net/mac80211/chan.c

   1 /*
   2  * mac80211 - channel management
   3  */
   4
   5 #include <linux/nl80211.h>
   6 #include <linux/export.h>
   7 #include <linux/rtnetlink.h>
   8 #include <net/cfg80211.h>
   9 #include "ieee80211_i.h"
  10 #include "driver-ops.h"
  11
  12 static int ieee80211_chanctx_num_assigned(struct ieee80211_local *local,
  13                                           struct ieee80211_chanctx *ctx)
  14 {
  15         struct ieee80211_sub_if_data *sdata;
  16         int num = 0;
  17
  18         lockdep_assert_held(&local->chanctx_mtx);
  19
  20         list_for_each_entry(sdata, &ctx->assigned_vifs, assigned_chanctx_list)
  21                 num++;
  22
  23         return num;
  24 }
  25
  26 static int ieee80211_chanctx_num_reserved(struct ieee80211_local *local,
  27                                           struct ieee80211_chanctx *ctx)
  28 {
  29         struct ieee80211_sub_if_data *sdata;
  30         int num = 0;
  31
  32         lockdep_assert_held(&local->chanctx_mtx);
  33
  34         list_for_each_entry(sdata, &ctx->reserved_vifs, reserved_chanctx_list)
  35                 num++;
  36
  37         return num;
  38 }
  39
  40 int ieee80211_chanctx_refcount(struct ieee80211_local *local,
  41                                struct ieee80211_chanctx *ctx)
  42 {
  43         return ieee80211_chanctx_num_assigned(local, ctx) +
  44                ieee80211_chanctx_num_reserved(local, ctx);
  45 }
  46
  47 static int ieee80211_num_chanctx(struct ieee80211_local *local)
  48 {
  49         struct ieee80211_chanctx *ctx;
  50         int num = 0;
  51
  52         lockdep_assert_held(&local->chanctx_mtx);
  53
  54         list_for_each_entry(ctx, &local->chanctx_list, list)
  55                 num++;
  56
  57         return num;
  58 }
  59
  60 static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local)
  61 {
  62         lockdep_assert_held(&local->chanctx_mtx);
  63         return ieee80211_num_chanctx(local) < ieee80211_max_num_channels(local);
  64 }
  65
  66 static struct ieee80211_chanctx *
  67 ieee80211_vif_get_chanctx(struct ieee80211_sub_if_data *sdata)
  68 {
  69         struct ieee80211_local *local __maybe_unused = sdata->local;
  70         struct ieee80211_chanctx_conf *conf;
  71
  72         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
  73                                          lockdep_is_held(&local->chanctx_mtx));
  74         if (!conf)
  75                 return NULL;
  76
  77         return container_of(conf, struct ieee80211_chanctx, conf);
  78 }
  79
  80 static const struct cfg80211_chan_def *
  81 ieee80211_chanctx_reserved_chandef(struct ieee80211_local *local,
  82                                    struct ieee80211_chanctx *ctx,
  83                                    const struct cfg80211_chan_def *compat)
  84 {
  85         struct ieee80211_sub_if_data *sdata;
  86
  87         lockdep_assert_held(&local->chanctx_mtx);
  88
  89         list_for_each_entry(sdata, &ctx->reserved_vifs,
  90                             reserved_chanctx_list) {
  91                 if (!compat)
  92                         compat = &sdata->reserved_chandef;
  93
  94                 compat = cfg80211_chandef_compatible(&sdata->reserved_chandef,
  95                                                      compat);
  96                 if (!compat)
  97                         break;
  98         }
  99
 100         return compat;
 101 }
 102
 103 static const struct cfg80211_chan_def *
 104 ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local,
 105                                        struct ieee80211_chanctx *ctx,
 106                                        const struct cfg80211_chan_def *compat)
 107 {
 108         struct ieee80211_sub_if_data *sdata;
 109
 110         lockdep_assert_held(&local->chanctx_mtx);
 111
 112         list_for_each_entry(sdata, &ctx->assigned_vifs,
 113                             assigned_chanctx_list) {
 114                 if (sdata->reserved_chanctx != NULL)
 115                         continue;
 116
 117                 if (!compat)
 118                         compat = &sdata->vif.bss_conf.chandef;
 119
 120                 compat = cfg80211_chandef_compatible(
 121                                 &sdata->vif.bss_conf.chandef, compat);
 122                 if (!compat)
 123                         break;
 124         }
 125
 126         return compat;
 127 }
 128
 129 static const struct cfg80211_chan_def *
 130 ieee80211_chanctx_combined_chandef(struct ieee80211_local *local,
 131                                    struct ieee80211_chanctx *ctx,
 132                                    const struct cfg80211_chan_def *compat)
 133 {
 134         lockdep_assert_held(&local->chanctx_mtx);
 135
 136         compat = ieee80211_chanctx_reserved_chandef(local, ctx, compat);
 137         if (!compat)
 138                 return NULL;
 139
 140         compat = ieee80211_chanctx_non_reserved_chandef(local, ctx, compat);
 141         if (!compat)
 142                 return NULL;
 143
 144         return compat;
 145 }
 146
 147 static bool
 148 ieee80211_chanctx_can_reserve_chandef(struct ieee80211_local *local,
 149                                       struct ieee80211_chanctx *ctx,
 150                                       const struct cfg80211_chan_def *def)
 151 {
 152         lockdep_assert_held(&local->chanctx_mtx);
 153
 154         if (ieee80211_chanctx_combined_chandef(local, ctx, def))
 155                 return true;
 156
 157         if (!list_empty(&ctx->reserved_vifs) &&
 158             ieee80211_chanctx_reserved_chandef(local, ctx, def))
 159                 return true;
 160
 161         return false;
 162 }
 163
 164 static struct ieee80211_chanctx *
 165 ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
 166                                    const struct cfg80211_chan_def *chandef,
 167                                    enum ieee80211_chanctx_mode mode)
 168 {
 169         struct ieee80211_chanctx *ctx;
 170
 171         lockdep_assert_held(&local->chanctx_mtx);
 172
 173         if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
 174                 return NULL;
 175
 176         list_for_each_entry(ctx, &local->chanctx_list, list) {
 177                 if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
 178                         continue;
 179
 180                 if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
 181                         continue;
 182
 183                 if (!ieee80211_chanctx_can_reserve_chandef(local, ctx,
 184                                                            chandef))
 185                         continue;
 186
 187                 return ctx;
 188         }
 189
 190         return NULL;
 191 }
 192
 193 enum nl80211_chan_width ieee80211_get_sta_bw(struct ieee80211_sta *sta)
 194 {
 195         switch (sta->bandwidth) {
 196         case IEEE80211_STA_RX_BW_20:
 197                 if (sta->ht_cap.ht_supported)
 198                         return NL80211_CHAN_WIDTH_20;
 199                 else
 200                         return NL80211_CHAN_WIDTH_20_NOHT;
 201         case IEEE80211_STA_RX_BW_40:
 202                 return NL80211_CHAN_WIDTH_40;
 203         case IEEE80211_STA_RX_BW_80:
 204                 return NL80211_CHAN_WIDTH_80;
 205         case IEEE80211_STA_RX_BW_160:
 206                 /*
 207                  * This applied for both 160 and 80+80. since we use
 208                  * the returned value to consider degradation of
 209                  * ctx->conf.min_def, we have to make sure to take
 210                  * the bigger one (NL80211_CHAN_WIDTH_160).
 211                  * Otherwise we might try degrading even when not
 212                  * needed, as the max required sta_bw returned (80+80)
 213                  * might be smaller than the configured bw (160).
 214                  */
 215                 return NL80211_CHAN_WIDTH_160;
 216         default:
 217                 WARN_ON(1);
 218                 return NL80211_CHAN_WIDTH_20;
 219         }
 220 }
 221
 222 static enum nl80211_chan_width
 223 ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata)
 224 {
 225         enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
 226         struct sta_info *sta;
 227
 228         rcu_read_lock();
 229         list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
 230                 if (sdata != sta->sdata &&
 231                     !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
 232                         continue;
 233
 234                 if (!sta->uploaded || !test_sta_flag(sta, WLAN_STA_ASSOC))
 235                         continue;
 236
 237                 max_bw = max(max_bw, ieee80211_get_sta_bw(&sta->sta));
 238         }
 239         rcu_read_unlock();
 240
 241         return max_bw;
 242 }
 243
 244 static enum nl80211_chan_width
 245 ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
 246                                       struct ieee80211_chanctx_conf *conf)
 247 {
 248         struct ieee80211_sub_if_data *sdata;
 249         enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
 250
 251         rcu_read_lock();
 252         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 253                 struct ieee80211_vif *vif = &sdata->vif;
 254                 enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
 255
 256                 if (!ieee80211_sdata_running(sdata))
 257                         continue;
 258
 259                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 260                         continue;
 261
 262                 switch (vif->type) {
 263                 case NL80211_IFTYPE_AP:
 264                 case NL80211_IFTYPE_AP_VLAN:
 265                         width = ieee80211_get_max_required_bw(sdata);
 266                         break;
 267                 case NL80211_IFTYPE_STATION:
 268                         /*
 269                          * The ap's sta->bandwidth is not set yet at this
 270                          * point, so take the width from the chandef, but
 271                          * account also for TDLS peers
 272                          */
 273                         width = max(vif->bss_conf.chandef.width,
 274                                     ieee80211_get_max_required_bw(sdata));
 275                         break;
 276                 case NL80211_IFTYPE_P2P_DEVICE:
 277                 case NL80211_IFTYPE_NAN:
 278                         continue;
 279                 case NL80211_IFTYPE_ADHOC:
 280                 case NL80211_IFTYPE_WDS:
 281                 case NL80211_IFTYPE_MESH_POINT:
 282                 case NL80211_IFTYPE_OCB:
 283                         width = vif->bss_conf.chandef.width;
 284                         break;
 285                 case NL80211_IFTYPE_UNSPECIFIED:
 286                 case NUM_NL80211_IFTYPES:
 287                 case NL80211_IFTYPE_MONITOR:
 288                 case NL80211_IFTYPE_P2P_CLIENT:
 289                 case NL80211_IFTYPE_P2P_GO:
 290                         WARN_ON_ONCE(1);
 291                 }
 292                 max_bw = max(max_bw, width);
 293         }
 294
 295         /* use the configured bandwidth in case of monitor interface */
 296         sdata = rcu_dereference(local->monitor_sdata);
 297         if (sdata && rcu_access_pointer(sdata->vif.chanctx_conf) == conf)
 298                 max_bw = max(max_bw, conf->def.width);
 299
 300         rcu_read_unlock();
 301
 302         return max_bw;
 303 }
 304
 305 /*
 306  * recalc the min required chan width of the channel context, which is
 307  * the max of min required widths of all the interfaces bound to this
 308  * channel context.
 309  */
 310 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
 311                                       struct ieee80211_chanctx *ctx)
 312 {
 313         enum nl80211_chan_width max_bw;
 314         struct cfg80211_chan_def min_def;
 315
 316         lockdep_assert_held(&local->chanctx_mtx);
 317
 318         /* don't optimize 5MHz, 10MHz, and radar_enabled confs */
 319         if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
 320             ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
 321             ctx->conf.radar_enabled) {
 322                 ctx->conf.min_def = ctx->conf.def;
 323                 return;
 324         }
 325
 326         max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
 327
 328         /* downgrade chandef up to max_bw */
 329         min_def = ctx->conf.def;
 330         while (min_def.width > max_bw)
 331                 ieee80211_chandef_downgrade(&min_def);
 332
 333         if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
 334                 return;
 335
 336         ctx->conf.min_def = min_def;
 337         if (!ctx->driver_present)
 338                 return;
 339
 340         drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_MIN_WIDTH);
 341 }
 342
 343 static void ieee80211_change_chanctx(struct ieee80211_local *local,
 344                                      struct ieee80211_chanctx *ctx,
 345                                      const struct cfg80211_chan_def *chandef)
 346 {
 347         if (cfg80211_chandef_identical(&ctx->conf.def, chandef)) {
 348                 ieee80211_recalc_chanctx_min_def(local, ctx);
 349                 return;
 350         }
 351
 352         WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
 353
 354         ctx->conf.def = *chandef;
 355         drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
 356         ieee80211_recalc_chanctx_min_def(local, ctx);
 357
 358         if (!local->use_chanctx) {
 359                 local->_oper_chandef = *chandef;
 360                 ieee80211_hw_config(local, 0);
 361         }
 362 }
 363
 364 static struct ieee80211_chanctx *
 365 ieee80211_find_chanctx(struct ieee80211_local *local,
 366                        const struct cfg80211_chan_def *chandef,
 367                        enum ieee80211_chanctx_mode mode)
 368 {
 369         struct ieee80211_chanctx *ctx;
 370
 371         lockdep_assert_held(&local->chanctx_mtx);
 372
 373         if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
 374                 return NULL;
 375
 376         list_for_each_entry(ctx, &local->chanctx_list, list) {
 377                 const struct cfg80211_chan_def *compat;
 378
 379                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
 380                         continue;
 381
 382                 if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
 383                         continue;
 384
 385                 compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
 386                 if (!compat)
 387                         continue;
 388
 389                 compat = ieee80211_chanctx_reserved_chandef(local, ctx,
 390                                                             compat);
 391                 if (!compat)
 392                         continue;
 393
 394                 ieee80211_change_chanctx(local, ctx, compat);
 395
 396                 return ctx;
 397         }
 398
 399         return NULL;
 400 }
 401
 402 bool ieee80211_is_radar_required(struct ieee80211_local *local)
 403 {
 404         struct ieee80211_sub_if_data *sdata;
 405
 406         lockdep_assert_held(&local->mtx);
 407
 408         rcu_read_lock();
 409         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 410                 if (sdata->radar_required) {
 411                         rcu_read_unlock();
 412                         return true;
 413                 }
 414         }
 415         rcu_read_unlock();
 416
 417         return false;
 418 }
 419
 420 static bool
 421 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
 422                                  struct ieee80211_chanctx *ctx)
 423 {
 424         struct ieee80211_chanctx_conf *conf = &ctx->conf;
 425         struct ieee80211_sub_if_data *sdata;
 426         bool required = false;
 427
 428         lockdep_assert_held(&local->chanctx_mtx);
 429         lockdep_assert_held(&local->mtx);
 430
 431         rcu_read_lock();
 432         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 433                 if (!ieee80211_sdata_running(sdata))
 434                         continue;
 435                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 436                         continue;
 437                 if (!sdata->radar_required)
 438                         continue;
 439
 440                 required = true;
 441                 break;
 442         }
 443         rcu_read_unlock();
 444
 445         return required;
 446 }
 447
 448 static struct ieee80211_chanctx *
 449 ieee80211_alloc_chanctx(struct ieee80211_local *local,
 450                         const struct cfg80211_chan_def *chandef,
 451                         enum ieee80211_chanctx_mode mode)
 452 {
 453         struct ieee80211_chanctx *ctx;
 454
 455         lockdep_assert_held(&local->chanctx_mtx);
 456
 457         ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
 458         if (!ctx)
 459                 return NULL;
 460
 461         INIT_LIST_HEAD(&ctx->assigned_vifs);
 462         INIT_LIST_HEAD(&ctx->reserved_vifs);
 463         ctx->conf.def = *chandef;
 464         ctx->conf.rx_chains_static = 1;
 465         ctx->conf.rx_chains_dynamic = 1;
 466         ctx->mode = mode;
 467         ctx->conf.radar_enabled = false;
 468         ieee80211_recalc_chanctx_min_def(local, ctx);
 469
 470         return ctx;
 471 }
 472
 473 static int ieee80211_add_chanctx(struct ieee80211_local *local,
 474                                  struct ieee80211_chanctx *ctx)
 475 {
 476         u32 changed;
 477         int err;
 478
 479         lockdep_assert_held(&local->mtx);
 480         lockdep_assert_held(&local->chanctx_mtx);
 481
 482         if (!local->use_chanctx)
 483                 local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
 484
 485         /* turn idle off *before* setting channel -- some drivers need that */
 486         changed = ieee80211_idle_off(local);
 487         if (changed)
 488                 ieee80211_hw_config(local, changed);
 489
 490         if (!local->use_chanctx) {
 491                 local->_oper_chandef = ctx->conf.def;
 492                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 493         } else {
 494                 err = drv_add_chanctx(local, ctx);
 495                 if (err) {
 496                         ieee80211_recalc_idle(local);
 497                         return err;
 498                 }
 499         }
 500
 501         return 0;
 502 }
 503
 504 static struct ieee80211_chanctx *
 505 ieee80211_new_chanctx(struct ieee80211_local *local,
 506                       const struct cfg80211_chan_def *chandef,
 507                       enum ieee80211_chanctx_mode mode)
 508 {
 509         struct ieee80211_chanctx *ctx;
 510         int err;
 511
 512         lockdep_assert_held(&local->mtx);
 513         lockdep_assert_held(&local->chanctx_mtx);
 514
 515         ctx = ieee80211_alloc_chanctx(local, chandef, mode);
 516         if (!ctx)
 517                 return ERR_PTR(-ENOMEM);
 518
 519         err = ieee80211_add_chanctx(local, ctx);
 520         if (err) {
 521                 kfree(ctx);
 522                 return ERR_PTR(err);
 523         }
 524
 525         list_add_rcu(&ctx->list, &local->chanctx_list);
 526         return ctx;
 527 }
 528
 529 static void ieee80211_del_chanctx(struct ieee80211_local *local,
 530                                   struct ieee80211_chanctx *ctx)
 531 {
 532         lockdep_assert_held(&local->chanctx_mtx);
 533
 534         if (!local->use_chanctx) {
 535                 struct cfg80211_chan_def *chandef = &local->_oper_chandef;
 536                 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 537                 chandef->center_freq1 = chandef->chan->center_freq;
 538                 chandef->center_freq2 = 0;
 539
 540                 /* NOTE: Disabling radar is only valid here for
 541                  * single channel context. To be sure, check it ...
 542                  */
 543                 WARN_ON(local->hw.conf.radar_enabled &&
 544                         !list_empty(&local->chanctx_list));
 545
 546                 local->hw.conf.radar_enabled = false;
 547
 548                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 549         } else {
 550                 drv_remove_chanctx(local, ctx);
 551         }
 552
 553         ieee80211_recalc_idle(local);
 554 }
 555
 556 static void ieee80211_free_chanctx(struct ieee80211_local *local,
 557                                    struct ieee80211_chanctx *ctx)
 558 {
 559         lockdep_assert_held(&local->chanctx_mtx);
 560
 561         WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
 562
 563         list_del_rcu(&ctx->list);
 564         ieee80211_del_chanctx(local, ctx);
 565         kfree_rcu(ctx, rcu_head);
 566 }
 567
 568 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
 569                                        struct ieee80211_chanctx *ctx)
 570 {
 571         struct ieee80211_chanctx_conf *conf = &ctx->conf;
 572         struct ieee80211_sub_if_data *sdata;
 573         const struct cfg80211_chan_def *compat = NULL;
 574         struct sta_info *sta;
 575
 576         lockdep_assert_held(&local->chanctx_mtx);
 577
 578         rcu_read_lock();
 579         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 580
 581                 if (!ieee80211_sdata_running(sdata))
 582                         continue;
 583                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 584                         continue;
 585                 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 586                         continue;
 587
 588                 if (!compat)
 589                         compat = &sdata->vif.bss_conf.chandef;
 590
 591                 compat = cfg80211_chandef_compatible(
 592                                 &sdata->vif.bss_conf.chandef, compat);
 593                 if (WARN_ON_ONCE(!compat))
 594                         break;
 595         }
 596
 597         /* TDLS peers can sometimes affect the chandef width */
 598         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 599                 if (!sta->uploaded ||
 600                     !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
 601                     !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
 602                     !sta->tdls_chandef.chan)
 603                         continue;
 604
 605                 compat = cfg80211_chandef_compatible(&sta->tdls_chandef,
 606                                                      compat);
 607                 if (WARN_ON_ONCE(!compat))
 608                         break;
 609         }
 610         rcu_read_unlock();
 611
 612         if (!compat)
 613                 return;
 614
 615         ieee80211_change_chanctx(local, ctx, compat);
 616 }
 617
 618 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
 619                                            struct ieee80211_chanctx *chanctx)
 620 {
 621         bool radar_enabled;
 622
 623         lockdep_assert_held(&local->chanctx_mtx);
 624         /* for ieee80211_is_radar_required */
 625         lockdep_assert_held(&local->mtx);
 626
 627         radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
 628
 629         if (radar_enabled == chanctx->conf.radar_enabled)
 630                 return;
 631
 632         chanctx->conf.radar_enabled = radar_enabled;
 633
 634         if (!local->use_chanctx) {
 635                 local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
 636                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 637         }
 638
 639         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
 640 }
 641
 642 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 643                                         struct ieee80211_chanctx *new_ctx)
 644 {
 645         struct ieee80211_local *local = sdata->local;
 646         struct ieee80211_chanctx_conf *conf;
 647         struct ieee80211_chanctx *curr_ctx = NULL;
 648         int ret = 0;
 649
 650         if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
 651                 return -ENOTSUPP;
 652
 653         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 654                                          lockdep_is_held(&local->chanctx_mtx));
 655
 656         if (conf) {
 657                 curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
 658
 659                 drv_unassign_vif_chanctx(local, sdata, curr_ctx);
 660                 conf = NULL;
 661                 list_del(&sdata->assigned_chanctx_list);
 662         }
 663
 664         if (new_ctx) {
 665                 ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
 666                 if (ret)
 667                         goto out;
 668
 669                 conf = &new_ctx->conf;
 670                 list_add(&sdata->assigned_chanctx_list,
 671                          &new_ctx->assigned_vifs);
 672         }
 673
 674 out:
 675         rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
 676
 677         sdata->vif.bss_conf.idle = !conf;
 678
 679         if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
 680                 ieee80211_recalc_chanctx_chantype(local, curr_ctx);
 681                 ieee80211_recalc_smps_chanctx(local, curr_ctx);
 682                 ieee80211_recalc_radar_chanctx(local, curr_ctx);
 683                 ieee80211_recalc_chanctx_min_def(local, curr_ctx);
 684         }
 685
 686         if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
 687                 ieee80211_recalc_txpower(sdata, false);
 688                 ieee80211_recalc_chanctx_min_def(local, new_ctx);
 689         }
 690
 691         if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
 692             sdata->vif.type != NL80211_IFTYPE_MONITOR)
 693                 ieee80211_bss_info_change_notify(sdata,
 694                                                  BSS_CHANGED_IDLE);
 695
 696         ieee80211_check_fast_xmit_iface(sdata);
 697
 698         return ret;
 699 }
 700
 701 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
 702                                    struct ieee80211_chanctx *chanctx)
 703 {
 704         struct ieee80211_sub_if_data *sdata;
 705         u8 rx_chains_static, rx_chains_dynamic;
 706
 707         lockdep_assert_held(&local->chanctx_mtx);
 708
 709         rx_chains_static = 1;
 710         rx_chains_dynamic = 1;
 711
 712         rcu_read_lock();
 713         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 714                 u8 needed_static, needed_dynamic;
 715
 716                 if (!ieee80211_sdata_running(sdata))
 717                         continue;
 718
 719                 if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
 720                                                 &chanctx->conf)
 721                         continue;
 722
 723                 switch (sdata->vif.type) {
 724                 case NL80211_IFTYPE_P2P_DEVICE:
 725                 case NL80211_IFTYPE_NAN:
 726                         continue;
 727                 case NL80211_IFTYPE_STATION:
 728                         if (!sdata->u.mgd.associated)
 729                                 continue;
 730                         break;
 731                 case NL80211_IFTYPE_AP_VLAN:
 732                         continue;
 733                 case NL80211_IFTYPE_AP:
 734                 case NL80211_IFTYPE_ADHOC:
 735                 case NL80211_IFTYPE_WDS:
 736                 case NL80211_IFTYPE_MESH_POINT:
 737                 case NL80211_IFTYPE_OCB:
 738                         break;
 739                 default:
 740                         WARN_ON_ONCE(1);
 741                 }
 742
 743                 switch (sdata->smps_mode) {
 744                 default:
 745                         WARN_ONCE(1, "Invalid SMPS mode %d\n",
 746                                   sdata->smps_mode);
 747                         /* fall through */
 748                 case IEEE80211_SMPS_OFF:
 749                         needed_static = sdata->needed_rx_chains;
 750                         needed_dynamic = sdata->needed_rx_chains;
 751                         break;
 752                 case IEEE80211_SMPS_DYNAMIC:
 753                         needed_static = 1;
 754                         needed_dynamic = sdata->needed_rx_chains;
 755                         break;
 756                 case IEEE80211_SMPS_STATIC:
 757                         needed_static = 1;
 758                         needed_dynamic = 1;
 759                         break;
 760                 }
 761
 762                 rx_chains_static = max(rx_chains_static, needed_static);
 763                 rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
 764         }
 765
 766         /* Disable SMPS for the monitor interface */
 767         sdata = rcu_dereference(local->monitor_sdata);
 768         if (sdata &&
 769             rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
 770                 rx_chains_dynamic = rx_chains_static = local->rx_chains;
 771
 772         rcu_read_unlock();
 773
 774         if (!local->use_chanctx) {
 775                 if (rx_chains_static > 1)
 776                         local->smps_mode = IEEE80211_SMPS_OFF;
 777                 else if (rx_chains_dynamic > 1)
 778                         local->smps_mode = IEEE80211_SMPS_DYNAMIC;
 779                 else
 780                         local->smps_mode = IEEE80211_SMPS_STATIC;
 781                 ieee80211_hw_config(local, 0);
 782         }
 783
 784         if (rx_chains_static == chanctx->conf.rx_chains_static &&
 785             rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
 786                 return;
 787
 788         chanctx->conf.rx_chains_static = rx_chains_static;
 789         chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
 790         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
 791 }
 792
 793 static void
 794 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 795                                       bool clear)
 796 {
 797         struct ieee80211_local *local __maybe_unused = sdata->local;
 798         struct ieee80211_sub_if_data *vlan;
 799         struct ieee80211_chanctx_conf *conf;
 800
 801         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
 802                 return;
 803
 804         lockdep_assert_held(&local->mtx);
 805
 806         /* Check that conf exists, even when clearing this function
 807          * must be called with the AP's channel context still there
 808          * as it would otherwise cause VLANs to have an invalid
 809          * channel context pointer for a while, possibly pointing
 810          * to a channel context that has already been freed.
 811          */
 812         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 813                                          lockdep_is_held(&local->chanctx_mtx));
 814         WARN_ON(!conf);
 815
 816         if (clear)
 817                 conf = NULL;
 818
 819         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 820                 rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
 821 }
 822
 823 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 824                                          bool clear)
 825 {
 826         struct ieee80211_local *local = sdata->local;
 827
 828         mutex_lock(&local->chanctx_mtx);
 829
 830         __ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
 831
 832         mutex_unlock(&local->chanctx_mtx);
 833 }
 834
 835 int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
 836 {
 837         struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;
 838
 839         lockdep_assert_held(&sdata->local->chanctx_mtx);
 840
 841         if (WARN_ON(!ctx))
 842                 return -EINVAL;
 843
 844         list_del(&sdata->reserved_chanctx_list);
 845         sdata->reserved_chanctx = NULL;
 846
 847         if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
 848                 if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
 849                         if (WARN_ON(!ctx->replace_ctx))
 850                                 return -EINVAL;
 851
 852                         WARN_ON(ctx->replace_ctx->replace_state !=
 853                                 IEEE80211_CHANCTX_WILL_BE_REPLACED);
 854                         WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
 855
 856                         ctx->replace_ctx->replace_ctx = NULL;
 857                         ctx->replace_ctx->replace_state =
 858                                         IEEE80211_CHANCTX_REPLACE_NONE;
 859
 860                         list_del_rcu(&ctx->list);
 861                         kfree_rcu(ctx, rcu_head);
 862                 } else {
 863                         ieee80211_free_chanctx(sdata->local, ctx);
 864                 }
 865         }
 866
 867         return 0;
 868 }
 869
 870 int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
 871                                   const struct cfg80211_chan_def *chandef,
 872                                   enum ieee80211_chanctx_mode mode,
 873                                   bool radar_required)
 874 {
 875         struct ieee80211_local *local = sdata->local;
 876         struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
 877
 878         lockdep_assert_held(&local->chanctx_mtx);
 879
 880         curr_ctx = ieee80211_vif_get_chanctx(sdata);
 881         if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
 882                 return -ENOTSUPP;
 883
 884         new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
 885         if (!new_ctx) {
 886                 if (ieee80211_can_create_new_chanctx(local)) {
 887                         new_ctx = ieee80211_new_chanctx(local, chandef, mode);
 888                         if (IS_ERR(new_ctx))
 889                                 return PTR_ERR(new_ctx);
 890                 } else {
 891                         if (!curr_ctx ||
 892                             (curr_ctx->replace_state ==
 893                              IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
 894                             !list_empty(&curr_ctx->reserved_vifs)) {
 895                                 /*
 896                                  * Another vif already requested this context
 897                                  * for a reservation. Find another one hoping
 898                                  * all vifs assigned to it will also switch
 899                                  * soon enough.
 900                                  *
 901                                  * TODO: This needs a little more work as some
 902                                  * cases (more than 2 chanctx capable devices)
 903                                  * may fail which could otherwise succeed
 904                                  * provided some channel context juggling was
 905                                  * performed.
 906                                  *
 907                                  * Consider ctx1..3, vif1..6, each ctx has 2
 908                                  * vifs. vif1 and vif2 from ctx1 request new
 909                                  * different chandefs starting 2 in-place
 910                                  * reserations with ctx4 and ctx5 replacing
 911                                  * ctx1 and ctx2 respectively. Next vif5 and
 912                                  * vif6 from ctx3 reserve ctx4. If vif3 and
 913                                  * vif4 remain on ctx2 as they are then this
 914                                  * fails unless `replace_ctx` from ctx5 is
 915                                  * replaced with ctx3.
 916                                  */
 917                                 list_for_each_entry(ctx, &local->chanctx_list,
 918                                                     list) {
 919                                         if (ctx->replace_state !=
 920                                             IEEE80211_CHANCTX_REPLACE_NONE)
 921                                                 continue;
 922
 923                                         if (!list_empty(&ctx->reserved_vifs))
 924                                                 continue;
 925
 926                                         curr_ctx = ctx;
 927                                         break;
 928                                 }
 929                         }
 930
 931                         /*
 932                          * If that's true then all available contexts already
 933                          * have reservations and cannot be used.
 934                          */
 935                         if (!curr_ctx ||
 936                             (curr_ctx->replace_state ==
 937                              IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
 938                             !list_empty(&curr_ctx->reserved_vifs))
 939                                 return -EBUSY;
 940
 941                         new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
 942                         if (!new_ctx)
 943                                 return -ENOMEM;
 944
 945                         new_ctx->replace_ctx = curr_ctx;
 946                         new_ctx->replace_state =
 947                                         IEEE80211_CHANCTX_REPLACES_OTHER;
 948
 949                         curr_ctx->replace_ctx = new_ctx;
 950                         curr_ctx->replace_state =
 951                                         IEEE80211_CHANCTX_WILL_BE_REPLACED;
 952
 953                         list_add_rcu(&new_ctx->list, &local->chanctx_list);
 954                 }
 955         }
 956
 957         list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
 958         sdata->reserved_chanctx = new_ctx;
 959         sdata->reserved_chandef = *chandef;
 960         sdata->reserved_radar_required = radar_required;
 961         sdata->reserved_ready = false;
 962
 963         return 0;
 964 }
 965
 966 static void
 967 ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
 968 {
 969         switch (sdata->vif.type) {
 970         case NL80211_IFTYPE_ADHOC:
 971         case NL80211_IFTYPE_AP:
 972         case NL80211_IFTYPE_MESH_POINT:
 973         case NL80211_IFTYPE_OCB:
 974                 ieee80211_queue_work(&sdata->local->hw,
 975                                      &sdata->csa_finalize_work);
 976                 break;
 977         case NL80211_IFTYPE_STATION:
 978                 ieee80211_queue_work(&sdata->local->hw,
 979                                      &sdata->u.mgd.chswitch_work);
 980                 break;
 981         case NL80211_IFTYPE_UNSPECIFIED:
 982         case NL80211_IFTYPE_AP_VLAN:
 983         case NL80211_IFTYPE_WDS:
 984         case NL80211_IFTYPE_MONITOR:
 985         case NL80211_IFTYPE_P2P_CLIENT:
 986         case NL80211_IFTYPE_P2P_GO:
 987         case NL80211_IFTYPE_P2P_DEVICE:
 988         case NL80211_IFTYPE_NAN:
 989         case NUM_NL80211_IFTYPES:
 990                 WARN_ON(1);
 991                 break;
 992         }
 993 }
 994
 995 static void
 996 ieee80211_vif_update_chandef(struct ieee80211_sub_if_data *sdata,
 997                              const struct cfg80211_chan_def *chandef)
 998 {
 999         struct ieee80211_sub_if_data *vlan;
1000
1001         sdata->vif.bss_conf.chandef = *chandef;
1002
1003         if (sdata->vif.type != NL80211_IFTYPE_AP)
1004                 return;
1005
1006         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
1007                 vlan->vif.bss_conf.chandef = *chandef;
1008 }
1009
1010 static int
1011 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
1012 {
1013         struct ieee80211_local *local = sdata->local;
1014         struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1015         struct ieee80211_chanctx *old_ctx, *new_ctx;
1016         const struct cfg80211_chan_def *chandef;
1017         u32 changed = 0;
1018         int err;
1019
1020         lockdep_assert_held(&local->mtx);
1021         lockdep_assert_held(&local->chanctx_mtx);
1022
1023         new_ctx = sdata->reserved_chanctx;
1024         old_ctx = ieee80211_vif_get_chanctx(sdata);
1025
1026         if (WARN_ON(!sdata->reserved_ready))
1027                 return -EBUSY;
1028
1029         if (WARN_ON(!new_ctx))
1030                 return -EINVAL;
1031
1032         if (WARN_ON(!old_ctx))
1033                 return -EINVAL;
1034
1035         if (WARN_ON(new_ctx->replace_state ==
1036                     IEEE80211_CHANCTX_REPLACES_OTHER))
1037                 return -EINVAL;
1038
1039         chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1040                                 &sdata->reserved_chandef);
1041         if (WARN_ON(!chandef))
1042                 return -EINVAL;
1043
1044         ieee80211_change_chanctx(local, new_ctx, chandef);
1045
1046         vif_chsw[0].vif = &sdata->vif;
1047         vif_chsw[0].old_ctx = &old_ctx->conf;
1048         vif_chsw[0].new_ctx = &new_ctx->conf;
1049
1050         list_del(&sdata->reserved_chanctx_list);
1051         sdata->reserved_chanctx = NULL;
1052
1053         err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1054                                      CHANCTX_SWMODE_REASSIGN_VIF);
1055         if (err) {
1056                 if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1057                         ieee80211_free_chanctx(local, new_ctx);
1058
1059                 goto out;
1060         }
1061
1062         list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
1063         rcu_assign_pointer(sdata->vif.chanctx_conf, &new_ctx->conf);
1064
1065         if (sdata->vif.type == NL80211_IFTYPE_AP)
1066                 __ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
1067
1068         ieee80211_check_fast_xmit_iface(sdata);
1069
1070         if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1071                 ieee80211_free_chanctx(local, old_ctx);
1072
1073         if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
1074                 changed = BSS_CHANGED_BANDWIDTH;
1075
1076         ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1077
1078         ieee80211_recalc_smps_chanctx(local, new_ctx);
1079         ieee80211_recalc_radar_chanctx(local, new_ctx);
1080         ieee80211_recalc_chanctx_min_def(local, new_ctx);
1081
1082         if (changed)
1083                 ieee80211_bss_info_change_notify(sdata, changed);
1084
1085 out:
1086         ieee80211_vif_chanctx_reservation_complete(sdata);
1087         return err;
1088 }
1089
1090 static int
1091 ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
1092 {
1093         struct ieee80211_local *local = sdata->local;
1094         struct ieee80211_chanctx *old_ctx, *new_ctx;
1095         const struct cfg80211_chan_def *chandef;
1096         int err;
1097
1098         old_ctx = ieee80211_vif_get_chanctx(sdata);
1099         new_ctx = sdata->reserved_chanctx;
1100
1101         if (WARN_ON(!sdata->reserved_ready))
1102                 return -EINVAL;
1103
1104         if (WARN_ON(old_ctx))
1105                 return -EINVAL;
1106
1107         if (WARN_ON(!new_ctx))
1108                 return -EINVAL;
1109
1110         if (WARN_ON(new_ctx->replace_state ==
1111                     IEEE80211_CHANCTX_REPLACES_OTHER))
1112                 return -EINVAL;
1113
1114         chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1115                                 &sdata->reserved_chandef);
1116         if (WARN_ON(!chandef))
1117                 return -EINVAL;
1118
1119         ieee80211_change_chanctx(local, new_ctx, chandef);
1120
1121         list_del(&sdata->reserved_chanctx_list);
1122         sdata->reserved_chanctx = NULL;
1123
1124         err = ieee80211_assign_vif_chanctx(sdata, new_ctx);
1125         if (err) {
1126                 if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1127                         ieee80211_free_chanctx(local, new_ctx);
1128
1129                 goto out;
1130         }
1131
1132 out:
1133         ieee80211_vif_chanctx_reservation_complete(sdata);
1134         return err;
1135 }
1136
1137 static bool
1138 ieee80211_vif_has_in_place_reservation(struct ieee80211_sub_if_data *sdata)
1139 {
1140         struct ieee80211_chanctx *old_ctx, *new_ctx;
1141
1142         lockdep_assert_held(&sdata->local->chanctx_mtx);
1143
1144         new_ctx = sdata->reserved_chanctx;
1145         old_ctx = ieee80211_vif_get_chanctx(sdata);
1146
1147         if (!old_ctx)
1148                 return false;
1149
1150         if (WARN_ON(!new_ctx))
1151                 return false;
1152
1153         if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1154                 return false;
1155
1156         if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1157                 return false;
1158
1159         return true;
1160 }
1161
1162 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1163                                         struct ieee80211_chanctx *new_ctx)
1164 {
1165         const struct cfg80211_chan_def *chandef;
1166
1167         lockdep_assert_held(&local->mtx);
1168         lockdep_assert_held(&local->chanctx_mtx);
1169
1170         chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1171         if (WARN_ON(!chandef))
1172                 return -EINVAL;
1173
1174         local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1175         local->_oper_chandef = *chandef;
1176         ieee80211_hw_config(local, 0);
1177
1178         return 0;
1179 }
1180
1181 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1182                                       int n_vifs)
1183 {
1184         struct ieee80211_vif_chanctx_switch *vif_chsw;
1185         struct ieee80211_sub_if_data *sdata;
1186         struct ieee80211_chanctx *ctx, *old_ctx;
1187         int i, err;
1188
1189         lockdep_assert_held(&local->mtx);
1190         lockdep_assert_held(&local->chanctx_mtx);
1191
1192         vif_chsw = kzalloc(sizeof(vif_chsw[0]) * n_vifs, GFP_KERNEL);
1193         if (!vif_chsw)
1194                 return -ENOMEM;
1195
1196         i = 0;
1197         list_for_each_entry(ctx, &local->chanctx_list, list) {
1198                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1199                         continue;
1200
1201                 if (WARN_ON(!ctx->replace_ctx)) {
1202                         err = -EINVAL;
1203                         goto out;
1204                 }
1205
1206                 list_for_each_entry(sdata, &ctx->reserved_vifs,
1207                                     reserved_chanctx_list) {
1208                         if (!ieee80211_vif_has_in_place_reservation(
1209                                         sdata))
1210                                 continue;
1211
1212                         old_ctx = ieee80211_vif_get_chanctx(sdata);
1213                         vif_chsw[i].vif = &sdata->vif;
1214                         vif_chsw[i].old_ctx = &old_ctx->conf;
1215                         vif_chsw[i].new_ctx = &ctx->conf;
1216
1217                         i++;
1218                 }
1219         }
1220
1221         err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1222                                      CHANCTX_SWMODE_SWAP_CONTEXTS);
1223
1224 out:
1225         kfree(vif_chsw);
1226         return err;
1227 }
1228
1229 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1230 {
1231         struct ieee80211_chanctx *ctx;
1232         int err;
1233
1234         lockdep_assert_held(&local->mtx);
1235         lockdep_assert_held(&local->chanctx_mtx);
1236
1237         list_for_each_entry(ctx, &local->chanctx_list, list) {
1238                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1239                         continue;
1240
1241                 if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1242                         continue;
1243
1244                 ieee80211_del_chanctx(local, ctx->replace_ctx);
1245                 err = ieee80211_add_chanctx(local, ctx);
1246                 if (err)
1247                         goto err;
1248         }
1249
1250         return 0;
1251
1252 err:
1253         WARN_ON(ieee80211_add_chanctx(local, ctx));
1254         list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1255                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1256                         continue;
1257
1258                 if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1259                         continue;
1260
1261                 ieee80211_del_chanctx(local, ctx);
1262                 WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1263         }
1264
1265         return err;
1266 }
1267
1268 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1269 {
1270         struct ieee80211_sub_if_data *sdata, *sdata_tmp;
1271         struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1272         struct ieee80211_chanctx *new_ctx = NULL;
1273         int i, err, n_assigned, n_reserved, n_ready;
1274         int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1275
1276         lockdep_assert_held(&local->mtx);
1277         lockdep_assert_held(&local->chanctx_mtx);
1278
1279         /*
1280          * If there are 2 independent pairs of channel contexts performing
1281          * cross-switch of their vifs this code will still wait until both are
1282          * ready even though it could be possible to switch one before the
1283          * other is ready.
1284          *
1285          * For practical reasons and code simplicity just do a single huge
1286          * switch.
1287          */
1288
1289         /*
1290          * Verify if the reservation is still feasible.
1291          *  - if it's not then disconnect
1292          *  - if it is but not all vifs necessary are ready then defer
1293          */
1294
1295         list_for_each_entry(ctx, &local->chanctx_list, list) {
1296                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1297                         continue;
1298
1299                 if (WARN_ON(!ctx->replace_ctx)) {
1300                         err = -EINVAL;
1301                         goto err;
1302                 }
1303
1304                 if (!local->use_chanctx)
1305                         new_ctx = ctx;
1306
1307                 n_ctx++;
1308
1309                 n_assigned = 0;
1310                 n_reserved = 0;
1311                 n_ready = 0;
1312
1313                 list_for_each_entry(sdata, &ctx->replace_ctx->assigned_vifs,
1314                                     assigned_chanctx_list) {
1315                         n_assigned++;
1316                         if (sdata->reserved_chanctx) {
1317                                 n_reserved++;
1318                                 if (sdata->reserved_ready)
1319                                         n_ready++;
1320                         }
1321                 }
1322
1323                 if (n_assigned != n_reserved) {
1324                         if (n_ready == n_reserved) {
1325                                 wiphy_info(local->hw.wiphy,
1326                                            "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1327                                 err = -EBUSY;
1328                                 goto err;
1329                         }
1330
1331                         return -EAGAIN;
1332                 }
1333
1334                 ctx->conf.radar_enabled = false;
1335                 list_for_each_entry(sdata, &ctx->reserved_vifs,
1336                                     reserved_chanctx_list) {
1337                         if (ieee80211_vif_has_in_place_reservation(sdata) &&
1338                             !sdata->reserved_ready)
1339                                 return -EAGAIN;
1340
1341                         old_ctx = ieee80211_vif_get_chanctx(sdata);
1342                         if (old_ctx) {
1343                                 if (old_ctx->replace_state ==
1344                                     IEEE80211_CHANCTX_WILL_BE_REPLACED)
1345                                         n_vifs_switch++;
1346                                 else
1347                                         n_vifs_assign++;
1348                         } else {
1349                                 n_vifs_ctxless++;
1350                         }
1351
1352                         if (sdata->reserved_radar_required)
1353                                 ctx->conf.radar_enabled = true;
1354                 }
1355         }
1356
1357         if (WARN_ON(n_ctx == 0) ||
1358             WARN_ON(n_vifs_switch == 0 &&
1359                     n_vifs_assign == 0 &&
1360                     n_vifs_ctxless == 0) ||
1361             WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1362             WARN_ON(!new_ctx && !local->use_chanctx)) {
1363                 err = -EINVAL;
1364                 goto err;
1365         }
1366
1367         /*
1368          * All necessary vifs are ready. Perform the switch now depending on
1369          * reservations and driver capabilities.
1370          */
1371
1372         if (local->use_chanctx) {
1373                 if (n_vifs_switch > 0) {
1374                         err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1375                         if (err)
1376                                 goto err;
1377                 }
1378
1379                 if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1380                         err = ieee80211_chsw_switch_ctxs(local);
1381                         if (err)
1382                                 goto err;
1383                 }
1384         } else {
1385                 err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1386                 if (err)
1387                         goto err;
1388         }
1389
1390         /*
1391          * Update all structures, values and pointers to point to new channel
1392          * context(s).
1393          */
1394
1395         i = 0;
1396         list_for_each_entry(ctx, &local->chanctx_list, list) {
1397                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1398                         continue;
1399
1400                 if (WARN_ON(!ctx->replace_ctx)) {
1401                         err = -EINVAL;
1402                         goto err;
1403                 }
1404
1405                 list_for_each_entry(sdata, &ctx->reserved_vifs,
1406                                     reserved_chanctx_list) {
1407                         u32 changed = 0;
1408
1409                         if (!ieee80211_vif_has_in_place_reservation(sdata))
1410                                 continue;
1411
1412                         rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
1413
1414                         if (sdata->vif.type == NL80211_IFTYPE_AP)
1415                                 __ieee80211_vif_copy_chanctx_to_vlans(sdata,
1416                                                                       false);
1417
1418                         ieee80211_check_fast_xmit_iface(sdata);
1419
1420                         sdata->radar_required = sdata->reserved_radar_required;
1421
1422                         if (sdata->vif.bss_conf.chandef.width !=
1423                             sdata->reserved_chandef.width)
1424                                 changed = BSS_CHANGED_BANDWIDTH;
1425
1426                         ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1427                         if (changed)
1428                                 ieee80211_bss_info_change_notify(sdata,
1429                                                                  changed);
1430
1431                         ieee80211_recalc_txpower(sdata, false);
1432                 }
1433
1434                 ieee80211_recalc_chanctx_chantype(local, ctx);
1435                 ieee80211_recalc_smps_chanctx(local, ctx);
1436                 ieee80211_recalc_radar_chanctx(local, ctx);
1437                 ieee80211_recalc_chanctx_min_def(local, ctx);
1438
1439                 list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1440                                          reserved_chanctx_list) {
1441                         if (ieee80211_vif_get_chanctx(sdata) != ctx)
1442                                 continue;
1443
1444                         list_del(&sdata->reserved_chanctx_list);
1445                         list_move(&sdata->assigned_chanctx_list,
1446                                   &ctx->assigned_vifs);
1447                         sdata->reserved_chanctx = NULL;
1448
1449                         ieee80211_vif_chanctx_reservation_complete(sdata);
1450                 }
1451
1452                 /*
1453                  * This context might have been a dependency for an already
1454                  * ready re-assign reservation interface that was deferred. Do
1455                  * not propagate error to the caller though. The in-place
1456                  * reservation for originally requested interface has already
1457                  * succeeded at this point.
1458                  */
1459                 list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1460                                          reserved_chanctx_list) {
1461                         if (WARN_ON(ieee80211_vif_has_in_place_reservation(
1462                                         sdata)))
1463                                 continue;
1464
1465                         if (WARN_ON(sdata->reserved_chanctx != ctx))
1466                                 continue;
1467
1468                         if (!sdata->reserved_ready)
1469                                 continue;
1470
1471                         if (ieee80211_vif_get_chanctx(sdata))
1472                                 err = ieee80211_vif_use_reserved_reassign(
1473                                                 sdata);
1474                         else
1475                                 err = ieee80211_vif_use_reserved_assign(sdata);
1476
1477                         if (err) {
1478                                 sdata_info(sdata,
1479                                            "failed to finalize (re-)assign reservation (err=%d)\n",
1480                                            err);
1481                                 ieee80211_vif_unreserve_chanctx(sdata);
1482                                 cfg80211_stop_iface(local->hw.wiphy,
1483                                                     &sdata->wdev,
1484                                                     GFP_KERNEL);
1485                         }
1486                 }
1487         }
1488
1489         /*
1490          * Finally free old contexts
1491          */
1492
1493         list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1494                 if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1495                         continue;
1496
1497                 ctx->replace_ctx->replace_ctx = NULL;
1498                 ctx->replace_ctx->replace_state =
1499                                 IEEE80211_CHANCTX_REPLACE_NONE;
1500
1501                 list_del_rcu(&ctx->list);
1502                 kfree_rcu(ctx, rcu_head);
1503         }
1504
1505         return 0;
1506
1507 err:
1508         list_for_each_entry(ctx, &local->chanctx_list, list) {
1509                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1510                         continue;
1511
1512                 list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1513                                          reserved_chanctx_list) {
1514                         ieee80211_vif_unreserve_chanctx(sdata);
1515                         ieee80211_vif_chanctx_reservation_complete(sdata);
1516                 }
1517         }
1518
1519         return err;
1520 }
1521
1522 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1523 {
1524         struct ieee80211_local *local = sdata->local;
1525         struct ieee80211_chanctx_conf *conf;
1526         struct ieee80211_chanctx *ctx;
1527         bool use_reserved_switch = false;
1528
1529         lockdep_assert_held(&local->chanctx_mtx);
1530
1531         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1532                                          lockdep_is_held(&local->chanctx_mtx));
1533         if (!conf)
1534                 return;
1535
1536         ctx = container_of(conf, struct ieee80211_chanctx, conf);
1537
1538         if (sdata->reserved_chanctx) {
1539                 if (sdata->reserved_chanctx->replace_state ==
1540                     IEEE80211_CHANCTX_REPLACES_OTHER &&
1541                     ieee80211_chanctx_num_reserved(local,
1542                                                    sdata->reserved_chanctx) > 1)
1543                         use_reserved_switch = true;
1544
1545                 ieee80211_vif_unreserve_chanctx(sdata);
1546         }
1547
1548         ieee80211_assign_vif_chanctx(sdata, NULL);
1549         if (ieee80211_chanctx_refcount(local, ctx) == 0)
1550                 ieee80211_free_chanctx(local, ctx);
1551
1552         sdata->radar_required = false;
1553
1554         /* Unreserving may ready an in-place reservation. */
1555         if (use_reserved_switch)
1556                 ieee80211_vif_use_reserved_switch(local);
1557 }
1558
1559 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
1560                               const struct cfg80211_chan_def *chandef,
1561                               enum ieee80211_chanctx_mode mode)
1562 {
1563         struct ieee80211_local *local = sdata->local;
1564         struct ieee80211_chanctx *ctx;
1565         u8 radar_detect_width = 0;
1566         int ret;
1567
1568         lockdep_assert_held(&local->mtx);
1569
1570         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1571
1572         mutex_lock(&local->chanctx_mtx);
1573
1574         ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1575                                             chandef,
1576                                             sdata->wdev.iftype);
1577         if (ret < 0)
1578                 goto out;
1579         if (ret > 0)
1580                 radar_detect_width = BIT(chandef->width);
1581
1582         sdata->radar_required = ret;
1583
1584         ret = ieee80211_check_combinations(sdata, chandef, mode,
1585                                            radar_detect_width);
1586         if (ret < 0)
1587                 goto out;
1588
1589         __ieee80211_vif_release_channel(sdata);
1590
1591         ctx = ieee80211_find_chanctx(local, chandef, mode);
1592         if (!ctx)
1593                 ctx = ieee80211_new_chanctx(local, chandef, mode);
1594         if (IS_ERR(ctx)) {
1595                 ret = PTR_ERR(ctx);
1596                 goto out;
1597         }
1598
1599         ieee80211_vif_update_chandef(sdata, chandef);
1600
1601         ret = ieee80211_assign_vif_chanctx(sdata, ctx);
1602         if (ret) {
1603                 /* if assign fails refcount stays the same */
1604                 if (ieee80211_chanctx_refcount(local, ctx) == 0)
1605                         ieee80211_free_chanctx(local, ctx);
1606                 goto out;
1607         }
1608
1609         ieee80211_recalc_smps_chanctx(local, ctx);
1610         ieee80211_recalc_radar_chanctx(local, ctx);
1611  out:
1612         if (ret)
1613                 sdata->radar_required = false;
1614
1615         mutex_unlock(&local->chanctx_mtx);
1616         return ret;
1617 }
1618
1619 int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
1620 {
1621         struct ieee80211_local *local = sdata->local;
1622         struct ieee80211_chanctx *new_ctx;
1623         struct ieee80211_chanctx *old_ctx;
1624         int err;
1625
1626         lockdep_assert_held(&local->mtx);
1627         lockdep_assert_held(&local->chanctx_mtx);
1628
1629         new_ctx = sdata->reserved_chanctx;
1630         old_ctx = ieee80211_vif_get_chanctx(sdata);
1631
1632         if (WARN_ON(!new_ctx))
1633                 return -EINVAL;
1634
1635         if (WARN_ON(new_ctx->replace_state ==
1636                     IEEE80211_CHANCTX_WILL_BE_REPLACED))
1637                 return -EINVAL;
1638
1639         if (WARN_ON(sdata->reserved_ready))
1640                 return -EINVAL;
1641
1642         sdata->reserved_ready = true;
1643
1644         if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1645                 if (old_ctx)
1646                         err = ieee80211_vif_use_reserved_reassign(sdata);
1647                 else
1648                         err = ieee80211_vif_use_reserved_assign(sdata);
1649
1650                 if (err)
1651                         return err;
1652         }
1653
1654         /*
1655          * In-place reservation may need to be finalized now either if:
1656          *  a) sdata is taking part in the swapping itself and is the last one
1657          *  b) sdata has switched with a re-assign reservation to an existing
1658          *     context readying in-place switching of old_ctx
1659          *
1660          * In case of (b) do not propagate the error up because the requested
1661          * sdata already switched successfully. Just spill an extra warning.
1662          * The ieee80211_vif_use_reserved_switch() already stops all necessary
1663          * interfaces upon failure.
1664          */
1665         if ((old_ctx &&
1666              old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1667             new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1668                 err = ieee80211_vif_use_reserved_switch(local);
1669                 if (err && err != -EAGAIN) {
1670                         if (new_ctx->replace_state ==
1671                             IEEE80211_CHANCTX_REPLACES_OTHER)
1672                                 return err;
1673
1674                         wiphy_info(local->hw.wiphy,
1675                                    "depending in-place reservation failed (err=%d)\n",
1676                                    err);
1677                 }
1678         }
1679
1680         return 0;
1681 }
1682
1683 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
1684                                    const struct cfg80211_chan_def *chandef,
1685                                    u32 *changed)
1686 {
1687         struct ieee80211_local *local = sdata->local;
1688         struct ieee80211_chanctx_conf *conf;
1689         struct ieee80211_chanctx *ctx;
1690         const struct cfg80211_chan_def *compat;
1691         int ret;
1692
1693         if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1694                                      IEEE80211_CHAN_DISABLED))
1695                 return -EINVAL;
1696
1697         mutex_lock(&local->chanctx_mtx);
1698         if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
1699                 ret = 0;
1700                 goto out;
1701         }
1702
1703         if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1704             sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1705                 ret = -EINVAL;
1706                 goto out;
1707         }
1708
1709         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1710                                          lockdep_is_held(&local->chanctx_mtx));
1711         if (!conf) {
1712                 ret = -EINVAL;
1713                 goto out;
1714         }
1715
1716         ctx = container_of(conf, struct ieee80211_chanctx, conf);
1717
1718         compat = cfg80211_chandef_compatible(&conf->def, chandef);
1719         if (!compat) {
1720                 ret = -EINVAL;
1721                 goto out;
1722         }
1723
1724         switch (ctx->replace_state) {
1725         case IEEE80211_CHANCTX_REPLACE_NONE:
1726                 if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1727                         ret = -EBUSY;
1728                         goto out;
1729                 }
1730                 break;
1731         case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1732                 /* TODO: Perhaps the bandwidth change could be treated as a
1733                  * reservation itself? */
1734                 ret = -EBUSY;
1735                 goto out;
1736         case IEEE80211_CHANCTX_REPLACES_OTHER:
1737                 /* channel context that is going to replace another channel
1738                  * context doesn't really exist and shouldn't be assigned
1739                  * anywhere yet */
1740                 WARN_ON(1);
1741                 break;
1742         }
1743
1744         ieee80211_vif_update_chandef(sdata, chandef);
1745
1746         ieee80211_recalc_chanctx_chantype(local, ctx);
1747
1748         *changed |= BSS_CHANGED_BANDWIDTH;
1749         ret = 0;
1750  out:
1751         mutex_unlock(&local->chanctx_mtx);
1752         return ret;
1753 }
1754
1755 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1756 {
1757         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1758
1759         lockdep_assert_held(&sdata->local->mtx);
1760
1761         mutex_lock(&sdata->local->chanctx_mtx);
1762         __ieee80211_vif_release_channel(sdata);
1763         mutex_unlock(&sdata->local->chanctx_mtx);
1764 }
1765
1766 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
1767 {
1768         struct ieee80211_local *local = sdata->local;
1769         struct ieee80211_sub_if_data *ap;
1770         struct ieee80211_chanctx_conf *conf;
1771
1772         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
1773                 return;
1774
1775         ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
1776
1777         mutex_lock(&local->chanctx_mtx);
1778
1779         conf = rcu_dereference_protected(ap->vif.chanctx_conf,
1780                                          lockdep_is_held(&local->chanctx_mtx));
1781         rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
1782         mutex_unlock(&local->chanctx_mtx);
1783 }
1784
1785 void ieee80211_iter_chan_contexts_atomic(
1786         struct ieee80211_hw *hw,
1787         void (*iter)(struct ieee80211_hw *hw,
1788                      struct ieee80211_chanctx_conf *chanctx_conf,
1789                      void *data),
1790         void *iter_data)
1791 {
1792         struct ieee80211_local *local = hw_to_local(hw);
1793         struct ieee80211_chanctx *ctx;
1794
1795         rcu_read_lock();
1796         list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
1797                 if (ctx->driver_present)
1798                         iter(hw, &ctx->conf, iter_data);
1799         rcu_read_unlock();
1800 }
1801 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);