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