net/mac80211/chan.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * mac80211 - channel management
   4  */
   5
   6 #include <linux/nl80211.h>
   7 #include <linux/export.h>
   8 #include <linux/rtnetlink.h>
   9 #include <net/cfg80211.h>
  10 #include "ieee80211_i.h"
  11 #include "driver-ops.h"
  12
  13 static int ieee80211_chanctx_num_assigned(struct ieee80211_local *local,
  14                                           struct ieee80211_chanctx *ctx)
  15 {
  16         struct ieee80211_sub_if_data *sdata;
  17         int num = 0;
  18
  19         lockdep_assert_held(&local->chanctx_mtx);
  20
  21         list_for_each_entry(sdata, &ctx->assigned_vifs, assigned_chanctx_list)
  22                 num++;
  23
  24         return num;
  25 }
  26
  27 static int ieee80211_chanctx_num_reserved(struct ieee80211_local *local,
  28                                           struct ieee80211_chanctx *ctx)
  29 {
  30         struct ieee80211_sub_if_data *sdata;
  31         int num = 0;
  32
  33         lockdep_assert_held(&local->chanctx_mtx);
  34
  35         list_for_each_entry(sdata, &ctx->reserved_vifs, reserved_chanctx_list)
  36                 num++;
  37
  38         return num;
  39 }
  40
  41 int ieee80211_chanctx_refcount(struct ieee80211_local *local,
  42                                struct ieee80211_chanctx *ctx)
  43 {
  44         return ieee80211_chanctx_num_assigned(local, ctx) +
  45                ieee80211_chanctx_num_reserved(local, ctx);
  46 }
  47
  48 static int ieee80211_num_chanctx(struct ieee80211_local *local)
  49 {
  50         struct ieee80211_chanctx *ctx;
  51         int num = 0;
  52
  53         lockdep_assert_held(&local->chanctx_mtx);
  54
  55         list_for_each_entry(ctx, &local->chanctx_list, list)
  56                 num++;
  57
  58         return num;
  59 }
  60
  61 static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local)
  62 {
  63         lockdep_assert_held(&local->chanctx_mtx);
  64         return ieee80211_num_chanctx(local) < ieee80211_max_num_channels(local);
  65 }
  66
  67 static struct ieee80211_chanctx *
  68 ieee80211_vif_get_chanctx(struct ieee80211_sub_if_data *sdata)
  69 {
  70         struct ieee80211_local *local __maybe_unused = sdata->local;
  71         struct ieee80211_chanctx_conf *conf;
  72
  73         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
  74                                          lockdep_is_held(&local->chanctx_mtx));
  75         if (!conf)
  76                 return NULL;
  77
  78         return container_of(conf, struct ieee80211_chanctx, conf);
  79 }
  80
  81 static const struct cfg80211_chan_def *
  82 ieee80211_chanctx_reserved_chandef(struct ieee80211_local *local,
  83                                    struct ieee80211_chanctx *ctx,
  84                                    const struct cfg80211_chan_def *compat)
  85 {
  86         struct ieee80211_sub_if_data *sdata;
  87
  88         lockdep_assert_held(&local->chanctx_mtx);
  89
  90         list_for_each_entry(sdata, &ctx->reserved_vifs,
  91                             reserved_chanctx_list) {
  92                 if (!compat)
  93                         compat = &sdata->reserved_chandef;
  94
  95                 compat = cfg80211_chandef_compatible(&sdata->reserved_chandef,
  96                                                      compat);
  97                 if (!compat)
  98                         break;
  99         }
 100
 101         return compat;
 102 }
 103
 104 static const struct cfg80211_chan_def *
 105 ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local,
 106                                        struct ieee80211_chanctx *ctx,
 107                                        const struct cfg80211_chan_def *compat)
 108 {
 109         struct ieee80211_sub_if_data *sdata;
 110
 111         lockdep_assert_held(&local->chanctx_mtx);
 112
 113         list_for_each_entry(sdata, &ctx->assigned_vifs,
 114                             assigned_chanctx_list) {
 115                 if (sdata->reserved_chanctx != NULL)
 116                         continue;
 117
 118                 if (!compat)
 119                         compat = &sdata->vif.bss_conf.chandef;
 120
 121                 compat = cfg80211_chandef_compatible(
 122                                 &sdata->vif.bss_conf.chandef, compat);
 123                 if (!compat)
 124                         break;
 125         }
 126
 127         return compat;
 128 }
 129
 130 static const struct cfg80211_chan_def *
 131 ieee80211_chanctx_combined_chandef(struct ieee80211_local *local,
 132                                    struct ieee80211_chanctx *ctx,
 133                                    const struct cfg80211_chan_def *compat)
 134 {
 135         lockdep_assert_held(&local->chanctx_mtx);
 136
 137         compat = ieee80211_chanctx_reserved_chandef(local, ctx, compat);
 138         if (!compat)
 139                 return NULL;
 140
 141         compat = ieee80211_chanctx_non_reserved_chandef(local, ctx, compat);
 142         if (!compat)
 143                 return NULL;
 144
 145         return compat;
 146 }
 147
 148 static bool
 149 ieee80211_chanctx_can_reserve_chandef(struct ieee80211_local *local,
 150                                       struct ieee80211_chanctx *ctx,
 151                                       const struct cfg80211_chan_def *def)
 152 {
 153         lockdep_assert_held(&local->chanctx_mtx);
 154
 155         if (ieee80211_chanctx_combined_chandef(local, ctx, def))
 156                 return true;
 157
 158         if (!list_empty(&ctx->reserved_vifs) &&
 159             ieee80211_chanctx_reserved_chandef(local, ctx, def))
 160                 return true;
 161
 162         return false;
 163 }
 164
 165 static struct ieee80211_chanctx *
 166 ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
 167                                    const struct cfg80211_chan_def *chandef,
 168                                    enum ieee80211_chanctx_mode mode)
 169 {
 170         struct ieee80211_chanctx *ctx;
 171
 172         lockdep_assert_held(&local->chanctx_mtx);
 173
 174         if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
 175                 return NULL;
 176
 177         list_for_each_entry(ctx, &local->chanctx_list, list) {
 178                 if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
 179                         continue;
 180
 181                 if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
 182                         continue;
 183
 184                 if (!ieee80211_chanctx_can_reserve_chandef(local, ctx,
 185                                                            chandef))
 186                         continue;
 187
 188                 return ctx;
 189         }
 190
 191         return NULL;
 192 }
 193
 194 enum nl80211_chan_width ieee80211_get_sta_bw(struct ieee80211_sta *sta)
 195 {
 196         switch (sta->bandwidth) {
 197         case IEEE80211_STA_RX_BW_20:
 198                 if (sta->ht_cap.ht_supported)
 199                         return NL80211_CHAN_WIDTH_20;
 200                 else
 201                         return NL80211_CHAN_WIDTH_20_NOHT;
 202         case IEEE80211_STA_RX_BW_40:
 203                 return NL80211_CHAN_WIDTH_40;
 204         case IEEE80211_STA_RX_BW_80:
 205                 return NL80211_CHAN_WIDTH_80;
 206         case IEEE80211_STA_RX_BW_160:
 207                 /*
 208                  * This applied for both 160 and 80+80. since we use
 209                  * the returned value to consider degradation of
 210                  * ctx->conf.min_def, we have to make sure to take
 211                  * the bigger one (NL80211_CHAN_WIDTH_160).
 212                  * Otherwise we might try degrading even when not
 213                  * needed, as the max required sta_bw returned (80+80)
 214                  * might be smaller than the configured bw (160).
 215                  */
 216                 return NL80211_CHAN_WIDTH_160;
 217         default:
 218                 WARN_ON(1);
 219                 return NL80211_CHAN_WIDTH_20;
 220         }
 221 }
 222
 223 static enum nl80211_chan_width
 224 ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata)
 225 {
 226         enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
 227         struct sta_info *sta;
 228
 229         rcu_read_lock();
 230         list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
 231                 if (sdata != sta->sdata &&
 232                     !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
 233                         continue;
 234
 235                 max_bw = max(max_bw, ieee80211_get_sta_bw(&sta->sta));
 236         }
 237         rcu_read_unlock();
 238
 239         return max_bw;
 240 }
 241
 242 static enum nl80211_chan_width
 243 ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
 244                                       struct ieee80211_chanctx_conf *conf)
 245 {
 246         struct ieee80211_sub_if_data *sdata;
 247         enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
 248
 249         rcu_read_lock();
 250         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 251                 struct ieee80211_vif *vif = &sdata->vif;
 252                 enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
 253
 254                 if (!ieee80211_sdata_running(sdata))
 255                         continue;
 256
 257                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 258                         continue;
 259
 260                 switch (vif->type) {
 261                 case NL80211_IFTYPE_AP:
 262                 case NL80211_IFTYPE_AP_VLAN:
 263                         width = ieee80211_get_max_required_bw(sdata);
 264                         break;
 265                 case NL80211_IFTYPE_STATION:
 266                         /*
 267                          * The ap's sta->bandwidth is not set yet at this
 268                          * point, so take the width from the chandef, but
 269                          * account also for TDLS peers
 270                          */
 271                         width = max(vif->bss_conf.chandef.width,
 272                                     ieee80211_get_max_required_bw(sdata));
 273                         break;
 274                 case NL80211_IFTYPE_P2P_DEVICE:
 275                 case NL80211_IFTYPE_NAN:
 276                         continue;
 277                 case NL80211_IFTYPE_ADHOC:
 278                 case NL80211_IFTYPE_WDS:
 279                 case NL80211_IFTYPE_MESH_POINT:
 280                 case NL80211_IFTYPE_OCB:
 281                         width = vif->bss_conf.chandef.width;
 282                         break;
 283                 case NL80211_IFTYPE_UNSPECIFIED:
 284                 case NUM_NL80211_IFTYPES:
 285                 case NL80211_IFTYPE_MONITOR:
 286                 case NL80211_IFTYPE_P2P_CLIENT:
 287                 case NL80211_IFTYPE_P2P_GO:
 288                         WARN_ON_ONCE(1);
 289                 }
 290                 max_bw = max(max_bw, width);
 291         }
 292
 293         /* use the configured bandwidth in case of monitor interface */
 294         sdata = rcu_dereference(local->monitor_sdata);
 295         if (sdata && rcu_access_pointer(sdata->vif.chanctx_conf) == conf)
 296                 max_bw = max(max_bw, conf->def.width);
 297
 298         rcu_read_unlock();
 299
 300         return max_bw;
 301 }
 302
 303 /*
 304  * recalc the min required chan width of the channel context, which is
 305  * the max of min required widths of all the interfaces bound to this
 306  * channel context.
 307  */
 308 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
 309                                       struct ieee80211_chanctx *ctx)
 310 {
 311         enum nl80211_chan_width max_bw;
 312         struct cfg80211_chan_def min_def;
 313
 314         lockdep_assert_held(&local->chanctx_mtx);
 315
 316         /* don't optimize 5MHz, 10MHz, and radar_enabled confs */
 317         if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
 318             ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
 319             ctx->conf.radar_enabled) {
 320                 ctx->conf.min_def = ctx->conf.def;
 321                 return;
 322         }
 323
 324         max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
 325
 326         /* downgrade chandef up to max_bw */
 327         min_def = ctx->conf.def;
 328         while (min_def.width > max_bw)
 329                 ieee80211_chandef_downgrade(&min_def);
 330
 331         if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
 332                 return;
 333
 334         ctx->conf.min_def = min_def;
 335         if (!ctx->driver_present)
 336                 return;
 337
 338         drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_MIN_WIDTH);
 339 }
 340
 341 static void ieee80211_change_chanctx(struct ieee80211_local *local,
 342                                      struct ieee80211_chanctx *ctx,
 343                                      const struct cfg80211_chan_def *chandef)
 344 {
 345         if (cfg80211_chandef_identical(&ctx->conf.def, chandef)) {
 346                 ieee80211_recalc_chanctx_min_def(local, ctx);
 347                 return;
 348         }
 349
 350         WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
 351
 352         ctx->conf.def = *chandef;
 353         drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
 354         ieee80211_recalc_chanctx_min_def(local, ctx);
 355
 356         if (!local->use_chanctx) {
 357                 local->_oper_chandef = *chandef;
 358                 ieee80211_hw_config(local, 0);
 359         }
 360 }
 361
 362 static struct ieee80211_chanctx *
 363 ieee80211_find_chanctx(struct ieee80211_local *local,
 364                        const struct cfg80211_chan_def *chandef,
 365                        enum ieee80211_chanctx_mode mode)
 366 {
 367         struct ieee80211_chanctx *ctx;
 368
 369         lockdep_assert_held(&local->chanctx_mtx);
 370
 371         if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
 372                 return NULL;
 373
 374         list_for_each_entry(ctx, &local->chanctx_list, list) {
 375                 const struct cfg80211_chan_def *compat;
 376
 377                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
 378                         continue;
 379
 380                 if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
 381                         continue;
 382
 383                 compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
 384                 if (!compat)
 385                         continue;
 386
 387                 compat = ieee80211_chanctx_reserved_chandef(local, ctx,
 388                                                             compat);
 389                 if (!compat)
 390                         continue;
 391
 392                 ieee80211_change_chanctx(local, ctx, compat);
 393
 394                 return ctx;
 395         }
 396
 397         return NULL;
 398 }
 399
 400 bool ieee80211_is_radar_required(struct ieee80211_local *local)
 401 {
 402         struct ieee80211_sub_if_data *sdata;
 403
 404         lockdep_assert_held(&local->mtx);
 405
 406         rcu_read_lock();
 407         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 408                 if (sdata->radar_required) {
 409                         rcu_read_unlock();
 410                         return true;
 411                 }
 412         }
 413         rcu_read_unlock();
 414
 415         return false;
 416 }
 417
 418 static bool
 419 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
 420                                  struct ieee80211_chanctx *ctx)
 421 {
 422         struct ieee80211_chanctx_conf *conf = &ctx->conf;
 423         struct ieee80211_sub_if_data *sdata;
 424         bool required = false;
 425
 426         lockdep_assert_held(&local->chanctx_mtx);
 427         lockdep_assert_held(&local->mtx);
 428
 429         rcu_read_lock();
 430         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 431                 if (!ieee80211_sdata_running(sdata))
 432                         continue;
 433                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 434                         continue;
 435                 if (!sdata->radar_required)
 436                         continue;
 437
 438                 required = true;
 439                 break;
 440         }
 441         rcu_read_unlock();
 442
 443         return required;
 444 }
 445
 446 static struct ieee80211_chanctx *
 447 ieee80211_alloc_chanctx(struct ieee80211_local *local,
 448                         const struct cfg80211_chan_def *chandef,
 449                         enum ieee80211_chanctx_mode mode)
 450 {
 451         struct ieee80211_chanctx *ctx;
 452
 453         lockdep_assert_held(&local->chanctx_mtx);
 454
 455         ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
 456         if (!ctx)
 457                 return NULL;
 458
 459         INIT_LIST_HEAD(&ctx->assigned_vifs);
 460         INIT_LIST_HEAD(&ctx->reserved_vifs);
 461         ctx->conf.def = *chandef;
 462         ctx->conf.rx_chains_static = 1;
 463         ctx->conf.rx_chains_dynamic = 1;
 464         ctx->mode = mode;
 465         ctx->conf.radar_enabled = false;
 466         ieee80211_recalc_chanctx_min_def(local, ctx);
 467
 468         return ctx;
 469 }
 470
 471 static int ieee80211_add_chanctx(struct ieee80211_local *local,
 472                                  struct ieee80211_chanctx *ctx)
 473 {
 474         u32 changed;
 475         int err;
 476
 477         lockdep_assert_held(&local->mtx);
 478         lockdep_assert_held(&local->chanctx_mtx);
 479
 480         if (!local->use_chanctx)
 481                 local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
 482
 483         /* turn idle off *before* setting channel -- some drivers need that */
 484         changed = ieee80211_idle_off(local);
 485         if (changed)
 486                 ieee80211_hw_config(local, changed);
 487
 488         if (!local->use_chanctx) {
 489                 local->_oper_chandef = ctx->conf.def;
 490                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 491         } else {
 492                 err = drv_add_chanctx(local, ctx);
 493                 if (err) {
 494                         ieee80211_recalc_idle(local);
 495                         return err;
 496                 }
 497         }
 498
 499         return 0;
 500 }
 501
 502 static struct ieee80211_chanctx *
 503 ieee80211_new_chanctx(struct ieee80211_local *local,
 504                       const struct cfg80211_chan_def *chandef,
 505                       enum ieee80211_chanctx_mode mode)
 506 {
 507         struct ieee80211_chanctx *ctx;
 508         int err;
 509
 510         lockdep_assert_held(&local->mtx);
 511         lockdep_assert_held(&local->chanctx_mtx);
 512
 513         ctx = ieee80211_alloc_chanctx(local, chandef, mode);
 514         if (!ctx)
 515                 return ERR_PTR(-ENOMEM);
 516
 517         err = ieee80211_add_chanctx(local, ctx);
 518         if (err) {
 519                 kfree(ctx);
 520                 return ERR_PTR(err);
 521         }
 522
 523         list_add_rcu(&ctx->list, &local->chanctx_list);
 524         return ctx;
 525 }
 526
 527 static void ieee80211_del_chanctx(struct ieee80211_local *local,
 528                                   struct ieee80211_chanctx *ctx)
 529 {
 530         lockdep_assert_held(&local->chanctx_mtx);
 531
 532         if (!local->use_chanctx) {
 533                 struct cfg80211_chan_def *chandef = &local->_oper_chandef;
 534                 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 535                 chandef->center_freq1 = chandef->chan->center_freq;
 536                 chandef->freq1_offset = chandef->chan->freq_offset;
 537                 chandef->center_freq2 = 0;
 538
 539                 /* NOTE: Disabling radar is only valid here for
 540                  * single channel context. To be sure, check it ...
 541                  */
 542                 WARN_ON(local->hw.conf.radar_enabled &&
 543                         !list_empty(&local->chanctx_list));
 544
 545                 local->hw.conf.radar_enabled = false;
 546
 547                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 548         } else {
 549                 drv_remove_chanctx(local, ctx);
 550         }
 551
 552         ieee80211_recalc_idle(local);
 553 }
 554
 555 static void ieee80211_free_chanctx(struct ieee80211_local *local,
 556                                    struct ieee80211_chanctx *ctx)
 557 {
 558         lockdep_assert_held(&local->chanctx_mtx);
 559
 560         WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
 561
 562         list_del_rcu(&ctx->list);
 563         ieee80211_del_chanctx(local, ctx);
 564         kfree_rcu(ctx, rcu_head);
 565 }
 566
 567 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
 568                                        struct ieee80211_chanctx *ctx)
 569 {
 570         struct ieee80211_chanctx_conf *conf = &ctx->conf;
 571         struct ieee80211_sub_if_data *sdata;
 572         const struct cfg80211_chan_def *compat = NULL;
 573         struct sta_info *sta;
 574
 575         lockdep_assert_held(&local->chanctx_mtx);
 576
 577         rcu_read_lock();
 578         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 579
 580                 if (!ieee80211_sdata_running(sdata))
 581                         continue;
 582                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 583                         continue;
 584                 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 585                         continue;
 586
 587                 if (!compat)
 588                         compat = &sdata->vif.bss_conf.chandef;
 589
 590                 compat = cfg80211_chandef_compatible(
 591                                 &sdata->vif.bss_conf.chandef, compat);
 592                 if (WARN_ON_ONCE(!compat))
 593                         break;
 594         }
 595
 596         /* TDLS peers can sometimes affect the chandef width */
 597         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 598                 if (!sta->uploaded ||
 599                     !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
 600                     !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
 601                     !sta->tdls_chandef.chan)
 602                         continue;
 603
 604                 compat = cfg80211_chandef_compatible(&sta->tdls_chandef,
 605                                                      compat);
 606                 if (WARN_ON_ONCE(!compat))
 607                         break;
 608         }
 609         rcu_read_unlock();
 610
 611         if (!compat)
 612                 return;
 613
 614         ieee80211_change_chanctx(local, ctx, compat);
 615 }
 616
 617 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
 618                                            struct ieee80211_chanctx *chanctx)
 619 {
 620         bool radar_enabled;
 621
 622         lockdep_assert_held(&local->chanctx_mtx);
 623         /* for ieee80211_is_radar_required */
 624         lockdep_assert_held(&local->mtx);
 625
 626         radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
 627
 628         if (radar_enabled == chanctx->conf.radar_enabled)
 629                 return;
 630
 631         chanctx->conf.radar_enabled = radar_enabled;
 632
 633         if (!local->use_chanctx) {
 634                 local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
 635                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 636         }
 637
 638         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
 639 }
 640
 641 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 642                                         struct ieee80211_chanctx *new_ctx)
 643 {
 644         struct ieee80211_local *local = sdata->local;
 645         struct ieee80211_chanctx_conf *conf;
 646         struct ieee80211_chanctx *curr_ctx = NULL;
 647         int ret = 0;
 648
 649         if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
 650                 return -ENOTSUPP;
 651
 652         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 653                                          lockdep_is_held(&local->chanctx_mtx));
 654
 655         if (conf) {
 656                 curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
 657
 658                 drv_unassign_vif_chanctx(local, sdata, curr_ctx);
 659                 conf = NULL;
 660                 list_del(&sdata->assigned_chanctx_list);
 661         }
 662
 663         if (new_ctx) {
 664                 ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
 665                 if (ret)
 666                         goto out;
 667
 668                 conf = &new_ctx->conf;
 669                 list_add(&sdata->assigned_chanctx_list,
 670                          &new_ctx->assigned_vifs);
 671         }
 672
 673 out:
 674         rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
 675
 676         sdata->vif.bss_conf.idle = !conf;
 677
 678         if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
 679                 ieee80211_recalc_chanctx_chantype(local, curr_ctx);
 680                 ieee80211_recalc_smps_chanctx(local, curr_ctx);
 681                 ieee80211_recalc_radar_chanctx(local, curr_ctx);
 682                 ieee80211_recalc_chanctx_min_def(local, curr_ctx);
 683         }
 684
 685         if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
 686                 ieee80211_recalc_txpower(sdata, false);
 687                 ieee80211_recalc_chanctx_min_def(local, new_ctx);
 688         }
 689
 690         if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
 691             sdata->vif.type != NL80211_IFTYPE_MONITOR)
 692                 ieee80211_bss_info_change_notify(sdata,
 693                                                  BSS_CHANGED_IDLE);
 694
 695         ieee80211_check_fast_xmit_iface(sdata);
 696
 697         return ret;
 698 }
 699
 700 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
 701                                    struct ieee80211_chanctx *chanctx)
 702 {
 703         struct ieee80211_sub_if_data *sdata;
 704         u8 rx_chains_static, rx_chains_dynamic;
 705
 706         lockdep_assert_held(&local->chanctx_mtx);
 707
 708         rx_chains_static = 1;
 709         rx_chains_dynamic = 1;
 710
 711         rcu_read_lock();
 712         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 713                 u8 needed_static, needed_dynamic;
 714
 715                 if (!ieee80211_sdata_running(sdata))
 716                         continue;
 717
 718                 if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
 719                                                 &chanctx->conf)
 720                         continue;
 721
 722                 switch (sdata->vif.type) {
 723                 case NL80211_IFTYPE_P2P_DEVICE:
 724                 case NL80211_IFTYPE_NAN:
 725                         continue;
 726                 case NL80211_IFTYPE_STATION:
 727                         if (!sdata->u.mgd.associated)
 728                                 continue;
 729                         break;
 730                 case NL80211_IFTYPE_AP_VLAN:
 731                         continue;
 732                 case NL80211_IFTYPE_AP:
 733                 case NL80211_IFTYPE_ADHOC:
 734                 case NL80211_IFTYPE_WDS:
 735                 case NL80211_IFTYPE_MESH_POINT:
 736                 case NL80211_IFTYPE_OCB:
 737                         break;
 738                 default:
 739                         WARN_ON_ONCE(1);
 740                 }
 741
 742                 switch (sdata->smps_mode) {
 743                 default:
 744                         WARN_ONCE(1, "Invalid SMPS mode %d\n",
 745                                   sdata->smps_mode);
 746                         /* fall through */
 747                 case IEEE80211_SMPS_OFF:
 748                         needed_static = sdata->needed_rx_chains;
 749                         needed_dynamic = sdata->needed_rx_chains;
 750                         break;
 751                 case IEEE80211_SMPS_DYNAMIC:
 752                         needed_static = 1;
 753                         needed_dynamic = sdata->needed_rx_chains;
 754                         break;
 755                 case IEEE80211_SMPS_STATIC:
 756                         needed_static = 1;
 757                         needed_dynamic = 1;
 758                         break;
 759                 }
 760
 761                 rx_chains_static = max(rx_chains_static, needed_static);
 762                 rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
 763         }
 764
 765         /* Disable SMPS for the monitor interface */
 766         sdata = rcu_dereference(local->monitor_sdata);
 767         if (sdata &&
 768             rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
 769                 rx_chains_dynamic = rx_chains_static = local->rx_chains;
 770
 771         rcu_read_unlock();
 772
 773         if (!local->use_chanctx) {
 774                 if (rx_chains_static > 1)
 775                         local->smps_mode = IEEE80211_SMPS_OFF;
 776                 else if (rx_chains_dynamic > 1)
 777                         local->smps_mode = IEEE80211_SMPS_DYNAMIC;
 778                 else
 779                         local->smps_mode = IEEE80211_SMPS_STATIC;
 780                 ieee80211_hw_config(local, 0);
 781         }
 782
 783         if (rx_chains_static == chanctx->conf.rx_chains_static &&
 784             rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
 785                 return;
 786
 787         chanctx->conf.rx_chains_static = rx_chains_static;
 788         chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
 789         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
 790 }
 791
 792 static void
 793 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 794                                       bool clear)
 795 {
 796         struct ieee80211_local *local __maybe_unused = sdata->local;
 797         struct ieee80211_sub_if_data *vlan;
 798         struct ieee80211_chanctx_conf *conf;
 799
 800         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
 801                 return;
 802
 803         lockdep_assert_held(&local->mtx);
 804
 805         /* Check that conf exists, even when clearing this function
 806          * must be called with the AP's channel context still there
 807          * as it would otherwise cause VLANs to have an invalid
 808          * channel context pointer for a while, possibly pointing
 809          * to a channel context that has already been freed.
 810          */
 811         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 812                                          lockdep_is_held(&local->chanctx_mtx));
 813         WARN_ON(!conf);
 814
 815         if (clear)
 816                 conf = NULL;
 817
 818         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 819                 rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
 820 }
 821
 822 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 823                                          bool clear)
 824 {
 825         struct ieee80211_local *local = sdata->local;
 826
 827         mutex_lock(&local->chanctx_mtx);
 828
 829         __ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
 830
 831         mutex_unlock(&local->chanctx_mtx);
 832 }
 833
 834 int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
 835 {
 836         struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;
 837
 838         lockdep_assert_held(&sdata->local->chanctx_mtx);
 839
 840         if (WARN_ON(!ctx))
 841                 return -EINVAL;
 842
 843         list_del(&sdata->reserved_chanctx_list);
 844         sdata->reserved_chanctx = NULL;
 845
 846         if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
 847                 if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
 848                         if (WARN_ON(!ctx->replace_ctx))
 849                                 return -EINVAL;
 850
 851                         WARN_ON(ctx->replace_ctx->replace_state !=
 852                                 IEEE80211_CHANCTX_WILL_BE_REPLACED);
 853                         WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
 854
 855                         ctx->replace_ctx->replace_ctx = NULL;
 856                         ctx->replace_ctx->replace_state =
 857                                         IEEE80211_CHANCTX_REPLACE_NONE;
 858
 859                         list_del_rcu(&ctx->list);
 860                         kfree_rcu(ctx, rcu_head);
 861                 } else {
 862                         ieee80211_free_chanctx(sdata->local, ctx);
 863                 }
 864         }
 865
 866         return 0;
 867 }
 868
 869 int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
 870                                   const struct cfg80211_chan_def *chandef,
 871                                   enum ieee80211_chanctx_mode mode,
 872                                   bool radar_required)
 873 {
 874         struct ieee80211_local *local = sdata->local;
 875         struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
 876
 877         lockdep_assert_held(&local->chanctx_mtx);
 878
 879         curr_ctx = ieee80211_vif_get_chanctx(sdata);
 880         if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
 881                 return -ENOTSUPP;
 882
 883         new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
 884         if (!new_ctx) {
 885                 if (ieee80211_can_create_new_chanctx(local)) {
 886                         new_ctx = ieee80211_new_chanctx(local, chandef, mode);
 887                         if (IS_ERR(new_ctx))
 888                                 return PTR_ERR(new_ctx);
 889                 } else {
 890                         if (!curr_ctx ||
 891                             (curr_ctx->replace_state ==
 892                              IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
 893                             !list_empty(&curr_ctx->reserved_vifs)) {
 894                                 /*
 895                                  * Another vif already requested this context
 896                                  * for a reservation. Find another one hoping
 897                                  * all vifs assigned to it will also switch
 898                                  * soon enough.
 899                                  *
 900                                  * TODO: This needs a little more work as some
 901                                  * cases (more than 2 chanctx capable devices)
 902                                  * may fail which could otherwise succeed
 903                                  * provided some channel context juggling was
 904                                  * performed.
 905                                  *
 906                                  * Consider ctx1..3, vif1..6, each ctx has 2
 907                                  * vifs. vif1 and vif2 from ctx1 request new
 908                                  * different chandefs starting 2 in-place
 909                                  * reserations with ctx4 and ctx5 replacing
 910                                  * ctx1 and ctx2 respectively. Next vif5 and
 911                                  * vif6 from ctx3 reserve ctx4. If vif3 and
 912                                  * vif4 remain on ctx2 as they are then this
 913                                  * fails unless `replace_ctx` from ctx5 is
 914                                  * replaced with ctx3.
 915                                  */
 916                                 list_for_each_entry(ctx, &local->chanctx_list,
 917                                                     list) {
 918                                         if (ctx->replace_state !=
 919                                             IEEE80211_CHANCTX_REPLACE_NONE)
 920                                                 continue;
 921
 922                                         if (!list_empty(&ctx->reserved_vifs))
 923                                                 continue;
 924
 925                                         curr_ctx = ctx;
 926                                         break;
 927                                 }
 928                         }
 929
 930                         /*
 931                          * If that's true then all available contexts already
 932                          * have reservations and cannot be used.
 933                          */
 934                         if (!curr_ctx ||
 935                             (curr_ctx->replace_state ==
 936                              IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
 937                             !list_empty(&curr_ctx->reserved_vifs))
 938                                 return -EBUSY;
 939
 940                         new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
 941                         if (!new_ctx)
 942                                 return -ENOMEM;
 943
 944                         new_ctx->replace_ctx = curr_ctx;
 945                         new_ctx->replace_state =
 946                                         IEEE80211_CHANCTX_REPLACES_OTHER;
 947
 948                         curr_ctx->replace_ctx = new_ctx;
 949                         curr_ctx->replace_state =
 950                                         IEEE80211_CHANCTX_WILL_BE_REPLACED;
 951
 952                         list_add_rcu(&new_ctx->list, &local->chanctx_list);
 953                 }
 954         }
 955
 956         list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
 957         sdata->reserved_chanctx = new_ctx;
 958         sdata->reserved_chandef = *chandef;
 959         sdata->reserved_radar_required = radar_required;
 960         sdata->reserved_ready = false;
 961
 962         return 0;
 963 }
 964
 965 static void
 966 ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
 967 {
 968         switch (sdata->vif.type) {
 969         case NL80211_IFTYPE_ADHOC:
 970         case NL80211_IFTYPE_AP:
 971         case NL80211_IFTYPE_MESH_POINT:
 972         case NL80211_IFTYPE_OCB:
 973                 ieee80211_queue_work(&sdata->local->hw,
 974                                      &sdata->csa_finalize_work);
 975                 break;
 976         case NL80211_IFTYPE_STATION:
 977                 ieee80211_queue_work(&sdata->local->hw,
 978                                      &sdata->u.mgd.chswitch_work);
 979                 break;
 980         case NL80211_IFTYPE_UNSPECIFIED:
 981         case NL80211_IFTYPE_AP_VLAN:
 982         case NL80211_IFTYPE_WDS:
 983         case NL80211_IFTYPE_MONITOR:
 984         case NL80211_IFTYPE_P2P_CLIENT:
 985         case NL80211_IFTYPE_P2P_GO:
 986         case NL80211_IFTYPE_P2P_DEVICE:
 987         case NL80211_IFTYPE_NAN:
 988         case NUM_NL80211_IFTYPES:
 989                 WARN_ON(1);
 990                 break;
 991         }
 992 }
 993
 994 static void
 995 ieee80211_vif_update_chandef(struct ieee80211_sub_if_data *sdata,
 996                              const struct cfg80211_chan_def *chandef)
 997 {
 998         struct ieee80211_sub_if_data *vlan;
 999
1000         sdata->vif.bss_conf.chandef = *chandef;
1001
1002         if (sdata->vif.type != NL80211_IFTYPE_AP)
1003                 return;
1004
1005         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
1006                 vlan->vif.bss_conf.chandef = *chandef;
1007 }
1008
1009 static int
1010 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
1011 {
1012         struct ieee80211_local *local = sdata->local;
1013         struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1014         struct ieee80211_chanctx *old_ctx, *new_ctx;
1015         const struct cfg80211_chan_def *chandef;
1016         u32 changed = 0;
1017         int err;
1018
1019         lockdep_assert_held(&local->mtx);
1020         lockdep_assert_held(&local->chanctx_mtx);
1021
1022         new_ctx = sdata->reserved_chanctx;
1023         old_ctx = ieee80211_vif_get_chanctx(sdata);
1024
1025         if (WARN_ON(!sdata->reserved_ready))
1026                 return -EBUSY;
1027
1028         if (WARN_ON(!new_ctx))
1029                 return -EINVAL;
1030
1031         if (WARN_ON(!old_ctx))
1032                 return -EINVAL;
1033
1034         if (WARN_ON(new_ctx->replace_state ==
1035                     IEEE80211_CHANCTX_REPLACES_OTHER))
1036                 return -EINVAL;
1037
1038         chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1039                                 &sdata->reserved_chandef);
1040         if (WARN_ON(!chandef))
1041                 return -EINVAL;
1042
1043         ieee80211_change_chanctx(local, new_ctx, chandef);
1044
1045         vif_chsw[0].vif = &sdata->vif;
1046         vif_chsw[0].old_ctx = &old_ctx->conf;
1047         vif_chsw[0].new_ctx = &new_ctx->conf;
1048
1049         list_del(&sdata->reserved_chanctx_list);
1050         sdata->reserved_chanctx = NULL;
1051
1052         err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1053                                      CHANCTX_SWMODE_REASSIGN_VIF);
1054         if (err) {
1055                 if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1056                         ieee80211_free_chanctx(local, new_ctx);
1057
1058                 goto out;
1059         }
1060
1061         list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
1062         rcu_assign_pointer(sdata->vif.chanctx_conf, &new_ctx->conf);
1063
1064         if (sdata->vif.type == NL80211_IFTYPE_AP)
1065                 __ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
1066
1067         ieee80211_check_fast_xmit_iface(sdata);
1068
1069         if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1070                 ieee80211_free_chanctx(local, old_ctx);
1071
1072         if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
1073                 changed = BSS_CHANGED_BANDWIDTH;
1074
1075         ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1076
1077         ieee80211_recalc_smps_chanctx(local, new_ctx);
1078         ieee80211_recalc_radar_chanctx(local, new_ctx);
1079         ieee80211_recalc_chanctx_min_def(local, new_ctx);
1080
1081         if (changed)
1082                 ieee80211_bss_info_change_notify(sdata, changed);
1083
1084 out:
1085         ieee80211_vif_chanctx_reservation_complete(sdata);
1086         return err;
1087 }
1088
1089 static int
1090 ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
1091 {
1092         struct ieee80211_local *local = sdata->local;
1093         struct ieee80211_chanctx *old_ctx, *new_ctx;
1094         const struct cfg80211_chan_def *chandef;
1095         int err;
1096
1097         old_ctx = ieee80211_vif_get_chanctx(sdata);
1098         new_ctx = sdata->reserved_chanctx;
1099
1100         if (WARN_ON(!sdata->reserved_ready))
1101                 return -EINVAL;
1102
1103         if (WARN_ON(old_ctx))
1104                 return -EINVAL;
1105
1106         if (WARN_ON(!new_ctx))
1107                 return -EINVAL;
1108
1109         if (WARN_ON(new_ctx->replace_state ==
1110                     IEEE80211_CHANCTX_REPLACES_OTHER))
1111                 return -EINVAL;
1112
1113         chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1114                                 &sdata->reserved_chandef);
1115         if (WARN_ON(!chandef))
1116                 return -EINVAL;
1117
1118         ieee80211_change_chanctx(local, new_ctx, chandef);
1119
1120         list_del(&sdata->reserved_chanctx_list);
1121         sdata->reserved_chanctx = NULL;
1122
1123         err = ieee80211_assign_vif_chanctx(sdata, new_ctx);
1124         if (err) {
1125                 if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1126                         ieee80211_free_chanctx(local, new_ctx);
1127
1128                 goto out;
1129         }
1130
1131 out:
1132         ieee80211_vif_chanctx_reservation_complete(sdata);
1133         return err;
1134 }
1135
1136 static bool
1137 ieee80211_vif_has_in_place_reservation(struct ieee80211_sub_if_data *sdata)
1138 {
1139         struct ieee80211_chanctx *old_ctx, *new_ctx;
1140
1141         lockdep_assert_held(&sdata->local->chanctx_mtx);
1142
1143         new_ctx = sdata->reserved_chanctx;
1144         old_ctx = ieee80211_vif_get_chanctx(sdata);
1145
1146         if (!old_ctx)
1147                 return false;
1148
1149         if (WARN_ON(!new_ctx))
1150                 return false;
1151
1152         if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1153                 return false;
1154
1155         if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1156                 return false;
1157
1158         return true;
1159 }
1160
1161 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1162                                         struct ieee80211_chanctx *new_ctx)
1163 {
1164         const struct cfg80211_chan_def *chandef;
1165
1166         lockdep_assert_held(&local->mtx);
1167         lockdep_assert_held(&local->chanctx_mtx);
1168
1169         chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1170         if (WARN_ON(!chandef))
1171                 return -EINVAL;
1172
1173         local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1174         local->_oper_chandef = *chandef;
1175         ieee80211_hw_config(local, 0);
1176
1177         return 0;
1178 }
1179
1180 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1181                                       int n_vifs)
1182 {
1183         struct ieee80211_vif_chanctx_switch *vif_chsw;
1184         struct ieee80211_sub_if_data *sdata;
1185         struct ieee80211_chanctx *ctx, *old_ctx;
1186         int i, err;
1187
1188         lockdep_assert_held(&local->mtx);
1189         lockdep_assert_held(&local->chanctx_mtx);
1190
1191         vif_chsw = kcalloc(n_vifs, sizeof(vif_chsw[0]), GFP_KERNEL);
1192         if (!vif_chsw)
1193                 return -ENOMEM;
1194
1195         i = 0;
1196         list_for_each_entry(ctx, &local->chanctx_list, list) {
1197                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1198                         continue;
1199
1200                 if (WARN_ON(!ctx->replace_ctx)) {
1201                         err = -EINVAL;
1202                         goto out;
1203                 }
1204
1205                 list_for_each_entry(sdata, &ctx->reserved_vifs,
1206                                     reserved_chanctx_list) {
1207                         if (!ieee80211_vif_has_in_place_reservation(
1208                                         sdata))
1209                                 continue;
1210
1211                         old_ctx = ieee80211_vif_get_chanctx(sdata);
1212                         vif_chsw[i].vif = &sdata->vif;
1213                         vif_chsw[i].old_ctx = &old_ctx->conf;
1214                         vif_chsw[i].new_ctx = &ctx->conf;
1215
1216                         i++;
1217                 }
1218         }
1219
1220         err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1221                                      CHANCTX_SWMODE_SWAP_CONTEXTS);
1222
1223 out:
1224         kfree(vif_chsw);
1225         return err;
1226 }
1227
1228 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1229 {
1230         struct ieee80211_chanctx *ctx;
1231         int err;
1232
1233         lockdep_assert_held(&local->mtx);
1234         lockdep_assert_held(&local->chanctx_mtx);
1235
1236         list_for_each_entry(ctx, &local->chanctx_list, list) {
1237                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1238                         continue;
1239
1240                 if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1241                         continue;
1242
1243                 ieee80211_del_chanctx(local, ctx->replace_ctx);
1244                 err = ieee80211_add_chanctx(local, ctx);
1245                 if (err)
1246                         goto err;
1247         }
1248
1249         return 0;
1250
1251 err:
1252         WARN_ON(ieee80211_add_chanctx(local, ctx));
1253         list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1254                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1255                         continue;
1256
1257                 if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1258                         continue;
1259
1260                 ieee80211_del_chanctx(local, ctx);
1261                 WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1262         }
1263
1264         return err;
1265 }
1266
1267 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1268 {
1269         struct ieee80211_sub_if_data *sdata, *sdata_tmp;
1270         struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1271         struct ieee80211_chanctx *new_ctx = NULL;
1272         int err, n_assigned, n_reserved, n_ready;
1273         int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1274
1275         lockdep_assert_held(&local->mtx);
1276         lockdep_assert_held(&local->chanctx_mtx);
1277
1278         /*
1279          * If there are 2 independent pairs of channel contexts performing
1280          * cross-switch of their vifs this code will still wait until both are
1281          * ready even though it could be possible to switch one before the
1282          * other is ready.
1283          *
1284          * For practical reasons and code simplicity just do a single huge
1285          * switch.
1286          */
1287
1288         /*
1289          * Verify if the reservation is still feasible.
1290          *  - if it's not then disconnect
1291          *  - if it is but not all vifs necessary are ready then defer
1292          */
1293
1294         list_for_each_entry(ctx, &local->chanctx_list, list) {
1295                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1296                         continue;
1297
1298                 if (WARN_ON(!ctx->replace_ctx)) {
1299                         err = -EINVAL;
1300                         goto err;
1301                 }
1302
1303                 if (!local->use_chanctx)
1304                         new_ctx = ctx;
1305
1306                 n_ctx++;
1307
1308                 n_assigned = 0;
1309                 n_reserved = 0;
1310                 n_ready = 0;
1311
1312                 list_for_each_entry(sdata, &ctx->replace_ctx->assigned_vifs,
1313                                     assigned_chanctx_list) {
1314                         n_assigned++;
1315                         if (sdata->reserved_chanctx) {
1316                                 n_reserved++;
1317                                 if (sdata->reserved_ready)
1318                                         n_ready++;
1319                         }
1320                 }
1321
1322                 if (n_assigned != n_reserved) {
1323                         if (n_ready == n_reserved) {
1324                                 wiphy_info(local->hw.wiphy,
1325                                            "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1326                                 err = -EBUSY;
1327                                 goto err;
1328                         }
1329
1330                         return -EAGAIN;
1331                 }
1332
1333                 ctx->conf.radar_enabled = false;
1334                 list_for_each_entry(sdata, &ctx->reserved_vifs,
1335                                     reserved_chanctx_list) {
1336                         if (ieee80211_vif_has_in_place_reservation(sdata) &&
1337                             !sdata->reserved_ready)
1338                                 return -EAGAIN;
1339
1340                         old_ctx = ieee80211_vif_get_chanctx(sdata);
1341                         if (old_ctx) {
1342                                 if (old_ctx->replace_state ==
1343                                     IEEE80211_CHANCTX_WILL_BE_REPLACED)
1344                                         n_vifs_switch++;
1345                                 else
1346                                         n_vifs_assign++;
1347                         } else {
1348                                 n_vifs_ctxless++;
1349                         }
1350
1351                         if (sdata->reserved_radar_required)
1352                                 ctx->conf.radar_enabled = true;
1353                 }
1354         }
1355
1356         if (WARN_ON(n_ctx == 0) ||
1357             WARN_ON(n_vifs_switch == 0 &&
1358                     n_vifs_assign == 0 &&
1359                     n_vifs_ctxless == 0) ||
1360             WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1361             WARN_ON(!new_ctx && !local->use_chanctx)) {
1362                 err = -EINVAL;
1363                 goto err;
1364         }
1365
1366         /*
1367          * All necessary vifs are ready. Perform the switch now depending on
1368          * reservations and driver capabilities.
1369          */
1370
1371         if (local->use_chanctx) {
1372                 if (n_vifs_switch > 0) {
1373                         err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1374                         if (err)
1375                                 goto err;
1376                 }
1377
1378                 if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1379                         err = ieee80211_chsw_switch_ctxs(local);
1380                         if (err)
1381                                 goto err;
1382                 }
1383         } else {
1384                 err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1385                 if (err)
1386                         goto err;
1387         }
1388
1389         /*
1390          * Update all structures, values and pointers to point to new channel
1391          * context(s).
1392          */
1393         list_for_each_entry(ctx, &local->chanctx_list, list) {
1394                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1395                         continue;
1396
1397                 if (WARN_ON(!ctx->replace_ctx)) {
1398                         err = -EINVAL;
1399                         goto err;
1400                 }
1401
1402                 list_for_each_entry(sdata, &ctx->reserved_vifs,
1403                                     reserved_chanctx_list) {
1404                         u32 changed = 0;
1405
1406                         if (!ieee80211_vif_has_in_place_reservation(sdata))
1407                                 continue;
1408
1409                         rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
1410
1411                         if (sdata->vif.type == NL80211_IFTYPE_AP)
1412                                 __ieee80211_vif_copy_chanctx_to_vlans(sdata,
1413                                                                       false);
1414
1415                         ieee80211_check_fast_xmit_iface(sdata);
1416
1417                         sdata->radar_required = sdata->reserved_radar_required;
1418
1419                         if (sdata->vif.bss_conf.chandef.width !=
1420                             sdata->reserved_chandef.width)
1421                                 changed = BSS_CHANGED_BANDWIDTH;
1422
1423                         ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1424                         if (changed)
1425                                 ieee80211_bss_info_change_notify(sdata,
1426                                                                  changed);
1427
1428                         ieee80211_recalc_txpower(sdata, false);
1429                 }
1430
1431                 ieee80211_recalc_chanctx_chantype(local, ctx);
1432                 ieee80211_recalc_smps_chanctx(local, ctx);
1433                 ieee80211_recalc_radar_chanctx(local, ctx);
1434                 ieee80211_recalc_chanctx_min_def(local, ctx);
1435
1436                 list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1437                                          reserved_chanctx_list) {
1438                         if (ieee80211_vif_get_chanctx(sdata) != ctx)
1439                                 continue;
1440
1441                         list_del(&sdata->reserved_chanctx_list);
1442                         list_move(&sdata->assigned_chanctx_list,
1443                                   &ctx->assigned_vifs);
1444                         sdata->reserved_chanctx = NULL;
1445
1446                         ieee80211_vif_chanctx_reservation_complete(sdata);
1447                 }
1448
1449                 /*
1450                  * This context might have been a dependency for an already
1451                  * ready re-assign reservation interface that was deferred. Do
1452                  * not propagate error to the caller though. The in-place
1453                  * reservation for originally requested interface has already
1454                  * succeeded at this point.
1455                  */
1456                 list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1457                                          reserved_chanctx_list) {
1458                         if (WARN_ON(ieee80211_vif_has_in_place_reservation(
1459                                         sdata)))
1460                                 continue;
1461
1462                         if (WARN_ON(sdata->reserved_chanctx != ctx))
1463                                 continue;
1464
1465                         if (!sdata->reserved_ready)
1466                                 continue;
1467
1468                         if (ieee80211_vif_get_chanctx(sdata))
1469                                 err = ieee80211_vif_use_reserved_reassign(
1470                                                 sdata);
1471                         else
1472                                 err = ieee80211_vif_use_reserved_assign(sdata);
1473
1474                         if (err) {
1475                                 sdata_info(sdata,
1476                                            "failed to finalize (re-)assign reservation (err=%d)\n",
1477                                            err);
1478                                 ieee80211_vif_unreserve_chanctx(sdata);
1479                                 cfg80211_stop_iface(local->hw.wiphy,
1480                                                     &sdata->wdev,
1481                                                     GFP_KERNEL);
1482                         }
1483                 }
1484         }
1485
1486         /*
1487          * Finally free old contexts
1488          */
1489
1490         list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1491                 if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1492                         continue;
1493
1494                 ctx->replace_ctx->replace_ctx = NULL;
1495                 ctx->replace_ctx->replace_state =
1496                                 IEEE80211_CHANCTX_REPLACE_NONE;
1497
1498                 list_del_rcu(&ctx->list);
1499                 kfree_rcu(ctx, rcu_head);
1500         }
1501
1502         return 0;
1503
1504 err:
1505         list_for_each_entry(ctx, &local->chanctx_list, list) {
1506                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1507                         continue;
1508
1509                 list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1510                                          reserved_chanctx_list) {
1511                         ieee80211_vif_unreserve_chanctx(sdata);
1512                         ieee80211_vif_chanctx_reservation_complete(sdata);
1513                 }
1514         }
1515
1516         return err;
1517 }
1518
1519 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1520 {
1521         struct ieee80211_local *local = sdata->local;
1522         struct ieee80211_chanctx_conf *conf;
1523         struct ieee80211_chanctx *ctx;
1524         bool use_reserved_switch = false;
1525
1526         lockdep_assert_held(&local->chanctx_mtx);
1527
1528         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1529                                          lockdep_is_held(&local->chanctx_mtx));
1530         if (!conf)
1531                 return;
1532
1533         ctx = container_of(conf, struct ieee80211_chanctx, conf);
1534
1535         if (sdata->reserved_chanctx) {
1536                 if (sdata->reserved_chanctx->replace_state ==
1537                     IEEE80211_CHANCTX_REPLACES_OTHER &&
1538                     ieee80211_chanctx_num_reserved(local,
1539                                                    sdata->reserved_chanctx) > 1)
1540                         use_reserved_switch = true;
1541
1542                 ieee80211_vif_unreserve_chanctx(sdata);
1543         }
1544
1545         ieee80211_assign_vif_chanctx(sdata, NULL);
1546         if (ieee80211_chanctx_refcount(local, ctx) == 0)
1547                 ieee80211_free_chanctx(local, ctx);
1548
1549         sdata->radar_required = false;
1550
1551         /* Unreserving may ready an in-place reservation. */
1552         if (use_reserved_switch)
1553                 ieee80211_vif_use_reserved_switch(local);
1554 }
1555
1556 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
1557                               const struct cfg80211_chan_def *chandef,
1558                               enum ieee80211_chanctx_mode mode)
1559 {
1560         struct ieee80211_local *local = sdata->local;
1561         struct ieee80211_chanctx *ctx;
1562         u8 radar_detect_width = 0;
1563         int ret;
1564
1565         lockdep_assert_held(&local->mtx);
1566
1567         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1568
1569         mutex_lock(&local->chanctx_mtx);
1570
1571         ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1572                                             chandef,
1573                                             sdata->wdev.iftype);
1574         if (ret < 0)
1575                 goto out;
1576         if (ret > 0)
1577                 radar_detect_width = BIT(chandef->width);
1578
1579         sdata->radar_required = ret;
1580
1581         ret = ieee80211_check_combinations(sdata, chandef, mode,
1582                                            radar_detect_width);
1583         if (ret < 0)
1584                 goto out;
1585
1586         __ieee80211_vif_release_channel(sdata);
1587
1588         ctx = ieee80211_find_chanctx(local, chandef, mode);
1589         if (!ctx)
1590                 ctx = ieee80211_new_chanctx(local, chandef, mode);
1591         if (IS_ERR(ctx)) {
1592                 ret = PTR_ERR(ctx);
1593                 goto out;
1594         }
1595
1596         ieee80211_vif_update_chandef(sdata, chandef);
1597
1598         ret = ieee80211_assign_vif_chanctx(sdata, ctx);
1599         if (ret) {
1600                 /* if assign fails refcount stays the same */
1601                 if (ieee80211_chanctx_refcount(local, ctx) == 0)
1602                         ieee80211_free_chanctx(local, ctx);
1603                 goto out;
1604         }
1605
1606         ieee80211_recalc_smps_chanctx(local, ctx);
1607         ieee80211_recalc_radar_chanctx(local, ctx);
1608  out:
1609         if (ret)
1610                 sdata->radar_required = false;
1611
1612         mutex_unlock(&local->chanctx_mtx);
1613         return ret;
1614 }
1615
1616 int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
1617 {
1618         struct ieee80211_local *local = sdata->local;
1619         struct ieee80211_chanctx *new_ctx;
1620         struct ieee80211_chanctx *old_ctx;
1621         int err;
1622
1623         lockdep_assert_held(&local->mtx);
1624         lockdep_assert_held(&local->chanctx_mtx);
1625
1626         new_ctx = sdata->reserved_chanctx;
1627         old_ctx = ieee80211_vif_get_chanctx(sdata);
1628
1629         if (WARN_ON(!new_ctx))
1630                 return -EINVAL;
1631
1632         if (WARN_ON(new_ctx->replace_state ==
1633                     IEEE80211_CHANCTX_WILL_BE_REPLACED))
1634                 return -EINVAL;
1635
1636         if (WARN_ON(sdata->reserved_ready))
1637                 return -EINVAL;
1638
1639         sdata->reserved_ready = true;
1640
1641         if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1642                 if (old_ctx)
1643                         err = ieee80211_vif_use_reserved_reassign(sdata);
1644                 else
1645                         err = ieee80211_vif_use_reserved_assign(sdata);
1646
1647                 if (err)
1648                         return err;
1649         }
1650
1651         /*
1652          * In-place reservation may need to be finalized now either if:
1653          *  a) sdata is taking part in the swapping itself and is the last one
1654          *  b) sdata has switched with a re-assign reservation to an existing
1655          *     context readying in-place switching of old_ctx
1656          *
1657          * In case of (b) do not propagate the error up because the requested
1658          * sdata already switched successfully. Just spill an extra warning.
1659          * The ieee80211_vif_use_reserved_switch() already stops all necessary
1660          * interfaces upon failure.
1661          */
1662         if ((old_ctx &&
1663              old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1664             new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1665                 err = ieee80211_vif_use_reserved_switch(local);
1666                 if (err && err != -EAGAIN) {
1667                         if (new_ctx->replace_state ==
1668                             IEEE80211_CHANCTX_REPLACES_OTHER)
1669                                 return err;
1670
1671                         wiphy_info(local->hw.wiphy,
1672                                    "depending in-place reservation failed (err=%d)\n",
1673                                    err);
1674                 }
1675         }
1676
1677         return 0;
1678 }
1679
1680 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
1681                                    const struct cfg80211_chan_def *chandef,
1682                                    u32 *changed)
1683 {
1684         struct ieee80211_local *local = sdata->local;
1685         struct ieee80211_chanctx_conf *conf;
1686         struct ieee80211_chanctx *ctx;
1687         const struct cfg80211_chan_def *compat;
1688         int ret;
1689
1690         if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1691                                      IEEE80211_CHAN_DISABLED))
1692                 return -EINVAL;
1693
1694         mutex_lock(&local->chanctx_mtx);
1695         if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
1696                 ret = 0;
1697                 goto out;
1698         }
1699
1700         if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1701             sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1702                 ret = -EINVAL;
1703                 goto out;
1704         }
1705
1706         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1707                                          lockdep_is_held(&local->chanctx_mtx));
1708         if (!conf) {
1709                 ret = -EINVAL;
1710                 goto out;
1711         }
1712
1713         ctx = container_of(conf, struct ieee80211_chanctx, conf);
1714
1715         compat = cfg80211_chandef_compatible(&conf->def, chandef);
1716         if (!compat) {
1717                 ret = -EINVAL;
1718                 goto out;
1719         }
1720
1721         switch (ctx->replace_state) {
1722         case IEEE80211_CHANCTX_REPLACE_NONE:
1723                 if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1724                         ret = -EBUSY;
1725                         goto out;
1726                 }
1727                 break;
1728         case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1729                 /* TODO: Perhaps the bandwidth change could be treated as a
1730                  * reservation itself? */
1731                 ret = -EBUSY;
1732                 goto out;
1733         case IEEE80211_CHANCTX_REPLACES_OTHER:
1734                 /* channel context that is going to replace another channel
1735                  * context doesn't really exist and shouldn't be assigned
1736                  * anywhere yet */
1737                 WARN_ON(1);
1738                 break;
1739         }
1740
1741         ieee80211_vif_update_chandef(sdata, chandef);
1742
1743         ieee80211_recalc_chanctx_chantype(local, ctx);
1744
1745         *changed |= BSS_CHANGED_BANDWIDTH;
1746         ret = 0;
1747  out:
1748         mutex_unlock(&local->chanctx_mtx);
1749         return ret;
1750 }
1751
1752 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1753 {
1754         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1755
1756         lockdep_assert_held(&sdata->local->mtx);
1757
1758         mutex_lock(&sdata->local->chanctx_mtx);
1759         __ieee80211_vif_release_channel(sdata);
1760         mutex_unlock(&sdata->local->chanctx_mtx);
1761 }
1762
1763 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
1764 {
1765         struct ieee80211_local *local = sdata->local;
1766         struct ieee80211_sub_if_data *ap;
1767         struct ieee80211_chanctx_conf *conf;
1768
1769         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
1770                 return;
1771
1772         ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
1773
1774         mutex_lock(&local->chanctx_mtx);
1775
1776         conf = rcu_dereference_protected(ap->vif.chanctx_conf,
1777                                          lockdep_is_held(&local->chanctx_mtx));
1778         rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
1779         mutex_unlock(&local->chanctx_mtx);
1780 }
1781
1782 void ieee80211_iter_chan_contexts_atomic(
1783         struct ieee80211_hw *hw,
1784         void (*iter)(struct ieee80211_hw *hw,
1785                      struct ieee80211_chanctx_conf *chanctx_conf,
1786                      void *data),
1787         void *iter_data)
1788 {
1789         struct ieee80211_local *local = hw_to_local(hw);
1790         struct ieee80211_chanctx *ctx;
1791
1792         rcu_read_lock();
1793         list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
1794                 if (ctx->driver_present)
1795                         iter(hw, &ctx->conf, iter_data);
1796         rcu_read_unlock();
1797 }
1798 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);