net/mac80211/chan.c

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