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 static 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)
 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_P2P_DEVICE:
 268                         continue;
 269                 case NL80211_IFTYPE_STATION:
 270                 case NL80211_IFTYPE_ADHOC:
 271                 case NL80211_IFTYPE_WDS:
 272                 case NL80211_IFTYPE_MESH_POINT:
 273                         width = vif->bss_conf.chandef.width;
 274                         break;
 275                 case NL80211_IFTYPE_UNSPECIFIED:
 276                 case NUM_NL80211_IFTYPES:
 277                 case NL80211_IFTYPE_MONITOR:
 278                 case NL80211_IFTYPE_P2P_CLIENT:
 279                 case NL80211_IFTYPE_P2P_GO:
 280                         WARN_ON_ONCE(1);
 281                 }
 282                 max_bw = max(max_bw, width);
 283         }
 284
 285         /* use the configured bandwidth in case of monitor interface */
 286         sdata = rcu_dereference(local->monitor_sdata);
 287         if (sdata && rcu_access_pointer(sdata->vif.chanctx_conf) == conf)
 288                 max_bw = max(max_bw, conf->def.width);
 289
 290         rcu_read_unlock();
 291
 292         return max_bw;
 293 }
 294
 295 /*
 296  * recalc the min required chan width of the channel context, which is
 297  * the max of min required widths of all the interfaces bound to this
 298  * channel context.
 299  */
 300 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
 301                                       struct ieee80211_chanctx *ctx)
 302 {
 303         enum nl80211_chan_width max_bw;
 304         struct cfg80211_chan_def min_def;
 305
 306         lockdep_assert_held(&local->chanctx_mtx);
 307
 308         /* don't optimize 5MHz, 10MHz, and radar_enabled confs */
 309         if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
 310             ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
 311             ctx->conf.radar_enabled) {
 312                 ctx->conf.min_def = ctx->conf.def;
 313                 return;
 314         }
 315
 316         max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
 317
 318         /* downgrade chandef up to max_bw */
 319         min_def = ctx->conf.def;
 320         while (min_def.width > max_bw)
 321                 ieee80211_chandef_downgrade(&min_def);
 322
 323         if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
 324                 return;
 325
 326         ctx->conf.min_def = min_def;
 327         if (!ctx->driver_present)
 328                 return;
 329
 330         drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_MIN_WIDTH);
 331 }
 332
 333 static void ieee80211_change_chanctx(struct ieee80211_local *local,
 334                                      struct ieee80211_chanctx *ctx,
 335                                      const struct cfg80211_chan_def *chandef)
 336 {
 337         if (cfg80211_chandef_identical(&ctx->conf.def, chandef))
 338                 return;
 339
 340         WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
 341
 342         ctx->conf.def = *chandef;
 343         drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
 344         ieee80211_recalc_chanctx_min_def(local, ctx);
 345
 346         if (!local->use_chanctx) {
 347                 local->_oper_chandef = *chandef;
 348                 ieee80211_hw_config(local, 0);
 349         }
 350 }
 351
 352 static struct ieee80211_chanctx *
 353 ieee80211_find_chanctx(struct ieee80211_local *local,
 354                        const struct cfg80211_chan_def *chandef,
 355                        enum ieee80211_chanctx_mode mode)
 356 {
 357         struct ieee80211_chanctx *ctx;
 358
 359         lockdep_assert_held(&local->chanctx_mtx);
 360
 361         if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
 362                 return NULL;
 363
 364         list_for_each_entry(ctx, &local->chanctx_list, list) {
 365                 const struct cfg80211_chan_def *compat;
 366
 367                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
 368                         continue;
 369
 370                 if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
 371                         continue;
 372
 373                 compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
 374                 if (!compat)
 375                         continue;
 376
 377                 compat = ieee80211_chanctx_reserved_chandef(local, ctx,
 378                                                             compat);
 379                 if (!compat)
 380                         continue;
 381
 382                 ieee80211_change_chanctx(local, ctx, compat);
 383
 384                 return ctx;
 385         }
 386
 387         return NULL;
 388 }
 389
 390 static bool ieee80211_is_radar_required(struct ieee80211_local *local)
 391 {
 392         struct ieee80211_sub_if_data *sdata;
 393
 394         lockdep_assert_held(&local->mtx);
 395
 396         rcu_read_lock();
 397         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 398                 if (sdata->radar_required) {
 399                         rcu_read_unlock();
 400                         return true;
 401                 }
 402         }
 403         rcu_read_unlock();
 404
 405         return false;
 406 }
 407
 408 static struct ieee80211_chanctx *
 409 ieee80211_alloc_chanctx(struct ieee80211_local *local,
 410                         const struct cfg80211_chan_def *chandef,
 411                         enum ieee80211_chanctx_mode mode)
 412 {
 413         struct ieee80211_chanctx *ctx;
 414
 415         lockdep_assert_held(&local->chanctx_mtx);
 416
 417         ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
 418         if (!ctx)
 419                 return NULL;
 420
 421         INIT_LIST_HEAD(&ctx->assigned_vifs);
 422         INIT_LIST_HEAD(&ctx->reserved_vifs);
 423         ctx->conf.def = *chandef;
 424         ctx->conf.rx_chains_static = 1;
 425         ctx->conf.rx_chains_dynamic = 1;
 426         ctx->mode = mode;
 427         ctx->conf.radar_enabled = ieee80211_is_radar_required(local);
 428         ieee80211_recalc_chanctx_min_def(local, ctx);
 429
 430         return ctx;
 431 }
 432
 433 static int ieee80211_add_chanctx(struct ieee80211_local *local,
 434                                  struct ieee80211_chanctx *ctx)
 435 {
 436         u32 changed;
 437         int err;
 438
 439         lockdep_assert_held(&local->mtx);
 440         lockdep_assert_held(&local->chanctx_mtx);
 441
 442         if (!local->use_chanctx)
 443                 local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
 444
 445         /* turn idle off *before* setting channel -- some drivers need that */
 446         changed = ieee80211_idle_off(local);
 447         if (changed)
 448                 ieee80211_hw_config(local, changed);
 449
 450         if (!local->use_chanctx) {
 451                 local->_oper_chandef = ctx->conf.def;
 452                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 453         } else {
 454                 err = drv_add_chanctx(local, ctx);
 455                 if (err) {
 456                         ieee80211_recalc_idle(local);
 457                         return err;
 458                 }
 459         }
 460
 461         return 0;
 462 }
 463
 464 static struct ieee80211_chanctx *
 465 ieee80211_new_chanctx(struct ieee80211_local *local,
 466                       const struct cfg80211_chan_def *chandef,
 467                       enum ieee80211_chanctx_mode mode)
 468 {
 469         struct ieee80211_chanctx *ctx;
 470         int err;
 471
 472         lockdep_assert_held(&local->mtx);
 473         lockdep_assert_held(&local->chanctx_mtx);
 474
 475         ctx = ieee80211_alloc_chanctx(local, chandef, mode);
 476         if (!ctx)
 477                 return ERR_PTR(-ENOMEM);
 478
 479         err = ieee80211_add_chanctx(local, ctx);
 480         if (err) {
 481                 kfree(ctx);
 482                 return ERR_PTR(err);
 483         }
 484
 485         list_add_rcu(&ctx->list, &local->chanctx_list);
 486         return ctx;
 487 }
 488
 489 static void ieee80211_del_chanctx(struct ieee80211_local *local,
 490                                   struct ieee80211_chanctx *ctx)
 491 {
 492         lockdep_assert_held(&local->chanctx_mtx);
 493
 494         if (!local->use_chanctx) {
 495                 struct cfg80211_chan_def *chandef = &local->_oper_chandef;
 496                 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 497                 chandef->center_freq1 = chandef->chan->center_freq;
 498                 chandef->center_freq2 = 0;
 499
 500                 /* NOTE: Disabling radar is only valid here for
 501                  * single channel context. To be sure, check it ...
 502                  */
 503                 WARN_ON(local->hw.conf.radar_enabled &&
 504                         !list_empty(&local->chanctx_list));
 505
 506                 local->hw.conf.radar_enabled = false;
 507
 508                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 509         } else {
 510                 drv_remove_chanctx(local, ctx);
 511         }
 512
 513         ieee80211_recalc_idle(local);
 514 }
 515
 516 static void ieee80211_free_chanctx(struct ieee80211_local *local,
 517                                    struct ieee80211_chanctx *ctx)
 518 {
 519         lockdep_assert_held(&local->chanctx_mtx);
 520
 521         WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
 522
 523         list_del_rcu(&ctx->list);
 524         ieee80211_del_chanctx(local, ctx);
 525         kfree_rcu(ctx, rcu_head);
 526 }
 527
 528 static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
 529                                               struct ieee80211_chanctx *ctx)
 530 {
 531         struct ieee80211_chanctx_conf *conf = &ctx->conf;
 532         struct ieee80211_sub_if_data *sdata;
 533         const struct cfg80211_chan_def *compat = NULL;
 534
 535         lockdep_assert_held(&local->chanctx_mtx);
 536
 537         rcu_read_lock();
 538         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 539
 540                 if (!ieee80211_sdata_running(sdata))
 541                         continue;
 542                 if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 543                         continue;
 544                 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 545                         continue;
 546
 547                 if (!compat)
 548                         compat = &sdata->vif.bss_conf.chandef;
 549
 550                 compat = cfg80211_chandef_compatible(
 551                                 &sdata->vif.bss_conf.chandef, compat);
 552                 if (!compat)
 553                         break;
 554         }
 555         rcu_read_unlock();
 556
 557         if (WARN_ON_ONCE(!compat))
 558                 return;
 559
 560         ieee80211_change_chanctx(local, ctx, compat);
 561 }
 562
 563 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
 564                                            struct ieee80211_chanctx *chanctx)
 565 {
 566         bool radar_enabled;
 567
 568         lockdep_assert_held(&local->chanctx_mtx);
 569         /* for setting local->radar_detect_enabled */
 570         lockdep_assert_held(&local->mtx);
 571
 572         radar_enabled = ieee80211_is_radar_required(local);
 573
 574         if (radar_enabled == chanctx->conf.radar_enabled)
 575                 return;
 576
 577         chanctx->conf.radar_enabled = radar_enabled;
 578         local->radar_detect_enabled = chanctx->conf.radar_enabled;
 579
 580         if (!local->use_chanctx) {
 581                 local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
 582                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 583         }
 584
 585         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
 586 }
 587
 588 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 589                                         struct ieee80211_chanctx *new_ctx)
 590 {
 591         struct ieee80211_local *local = sdata->local;
 592         struct ieee80211_chanctx_conf *conf;
 593         struct ieee80211_chanctx *curr_ctx = NULL;
 594         int ret = 0;
 595
 596         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 597                                          lockdep_is_held(&local->chanctx_mtx));
 598
 599         if (conf) {
 600                 curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
 601
 602                 drv_unassign_vif_chanctx(local, sdata, curr_ctx);
 603                 conf = NULL;
 604                 list_del(&sdata->assigned_chanctx_list);
 605         }
 606
 607         if (new_ctx) {
 608                 ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
 609                 if (ret)
 610                         goto out;
 611
 612                 conf = &new_ctx->conf;
 613                 list_add(&sdata->assigned_chanctx_list,
 614                          &new_ctx->assigned_vifs);
 615         }
 616
 617 out:
 618         rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
 619
 620         sdata->vif.bss_conf.idle = !conf;
 621
 622         if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
 623                 ieee80211_recalc_chanctx_chantype(local, curr_ctx);
 624                 ieee80211_recalc_smps_chanctx(local, curr_ctx);
 625                 ieee80211_recalc_radar_chanctx(local, curr_ctx);
 626                 ieee80211_recalc_chanctx_min_def(local, curr_ctx);
 627         }
 628
 629         if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
 630                 ieee80211_recalc_txpower(sdata);
 631                 ieee80211_recalc_chanctx_min_def(local, new_ctx);
 632         }
 633
 634         if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
 635             sdata->vif.type != NL80211_IFTYPE_MONITOR)
 636                 ieee80211_bss_info_change_notify(sdata,
 637                                                  BSS_CHANGED_IDLE);
 638
 639         return ret;
 640 }
 641
 642 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 643 {
 644         struct ieee80211_local *local = sdata->local;
 645         struct ieee80211_chanctx_conf *conf;
 646         struct ieee80211_chanctx *ctx;
 647         bool use_reserved_switch = false;
 648
 649         lockdep_assert_held(&local->chanctx_mtx);
 650
 651         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 652                                          lockdep_is_held(&local->chanctx_mtx));
 653         if (!conf)
 654                 return;
 655
 656         ctx = container_of(conf, struct ieee80211_chanctx, conf);
 657
 658         if (sdata->reserved_chanctx) {
 659                 if (sdata->reserved_chanctx->replace_state ==
 660                     IEEE80211_CHANCTX_REPLACES_OTHER &&
 661                     ieee80211_chanctx_num_reserved(local,
 662                                                    sdata->reserved_chanctx) > 1)
 663                         use_reserved_switch = true;
 664
 665                 ieee80211_vif_unreserve_chanctx(sdata);
 666         }
 667
 668         ieee80211_assign_vif_chanctx(sdata, NULL);
 669         if (ieee80211_chanctx_refcount(local, ctx) == 0)
 670                 ieee80211_free_chanctx(local, ctx);
 671
 672         /* Unreserving may ready an in-place reservation. */
 673         if (use_reserved_switch)
 674                 ieee80211_vif_use_reserved_switch(local);
 675 }
 676
 677 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
 678                                    struct ieee80211_chanctx *chanctx)
 679 {
 680         struct ieee80211_sub_if_data *sdata;
 681         u8 rx_chains_static, rx_chains_dynamic;
 682
 683         lockdep_assert_held(&local->chanctx_mtx);
 684
 685         rx_chains_static = 1;
 686         rx_chains_dynamic = 1;
 687
 688         rcu_read_lock();
 689         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 690                 u8 needed_static, needed_dynamic;
 691
 692                 if (!ieee80211_sdata_running(sdata))
 693                         continue;
 694
 695                 if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
 696                                                 &chanctx->conf)
 697                         continue;
 698
 699                 switch (sdata->vif.type) {
 700                 case NL80211_IFTYPE_P2P_DEVICE:
 701                         continue;
 702                 case NL80211_IFTYPE_STATION:
 703                         if (!sdata->u.mgd.associated)
 704                                 continue;
 705                         break;
 706                 case NL80211_IFTYPE_AP_VLAN:
 707                         continue;
 708                 case NL80211_IFTYPE_AP:
 709                 case NL80211_IFTYPE_ADHOC:
 710                 case NL80211_IFTYPE_WDS:
 711                 case NL80211_IFTYPE_MESH_POINT:
 712                         break;
 713                 default:
 714                         WARN_ON_ONCE(1);
 715                 }
 716
 717                 switch (sdata->smps_mode) {
 718                 default:
 719                         WARN_ONCE(1, "Invalid SMPS mode %d\n",
 720                                   sdata->smps_mode);
 721                         /* fall through */
 722                 case IEEE80211_SMPS_OFF:
 723                         needed_static = sdata->needed_rx_chains;
 724                         needed_dynamic = sdata->needed_rx_chains;
 725                         break;
 726                 case IEEE80211_SMPS_DYNAMIC:
 727                         needed_static = 1;
 728                         needed_dynamic = sdata->needed_rx_chains;
 729                         break;
 730                 case IEEE80211_SMPS_STATIC:
 731                         needed_static = 1;
 732                         needed_dynamic = 1;
 733                         break;
 734                 }
 735
 736                 rx_chains_static = max(rx_chains_static, needed_static);
 737                 rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
 738         }
 739
 740         /* Disable SMPS for the monitor interface */
 741         sdata = rcu_dereference(local->monitor_sdata);
 742         if (sdata &&
 743             rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
 744                 rx_chains_dynamic = rx_chains_static = local->rx_chains;
 745
 746         rcu_read_unlock();
 747
 748         if (!local->use_chanctx) {
 749                 if (rx_chains_static > 1)
 750                         local->smps_mode = IEEE80211_SMPS_OFF;
 751                 else if (rx_chains_dynamic > 1)
 752                         local->smps_mode = IEEE80211_SMPS_DYNAMIC;
 753                 else
 754                         local->smps_mode = IEEE80211_SMPS_STATIC;
 755                 ieee80211_hw_config(local, 0);
 756         }
 757
 758         if (rx_chains_static == chanctx->conf.rx_chains_static &&
 759             rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
 760                 return;
 761
 762         chanctx->conf.rx_chains_static = rx_chains_static;
 763         chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
 764         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
 765 }
 766
 767 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 768                               const struct cfg80211_chan_def *chandef,
 769                               enum ieee80211_chanctx_mode mode)
 770 {
 771         struct ieee80211_local *local = sdata->local;
 772         struct ieee80211_chanctx *ctx;
 773         u8 radar_detect_width = 0;
 774         int ret;
 775
 776         lockdep_assert_held(&local->mtx);
 777
 778         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
 779
 780         mutex_lock(&local->chanctx_mtx);
 781
 782         ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
 783                                             chandef,
 784                                             sdata->wdev.iftype);
 785         if (ret < 0)
 786                 goto out;
 787         if (ret > 0)
 788                 radar_detect_width = BIT(chandef->width);
 789
 790         sdata->radar_required = ret;
 791
 792         ret = ieee80211_check_combinations(sdata, chandef, mode,
 793                                            radar_detect_width);
 794         if (ret < 0)
 795                 goto out;
 796
 797         __ieee80211_vif_release_channel(sdata);
 798
 799         ctx = ieee80211_find_chanctx(local, chandef, mode);
 800         if (!ctx)
 801                 ctx = ieee80211_new_chanctx(local, chandef, mode);
 802         if (IS_ERR(ctx)) {
 803                 ret = PTR_ERR(ctx);
 804                 goto out;
 805         }
 806
 807         sdata->vif.bss_conf.chandef = *chandef;
 808
 809         ret = ieee80211_assign_vif_chanctx(sdata, ctx);
 810         if (ret) {
 811                 /* if assign fails refcount stays the same */
 812                 if (ieee80211_chanctx_refcount(local, ctx) == 0)
 813                         ieee80211_free_chanctx(local, ctx);
 814                 goto out;
 815         }
 816
 817         ieee80211_recalc_smps_chanctx(local, ctx);
 818         ieee80211_recalc_radar_chanctx(local, ctx);
 819  out:
 820         mutex_unlock(&local->chanctx_mtx);
 821         return ret;
 822 }
 823
 824 static void
 825 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 826                                       bool clear)
 827 {
 828         struct ieee80211_local *local __maybe_unused = sdata->local;
 829         struct ieee80211_sub_if_data *vlan;
 830         struct ieee80211_chanctx_conf *conf;
 831
 832         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
 833                 return;
 834
 835         lockdep_assert_held(&local->mtx);
 836
 837         /* Check that conf exists, even when clearing this function
 838          * must be called with the AP's channel context still there
 839          * as it would otherwise cause VLANs to have an invalid
 840          * channel context pointer for a while, possibly pointing
 841          * to a channel context that has already been freed.
 842          */
 843         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
 844                                          lockdep_is_held(&local->chanctx_mtx));
 845         WARN_ON(!conf);
 846
 847         if (clear)
 848                 conf = NULL;
 849
 850         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
 851                 rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
 852 }
 853
 854 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 855                                          bool clear)
 856 {
 857         struct ieee80211_local *local = sdata->local;
 858
 859         mutex_lock(&local->chanctx_mtx);
 860
 861         __ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
 862
 863         mutex_unlock(&local->chanctx_mtx);
 864 }
 865
 866 int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
 867 {
 868         struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;
 869
 870         lockdep_assert_held(&sdata->local->chanctx_mtx);
 871
 872         if (WARN_ON(!ctx))
 873                 return -EINVAL;
 874
 875         list_del(&sdata->reserved_chanctx_list);
 876         sdata->reserved_chanctx = NULL;
 877
 878         if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
 879                 if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
 880                         if (WARN_ON(!ctx->replace_ctx))
 881                                 return -EINVAL;
 882
 883                         WARN_ON(ctx->replace_ctx->replace_state !=
 884                                 IEEE80211_CHANCTX_WILL_BE_REPLACED);
 885                         WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
 886
 887                         ctx->replace_ctx->replace_ctx = NULL;
 888                         ctx->replace_ctx->replace_state =
 889                                         IEEE80211_CHANCTX_REPLACE_NONE;
 890
 891                         list_del_rcu(&ctx->list);
 892                         kfree_rcu(ctx, rcu_head);
 893                 } else {
 894                         ieee80211_free_chanctx(sdata->local, ctx);
 895                 }
 896         }
 897
 898         return 0;
 899 }
 900
 901 int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
 902                                   const struct cfg80211_chan_def *chandef,
 903                                   enum ieee80211_chanctx_mode mode,
 904                                   bool radar_required)
 905 {
 906         struct ieee80211_local *local = sdata->local;
 907         struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
 908
 909         lockdep_assert_held(&local->chanctx_mtx);
 910
 911         curr_ctx = ieee80211_vif_get_chanctx(sdata);
 912         if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
 913                 return -ENOTSUPP;
 914
 915         new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
 916         if (!new_ctx) {
 917                 if (ieee80211_can_create_new_chanctx(local)) {
 918                         new_ctx = ieee80211_new_chanctx(local, chandef, mode);
 919                         if (IS_ERR(new_ctx))
 920                                 return PTR_ERR(new_ctx);
 921                 } else {
 922                         if (!curr_ctx ||
 923                             (curr_ctx->replace_state ==
 924                              IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
 925                             !list_empty(&curr_ctx->reserved_vifs)) {
 926                                 /*
 927                                  * Another vif already requested this context
 928                                  * for a reservation. Find another one hoping
 929                                  * all vifs assigned to it will also switch
 930                                  * soon enough.
 931                                  *
 932                                  * TODO: This needs a little more work as some
 933                                  * cases (more than 2 chanctx capable devices)
 934                                  * may fail which could otherwise succeed
 935                                  * provided some channel context juggling was
 936                                  * performed.
 937                                  *
 938                                  * Consider ctx1..3, vif1..6, each ctx has 2
 939                                  * vifs. vif1 and vif2 from ctx1 request new
 940                                  * different chandefs starting 2 in-place
 941                                  * reserations with ctx4 and ctx5 replacing
 942                                  * ctx1 and ctx2 respectively. Next vif5 and
 943                                  * vif6 from ctx3 reserve ctx4. If vif3 and
 944                                  * vif4 remain on ctx2 as they are then this
 945                                  * fails unless `replace_ctx` from ctx5 is
 946                                  * replaced with ctx3.
 947                                  */
 948                                 list_for_each_entry(ctx, &local->chanctx_list,
 949                                                     list) {
 950                                         if (ctx->replace_state !=
 951                                             IEEE80211_CHANCTX_REPLACE_NONE)
 952                                                 continue;
 953
 954                                         if (!list_empty(&ctx->reserved_vifs))
 955                                                 continue;
 956
 957                                         curr_ctx = ctx;
 958                                         break;
 959                                 }
 960                         }
 961
 962                         /*
 963                          * If that's true then all available contexts already
 964                          * have reservations and cannot be used.
 965                          */
 966                         if (!curr_ctx ||
 967                             (curr_ctx->replace_state ==
 968                              IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
 969                             !list_empty(&curr_ctx->reserved_vifs))
 970                                 return -EBUSY;
 971
 972                         new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
 973                         if (!new_ctx)
 974                                 return -ENOMEM;
 975
 976                         new_ctx->replace_ctx = curr_ctx;
 977                         new_ctx->replace_state =
 978                                         IEEE80211_CHANCTX_REPLACES_OTHER;
 979
 980                         curr_ctx->replace_ctx = new_ctx;
 981                         curr_ctx->replace_state =
 982                                         IEEE80211_CHANCTX_WILL_BE_REPLACED;
 983
 984                         list_add_rcu(&new_ctx->list, &local->chanctx_list);
 985                 }
 986         }
 987
 988         list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
 989         sdata->reserved_chanctx = new_ctx;
 990         sdata->reserved_chandef = *chandef;
 991         sdata->reserved_radar_required = radar_required;
 992         sdata->reserved_ready = false;
 993
 994         return 0;
 995 }
 996
 997 static void
 998 ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
 999 {
1000         switch (sdata->vif.type) {
1001         case NL80211_IFTYPE_ADHOC:
1002         case NL80211_IFTYPE_AP:
1003         case NL80211_IFTYPE_MESH_POINT:
1004                 ieee80211_queue_work(&sdata->local->hw,
1005                                      &sdata->csa_finalize_work);
1006                 break;
1007         case NL80211_IFTYPE_STATION:
1008                 ieee80211_queue_work(&sdata->local->hw,
1009                                      &sdata->u.mgd.chswitch_work);
1010                 break;
1011         case NL80211_IFTYPE_UNSPECIFIED:
1012         case NL80211_IFTYPE_AP_VLAN:
1013         case NL80211_IFTYPE_WDS:
1014         case NL80211_IFTYPE_MONITOR:
1015         case NL80211_IFTYPE_P2P_CLIENT:
1016         case NL80211_IFTYPE_P2P_GO:
1017         case NL80211_IFTYPE_P2P_DEVICE:
1018         case NUM_NL80211_IFTYPES:
1019                 WARN_ON(1);
1020                 break;
1021         }
1022 }
1023
1024 static int
1025 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
1026 {
1027         struct ieee80211_local *local = sdata->local;
1028         struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1029         struct ieee80211_chanctx *old_ctx, *new_ctx;
1030         const struct cfg80211_chan_def *chandef;
1031         u32 changed = 0;
1032         int err;
1033
1034         lockdep_assert_held(&local->mtx);
1035         lockdep_assert_held(&local->chanctx_mtx);
1036
1037         new_ctx = sdata->reserved_chanctx;
1038         old_ctx = ieee80211_vif_get_chanctx(sdata);
1039
1040         if (WARN_ON(!sdata->reserved_ready))
1041                 return -EBUSY;
1042
1043         if (WARN_ON(!new_ctx))
1044                 return -EINVAL;
1045
1046         if (WARN_ON(!old_ctx))
1047                 return -EINVAL;
1048
1049         if (WARN_ON(new_ctx->replace_state ==
1050                     IEEE80211_CHANCTX_REPLACES_OTHER))
1051                 return -EINVAL;
1052
1053         chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1054                                 &sdata->reserved_chandef);
1055         if (WARN_ON(!chandef))
1056                 return -EINVAL;
1057
1058         vif_chsw[0].vif = &sdata->vif;
1059         vif_chsw[0].old_ctx = &old_ctx->conf;
1060         vif_chsw[0].new_ctx = &new_ctx->conf;
1061
1062         list_del(&sdata->reserved_chanctx_list);
1063         sdata->reserved_chanctx = NULL;
1064
1065         err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1066                                      CHANCTX_SWMODE_REASSIGN_VIF);
1067         if (err) {
1068                 if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1069                         ieee80211_free_chanctx(local, new_ctx);
1070
1071                 goto out;
1072         }
1073
1074         list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
1075         rcu_assign_pointer(sdata->vif.chanctx_conf, &new_ctx->conf);
1076
1077         if (sdata->vif.type == NL80211_IFTYPE_AP)
1078                 __ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
1079
1080         if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1081                 ieee80211_free_chanctx(local, old_ctx);
1082
1083         if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
1084                 changed = BSS_CHANGED_BANDWIDTH;
1085
1086         sdata->vif.bss_conf.chandef = sdata->reserved_chandef;
1087
1088         if (changed)
1089                 ieee80211_bss_info_change_notify(sdata, changed);
1090
1091 out:
1092         ieee80211_vif_chanctx_reservation_complete(sdata);
1093         return err;
1094 }
1095
1096 static int
1097 ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
1098 {
1099         struct ieee80211_local *local = sdata->local;
1100         struct ieee80211_chanctx *old_ctx, *new_ctx;
1101         const struct cfg80211_chan_def *chandef;
1102         int err;
1103
1104         old_ctx = ieee80211_vif_get_chanctx(sdata);
1105         new_ctx = sdata->reserved_chanctx;
1106
1107         if (WARN_ON(!sdata->reserved_ready))
1108                 return -EINVAL;
1109
1110         if (WARN_ON(old_ctx))
1111                 return -EINVAL;
1112
1113         if (WARN_ON(!new_ctx))
1114                 return -EINVAL;
1115
1116         if (WARN_ON(new_ctx->replace_state ==
1117                     IEEE80211_CHANCTX_REPLACES_OTHER))
1118                 return -EINVAL;
1119
1120         chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1121                                 &sdata->reserved_chandef);
1122         if (WARN_ON(!chandef))
1123                 return -EINVAL;
1124
1125         list_del(&sdata->reserved_chanctx_list);
1126         sdata->reserved_chanctx = NULL;
1127
1128         err = ieee80211_assign_vif_chanctx(sdata, new_ctx);
1129         if (err) {
1130                 if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1131                         ieee80211_free_chanctx(local, new_ctx);
1132
1133                 goto out;
1134         }
1135
1136 out:
1137         ieee80211_vif_chanctx_reservation_complete(sdata);
1138         return err;
1139 }
1140
1141 static bool
1142 ieee80211_vif_has_in_place_reservation(struct ieee80211_sub_if_data *sdata)
1143 {
1144         struct ieee80211_chanctx *old_ctx, *new_ctx;
1145
1146         lockdep_assert_held(&sdata->local->chanctx_mtx);
1147
1148         new_ctx = sdata->reserved_chanctx;
1149         old_ctx = ieee80211_vif_get_chanctx(sdata);
1150
1151         if (!old_ctx)
1152                 return false;
1153
1154         if (WARN_ON(!new_ctx))
1155                 return false;
1156
1157         if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1158                 return false;
1159
1160         if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1161                 return false;
1162
1163         return true;
1164 }
1165
1166 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1167                                         struct ieee80211_chanctx *new_ctx)
1168 {
1169         const struct cfg80211_chan_def *chandef;
1170
1171         lockdep_assert_held(&local->mtx);
1172         lockdep_assert_held(&local->chanctx_mtx);
1173
1174         chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1175         if (WARN_ON(!chandef))
1176                 return -EINVAL;
1177
1178         local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1179         local->_oper_chandef = *chandef;
1180         ieee80211_hw_config(local, 0);
1181
1182         return 0;
1183 }
1184
1185 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1186                                       int n_vifs)
1187 {
1188         struct ieee80211_vif_chanctx_switch *vif_chsw;
1189         struct ieee80211_sub_if_data *sdata;
1190         struct ieee80211_chanctx *ctx, *old_ctx;
1191         int i, err;
1192
1193         lockdep_assert_held(&local->mtx);
1194         lockdep_assert_held(&local->chanctx_mtx);
1195
1196         vif_chsw = kzalloc(sizeof(vif_chsw[0]) * n_vifs, GFP_KERNEL);
1197         if (!vif_chsw)
1198                 return -ENOMEM;
1199
1200         i = 0;
1201         list_for_each_entry(ctx, &local->chanctx_list, list) {
1202                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1203                         continue;
1204
1205                 if (WARN_ON(!ctx->replace_ctx)) {
1206                         err = -EINVAL;
1207                         goto out;
1208                 }
1209
1210                 list_for_each_entry(sdata, &ctx->reserved_vifs,
1211                                     reserved_chanctx_list) {
1212                         if (!ieee80211_vif_has_in_place_reservation(
1213                                         sdata))
1214                                 continue;
1215
1216                         old_ctx = ieee80211_vif_get_chanctx(sdata);
1217                         vif_chsw[i].vif = &sdata->vif;
1218                         vif_chsw[i].old_ctx = &old_ctx->conf;
1219                         vif_chsw[i].new_ctx = &ctx->conf;
1220
1221                         i++;
1222                 }
1223         }
1224
1225         err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1226                                      CHANCTX_SWMODE_SWAP_CONTEXTS);
1227
1228 out:
1229         kfree(vif_chsw);
1230         return err;
1231 }
1232
1233 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1234 {
1235         struct ieee80211_chanctx *ctx;
1236         int err;
1237
1238         lockdep_assert_held(&local->mtx);
1239         lockdep_assert_held(&local->chanctx_mtx);
1240
1241         list_for_each_entry(ctx, &local->chanctx_list, list) {
1242                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1243                         continue;
1244
1245                 if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1246                         continue;
1247
1248                 ieee80211_del_chanctx(local, ctx->replace_ctx);
1249                 err = ieee80211_add_chanctx(local, ctx);
1250                 if (err)
1251                         goto err;
1252         }
1253
1254         return 0;
1255
1256 err:
1257         WARN_ON(ieee80211_add_chanctx(local, ctx));
1258         list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1259                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1260                         continue;
1261
1262                 if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1263                         continue;
1264
1265                 ieee80211_del_chanctx(local, ctx);
1266                 WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1267         }
1268
1269         return err;
1270 }
1271
1272 int
1273 ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1274 {
1275         struct ieee80211_sub_if_data *sdata, *sdata_tmp;
1276         struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1277         struct ieee80211_chanctx *new_ctx = NULL;
1278         int i, err, n_assigned, n_reserved, n_ready;
1279         int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1280
1281         lockdep_assert_held(&local->mtx);
1282         lockdep_assert_held(&local->chanctx_mtx);
1283
1284         /*
1285          * If there are 2 independent pairs of channel contexts performing
1286          * cross-switch of their vifs this code will still wait until both are
1287          * ready even though it could be possible to switch one before the
1288          * other is ready.
1289          *
1290          * For practical reasons and code simplicity just do a single huge
1291          * switch.
1292          */
1293
1294         /*
1295          * Verify if the reservation is still feasible.
1296          *  - if it's not then disconnect
1297          *  - if it is but not all vifs necessary are ready then defer
1298          */
1299
1300         list_for_each_entry(ctx, &local->chanctx_list, list) {
1301                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1302                         continue;
1303
1304                 if (WARN_ON(!ctx->replace_ctx)) {
1305                         err = -EINVAL;
1306                         goto err;
1307                 }
1308
1309                 if (!local->use_chanctx)
1310                         new_ctx = ctx;
1311
1312                 n_ctx++;
1313
1314                 n_assigned = 0;
1315                 n_reserved = 0;
1316                 n_ready = 0;
1317
1318                 list_for_each_entry(sdata, &ctx->replace_ctx->assigned_vifs,
1319                                     assigned_chanctx_list) {
1320                         n_assigned++;
1321                         if (sdata->reserved_chanctx) {
1322                                 n_reserved++;
1323                                 if (sdata->reserved_ready)
1324                                         n_ready++;
1325                         }
1326                 }
1327
1328                 if (n_assigned != n_reserved) {
1329                         if (n_ready == n_reserved) {
1330                                 wiphy_info(local->hw.wiphy,
1331                                            "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1332                                 err = -EBUSY;
1333                                 goto err;
1334                         }
1335
1336                         return -EAGAIN;
1337                 }
1338
1339                 ctx->conf.radar_enabled = false;
1340                 list_for_each_entry(sdata, &ctx->reserved_vifs,
1341                                     reserved_chanctx_list) {
1342                         if (ieee80211_vif_has_in_place_reservation(sdata) &&
1343                             !sdata->reserved_ready)
1344                                 return -EAGAIN;
1345
1346                         old_ctx = ieee80211_vif_get_chanctx(sdata);
1347                         if (old_ctx) {
1348                                 if (old_ctx->replace_state ==
1349                                     IEEE80211_CHANCTX_WILL_BE_REPLACED)
1350                                         n_vifs_switch++;
1351                                 else
1352                                         n_vifs_assign++;
1353                         } else {
1354                                 n_vifs_ctxless++;
1355                         }
1356
1357                         if (sdata->reserved_radar_required)
1358                                 ctx->conf.radar_enabled = true;
1359                 }
1360         }
1361
1362         if (WARN_ON(n_ctx == 0) ||
1363             WARN_ON(n_vifs_switch == 0 &&
1364                     n_vifs_assign == 0 &&
1365                     n_vifs_ctxless == 0) ||
1366             WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1367             WARN_ON(!new_ctx && !local->use_chanctx)) {
1368                 err = -EINVAL;
1369                 goto err;
1370         }
1371
1372         /*
1373          * All necessary vifs are ready. Perform the switch now depending on
1374          * reservations and driver capabilities.
1375          */
1376
1377         if (local->use_chanctx) {
1378                 if (n_vifs_switch > 0) {
1379                         err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1380                         if (err)
1381                                 goto err;
1382                 }
1383
1384                 if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1385                         err = ieee80211_chsw_switch_ctxs(local);
1386                         if (err)
1387                                 goto err;
1388                 }
1389         } else {
1390                 err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1391                 if (err)
1392                         goto err;
1393         }
1394
1395         /*
1396          * Update all structures, values and pointers to point to new channel
1397          * context(s).
1398          */
1399
1400         i = 0;
1401         list_for_each_entry(ctx, &local->chanctx_list, list) {
1402                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1403                         continue;
1404
1405                 if (WARN_ON(!ctx->replace_ctx)) {
1406                         err = -EINVAL;
1407                         goto err;
1408                 }
1409
1410                 list_for_each_entry(sdata, &ctx->reserved_vifs,
1411                                     reserved_chanctx_list) {
1412                         u32 changed = 0;
1413
1414                         if (!ieee80211_vif_has_in_place_reservation(sdata))
1415                                 continue;
1416
1417                         rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
1418
1419                         if (sdata->vif.type == NL80211_IFTYPE_AP)
1420                                 __ieee80211_vif_copy_chanctx_to_vlans(sdata,
1421                                                                       false);
1422
1423                         sdata->radar_required = sdata->reserved_radar_required;
1424
1425                         if (sdata->vif.bss_conf.chandef.width !=
1426                             sdata->reserved_chandef.width)
1427                                 changed = BSS_CHANGED_BANDWIDTH;
1428
1429                         sdata->vif.bss_conf.chandef = sdata->reserved_chandef;
1430                         if (changed)
1431                                 ieee80211_bss_info_change_notify(sdata,
1432                                                                  changed);
1433
1434                         ieee80211_recalc_txpower(sdata);
1435                 }
1436
1437                 ieee80211_recalc_chanctx_chantype(local, ctx);
1438                 ieee80211_recalc_smps_chanctx(local, ctx);
1439                 ieee80211_recalc_radar_chanctx(local, ctx);
1440                 ieee80211_recalc_chanctx_min_def(local, ctx);
1441
1442                 list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1443                                          reserved_chanctx_list) {
1444                         if (ieee80211_vif_get_chanctx(sdata) != ctx)
1445                                 continue;
1446
1447                         list_del(&sdata->reserved_chanctx_list);
1448                         list_move(&sdata->assigned_chanctx_list,
1449                                   &ctx->assigned_vifs);
1450                         sdata->reserved_chanctx = NULL;
1451
1452                         ieee80211_vif_chanctx_reservation_complete(sdata);
1453                 }
1454
1455                 /*
1456                  * This context might have been a dependency for an already
1457                  * ready re-assign reservation interface that was deferred. Do
1458                  * not propagate error to the caller though. The in-place
1459                  * reservation for originally requested interface has already
1460                  * succeeded at this point.
1461                  */
1462                 list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1463                                          reserved_chanctx_list) {
1464                         if (WARN_ON(ieee80211_vif_has_in_place_reservation(
1465                                         sdata)))
1466                                 continue;
1467
1468                         if (WARN_ON(sdata->reserved_chanctx != ctx))
1469                                 continue;
1470
1471                         if (!sdata->reserved_ready)
1472                                 continue;
1473
1474                         if (ieee80211_vif_get_chanctx(sdata))
1475                                 err = ieee80211_vif_use_reserved_reassign(
1476                                                 sdata);
1477                         else
1478                                 err = ieee80211_vif_use_reserved_assign(sdata);
1479
1480                         if (err) {
1481                                 sdata_info(sdata,
1482                                            "failed to finalize (re-)assign reservation (err=%d)\n",
1483                                            err);
1484                                 ieee80211_vif_unreserve_chanctx(sdata);
1485                                 cfg80211_stop_iface(local->hw.wiphy,
1486                                                     &sdata->wdev,
1487                                                     GFP_KERNEL);
1488                         }
1489                 }
1490         }
1491
1492         /*
1493          * Finally free old contexts
1494          */
1495
1496         list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1497                 if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1498                         continue;
1499
1500                 ctx->replace_ctx->replace_ctx = NULL;
1501                 ctx->replace_ctx->replace_state =
1502                                 IEEE80211_CHANCTX_REPLACE_NONE;
1503
1504                 list_del_rcu(&ctx->list);
1505                 kfree_rcu(ctx, rcu_head);
1506         }
1507
1508         return 0;
1509
1510 err:
1511         list_for_each_entry(ctx, &local->chanctx_list, list) {
1512                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1513                         continue;
1514
1515                 list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1516                                          reserved_chanctx_list) {
1517                         ieee80211_vif_unreserve_chanctx(sdata);
1518                         ieee80211_vif_chanctx_reservation_complete(sdata);
1519                 }
1520         }
1521
1522         return err;
1523 }
1524
1525 int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
1526 {
1527         struct ieee80211_local *local = sdata->local;
1528         struct ieee80211_chanctx *new_ctx;
1529         struct ieee80211_chanctx *old_ctx;
1530         int err;
1531
1532         lockdep_assert_held(&local->mtx);
1533         lockdep_assert_held(&local->chanctx_mtx);
1534
1535         new_ctx = sdata->reserved_chanctx;
1536         old_ctx = ieee80211_vif_get_chanctx(sdata);
1537
1538         if (WARN_ON(!new_ctx))
1539                 return -EINVAL;
1540
1541         if (WARN_ON(new_ctx->replace_state ==
1542                     IEEE80211_CHANCTX_WILL_BE_REPLACED))
1543                 return -EINVAL;
1544
1545         if (WARN_ON(sdata->reserved_ready))
1546                 return -EINVAL;
1547
1548         sdata->reserved_ready = true;
1549
1550         if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1551                 if (old_ctx)
1552                         err = ieee80211_vif_use_reserved_reassign(sdata);
1553                 else
1554                         err = ieee80211_vif_use_reserved_assign(sdata);
1555
1556                 if (err)
1557                         return err;
1558         }
1559
1560         /*
1561          * In-place reservation may need to be finalized now either if:
1562          *  a) sdata is taking part in the swapping itself and is the last one
1563          *  b) sdata has switched with a re-assign reservation to an existing
1564          *     context readying in-place switching of old_ctx
1565          *
1566          * In case of (b) do not propagate the error up because the requested
1567          * sdata already switched successfully. Just spill an extra warning.
1568          * The ieee80211_vif_use_reserved_switch() already stops all necessary
1569          * interfaces upon failure.
1570          */
1571         if ((old_ctx &&
1572              old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1573             new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1574                 err = ieee80211_vif_use_reserved_switch(local);
1575                 if (err && err != -EAGAIN) {
1576                         if (new_ctx->replace_state ==
1577                             IEEE80211_CHANCTX_REPLACES_OTHER)
1578                                 return err;
1579
1580                         wiphy_info(local->hw.wiphy,
1581                                    "depending in-place reservation failed (err=%d)\n",
1582                                    err);
1583                 }
1584         }
1585
1586         return 0;
1587 }
1588
1589 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
1590                                    const struct cfg80211_chan_def *chandef,
1591                                    u32 *changed)
1592 {
1593         struct ieee80211_local *local = sdata->local;
1594         struct ieee80211_chanctx_conf *conf;
1595         struct ieee80211_chanctx *ctx;
1596         const struct cfg80211_chan_def *compat;
1597         int ret;
1598
1599         if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1600                                      IEEE80211_CHAN_DISABLED))
1601                 return -EINVAL;
1602
1603         mutex_lock(&local->chanctx_mtx);
1604         if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
1605                 ret = 0;
1606                 goto out;
1607         }
1608
1609         if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1610             sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1611                 ret = -EINVAL;
1612                 goto out;
1613         }
1614
1615         conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1616                                          lockdep_is_held(&local->chanctx_mtx));
1617         if (!conf) {
1618                 ret = -EINVAL;
1619                 goto out;
1620         }
1621
1622         ctx = container_of(conf, struct ieee80211_chanctx, conf);
1623
1624         compat = cfg80211_chandef_compatible(&conf->def, chandef);
1625         if (!compat) {
1626                 ret = -EINVAL;
1627                 goto out;
1628         }
1629
1630         switch (ctx->replace_state) {
1631         case IEEE80211_CHANCTX_REPLACE_NONE:
1632                 if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1633                         ret = -EBUSY;
1634                         goto out;
1635                 }
1636                 break;
1637         case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1638                 /* TODO: Perhaps the bandwith change could be treated as a
1639                  * reservation itself? */
1640                 ret = -EBUSY;
1641                 goto out;
1642         case IEEE80211_CHANCTX_REPLACES_OTHER:
1643                 /* channel context that is going to replace another channel
1644                  * context doesn't really exist and shouldn't be assigned
1645                  * anywhere yet */
1646                 WARN_ON(1);
1647                 break;
1648         }
1649
1650         sdata->vif.bss_conf.chandef = *chandef;
1651
1652         ieee80211_recalc_chanctx_chantype(local, ctx);
1653
1654         *changed |= BSS_CHANGED_BANDWIDTH;
1655         ret = 0;
1656  out:
1657         mutex_unlock(&local->chanctx_mtx);
1658         return ret;
1659 }
1660
1661 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1662 {
1663         WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1664
1665         lockdep_assert_held(&sdata->local->mtx);
1666
1667         mutex_lock(&sdata->local->chanctx_mtx);
1668         __ieee80211_vif_release_channel(sdata);
1669         mutex_unlock(&sdata->local->chanctx_mtx);
1670 }
1671
1672 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
1673 {
1674         struct ieee80211_local *local = sdata->local;
1675         struct ieee80211_sub_if_data *ap;
1676         struct ieee80211_chanctx_conf *conf;
1677
1678         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
1679                 return;
1680
1681         ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
1682
1683         mutex_lock(&local->chanctx_mtx);
1684
1685         conf = rcu_dereference_protected(ap->vif.chanctx_conf,
1686                                          lockdep_is_held(&local->chanctx_mtx));
1687         rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
1688         mutex_unlock(&local->chanctx_mtx);
1689 }
1690
1691 void ieee80211_iter_chan_contexts_atomic(
1692         struct ieee80211_hw *hw,
1693         void (*iter)(struct ieee80211_hw *hw,
1694                      struct ieee80211_chanctx_conf *chanctx_conf,
1695                      void *data),
1696         void *iter_data)
1697 {
1698         struct ieee80211_local *local = hw_to_local(hw);
1699         struct ieee80211_chanctx *ctx;
1700
1701         rcu_read_lock();
1702         list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
1703                 if (ctx->driver_present)
1704                         iter(hw, &ctx->conf, iter_data);
1705         rcu_read_unlock();
1706 }
1707 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);