel context that has already been freed.
 916          */
 917         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 918                                          lockdep_is_held(&local->chanctx_mtx));
 919         WARN_ON(!conf);
 920
 921         if (clear)
 922                 conf = NULL;
 923
 924         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 925                 rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
 926 }
 927
 928 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 929                                          bool clear)
 930 {
 931         struct ieee80211_local *local = sdata->local;
 932
 933         mutex_lock(&local->chanctx_mtx);
 934
 935         __ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
 936
 937         mutex_unlock(&local->chanctx_mtx);
 938 }
 939
 940 int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
 941 {
 942         struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;
 943
 944         lockdep_assert_held(&sdata->local->chanctx_mtx);
 945
 946         if (WARN_ON(!ctx))
 947                 return -EINVAL;
 948
 949         list_del(&sdata->reserved_chanctx_list);
 950         sdata->reserved_chanctx = NULL;
 951
 952         if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
 953                 if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
 954                         if (WARN_ON(!ctx->replace_ctx))
 955                                 return -EINVAL;
 956
 957                         WARN_ON(ctx->replace_ctx->replace_state !=
 958                                 IEEE80211_CHANCTX_WILL_BE_REPLACED);
 959                         WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
 960
 961                         ctx->replace_ctx->replace_ctx = NULL;
 962                         ctx->replace_ctx->replace_state =
 963                                         IEEE80211_CHANCTX_REPLACE_NONE;
 964
 965                         list_del_rcu(&ctx->list);
 966                         kfree_rcu(ctx, rcu_head);
 967                 } else {
 968                         ieee80211_free_chanctx(sdata->local, ctx);
 969                 }
 970         }
 971
 972         return 0;
 973 }
 974
 975 int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
 976                                   const struct cfg80211_chan_def *chandef,
 977                                   enum ieee80211_chanctx_mode mode,
 978                                   bool radar_required)
 979 {
 980         struct ieee80211_local *local = sdata->local;
 981         struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
 982
 983         lockdep_assert_held(&local->chanctx_mtx);
 984
 985         curr_ctx = ieee80211_vif_get_chanctx(sdata);
 986         if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
 987                 return -ENOTSUPP;
 988
 989         new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
 990         if (!new_ctx) {
 991                 if (ieee80211_can_create_new_chanctx(local)) {
 992                         new_ctx = ieee80211_new_chanctx(local, chandef, mode);
 993                         if (IS_ERR(new_ctx))
 994                                 return PTR_ERR(new_ctx);
 995                 } else {
 996                         if (!curr_ctx ||
 997                             (curr_ctx->replace_state ==
 998                              IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
 999                             !list_empty(&curr_ctx->reserved_vifs)) {
1000                                 /*
1001                                  * Another vif already requested this context
1002                                  * for a reservation. Find another one hoping
1003                                  * all vifs assigned to it will also switch
1004                                  * soon enough.
1005                                  *
1006                                  * TODO: This needs a little more work as some
1007                                  * cases (more than 2 chanctx capable devices)
1008                                  * may fail which could otherwise succeed
1009                                  * provided some channel context juggling was
1010                                  * performed.
1011                                  *
1012                                  * Consider ctx1..3, vif1..6, each ctx has 2
1013                                  * vifs. vif1 and vif2 from ctx1 request new
1014                                  * different chandefs starting 2 in-place
1015                                  * reserations with ctx4 and ctx5 replacing
1016                                  * ctx1 and ctx2 respectively. Next vif5 and
1017                                  * vif6 from ctx3 reserve ctx4. If vif3 and
1018                                  * vif4 remain on ctx2 as they are then this
1019                                  * fails unless `replace_ctx` from ctx5 is
1020                                  * replaced with ctx3.
1021                                  */
1022                                 list_for_each_entry(ctx, &local->chanctx_list,
1023                                                     list) {
1024                                         if (ctx->replace_state !=
1025                                             IEEE80211_CHANCTX_REPLACE_NONE)
1026                                                 continue;
1027
1028                                         if (!list_empty(&ctx->reserved_vifs))
1029                                                 continue;
1030
1031                                         curr_ctx = ctx;
1032                                         break;
1033                                 }
1034                         }
1035
1036                         /*
1037                          * If that's true then all available contexts already
1038                          * have reservations and cannot be used.
1039                          */
1040                         if (!curr_ctx ||
1041                             (curr_ctx->replace_state ==
1042                              IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1043                             !list_empty(&curr_ctx->reserved_vifs))
1044                                 return -EBUSY;
1045
1046                         new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
1047                         if (!new_ctx)
1048                                 return -ENOMEM;
1049
1050                         new_ctx->replace_ctx = curr_ctx;
1051                         new_ctx->replace_state =
1052                                         IEEE80211_CHANCTX_REPLACES_OTHER;
1053
1054                         curr_ctx->replace_ctx = new_ctx;
1055                         curr_ctx->replace_state =
1056                                         IEEE80211_CHANCTX_WILL_BE_REPLACED;
1057
1058                         list_add_rcu(&new_ctx->list, &local->chanctx_list);
1059                 }
1060         }
1061
1062         list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
1063         sdata->reserved_chanctx = new_ctx;
1064         sdata->reserved_chandef = *chandef;
1065         sdata->reserved_radar_required = radar_required;
1066         sdata->reserved_ready = false;
1067
1068         return 0;
1069 }
1070
1071 static void
1072 ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
1073 {
1074         switch (sdata->vif.type) {
1075         case NL80211_IFTYPE_ADHOC:
1076         case NL80211_IFTYPE_AP:
1077         case NL80211_IFTYPE_MESH_POINT:
1078         case NL80211_IFTYPE_OCB:
1079                 ieee80211_queue_work(&sdata->local->hw,
1080                                      &sdata->csa_finalize_work);
1081                 break;
1082         case NL80211_IFTYPE_STATION:
1083                 ieee80211_queue_work(&sdata->local->hw,
1084                                      &sdata->u.mgd.chswitch_work);
1085                 break;
1086         case NL80211_IFTYPE_UNSPECIFIED:
1087         case NL80211_IFTYPE_AP_VLAN:
1088         case NL80211_IFTYPE_WDS:
1089         case NL80211_IFTYPE_MONITOR:
1090         case NL80211_IFTYPE_P2P_CLIENT:
1091         case NL80211_IFTYPE_P2P_GO:
1092         case NL80211_IFTYPE_P2P_DEVICE:
1093         case NL80211_IFTYPE_NAN:
1094         case NUM_NL80211_IFTYPES:
1095                 WARN_ON(1);
1096                 break;
1097         }
1098 }
1099
1100 static void
1101 ieee80211_vif_update_chandef(struct ieee80211_sub_if_data *sdata,
1102                              const struct cfg80211_chan_def *chandef)
1103 {
1104         struct ieee80211_sub_if_data *vlan;
1105
1106         sdata->vif.bss_conf.chandef = *chandef;
1107
1108         if (sdata->vif.type != NL80211_IFTYPE_AP)
1109                 return;
1110
1111         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
1112                 vlan->vif.bss_conf.chandef = *chandef;
1113 }
1114
1115 static int
1116 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
1117 {
1118         struct ieee80211_local *local = sdata->local;
1119         struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1120         struct ieee80211_chanctx *old_ctx, *new_ctx;
1121         const struct cfg80211_chan_def *chandef;
1122         u32 changed = 0;
1123         int err;
1124
1125         lockdep_assert_held(&local->mtx);
1126         lockdep_assert_held(&local->chanctx_mtx);
1127
1128         new_ctx = sdata->reserved_chanctx;
1129         old_ctx = ieee80211_vif_get_chanctx(sdata);
1130
1131         if (WARN_ON(!sdata->reserved_ready))
1132                 return -EBUSY;
1133
1134         if (WARN_ON(!new_ctx))
1135                 return -EINVAL;
1136
1137         if (WARN_ON(!old_ctx))
1138                 return -EINVAL;
1139
1140         if (WARN_ON(new_ctx->replace_state ==
1141                     IEEE80211_CHANCTX_REPLACES_OTHER))
1142                 return -EINVAL;
1143
1144         chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1145                                 &sdata->reserved_chandef);
1146         if (WARN_ON(!chandef))
1147                 return -EINVAL;
1148
1149         if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
1150                 changed = BSS_CHANGED_BANDWIDTH;
1151
1152         ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1153
1154         ieee80211_change_chanctx(local, new_ctx, old_ctx, chandef);
1155
1156         vif_chsw[0].vif = &sdata->vif;
1157         vif_chsw[0].old_ctx = &old_ctx->conf;
1158         vif_chsw[0].new_ctx = &new_ctx->conf;
1159
1160         list_del(&sdata->reserved_chanctx_list);
1161         sdata->reserved_chanctx = NULL;
1162
1163         err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1164                                      CHANCTX_SWMODE_REASSIGN_VIF);
1165         if (err) {
1166                 if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1167                         ieee80211_free_chanctx(local, new_ctx);
1168
1169                 goto out;
1170         }
1171
1172         list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
1173         rcu_assign_pointer(sdata->vif.chanctx_conf, &new_ctx->conf);
1174
1175         if (sdata->vif.type == NL80211_IFTYPE_AP)
1176                 __ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
1177
1178         ieee80211_check_fast_xmit_iface(sdata);
1179
1180         if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1181                 ieee80211_free_chanctx(local, old_ctx);
1182
1183         ieee80211_recalc_chanctx_min_def(local, new_ctx);
1184         ieee80211_recalc_smps_chanctx(local, new_ctx);
1185         ieee80211_recalc_radar_chanctx(local, new_ctx);
1186
1187         if (changed)
1188                 ieee80211_bss_info_change_notify(sdata, changed);
1189
1190 out:
1191         ieee80211_vif_chanctx_reservation_complete(sdata);
1192         return err;
1193 }
1194
1195 static int
1196 ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
1197 {
1198         struct ieee80211_local *local = sdata->local;
1199         struct ieee80211_chanctx *old_ctx, *new_ctx;
1200         const struct cfg80211_chan_def *chandef;
1201         int err;
1202
1203         old_ctx = ieee80211_vif_get_chanctx(sdata);
1204         new_ctx = sdata->reserved_chanctx;
1205
1206         if (WARN_ON(!sdata->reserved_ready))
1207                 return -EINVAL;
1208
1209         if (WARN_ON(old_ctx))
1210                 return -EINVAL;
1211
1212         if (WARN_ON(!new_ctx))
1213                 return -EINVAL;
1214
1215         if (WARN_ON(new_ctx->replace_state ==
1216                     IEEE80211_CHANCTX_REPLACES_OTHER))
1217                 return -EINVAL;
1218
1219         chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1220                                 &sdata->reserved_chandef);
1221         if (WARN_ON(!chandef))
1222                 return -EINVAL;
1223
1224         ieee80211_change_chanctx(local, new_ctx, new_ctx, chandef);
1225
1226         list_del(&sdata->reserved_chanctx_list);
1227         sdata->reserved_chanctx = NULL;
1228
1229         err = ieee80211_assign_vif_chanctx(sdata, new_ctx);
1230         if (err) {
1231                 if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1232                         ieee80211_free_chanctx(local, new_ctx);
1233
1234                 goto out;
1235         }
1236
1237 out:
1238         ieee80211_vif_chanctx_reservation_complete(sdata);
1239         return err;
1240 }
1241
1242 static bool
1243 ieee80211_vif_has_in_place_reservation(struct ieee80211_sub_if_data *sdata)
1244 {
1245         struct ieee80211_chanctx *old_ctx, *new_ctx;
1246
1247         lockdep_assert_held(&sdata->local->chanctx_mtx);
1248
1249         new_ctx = sdata->reserved_chanctx;
1250         old_ctx = ieee80211_vif_get_chanctx(sdata);
1251
1252         if (!old_ctx)
1253                 return false;
1254
1255         if (WARN_ON(!new_ctx))
1256                 return false;
1257
1258         if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1259                 return false;
1260
1261         if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1262                 return false;
1263
1264         return true;
1265 }
1266
1267 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1268                                         struct ieee80211_chanctx *new_ctx)
1269 {
1270         const struct cfg80211_chan_def *chandef;
1271
1272         lockdep_assert_held(&local->mtx);
1273         lockdep_assert_held(&local->chanctx_mtx);
1274
1275         chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1276         if (WARN_ON(!chandef))
1277                 return -EINVAL;
1278
1279         local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1280         local->_oper_chandef = *chandef;
1281         ieee80211_hw_config(local, 0);
1282
1283         return 0;
1284 }
1285
1286 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1287                                       int n_vifs)
1288 {
1289         struct ieee80211_vif_chanctx_switch *vif_chsw;
1290         struct ieee80211_sub_if_data *sdata;
1291         struct ieee80211_chanctx *ctx, *old_ctx;
1292         int i, err;
1293
1294         lockdep_assert_held(&local->mtx);
1295         lockdep_assert_held(&local->chanctx_mtx);
1296
1297         vif_chsw = kcalloc(n_vifs, sizeof(vif_chsw[0]), GFP_KERNEL);
1298         if (!vif_chsw)
1299                 return -ENOMEM;
1300
1301         i = 0;
1302         list_for_each_entry(ctx, &local->chanctx_list, list) {
1303                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1304                         continue;
1305
1306                 if (WARN_ON(!ctx->replace_ctx)) {
1307                         err = -EINVAL;
1308                         goto out;
1309                 }
1310
1311                 list_for_each_entry(sdata, &ctx->reserved_vifs,
1312                                     reserved_chanctx_list) {
1313                         if (!ieee80211_vif_has_in_place_reservation(
1314                                         sdata))
1315                                 continue;
1316
1317                         old_ctx = ieee80211_vif_get_chanctx(sdata);
1318                         vif_chsw[i].vif = &sdata->vif;
1319                         vif_chsw[i].old_ctx = &old_ctx->conf;
1320                         vif_chsw[i].new_ctx = &ctx->conf;
1321
1322                         i++;
1323                 }
1324         }
1325
1326         err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1327                                      CHANCTX_SWMODE_SWAP_CONTEXTS);
1328
1329 out:
1330         kfree(vif_chsw);
1331         return err;
1332 }
1333
1334 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1335 {
1336         struct ieee80211_chanctx *ctx;
1337         int err;
1338
1339         lockdep_assert_held(&local->mtx);
1340         lockdep_assert_held(&local->chanctx_mtx);
1341
1342         list_for_each_entry(ctx, &local->chanctx_list, list) {
1343                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1344                         continue;
1345
1346                 if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1347                         continue;
1348
1349                 ieee80211_del_chanctx(local, ctx->replace_ctx);
1350                 err = ieee80211_add_chanctx(local, ctx);
1351                 if (err)
1352                         goto err;
1353         }
1354
1355         return 0;
1356
1357 err:
1358         WARN_ON(ieee80211_add_chanctx(local, ctx));
1359         list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1360                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1361                         continue;
1362
1363                 if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1364                         continue;
1365
1366                 ieee80211_del_chanctx(local, ctx);
1367                 WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1368         }
1369
1370         return err;
1371 }
1372
1373 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1374 {
1375         struct ieee80211_sub_if_data *sdata, *sdata_tmp;
1376         struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1377         struct ieee80211_chanctx *new_ctx = NULL;
1378         int err, n_assigned, n_reserved, n_ready;
1379         int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1380
1381         lockdep_assert_held(&local->mtx);
1382         lockdep_assert_held(&local->chanctx_mtx);
1383
1384         /*
1385          * If there are 2 independent pairs of channel contexts performing
1386          * cross-switch of their vifs this code will still wait until both are
1387          * ready even though it could be possible to switch one before the
1388          * other is ready.
1389          *
1390          * For practical reasons and code simplicity just do a single huge
1391          * switch.
1392          */
1393
1394         /*
1395          * Verify if the reservation is still feasible.
1396          *  - if it's not then disconnect
1397          *  - if it is but not all vifs necessary are ready then defer
1398          */
1399
1400         list_for_each_entry(ctx, &local->chanctx_list, list) {
1401                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1402                         continue;
1403
1404                 if (WARN_ON(!ctx->replace_ctx)) {
1405                         err = -EINVAL;
1406                         goto err;
1407                 }
1408
1409                 if (!local->use_chanctx)
1410                         new_ctx = ctx;
1411
1412                 n_ctx++;
1413
1414                 n_assigned = 0;
1415                 n_reserved = 0;
1416                 n_ready = 0;
1417
1418                 list_for_each_entry(sdata, &ctx->replace_ctx->assigned_vifs,
1419                                     assigned_chanctx_list) {
1420                         n_assigned++;
1421                         if (sdata->reserved_chanctx) {
1422                                 n_reserved++;
1423                                 if (sdata->reserved_ready)
1424                                         n_ready++;
1425                         }
1426                 }
1427
1428                 if (n_assigned != n_reserved) {
1429                         if (n_ready == n_reserved) {
1430                                 wiphy_info(local->hw.wiphy,
1431                                            "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1432                                 err = -EBUSY;
1433                                 goto err;
1434                         }
1435
1436                         return -EAGAIN;
1437                 }
1438
1439                 ctx->conf.radar_enabled = false;
1440                 list_for_each_entry(sdata, &ctx->reserved_vifs,
1441                                     reserved_chanctx_list) {
1442                         if (ieee80211_vif_has_in_place_reservation(sdata) &&
1443                             !sdata->reserved_ready)
1444                                 return -EAGAIN;
1445
1446                         old_ctx = ieee80211_vif_get_chanctx(sdata);
1447                         if (old_ctx) {
1448                                 if (old_ctx->replace_state ==
1449                                     IEEE80211_CHANCTX_WILL_BE_REPLACED)
1450                                         n_vifs_switch++;
1451                                 else
1452                                         n_vifs_assign++;
1453                         } else {
1454                                 n_vifs_ctxless++;
1455                         }
1456
1457                         if (sdata->reserved_radar_required)
1458                                 ctx->conf.radar_enabled = true;
1459                 }
1460         }
1461
1462         if (WARN_ON(n_ctx == 0) ||
1463             WARN_ON(n_vifs_switch == 0 &&
1464                     n_vifs_assign == 0 &&
1465                     n_vifs_ctxless == 0) ||
1466             WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1467             WARN_ON(!new_ctx && !local->use_chanctx)) {
1468                 err = -EINVAL;
1469                 goto err;
1470         }
1471
1472         /*
1473          * All necessary vifs are ready. Perform the switch now depending on
1474          * reservations and driver capabilities.
1475          */
1476
1477         if (local->use_chanctx) {
1478                 if (n_vifs_switch > 0) {
1479                         err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1480                         if (err)
1481                                 goto err;
1482                 }
1483
1484                 if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1485                         err = ieee80211_chsw_switch_ctxs(local);
1486                         if (err)
1487                                 goto err;
1488                 }
1489         } else {
1490                 err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1491                 if (err)
1492                         goto err;
1493         }
1494
1495         /*
1496          * Update all structures, values and pointers to point to new channel
1497          * context(s).
1498          */
1499         list_for_each_entry(ctx, &local->chanctx_list, list) {
1500                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1501                         continue;
1502
1503                 if (WARN_ON(!ctx->replace_ctx)) {
1504                         err = -EINVAL;
1505                         goto err;
1506                 }
1507
1508                 list_for_each_entry(sdata, &ctx->reserved_vifs,
1509                                     reserved_chanctx_list) {
1510                         u32 changed = 0;
1511
1512                         if (!ieee80211_vif_has_in_place_reservation(sdata))
1513                                 continue;
1514
1515                         rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
1516
1517                         if (sdata->vif.type == NL80211_IFTYPE_AP)
1518                                 __ieee80211_vif_copy_chanctx_to_vlans(sdata,
1519                                                                       false);
1520
1521                         ieee80211_check_fast_xmit_iface(sdata);
1522
1523                         sdata->radar_required = sdata->reserved_radar_required;
1524
1525                         if (sdata->vif.bss_conf.chandef.width !=
1526                             sdata->reserved_chandef.width)
1527                                 changed = BSS_CHANGED_BANDWIDTH;
1528
1529                         ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1530                         if (changed)
1531                                 ieee80211_bss_info_change_notify(sdata,
1532                                                                  changed);
1533
1534                         ieee80211_recalc_txpower(sdata, false);
1535                 }
1536
1537                 ieee80211_recalc_chanctx_chantype(local, ctx);
1538                 ieee80211_recalc_smps_chanctx(local, ctx);
1539                 ieee80211_recalc_radar_chanctx(local, ctx);
1540                 ieee80211_recalc_chanctx_min_def(local, ctx);
1541
1542                 list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1543                                          reserved_chanctx_list) {
1544                         if (ieee80211_vif_get_chanctx(sdata) != ctx)
1545                                 continue;
1546
1547                         list_del(&sdata->reserved_chanctx_list);
1548                         list_move(&sdata->assigned_chanctx_list,
1549                                   &ctx->assigned_vifs);
1550                         sdata->reserved_chanctx = NULL;
1551
1552                         ieee80211_vif_chanctx_reservation_complete(sdata);
1553                 }
1554
1555                 /*
1556                  * This context might have been a dependency for an already
1557                  * ready re-assign reservation interface that was deferred. Do
1558                  * not propagate error to the caller though. The in-place
1559                  * reservation for originally requested interface has already
1560                  * succeeded at this point.
1561                  */
1562                 list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1563                                          reserved_chanctx_list) {
1564                         if (WARN_ON(ieee80211_vif_has_in_place_reservation(
1565                                         sdata)))
1566                                 continue;
1567
1568                         if (WARN_ON(sdata->reserved_chanctx != ctx))
1569                                 continue;
1570
1571                         if (!sdata->reserved_ready)
1572                                 continue;
1573
1574                         if (ieee80211_vif_get_chanctx(sdata))
1575                                 err = ieee80211_vif_use_reserved_reassign(
1576                                                 sdata);
1577                         else
1578                                 err = ieee80211_vif_use_reserved_assign(sdata);
1579
1580                         if (err) {
1581                                 sdata_info(sdata,
1582                                            "failed to finalize (re-)assign reservation (err=%d)\n",
1583                                            err);
1584                                 ieee80211_vif_unreserve_chanctx(sdata);
1585                                 cfg80211_stop_iface(local->hw.wiphy,
1586                                                     &sdata->wdev,
1587                                                     GFP_KERNEL);
1588                         }
1589                 }
1590         }
1591
1592         /*
1593          * Finally free old contexts
1594          */
1595
1596         list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1597                 if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1598                         continue;
1599
1600                 ctx->replace_ctx->replace_ctx = NULL;
1601                 ctx->replace_ctx->replace_state =
1602                                 IEEE80211_CHANCTX_REPLACE_NONE;
1603
1604                 list_del_rcu(&ctx->list);
1605                 kfree_rcu(ctx, rcu_head);
1606         }
1607
1608         return 0;
1609
1610 err:
1611         list_for_each_entry(ctx, &local->chanctx_list, list) {
1612                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1613                         continue;
1614
1615                 list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1616                                          reserved_chanctx_list) {
1617                         ieee80211_vif_unreserve_chanctx(sdata);
1618                         ieee80211_vif_chanctx_reservation_complete(sdata);
1619                 }
1620         }
1621
1622         return err;
1623 }
1624
1625 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1626 {
1627         struct ieee80211_local *local = sdata->local;
1628         struct ieee80211_chanctx_conf *conf;
1629         struct ieee80211_chanctx *ctx;
1630         bool use_reserved_switch = false;
1631
1632         lockdep_assert_held(&local->chanctx_mtx);
1633
1634         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1635                                          lockdep_is_held(&local->chanctx_mtx));
1636         if (!conf)
1637                 return;
1638
1639         ctx = container_of(conf, struct ieee80211_chanctx, conf);
1640
1641         if (sdata->reserved_chanctx) {
1642                 if (sdata->reserved_chanctx->replace_state ==
1643                     IEEE80211_CHANCTX_REPLACES_OTHER &&
1644                     ieee80211_chanctx_num_reserved(local,
1645                                                    sdata->reserved_chanctx) > 1)
1646                         use_reserved_switch = true;
1647
1648                 ieee80211_vif_unreserve_chanctx(sdata);
1649         }
1650
1651         ieee80211_assign_vif_chanctx(sdata, NULL);
1652         if (ieee80211_chanctx_refcount(local, ctx) == 0)
1653                 ieee80211_free_chanctx(local, ctx);
1654
1655         sdata->radar_required = false;
1656
1657         /* Unreserving may ready an in-place reservation. */
1658         if (use_reserved_switch)
1659                 ieee80211_vif_use_reserved_switch(local);
1660 }
1661
1662 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
1663                               const struct cfg80211_chan_def *chandef,
1664                               enum ieee80211_chanctx_mode mode)
1665 {
1666         struct ieee80211_local *local = sdata->local;
1667         struct ieee80211_chanctx *ctx;
1668         u8 radar_detect_width = 0;
1669         int ret;
1670
1671         lockdep_assert_held(&local->mtx);
1672
1673         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1674
1675         mutex_lock(&local->chanctx_mtx);
1676
1677         ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1678                                             chandef,
1679                                             sdata->wdev.iftype);
1680         if (ret < 0)
1681                 goto out;
1682         if (ret > 0)
1683                 radar_detect_width = BIT(chandef->width);
1684
1685         sdata->radar_required = ret;
1686
1687         ret = ieee80211_check_combinations(sdata, chandef, mode,
1688                                            radar_detect_width);
1689         if (ret < 0)
1690                 goto out;
1691
1692         __ieee80211_vif_release_channel(sdata);
1693
1694         ctx = ieee80211_find_chanctx(local, chandef, mode);
1695         if (!ctx)
1696                 ctx = ieee80211_new_chanctx(local, chandef, mode);
1697         if (IS_ERR(ctx)) {
1698                 ret = PTR_ERR(ctx);
1699                 goto out;
1700         }
1701
1702         ieee80211_vif_update_chandef(sdata, chandef);
1703
1704         ret = ieee80211_assign_vif_chanctx(sdata, ctx);
1705         if (ret) {
1706                 /* if assign fails refcount stays the same */
1707                 if (ieee80211_chanctx_refcount(local, ctx) == 0)
1708                         ieee80211_free_chanctx(local, ctx);
1709                 goto out;
1710         }
1711
1712         ieee80211_recalc_smps_chanctx(local, ctx);
1713         ieee80211_recalc_radar_chanctx(local, ctx);
1714  out:
1715         if (ret)
1716                 sdata->radar_required = false;
1717
1718         mutex_unlock(&local->chanctx_mtx);
1719         return ret;
1720 }
1721
1722 int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
1723 {
1724         struct ieee80211_local *local = sdata->local;
1725         struct ieee80211_chanctx *new_ctx;
1726         struct ieee80211_chanctx *old_ctx;
1727         int err;
1728
1729         lockdep_assert_held(&local->mtx);
1730         lockdep_assert_held(&local->chanctx_mtx);
1731
1732         new_ctx = sdata->reserved_chanctx;
1733         old_ctx = ieee80211_vif_get_chanctx(sdata);
1734
1735         if (WARN_ON(!new_ctx))
1736                 return -EINVAL;
1737
1738         if (WARN_ON(new_ctx->replace_state ==
1739                     IEEE80211_CHANCTX_WILL_BE_REPLACED))
1740                 return -EINVAL;
1741
1742         if (WARN_ON(sdata->reserved_ready))
1743                 return -EINVAL;
1744
1745         sdata->reserved_ready = true;
1746
1747         if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1748                 if (old_ctx)
1749                         err = ieee80211_vif_use_reserved_reassign(sdata);
1750                 else
1751                         err = ieee80211_vif_use_reserved_assign(sdata);
1752
1753                 if (err)
1754                         return err;
1755         }
1756
1757         /*
1758          * In-place reservation may need to be finalized now either if:
1759          *  a) sdata is taking part in the swapping itself and is the last one
1760          *  b) sdata has switched with a re-assign reservation to an existing
1761          *     context readying in-place switching of old_ctx
1762          *
1763          * In case of (b) do not propagate the error up because the requested
1764          * sdata already switched successfully. Just spill an extra warning.
1765          * The ieee80211_vif_use_reserved_switch() already stops all necessary
1766          * interfaces upon failure.
1767          */
1768         if ((old_ctx &&
1769              old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1770             new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1771                 err = ieee80211_vif_use_reserved_switch(local);
1772                 if (err && err != -EAGAIN) {
1773                         if (new_ctx->replace_state ==
1774                             IEEE80211_CHANCTX_REPLACES_OTHER)
1775                                 return err;
1776
1777                         wiphy_info(local->hw.wiphy,
1778                                    "depending in-place reservation failed (err=%d)\n",
1779                                    err);
1780                 }
1781         }
1782
1783         return 0;
1784 }
1785
1786 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
1787                                    const struct cfg80211_chan_def *chandef,
1788                                    u32 *changed)
1789 {
1790         struct ieee80211_local *local = sdata->local;
1791         struct ieee80211_chanctx_conf *conf;
1792         struct ieee80211_chanctx *ctx;
1793         const struct cfg80211_chan_def *compat;
1794         int ret;
1795
1796         if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1797                                      IEEE80211_CHAN_DISABLED))
1798                 return -EINVAL;
1799
1800         mutex_lock(&local->chanctx_mtx);
1801         if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
1802                 ret = 0;
1803                 goto out;
1804         }
1805
1806         if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1807             sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1808                 ret = -EINVAL;
1809                 goto out;
1810         }
1811
1812         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1813                                          lockdep_is_held(&local->chanctx_mtx));
1814         if (!conf) {
1815                 ret = -EINVAL;
1816                 goto out;
1817         }
1818
1819         ctx = container_of(conf, struct ieee80211_chanctx, conf);
1820
1821         compat = cfg80211_chandef_compatible(&conf->def, chandef);
1822         if (!compat) {
1823                 ret = -EINVAL;
1824                 goto out;
1825         }
1826
1827         switch (ctx->replace_state) {
1828         case IEEE80211_CHANCTX_REPLACE_NONE:
1829                 if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1830                         ret = -EBUSY;
1831                         goto out;
1832                 }
1833                 break;
1834         case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1835                 /* TODO: Perhaps the bandwidth change could be treated as a
1836                  * reservation itself? */
1837                 ret = -EBUSY;
1838                 goto out;
1839         case IEEE80211_CHANCTX_REPLACES_OTHER:
1840                 /* channel context that is going to replace another channel
1841                  * context doesn't really exist and shouldn't be assigned
1842                  * anywhere yet */
1843                 WARN_ON(1);
1844                 break;
1845         }
1846
1847         ieee80211_vif_update_chandef(sdata, chandef);
1848
1849         ieee80211_recalc_chanctx_chantype(local, ctx);
1850
1851         *changed |= BSS_CHANGED_BANDWIDTH;
1852         ret = 0;
1853  out:
1854         mutex_unlock(&local->chanctx_mtx);
1855         return ret;
1856 }
1857
1858 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1859 {
1860         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1861
1862         lockdep_assert_held(&sdata->local->mtx);
1863
1864         mutex_lock(&sdata->local->chanctx_mtx);
1865         __ieee80211_vif_release_channel(sdata);
1866         mutex_unlock(&sdata->local->chanctx_mtx);
1867 }
1868
1869 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
1870 {
1871         struct ieee80211_local *local = sdata->local;
1872         struct ieee80211_sub_if_data *ap;
1873         struct ieee80211_chanctx_conf *conf;
1874
1875         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
1876                 return;
1877
1878         ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
1879
1880         mutex_lock(&local->chanctx_mtx);
1881
1882         conf = rcu_dereference_protected(ap->vif.chanctx_conf,
1883                                          lockdep_is_held(&local->chanctx_mtx));
1884         rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
1885         mutex_unlock(&local->chanctx_mtx);
1886 }
1887
1888 void ieee80211_iter_chan_contexts_atomic(
1889         struct ieee80211_hw *hw,
1890         void (*iter)(struct ieee80211_hw *hw,
1891                      struct ieee80211_chanctx_conf *chanctx_conf,
1892                      void *data),
1893         void *iter_data)
1894 {
1895         struct ieee80211_local *local = hw_to_local(hw);
1896         struct ieee80211_chanctx *ctx;
1897
1898         rcu_read_lock();
1899         list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
1900                 if (ctx->driver_present)
1901                         iter(hw, &ctx->conf, iter_data);
1902         rcu_read_unlock();
1903 }
1904 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);