mac80211/chan.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * mac80211 - channel management
   4  * Copyright 2020 - 2022 Intel Corporation
   5  */
   6
   7 #include <linux/nl80211.h>
   8 #include <linux/export.h>
   9 #include <linux/rtnetlink.h>
  10 #include <net/cfg80211.h>
  11 #include "ieee80211_i.h"
  12 #include "driver-ops.h"
  13 #include "rate.h"
  14
  15 static int ieee80211_chanctx_num_assigned(struct ieee80211_local *local,
  16                                           struct ieee80211_chanctx *ctx)
  17 {
  18         struct ieee80211_link_data *link;
  19         int num = 0;
  20
  21         lockdep_assert_held(&local->chanctx_mtx);
  22
  23         list_for_each_entry(link, &ctx->assigned_links, assigned_chanctx_list)
  24                 num++;
  25
  26         return num;
  27 }
  28
  29 static int ieee80211_chanctx_num_reserved(struct ieee80211_local *local,
  30                                           struct ieee80211_chanctx *ctx)
  31 {
  32         struct ieee80211_link_data *link;
  33         int num = 0;
  34
  35         lockdep_assert_held(&local->chanctx_mtx);
  36
  37         list_for_each_entry(link, &ctx->reserved_links, reserved_chanctx_list)
  38                 num++;
  39
  40         return num;
  41 }
  42
  43 int ieee80211_chanctx_refcount(struct ieee80211_local *local,
  44                                struct ieee80211_chanctx *ctx)
  45 {
  46         return ieee80211_chanctx_num_assigned(local, ctx) +
  47                ieee80211_chanctx_num_reserved(local, ctx);
  48 }
  49
  50 static int ieee80211_num_chanctx(struct ieee80211_local *local)
  51 {
  52         struct ieee80211_chanctx *ctx;
  53         int num = 0;
  54
  55         lockdep_assert_held(&local->chanctx_mtx);
  56
  57         list_for_each_entry(ctx, &local->chanctx_list, list)
  58                 num++;
  59
  60         return num;
  61 }
  62
  63 static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local)
  64 {
  65         lockdep_assert_held(&local->chanctx_mtx);
  66         return ieee80211_num_chanctx(local) < ieee80211_max_num_channels(local);
  67 }
  68
  69 static struct ieee80211_chanctx *
  70 ieee80211_link_get_chanctx(struct ieee80211_link_data *link)
  71 {
  72         struct ieee80211_local *local __maybe_unused = link->sdata->local;
  73         struct ieee80211_chanctx_conf *conf;
  74
  75         conf = rcu_dereference_protected(link->conf->chanctx_conf,
  76                                          lockdep_is_held(&local->chanctx_mtx));
  77         if (!conf)
  78                 return NULL;
  79
  80         return container_of(conf, struct ieee80211_chanctx, conf);
  81 }
  82
  83 static const struct cfg80211_chan_def *
  84 ieee80211_chanctx_reserved_chandef(struct ieee80211_local *local,
  85                                    struct ieee80211_chanctx *ctx,
  86                                    const struct cfg80211_chan_def *compat)
  87 {
  88         struct ieee80211_link_data *link;
  89
  90         lockdep_assert_held(&local->chanctx_mtx);
  91
  92         list_for_each_entry(link, &ctx->reserved_links,
  93                             reserved_chanctx_list) {
  94                 if (!compat)
  95                         compat = &link->reserved_chandef;
  96
  97                 compat = cfg80211_chandef_compatible(&link->reserved_chandef,
  98                                                      compat);
  99                 if (!compat)
 100                         break;
 101         }
 102
 103         return compat;
 104 }
 105
 106 static const struct cfg80211_chan_def *
 107 ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local,
 108                                        struct ieee80211_chanctx *ctx,
 109                                        const struct cfg80211_chan_def *compat)
 110 {
 111         struct ieee80211_link_data *link;
 112
 113         lockdep_assert_held(&local->chanctx_mtx);
 114
 115         list_for_each_entry(link, &ctx->assigned_links,
 116                             assigned_chanctx_list) {
 117                 struct ieee80211_bss_conf *link_conf = link->conf;
 118
 119                 if (link->reserved_chanctx)
 120                         continue;
 121
 122                 if (!compat)
 123                         compat = &link_conf->chandef;
 124
 125                 compat = cfg80211_chandef_compatible(
 126                                 &link_conf->chandef, compat);
 127                 if (!compat)
 128                         break;
 129         }
 130
 131         return compat;
 132 }
 133
 134 static const struct cfg80211_chan_def *
 135 ieee80211_chanctx_combined_chandef(struct ieee80211_local *local,
 136                                    struct ieee80211_chanctx *ctx,
 137                                    const struct cfg80211_chan_def *compat)
 138 {
 139         lockdep_assert_held(&local->chanctx_mtx);
 140
 141         compat = ieee80211_chanctx_reserved_chandef(local, ctx, compat);
 142         if (!compat)
 143                 return NULL;
 144
 145         compat = ieee80211_chanctx_non_reserved_chandef(local, ctx, compat);
 146         if (!compat)
 147                 return NULL;
 148
 149         return compat;
 150 }
 151
 152 static bool
 153 ieee80211_chanctx_can_reserve_chandef(struct ieee80211_local *local,
 154                                       struct ieee80211_chanctx *ctx,
 155                                       const struct cfg80211_chan_def *def)
 156 {
 157         lockdep_assert_held(&local->chanctx_mtx);
 158
 159         if (ieee80211_chanctx_combined_chandef(local, ctx, def))
 160                 return true;
 161
 162         if (!list_empty(&ctx->reserved_links) &&
 163             ieee80211_chanctx_reserved_chandef(local, ctx, def))
 164                 return true;
 165
 166         return false;
 167 }
 168
 169 static struct ieee80211_chanctx *
 170 ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
 171                                    const struct cfg80211_chan_def *chandef,
 172                                    enum ieee80211_chanctx_mode mode)
 173 {
 174         struct ieee80211_chanctx *ctx;
 175
 176         lockdep_assert_held(&local->chanctx_mtx);
 177
 178         if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
 179                 return NULL;
 180
 181         list_for_each_entry(ctx, &local->chanctx_list, list) {
 182                 if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
 183                         continue;
 184
 185                 if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
 186                         continue;
 187
 188                 if (!ieee80211_chanctx_can_reserve_chandef(local, ctx,
 189                                                            chandef))
 190                         continue;
 191
 192                 return ctx;
 193         }
 194
 195         return NULL;
 196 }
 197
 198 static enum nl80211_chan_width ieee80211_get_sta_bw(struct sta_info *sta,
 199                                                     unsigned int link_id)
 200 {
 201         enum ieee80211_sta_rx_bandwidth width;
 202         struct link_sta_info *link_sta;
 203
 204         link_sta = rcu_dereference(sta->link[link_id]);
 205
 206         /* no effect if this STA has no presence on this link */
 207         if (!link_sta)
 208                 return NL80211_CHAN_WIDTH_20_NOHT;
 209
 210         width = ieee80211_sta_cap_rx_bw(link_sta);
 211
 212         switch (width) {
 213         case IEEE80211_STA_RX_BW_20:
 214                 if (link_sta->pub->ht_cap.ht_supported)
 215                         return NL80211_CHAN_WIDTH_20;
 216                 else
 217                         return NL80211_CHAN_WIDTH_20_NOHT;
 218         case IEEE80211_STA_RX_BW_40:
 219                 return NL80211_CHAN_WIDTH_40;
 220         case IEEE80211_STA_RX_BW_80:
 221                 return NL80211_CHAN_WIDTH_80;
 222         case IEEE80211_STA_RX_BW_160:
 223                 /*
 224                  * This applied for both 160 and 80+80. since we use
 225                  * the returned value to consider degradation of
 226                  * ctx->conf.min_def, we have to make sure to take
 227                  * the bigger one (NL80211_CHAN_WIDTH_160).
 228                  * Otherwise we might try degrading even when not
 229                  * needed, as the max required sta_bw returned (80+80)
 230                  * might be smaller than the configured bw (160).
 231                  */
 232                 return NL80211_CHAN_WIDTH_160;
 233         case IEEE80211_STA_RX_BW_320:
 234                 return NL80211_CHAN_WIDTH_320;
 235         default:
 236                 WARN_ON(1);
 237                 return NL80211_CHAN_WIDTH_20;
 238         }
 239 }
 240
 241 static enum nl80211_chan_width
 242 ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata,
 243                               unsigned int link_id)
 244 {
 245         enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
 246         struct sta_info *sta;
 247
 248         list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
 249                 if (sdata != sta->sdata &&
 250                     !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
 251                         continue;
 252
 253                 max_bw = max(max_bw, ieee80211_get_sta_bw(sta, link_id));
 254         }
 255
 256         return max_bw;
 257 }
 258
 259 static enum nl80211_chan_width
 260 ieee80211_get_chanctx_vif_max_required_bw(struct ieee80211_sub_if_data *sdata,
 261                                           struct ieee80211_chanctx *ctx,
 262                                           struct ieee80211_link_data *rsvd_for)
 263 {
 264         enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
 265         struct ieee80211_vif *vif = &sdata->vif;
 266         int link_id;
 267
 268         rcu_read_lock();
 269         for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
 270                 enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
 271                 struct ieee80211_link_data *link =
 272                         rcu_dereference(sdata->link[link_id]);
 273
 274                 if (!link)
 275                         continue;
 276
 277                 if (link != rsvd_for &&
 278                     rcu_access_pointer(link->conf->chanctx_conf) != &ctx->conf)
 279                         continue;
 280
 281                 switch (vif->type) {
 282                 case NL80211_IFTYPE_AP:
 283                 case NL80211_IFTYPE_AP_VLAN:
 284                         width = ieee80211_get_max_required_bw(sdata, link_id);
 285                         break;
 286                 case NL80211_IFTYPE_STATION:
 287                         /*
 288                          * The ap's sta->bandwidth is not set yet at this
 289                          * point, so take the width from the chandef, but
 290                          * account also for TDLS peers
 291                          */
 292                         width = max(link->conf->chandef.width,
 293                                     ieee80211_get_max_required_bw(sdata, link_id));
 294                         break;
 295                 case NL80211_IFTYPE_P2P_DEVICE:
 296                 case NL80211_IFTYPE_NAN:
 297                         continue;
 298                 case NL80211_IFTYPE_ADHOC:
 299                 case NL80211_IFTYPE_MESH_POINT:
 300                 case NL80211_IFTYPE_OCB:
 301                         width = link->conf->chandef.width;
 302                         break;
 303                 case NL80211_IFTYPE_WDS:
 304                 case NL80211_IFTYPE_UNSPECIFIED:
 305                 case NUM_NL80211_IFTYPES:
 306                 case NL80211_IFTYPE_MONITOR:
 307                 case NL80211_IFTYPE_P2P_CLIENT:
 308                 case NL80211_IFTYPE_P2P_GO:
 309                         WARN_ON_ONCE(1);
 310                 }
 311
 312                 max_bw = max(max_bw, width);
 313         }
 314         rcu_read_unlock();
 315
 316         return max_bw;
 317 }
 318
 319 static enum nl80211_chan_width
 320 ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
 321                                       struct ieee80211_chanctx *ctx,
 322                                       struct ieee80211_link_data *rsvd_for)
 323 {
 324         struct ieee80211_sub_if_data *sdata;
 325         enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
 326
 327         rcu_read_lock();
 328         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 329                 enum nl80211_chan_width width;
 330
 331                 if (!ieee80211_sdata_running(sdata))
 332                         continue;
 333
 334                 width = ieee80211_get_chanctx_vif_max_required_bw(sdata, ctx,
 335                                                                   rsvd_for);
 336
 337                 max_bw = max(max_bw, width);
 338         }
 339
 340         /* use the configured bandwidth in case of monitor interface */
 341         sdata = rcu_dereference(local->monitor_sdata);
 342         if (sdata &&
 343             rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == &ctx->conf)
 344                 max_bw = max(max_bw, ctx->conf.def.width);
 345
 346         rcu_read_unlock();
 347
 348         return max_bw;
 349 }
 350
 351 /*
 352  * recalc the min required chan width of the channel context, which is
 353  * the max of min required widths of all the interfaces bound to this
 354  * channel context.
 355  */
 356 static u32
 357 _ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
 358                                   struct ieee80211_chanctx *ctx,
 359                                   struct ieee80211_link_data *rsvd_for)
 360 {
 361         enum nl80211_chan_width max_bw;
 362         struct cfg80211_chan_def min_def;
 363
 364         lockdep_assert_held(&local->chanctx_mtx);
 365
 366         /* don't optimize non-20MHz based and radar_enabled confs */
 367         if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
 368             ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
 369             ctx->conf.def.width == NL80211_CHAN_WIDTH_1 ||
 370             ctx->conf.def.width == NL80211_CHAN_WIDTH_2 ||
 371             ctx->conf.def.width == NL80211_CHAN_WIDTH_4 ||
 372             ctx->conf.def.width == NL80211_CHAN_WIDTH_8 ||
 373             ctx->conf.def.width == NL80211_CHAN_WIDTH_16 ||
 374             ctx->conf.radar_enabled) {
 375                 ctx->conf.min_def = ctx->conf.def;
 376                 return 0;
 377         }
 378
 379         max_bw = ieee80211_get_chanctx_max_required_bw(local, ctx, rsvd_for);
 380
 381         /* downgrade chandef up to max_bw */
 382         min_def = ctx->conf.def;
 383         while (min_def.width > max_bw)
 384                 ieee80211_chandef_downgrade(&min_def);
 385
 386         if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
 387                 return 0;
 388
 389         ctx->conf.min_def = min_def;
 390         if (!ctx->driver_present)
 391                 return 0;
 392
 393         return IEEE80211_CHANCTX_CHANGE_MIN_WIDTH;
 394 }
 395
 396 /* calling this function is assuming that station vif is updated to
 397  * lates changes by calling ieee80211_link_update_chandef
 398  */
 399 static void ieee80211_chan_bw_change(struct ieee80211_local *local,
 400                                      struct ieee80211_chanctx *ctx,
 401                                      bool narrowed)
 402 {
 403         struct sta_info *sta;
 404         struct ieee80211_supported_band *sband =
 405                 local->hw.wiphy->bands[ctx->conf.def.chan->band];
 406
 407         rcu_read_lock();
 408         list_for_each_entry_rcu(sta, &local->sta_list,
 409                                 list) {
 410                 struct ieee80211_sub_if_data *sdata = sta->sdata;
 411                 enum ieee80211_sta_rx_bandwidth new_sta_bw;
 412                 unsigned int link_id;
 413
 414                 if (!ieee80211_sdata_running(sta->sdata))
 415                         continue;
 416
 417                 for (link_id = 0; link_id < ARRAY_SIZE(sta->sdata->link); link_id++) {
 418                         struct ieee80211_bss_conf *link_conf =
 419                                 rcu_dereference(sdata->vif.link_conf[link_id]);
 420                         struct link_sta_info *link_sta;
 421
 422                         if (!link_conf)
 423                                 continue;
 424
 425                         if (rcu_access_pointer(link_conf->chanctx_conf) != &ctx->conf)
 426                                 continue;
 427
 428                         link_sta = rcu_dereference(sta->link[link_id]);
 429                         if (!link_sta)
 430                                 continue;
 431
 432                         new_sta_bw = ieee80211_sta_cur_vht_bw(link_sta);
 433
 434                         /* nothing change */
 435                         if (new_sta_bw == link_sta->pub->bandwidth)
 436                                 continue;
 437
 438                         /* vif changed to narrow BW and narrow BW for station wasn't
 439                          * requested or vise versa */
 440                         if ((new_sta_bw < link_sta->pub->bandwidth) == !narrowed)
 441                                 continue;
 442
 443                         link_sta->pub->bandwidth = new_sta_bw;
 444                         rate_control_rate_update(local, sband, sta, link_id,
 445                                                  IEEE80211_RC_BW_CHANGED);
 446                 }
 447         }
 448         rcu_read_unlock();
 449 }
 450
 451 /*
 452  * recalc the min required chan width of the channel context, which is
 453  * the max of min required widths of all the interfaces bound to this
 454  * channel context.
 455  */
 456 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
 457                                       struct ieee80211_chanctx *ctx,
 458                                       struct ieee80211_link_data *rsvd_for)
 459 {
 460         u32 changed = _ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for);
 461
 462         if (!changed)
 463                 return;
 464
 465         /* check is BW narrowed */
 466         ieee80211_chan_bw_change(local, ctx, true);
 467
 468         drv_change_chanctx(local, ctx, changed);
 469
 470         /* check is BW wider */
 471         ieee80211_chan_bw_change(local, ctx, false);
 472 }
 473
 474 static void _ieee80211_change_chanctx(struct ieee80211_local *local,
 475                                       struct ieee80211_chanctx *ctx,
 476                                       struct ieee80211_chanctx *old_ctx,
 477                                       const struct cfg80211_chan_def *chandef,
 478                                       struct ieee80211_link_data *rsvd_for)
 479 {
 480         u32 changed;
 481
 482         /* expected to handle only 20/40/80/160/320 channel widths */
 483         switch (chandef->width) {
 484         case NL80211_CHAN_WIDTH_20_NOHT:
 485         case NL80211_CHAN_WIDTH_20:
 486         case NL80211_CHAN_WIDTH_40:
 487         case NL80211_CHAN_WIDTH_80:
 488         case NL80211_CHAN_WIDTH_80P80:
 489         case NL80211_CHAN_WIDTH_160:
 490         case NL80211_CHAN_WIDTH_320:
 491                 break;
 492         default:
 493                 WARN_ON(1);
 494         }
 495
 496         /* Check maybe BW narrowed - we do this _before_ calling recalc_chanctx_min_def
 497          * due to maybe not returning from it, e.g in case new context was added
 498          * first time with all parameters up to date.
 499          */
 500         ieee80211_chan_bw_change(local, old_ctx, true);
 501
 502         if (cfg80211_chandef_identical(&ctx->conf.def, chandef)) {
 503                 ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for);
 504                 return;
 505         }
 506
 507         WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
 508
 509         ctx->conf.def = *chandef;
 510
 511         /* check if min chanctx also changed */
 512         changed = IEEE80211_CHANCTX_CHANGE_WIDTH |
 513                   _ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for);
 514         drv_change_chanctx(local, ctx, changed);
 515
 516         if (!local->use_chanctx) {
 517                 local->_oper_chandef = *chandef;
 518                 ieee80211_hw_config(local, 0);
 519         }
 520
 521         /* check is BW wider */
 522         ieee80211_chan_bw_change(local, old_ctx, false);
 523 }
 524
 525 static void ieee80211_change_chanctx(struct ieee80211_local *local,
 526                                      struct ieee80211_chanctx *ctx,
 527                                      struct ieee80211_chanctx *old_ctx,
 528                                      const struct cfg80211_chan_def *chandef)
 529 {
 530         _ieee80211_change_chanctx(local, ctx, old_ctx, chandef, NULL);
 531 }
 532
 533 static struct ieee80211_chanctx *
 534 ieee80211_find_chanctx(struct ieee80211_local *local,
 535                        const struct cfg80211_chan_def *chandef,
 536                        enum ieee80211_chanctx_mode mode)
 537 {
 538         struct ieee80211_chanctx *ctx;
 539
 540         lockdep_assert_held(&local->chanctx_mtx);
 541
 542         if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
 543                 return NULL;
 544
 545         list_for_each_entry(ctx, &local->chanctx_list, list) {
 546                 const struct cfg80211_chan_def *compat;
 547
 548                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
 549                         continue;
 550
 551                 if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
 552                         continue;
 553
 554                 compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
 555                 if (!compat)
 556                         continue;
 557
 558                 compat = ieee80211_chanctx_reserved_chandef(local, ctx,
 559                                                             compat);
 560                 if (!compat)
 561                         continue;
 562
 563                 ieee80211_change_chanctx(local, ctx, ctx, compat);
 564
 565                 return ctx;
 566         }
 567
 568         return NULL;
 569 }
 570
 571 bool ieee80211_is_radar_required(struct ieee80211_local *local)
 572 {
 573         struct ieee80211_sub_if_data *sdata;
 574
 575         lockdep_assert_held(&local->mtx);
 576
 577         rcu_read_lock();
 578         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 579                 unsigned int link_id;
 580
 581                 for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
 582                         struct ieee80211_link_data *link;
 583
 584                         link = rcu_dereference(sdata->link[link_id]);
 585
 586                         if (link && link->radar_required) {
 587                                 rcu_read_unlock();
 588                                 return true;
 589                         }
 590                 }
 591         }
 592         rcu_read_unlock();
 593
 594         return false;
 595 }
 596
 597 static bool
 598 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
 599                                  struct ieee80211_chanctx *ctx)
 600 {
 601         struct ieee80211_chanctx_conf *conf = &ctx->conf;
 602         struct ieee80211_sub_if_data *sdata;
 603         bool required = false;
 604
 605         lockdep_assert_held(&local->chanctx_mtx);
 606         lockdep_assert_held(&local->mtx);
 607
 608         rcu_read_lock();
 609         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 610                 unsigned int link_id;
 611
 612                 if (!ieee80211_sdata_running(sdata))
 613                         continue;
 614                 for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
 615                         struct ieee80211_link_data *link;
 616
 617                         link = rcu_dereference(sdata->link[link_id]);
 618                         if (!link)
 619                                 continue;
 620
 621                         if (rcu_access_pointer(link->conf->chanctx_conf) != conf)
 622                                 continue;
 623                         if (!link->radar_required)
 624                                 continue;
 625                         required = true;
 626                         break;
 627                 }
 628
 629                 if (required)
 630                         break;
 631         }
 632         rcu_read_unlock();
 633
 634         return required;
 635 }
 636
 637 static struct ieee80211_chanctx *
 638 ieee80211_alloc_chanctx(struct ieee80211_local *local,
 639                         const struct cfg80211_chan_def *chandef,
 640                         enum ieee80211_chanctx_mode mode)
 641 {
 642         struct ieee80211_chanctx *ctx;
 643
 644         lockdep_assert_held(&local->chanctx_mtx);
 645
 646         ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
 647         if (!ctx)
 648                 return NULL;
 649
 650         INIT_LIST_HEAD(&ctx->assigned_links);
 651         INIT_LIST_HEAD(&ctx->reserved_links);
 652         ctx->conf.def = *chandef;
 653         ctx->conf.rx_chains_static = 1;
 654         ctx->conf.rx_chains_dynamic = 1;
 655         ctx->mode = mode;
 656         ctx->conf.radar_enabled = false;
 657         _ieee80211_recalc_chanctx_min_def(local, ctx, NULL);
 658
 659         return ctx;
 660 }
 661
 662 static int ieee80211_add_chanctx(struct ieee80211_local *local,
 663                                  struct ieee80211_chanctx *ctx)
 664 {
 665         u32 changed;
 666         int err;
 667
 668         lockdep_assert_held(&local->mtx);
 669         lockdep_assert_held(&local->chanctx_mtx);
 670
 671         if (!local->use_chanctx)
 672                 local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
 673
 674         /* turn idle off *before* setting channel -- some drivers need that */
 675         changed = ieee80211_idle_off(local);
 676         if (changed)
 677                 ieee80211_hw_config(local, changed);
 678
 679         if (!local->use_chanctx) {
 680                 local->_oper_chandef = ctx->conf.def;
 681                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 682         } else {
 683                 err = drv_add_chanctx(local, ctx);
 684                 if (err) {
 685                         ieee80211_recalc_idle(local);
 686                         return err;
 687                 }
 688         }
 689
 690         return 0;
 691 }
 692
 693 static struct ieee80211_chanctx *
 694 ieee80211_new_chanctx(struct ieee80211_local *local,
 695                       const struct cfg80211_chan_def *chandef,
 696                       enum ieee80211_chanctx_mode mode)
 697 {
 698         struct ieee80211_chanctx *ctx;
 699         int err;
 700
 701         lockdep_assert_held(&local->mtx);
 702         lockdep_assert_held(&local->chanctx_mtx);
 703
 704         ctx = ieee80211_alloc_chanctx(local, chandef, mode);
 705         if (!ctx)
 706                 return ERR_PTR(-ENOMEM);
 707
 708         err = ieee80211_add_chanctx(local, ctx);
 709         if (err) {
 710                 kfree(ctx);
 711                 return ERR_PTR(err);
 712         }
 713
 714         list_add_rcu(&ctx->list, &local->chanctx_list);
 715         return ctx;
 716 }
 717
 718 static void ieee80211_del_chanctx(struct ieee80211_local *local,
 719                                   struct ieee80211_chanctx *ctx)
 720 {
 721         lockdep_assert_held(&local->chanctx_mtx);
 722
 723         if (!local->use_chanctx) {
 724                 struct cfg80211_chan_def *chandef = &local->_oper_chandef;
 725                 /* S1G doesn't have 20MHz, so get the correct width for the
 726                  * current channel.
 727                  */
 728                 if (chandef->chan->band == NL80211_BAND_S1GHZ)
 729                         chandef->width =
 730                                 ieee80211_s1g_channel_width(chandef->chan);
 731                 else
 732                         chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 733                 chandef->center_freq1 = chandef->chan->center_freq;
 734                 chandef->freq1_offset = chandef->chan->freq_offset;
 735                 chandef->center_freq2 = 0;
 736
 737                 /* NOTE: Disabling radar is only valid here for
 738                  * single channel context. To be sure, check it ...
 739                  */
 740                 WARN_ON(local->hw.conf.radar_enabled &&
 741                         !list_empty(&local->chanctx_list));
 742
 743                 local->hw.conf.radar_enabled = false;
 744
 745                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 746         } else {
 747                 drv_remove_chanctx(local, ctx);
 748         }
 749
 750         ieee80211_recalc_idle(local);
 751 }
 752
 753 static void ieee80211_free_chanctx(struct ieee80211_local *local,
 754                                    struct ieee80211_chanctx *ctx)
 755 {
 756         lockdep_assert_held(&local->chanctx_mtx);
 757
 758         WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
 759
 760         list_del_rcu(&ctx->list);
 761         ieee80211_del_chanctx(local, ctx);
 762         kfree_rcu(ctx, rcu_head);
 763 }
 764
 765 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
 766                                        struct ieee80211_chanctx *ctx)
 767 {
 768         struct ieee80211_chanctx_conf *conf = &ctx->conf;
 769         struct ieee80211_sub_if_data *sdata;
 770         const struct cfg80211_chan_def *compat = NULL;
 771         struct sta_info *sta;
 772
 773         lockdep_assert_held(&local->chanctx_mtx);
 774
 775         rcu_read_lock();
 776         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 777                 int link_id;
 778
 779                 if (!ieee80211_sdata_running(sdata))
 780                         continue;
 781
 782                 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 783                         continue;
 784
 785                 for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
 786                         struct ieee80211_bss_conf *link_conf =
 787                                 rcu_dereference(sdata->vif.link_conf[link_id]);
 788
 789                         if (!link_conf)
 790                                 continue;
 791
 792                         if (rcu_access_pointer(link_conf->chanctx_conf) != conf)
 793                                 continue;
 794
 795                         if (!compat)
 796                                 compat = &link_conf->chandef;
 797
 798                         compat = cfg80211_chandef_compatible(&link_conf->chandef,
 799                                                              compat);
 800                         if (WARN_ON_ONCE(!compat))
 801                                 break;
 802                 }
 803         }
 804
 805         /* TDLS peers can sometimes affect the chandef width */
 806         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 807                 if (!sta->uploaded ||
 808                     !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
 809                     !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
 810                     !sta->tdls_chandef.chan)
 811                         continue;
 812
 813                 compat = cfg80211_chandef_compatible(&sta->tdls_chandef,
 814                                                      compat);
 815                 if (WARN_ON_ONCE(!compat))
 816                         break;
 817         }
 818         rcu_read_unlock();
 819
 820         if (!compat)
 821                 return;
 822
 823         ieee80211_change_chanctx(local, ctx, ctx, compat);
 824 }
 825
 826 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
 827                                            struct ieee80211_chanctx *chanctx)
 828 {
 829         bool radar_enabled;
 830
 831         lockdep_assert_held(&local->chanctx_mtx);
 832         /* for ieee80211_is_radar_required */
 833         lockdep_assert_held(&local->mtx);
 834
 835         radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
 836
 837         if (radar_enabled == chanctx->conf.radar_enabled)
 838                 return;
 839
 840         chanctx->conf.radar_enabled = radar_enabled;
 841
 842         if (!local->use_chanctx) {
 843                 local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
 844                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 845         }
 846
 847         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
 848 }
 849
 850 static int ieee80211_assign_link_chanctx(struct ieee80211_link_data *link,
 851                                          struct ieee80211_chanctx *new_ctx)
 852 {
 853         struct ieee80211_sub_if_data *sdata = link->sdata;
 854         struct ieee80211_local *local = sdata->local;
 855         struct ieee80211_chanctx_conf *conf;
 856         struct ieee80211_chanctx *curr_ctx = NULL;
 857         int ret = 0;
 858
 859         if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
 860                 return -ENOTSUPP;
 861
 862         conf = rcu_dereference_protected(link->conf->chanctx_conf,
 863                                          lockdep_is_held(&local->chanctx_mtx));
 864
 865         if (conf) {
 866                 curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
 867
 868                 drv_unassign_vif_chanctx(local, sdata, link->conf, curr_ctx);
 869                 conf = NULL;
 870                 list_del(&link->assigned_chanctx_list);
 871         }
 872
 873         if (new_ctx) {
 874                 /* recalc considering the link we'll use it for now */
 875                 ieee80211_recalc_chanctx_min_def(local, new_ctx, link);
 876
 877                 ret = drv_assign_vif_chanctx(local, sdata, link->conf, new_ctx);
 878                 if (ret)
 879                         goto out;
 880
 881                 conf = &new_ctx->conf;
 882                 list_add(&link->assigned_chanctx_list,
 883                          &new_ctx->assigned_links);
 884         }
 885
 886 out:
 887         rcu_assign_pointer(link->conf->chanctx_conf, conf);
 888
 889         sdata->vif.cfg.idle = !conf;
 890
 891         if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
 892                 ieee80211_recalc_chanctx_chantype(local, curr_ctx);
 893                 ieee80211_recalc_smps_chanctx(local, curr_ctx);
 894                 ieee80211_recalc_radar_chanctx(local, curr_ctx);
 895                 ieee80211_recalc_chanctx_min_def(local, curr_ctx, NULL);
 896         }
 897
 898         if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
 899                 ieee80211_recalc_txpower(sdata, false);
 900                 ieee80211_recalc_chanctx_min_def(local, new_ctx, NULL);
 901         }
 902
 903         if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
 904             sdata->vif.type != NL80211_IFTYPE_MONITOR)
 905                 ieee80211_vif_cfg_change_notify(sdata, BSS_CHANGED_IDLE);
 906
 907         ieee80211_check_fast_xmit_iface(sdata);
 908
 909         return ret;
 910 }
 911
 912 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
 913                                    struct ieee80211_chanctx *chanctx)
 914 {
 915         struct ieee80211_sub_if_data *sdata;
 916         u8 rx_chains_static, rx_chains_dynamic;
 917
 918         lockdep_assert_held(&local->chanctx_mtx);
 919
 920         rx_chains_static = 1;
 921         rx_chains_dynamic = 1;
 922
 923         rcu_read_lock();
 924         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 925                 u8 needed_static, needed_dynamic;
 926                 unsigned int link_id;
 927
 928                 if (!ieee80211_sdata_running(sdata))
 929                         continue;
 930
 931                 switch (sdata->vif.type) {
 932                 case NL80211_IFTYPE_STATION:
 933                         if (!sdata->u.mgd.associated)
 934                                 continue;
 935                         break;
 936                 case NL80211_IFTYPE_AP:
 937                 case NL80211_IFTYPE_ADHOC:
 938                 case NL80211_IFTYPE_MESH_POINT:
 939                 case NL80211_IFTYPE_OCB:
 940                         break;
 941                 default:
 942                         continue;
 943                 }
 944
 945                 for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
 946                         struct ieee80211_link_data *link;
 947
 948                         link = rcu_dereference(sdata->link[link_id]);
 949
 950                         if (!link)
 951                                 continue;
 952
 953                         if (rcu_access_pointer(link->conf->chanctx_conf) != &chanctx->conf)
 954                                 continue;
 955
 956                         switch (link->smps_mode) {
 957                         default:
 958                                 WARN_ONCE(1, "Invalid SMPS mode %d\n",
 959                                           link->smps_mode);
 960                                 fallthrough;
 961                         case IEEE80211_SMPS_OFF:
 962                                 needed_static = link->needed_rx_chains;
 963                                 needed_dynamic = link->needed_rx_chains;
 964                                 break;
 965                         case IEEE80211_SMPS_DYNAMIC:
 966                                 needed_static = 1;
 967                                 needed_dynamic = link->needed_rx_chains;
 968                                 break;
 969                         case IEEE80211_SMPS_STATIC:
 970                                 needed_static = 1;
 971                                 needed_dynamic = 1;
 972                                 break;
 973                         }
 974
 975                         rx_chains_static = max(rx_chains_static, needed_static);
 976                         rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
 977                 }
 978         }
 979
 980         /* Disable SMPS for the monitor interface */
 981         sdata = rcu_dereference(local->monitor_sdata);
 982         if (sdata &&
 983             rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == &chanctx->conf)
 984                 rx_chains_dynamic = rx_chains_static = local->rx_chains;
 985
 986         rcu_read_unlock();
 987
 988         if (!local->use_chanctx) {
 989                 if (rx_chains_static > 1)
 990                         local->smps_mode = IEEE80211_SMPS_OFF;
 991                 else if (rx_chains_dynamic > 1)
 992                         local->smps_mode = IEEE80211_SMPS_DYNAMIC;
 993                 else
 994                         local->smps_mode = IEEE80211_SMPS_STATIC;
 995                 ieee80211_hw_config(local, 0);
 996         }
 997
 998         if (rx_chains_static == chanctx->conf.rx_chains_static &&
 999             rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
1000                 return;
1001
1002         chanctx->conf.rx_chains_static = rx_chains_static;
1003         chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
1004         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
1005 }
1006
1007 static void
1008 __ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,
1009                                        bool clear)
1010 {
1011         struct ieee80211_sub_if_data *sdata = link->sdata;
1012         unsigned int link_id = link->link_id;
1013         struct ieee80211_bss_conf *link_conf = link->conf;
1014         struct ieee80211_local *local __maybe_unused = sdata->local;
1015         struct ieee80211_sub_if_data *vlan;
1016         struct ieee80211_chanctx_conf *conf;
1017
1018         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
1019                 return;
1020
1021         lockdep_assert_held(&local->mtx);
1022
1023         /* Check that conf exists, even when clearing this function
1024          * must be called with the AP's channel context still there
1025          * as it would otherwise cause VLANs to have an invalid
1026          * channel context pointer for a while, possibly pointing
1027          * to a channel context that has already been freed.
1028          */
1029         conf = rcu_dereference_protected(link_conf->chanctx_conf,
1030                                          lockdep_is_held(&local->chanctx_mtx));
1031         WARN_ON(!conf);
1032
1033         if (clear)
1034                 conf = NULL;
1035
1036         rcu_read_lock();
1037         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
1038                 struct ieee80211_bss_conf *vlan_conf;
1039
1040                 vlan_conf = rcu_dereference(vlan->vif.link_conf[link_id]);
1041                 if (WARN_ON(!vlan_conf))
1042                         continue;
1043
1044                 rcu_assign_pointer(vlan_conf->chanctx_conf, conf);
1045         }
1046         rcu_read_unlock();
1047 }
1048
1049 void ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,
1050                                           bool clear)
1051 {
1052         struct ieee80211_local *local = link->sdata->local;
1053
1054         mutex_lock(&local->chanctx_mtx);
1055
1056         __ieee80211_link_copy_chanctx_to_vlans(link, clear);
1057
1058         mutex_unlock(&local->chanctx_mtx);
1059 }
1060
1061 int ieee80211_link_unreserve_chanctx(struct ieee80211_link_data *link)
1062 {
1063         struct ieee80211_sub_if_data *sdata = link->sdata;
1064         struct ieee80211_chanctx *ctx = link->reserved_chanctx;
1065
1066         lockdep_assert_held(&sdata->local->chanctx_mtx);
1067
1068         if (WARN_ON(!ctx))
1069                 return -EINVAL;
1070
1071         list_del(&link->reserved_chanctx_list);
1072         link->reserved_chanctx = NULL;
1073
1074         if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
1075                 if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1076                         if (WARN_ON(!ctx->replace_ctx))
1077                                 return -EINVAL;
1078
1079                         WARN_ON(ctx->replace_ctx->replace_state !=
1080                                 IEEE80211_CHANCTX_WILL_BE_REPLACED);
1081                         WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
1082
1083                         ctx->replace_ctx->replace_ctx = NULL;
1084                         ctx->replace_ctx->replace_state =
1085                                         IEEE80211_CHANCTX_REPLACE_NONE;
1086
1087                         list_del_rcu(&ctx->list);
1088                         kfree_rcu(ctx, rcu_head);
1089                 } else {
1090                         ieee80211_free_chanctx(sdata->local, ctx);
1091                 }
1092         }
1093
1094         return 0;
1095 }
1096
1097 int ieee80211_link_reserve_chanctx(struct ieee80211_link_data *link,
1098                                    const struct cfg80211_chan_def *chandef,
1099                                    enum ieee80211_chanctx_mode mode,
1100                                    bool radar_required)
1101 {
1102         struct ieee80211_sub_if_data *sdata = link->sdata;
1103         struct ieee80211_local *local = sdata->local;
1104         struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
1105
1106         lockdep_assert_held(&local->chanctx_mtx);
1107
1108         curr_ctx = ieee80211_link_get_chanctx(link);
1109         if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
1110                 return -ENOTSUPP;
1111
1112         new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
1113         if (!new_ctx) {
1114                 if (ieee80211_can_create_new_chanctx(local)) {
1115                         new_ctx = ieee80211_new_chanctx(local, chandef, mode);
1116                         if (IS_ERR(new_ctx))
1117                                 return PTR_ERR(new_ctx);
1118                 } else {
1119                         if (!curr_ctx ||
1120                             (curr_ctx->replace_state ==
1121                              IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1122                             !list_empty(&curr_ctx->reserved_links)) {
1123                                 /*
1124                                  * Another link already requested this context
1125                                  * for a reservation. Find another one hoping
1126                                  * all links assigned to it will also switch
1127                                  * soon enough.
1128                                  *
1129                                  * TODO: This needs a little more work as some
1130                                  * cases (more than 2 chanctx capable devices)
1131                                  * may fail which could otherwise succeed
1132                                  * provided some channel context juggling was
1133                                  * performed.
1134                                  *
1135                                  * Consider ctx1..3, link1..6, each ctx has 2
1136                                  * links. link1 and link2 from ctx1 request new
1137                                  * different chandefs starting 2 in-place
1138                                  * reserations with ctx4 and ctx5 replacing
1139                                  * ctx1 and ctx2 respectively. Next link5 and
1140                                  * link6 from ctx3 reserve ctx4. If link3 and
1141                                  * link4 remain on ctx2 as they are then this
1142                                  * fails unless `replace_ctx` from ctx5 is
1143                                  * replaced with ctx3.
1144                                  */
1145                                 list_for_each_entry(ctx, &local->chanctx_list,
1146                                                     list) {
1147                                         if (ctx->replace_state !=
1148                                             IEEE80211_CHANCTX_REPLACE_NONE)
1149                                                 continue;
1150
1151                                         if (!list_empty(&ctx->reserved_links))
1152                                                 continue;
1153
1154                                         curr_ctx = ctx;
1155                                         break;
1156                                 }
1157                         }
1158
1159                         /*
1160                          * If that's true then all available contexts already
1161                          * have reservations and cannot be used.
1162                          */
1163                         if (!curr_ctx ||
1164                             (curr_ctx->replace_state ==
1165                              IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1166                             !list_empty(&curr_ctx->reserved_links))
1167                                 return -EBUSY;
1168
1169                         new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
1170                         if (!new_ctx)
1171                                 return -ENOMEM;
1172
1173                         new_ctx->replace_ctx = curr_ctx;
1174                         new_ctx->replace_state =
1175                                         IEEE80211_CHANCTX_REPLACES_OTHER;
1176
1177                         curr_ctx->replace_ctx = new_ctx;
1178                         curr_ctx->replace_state =
1179                                         IEEE80211_CHANCTX_WILL_BE_REPLACED;
1180
1181                         list_add_rcu(&new_ctx->list, &local->chanctx_list);
1182                 }
1183         }
1184
1185         list_add(&link->reserved_chanctx_list, &new_ctx->reserved_links);
1186         link->reserved_chanctx = new_ctx;
1187         link->reserved_chandef = *chandef;
1188         link->reserved_radar_required = radar_required;
1189         link->reserved_ready = false;
1190
1191         return 0;
1192 }
1193
1194 static void
1195 ieee80211_link_chanctx_reservation_complete(struct ieee80211_link_data *link)
1196 {
1197         struct ieee80211_sub_if_data *sdata = link->sdata;
1198
1199         switch (sdata->vif.type) {
1200         case NL80211_IFTYPE_ADHOC:
1201         case NL80211_IFTYPE_AP:
1202         case NL80211_IFTYPE_MESH_POINT:
1203         case NL80211_IFTYPE_OCB:
1204                 ieee80211_queue_work(&sdata->local->hw,
1205                                      &link->csa_finalize_work);
1206                 break;
1207         case NL80211_IFTYPE_STATION:
1208                 ieee80211_queue_work(&sdata->local->hw,
1209                                      &link->u.mgd.chswitch_work);
1210                 break;
1211         case NL80211_IFTYPE_UNSPECIFIED:
1212         case NL80211_IFTYPE_AP_VLAN:
1213         case NL80211_IFTYPE_WDS:
1214         case NL80211_IFTYPE_MONITOR:
1215         case NL80211_IFTYPE_P2P_CLIENT:
1216         case NL80211_IFTYPE_P2P_GO:
1217         case NL80211_IFTYPE_P2P_DEVICE:
1218         case NL80211_IFTYPE_NAN:
1219         case NUM_NL80211_IFTYPES:
1220                 WARN_ON(1);
1221                 break;
1222         }
1223 }
1224
1225 static void
1226 ieee80211_link_update_chandef(struct ieee80211_link_data *link,
1227                               const struct cfg80211_chan_def *chandef)
1228 {
1229         struct ieee80211_sub_if_data *sdata = link->sdata;
1230         unsigned int link_id = link->link_id;
1231         struct ieee80211_sub_if_data *vlan;
1232
1233         link->conf->chandef = *chandef;
1234
1235         if (sdata->vif.type != NL80211_IFTYPE_AP)
1236                 return;
1237
1238         rcu_read_lock();
1239         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
1240                 struct ieee80211_bss_conf *vlan_conf;
1241
1242                 vlan_conf = rcu_dereference(vlan->vif.link_conf[link_id]);
1243                 if (WARN_ON(!vlan_conf))
1244                         continue;
1245
1246                 vlan_conf->chandef = *chandef;
1247         }
1248         rcu_read_unlock();
1249 }
1250
1251 static int
1252 ieee80211_link_use_reserved_reassign(struct ieee80211_link_data *link)
1253 {
1254         struct ieee80211_sub_if_data *sdata = link->sdata;
1255         struct ieee80211_bss_conf *link_conf = link->conf;
1256         struct ieee80211_local *local = sdata->local;
1257         struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1258         struct ieee80211_chanctx *old_ctx, *new_ctx;
1259         const struct cfg80211_chan_def *chandef;
1260         u32 changed = 0;
1261         int err;
1262
1263         lockdep_assert_held(&local->mtx);
1264         lockdep_assert_held(&local->chanctx_mtx);
1265
1266         new_ctx = link->reserved_chanctx;
1267         old_ctx = ieee80211_link_get_chanctx(link);
1268
1269         if (WARN_ON(!link->reserved_ready))
1270                 return -EBUSY;
1271
1272         if (WARN_ON(!new_ctx))
1273                 return -EINVAL;
1274
1275         if (WARN_ON(!old_ctx))
1276                 return -EINVAL;
1277
1278         if (WARN_ON(new_ctx->replace_state ==
1279                     IEEE80211_CHANCTX_REPLACES_OTHER))
1280                 return -EINVAL;
1281
1282         chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1283                                 &link->reserved_chandef);
1284         if (WARN_ON(!chandef))
1285                 return -EINVAL;
1286
1287         if (link_conf->chandef.width != link->reserved_chandef.width)
1288                 changed = BSS_CHANGED_BANDWIDTH;
1289
1290         ieee80211_link_update_chandef(link, &link->reserved_chandef);
1291
1292         _ieee80211_change_chanctx(local, new_ctx, old_ctx, chandef, link);
1293
1294         vif_chsw[0].vif = &sdata->vif;
1295         vif_chsw[0].old_ctx = &old_ctx->conf;
1296         vif_chsw[0].new_ctx = &new_ctx->conf;
1297         vif_chsw[0].link_conf = link->conf;
1298
1299         list_del(&link->reserved_chanctx_list);
1300         link->reserved_chanctx = NULL;
1301
1302         err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1303                                      CHANCTX_SWMODE_REASSIGN_VIF);
1304         if (err) {
1305                 if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1306                         ieee80211_free_chanctx(local, new_ctx);
1307
1308                 goto out;
1309         }
1310
1311         list_move(&link->assigned_chanctx_list, &new_ctx->assigned_links);
1312         rcu_assign_pointer(link_conf->chanctx_conf, &new_ctx->conf);
1313
1314         if (sdata->vif.type == NL80211_IFTYPE_AP)
1315                 __ieee80211_link_copy_chanctx_to_vlans(link, false);
1316
1317         ieee80211_check_fast_xmit_iface(sdata);
1318
1319         if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1320                 ieee80211_free_chanctx(local, old_ctx);
1321
1322         ieee80211_recalc_chanctx_min_def(local, new_ctx, NULL);
1323         ieee80211_recalc_smps_chanctx(local, new_ctx);
1324         ieee80211_recalc_radar_chanctx(local, new_ctx);
1325
1326         if (changed)
1327                 ieee80211_link_info_change_notify(sdata, link, changed);
1328
1329 out:
1330         ieee80211_link_chanctx_reservation_complete(link);
1331         return err;
1332 }
1333
1334 static int
1335 ieee80211_link_use_reserved_assign(struct ieee80211_link_data *link)
1336 {
1337         struct ieee80211_sub_if_data *sdata = link->sdata;
1338         struct ieee80211_local *local = sdata->local;
1339         struct ieee80211_chanctx *old_ctx, *new_ctx;
1340         const struct cfg80211_chan_def *chandef;
1341         int err;
1342
1343         old_ctx = ieee80211_link_get_chanctx(link);
1344         new_ctx = link->reserved_chanctx;
1345
1346         if (WARN_ON(!link->reserved_ready))
1347                 return -EINVAL;
1348
1349         if (WARN_ON(old_ctx))
1350                 return -EINVAL;
1351
1352         if (WARN_ON(!new_ctx))
1353                 return -EINVAL;
1354
1355         if (WARN_ON(new_ctx->replace_state ==
1356                     IEEE80211_CHANCTX_REPLACES_OTHER))
1357                 return -EINVAL;
1358
1359         chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1360                                 &link->reserved_chandef);
1361         if (WARN_ON(!chandef))
1362                 return -EINVAL;
1363
1364         ieee80211_change_chanctx(local, new_ctx, new_ctx, chandef);
1365
1366         list_del(&link->reserved_chanctx_list);
1367         link->reserved_chanctx = NULL;
1368
1369         err = ieee80211_assign_link_chanctx(link, new_ctx);
1370         if (err) {
1371                 if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1372                         ieee80211_free_chanctx(local, new_ctx);
1373
1374                 goto out;
1375         }
1376
1377 out:
1378         ieee80211_link_chanctx_reservation_complete(link);
1379         return err;
1380 }
1381
1382 static bool
1383 ieee80211_link_has_in_place_reservation(struct ieee80211_link_data *link)
1384 {
1385         struct ieee80211_sub_if_data *sdata = link->sdata;
1386         struct ieee80211_chanctx *old_ctx, *new_ctx;
1387
1388         lockdep_assert_held(&sdata->local->chanctx_mtx);
1389
1390         new_ctx = link->reserved_chanctx;
1391         old_ctx = ieee80211_link_get_chanctx(link);
1392
1393         if (!old_ctx)
1394                 return false;
1395
1396         if (WARN_ON(!new_ctx))
1397                 return false;
1398
1399         if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1400                 return false;
1401
1402         if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1403                 return false;
1404
1405         return true;
1406 }
1407
1408 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1409                                         struct ieee80211_chanctx *new_ctx)
1410 {
1411         const struct cfg80211_chan_def *chandef;
1412
1413         lockdep_assert_held(&local->mtx);
1414         lockdep_assert_held(&local->chanctx_mtx);
1415
1416         chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1417         if (WARN_ON(!chandef))
1418                 return -EINVAL;
1419
1420         local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1421         local->_oper_chandef = *chandef;
1422         ieee80211_hw_config(local, 0);
1423
1424         return 0;
1425 }
1426
1427 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1428                                       int n_vifs)
1429 {
1430         struct ieee80211_vif_chanctx_switch *vif_chsw;
1431         struct ieee80211_link_data *link;
1432         struct ieee80211_chanctx *ctx, *old_ctx;
1433         int i, err;
1434
1435         lockdep_assert_held(&local->mtx);
1436         lockdep_assert_held(&local->chanctx_mtx);
1437
1438         vif_chsw = kcalloc(n_vifs, sizeof(vif_chsw[0]), GFP_KERNEL);
1439         if (!vif_chsw)
1440                 return -ENOMEM;
1441
1442         i = 0;
1443         list_for_each_entry(ctx, &local->chanctx_list, list) {
1444                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1445                         continue;
1446
1447                 if (WARN_ON(!ctx->replace_ctx)) {
1448                         err = -EINVAL;
1449                         goto out;
1450                 }
1451
1452                 list_for_each_entry(link, &ctx->reserved_links,
1453                                     reserved_chanctx_list) {
1454                         if (!ieee80211_link_has_in_place_reservation(link))
1455                                 continue;
1456
1457                         old_ctx = ieee80211_link_get_chanctx(link);
1458                         vif_chsw[i].vif = &link->sdata->vif;
1459                         vif_chsw[i].old_ctx = &old_ctx->conf;
1460                         vif_chsw[i].new_ctx = &ctx->conf;
1461                         vif_chsw[i].link_conf = link->conf;
1462
1463                         i++;
1464                 }
1465         }
1466
1467         err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1468                                      CHANCTX_SWMODE_SWAP_CONTEXTS);
1469
1470 out:
1471         kfree(vif_chsw);
1472         return err;
1473 }
1474
1475 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1476 {
1477         struct ieee80211_chanctx *ctx;
1478         int err;
1479
1480         lockdep_assert_held(&local->mtx);
1481         lockdep_assert_held(&local->chanctx_mtx);
1482
1483         list_for_each_entry(ctx, &local->chanctx_list, list) {
1484                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1485                         continue;
1486
1487                 if (!list_empty(&ctx->replace_ctx->assigned_links))
1488                         continue;
1489
1490                 ieee80211_del_chanctx(local, ctx->replace_ctx);
1491                 err = ieee80211_add_chanctx(local, ctx);
1492                 if (err)
1493                         goto err;
1494         }
1495
1496         return 0;
1497
1498 err:
1499         WARN_ON(ieee80211_add_chanctx(local, ctx));
1500         list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1501                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1502                         continue;
1503
1504                 if (!list_empty(&ctx->replace_ctx->assigned_links))
1505                         continue;
1506
1507                 ieee80211_del_chanctx(local, ctx);
1508                 WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1509         }
1510
1511         return err;
1512 }
1513
1514 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1515 {
1516         struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1517         struct ieee80211_chanctx *new_ctx = NULL;
1518         int err, n_assigned, n_reserved, n_ready;
1519         int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1520
1521         lockdep_assert_held(&local->mtx);
1522         lockdep_assert_held(&local->chanctx_mtx);
1523
1524         /*
1525          * If there are 2 independent pairs of channel contexts performing
1526          * cross-switch of their vifs this code will still wait until both are
1527          * ready even though it could be possible to switch one before the
1528          * other is ready.
1529          *
1530          * For practical reasons and code simplicity just do a single huge
1531          * switch.
1532          */
1533
1534         /*
1535          * Verify if the reservation is still feasible.
1536          *  - if it's not then disconnect
1537          *  - if it is but not all vifs necessary are ready then defer
1538          */
1539
1540         list_for_each_entry(ctx, &local->chanctx_list, list) {
1541                 struct ieee80211_link_data *link;
1542
1543                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1544                         continue;
1545
1546                 if (WARN_ON(!ctx->replace_ctx)) {
1547                         err = -EINVAL;
1548                         goto err;
1549                 }
1550
1551                 if (!local->use_chanctx)
1552                         new_ctx = ctx;
1553
1554                 n_ctx++;
1555
1556                 n_assigned = 0;
1557                 n_reserved = 0;
1558                 n_ready = 0;
1559
1560                 list_for_each_entry(link, &ctx->replace_ctx->assigned_links,
1561                                     assigned_chanctx_list) {
1562                         n_assigned++;
1563                         if (link->reserved_chanctx) {
1564                                 n_reserved++;
1565                                 if (link->reserved_ready)
1566                                         n_ready++;
1567                         }
1568                 }
1569
1570                 if (n_assigned != n_reserved) {
1571                         if (n_ready == n_reserved) {
1572                                 wiphy_info(local->hw.wiphy,
1573                                            "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1574                                 err = -EBUSY;
1575                                 goto err;
1576                         }
1577
1578                         return -EAGAIN;
1579                 }
1580
1581                 ctx->conf.radar_enabled = false;
1582                 list_for_each_entry(link, &ctx->reserved_links,
1583                                     reserved_chanctx_list) {
1584                         if (ieee80211_link_has_in_place_reservation(link) &&
1585                             !link->reserved_ready)
1586                                 return -EAGAIN;
1587
1588                         old_ctx = ieee80211_link_get_chanctx(link);
1589                         if (old_ctx) {
1590                                 if (old_ctx->replace_state ==
1591                                     IEEE80211_CHANCTX_WILL_BE_REPLACED)
1592                                         n_vifs_switch++;
1593                                 else
1594                                         n_vifs_assign++;
1595                         } else {
1596                                 n_vifs_ctxless++;
1597                         }
1598
1599                         if (link->reserved_radar_required)
1600                                 ctx->conf.radar_enabled = true;
1601                 }
1602         }
1603
1604         if (WARN_ON(n_ctx == 0) ||
1605             WARN_ON(n_vifs_switch == 0 &&
1606                     n_vifs_assign == 0 &&
1607                     n_vifs_ctxless == 0) ||
1608             WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1609             WARN_ON(!new_ctx && !local->use_chanctx)) {
1610                 err = -EINVAL;
1611                 goto err;
1612         }
1613
1614         /*
1615          * All necessary vifs are ready. Perform the switch now depending on
1616          * reservations and driver capabilities.
1617          */
1618
1619         if (local->use_chanctx) {
1620                 if (n_vifs_switch > 0) {
1621                         err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1622                         if (err)
1623                                 goto err;
1624                 }
1625
1626                 if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1627                         err = ieee80211_chsw_switch_ctxs(local);
1628                         if (err)
1629                                 goto err;
1630                 }
1631         } else {
1632                 err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1633                 if (err)
1634                         goto err;
1635         }
1636
1637         /*
1638          * Update all structures, values and pointers to point to new channel
1639          * context(s).
1640          */
1641         list_for_each_entry(ctx, &local->chanctx_list, list) {
1642                 struct ieee80211_link_data *link, *link_tmp;
1643
1644                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1645                         continue;
1646
1647                 if (WARN_ON(!ctx->replace_ctx)) {
1648                         err = -EINVAL;
1649                         goto err;
1650                 }
1651
1652                 list_for_each_entry(link, &ctx->reserved_links,
1653                                     reserved_chanctx_list) {
1654                         struct ieee80211_sub_if_data *sdata = link->sdata;
1655                         struct ieee80211_bss_conf *link_conf = link->conf;
1656                         u32 changed = 0;
1657
1658                         if (!ieee80211_link_has_in_place_reservation(link))
1659                                 continue;
1660
1661                         rcu_assign_pointer(link_conf->chanctx_conf,
1662                                            &ctx->conf);
1663
1664                         if (sdata->vif.type == NL80211_IFTYPE_AP)
1665                                 __ieee80211_link_copy_chanctx_to_vlans(link,
1666                                                                        false);
1667
1668                         ieee80211_check_fast_xmit_iface(sdata);
1669
1670                         link->radar_required = link->reserved_radar_required;
1671
1672                         if (link_conf->chandef.width != link->reserved_chandef.width)
1673                                 changed = BSS_CHANGED_BANDWIDTH;
1674
1675                         ieee80211_link_update_chandef(link, &link->reserved_chandef);
1676                         if (changed)
1677                                 ieee80211_link_info_change_notify(sdata,
1678                                                                   link,
1679                                                                   changed);
1680
1681                         ieee80211_recalc_txpower(sdata, false);
1682                 }
1683
1684                 ieee80211_recalc_chanctx_chantype(local, ctx);
1685                 ieee80211_recalc_smps_chanctx(local, ctx);
1686                 ieee80211_recalc_radar_chanctx(local, ctx);
1687                 ieee80211_recalc_chanctx_min_def(local, ctx, NULL);
1688
1689                 list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1690                                          reserved_chanctx_list) {
1691                         if (ieee80211_link_get_chanctx(link) != ctx)
1692                                 continue;
1693
1694                         list_del(&link->reserved_chanctx_list);
1695                         list_move(&link->assigned_chanctx_list,
1696                                   &ctx->assigned_links);
1697                         link->reserved_chanctx = NULL;
1698
1699                         ieee80211_link_chanctx_reservation_complete(link);
1700                 }
1701
1702                 /*
1703                  * This context might have been a dependency for an already
1704                  * ready re-assign reservation interface that was deferred. Do
1705                  * not propagate error to the caller though. The in-place
1706                  * reservation for originally requested interface has already
1707                  * succeeded at this point.
1708                  */
1709                 list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1710                                          reserved_chanctx_list) {
1711                         if (WARN_ON(ieee80211_link_has_in_place_reservation(link)))
1712                                 continue;
1713
1714                         if (WARN_ON(link->reserved_chanctx != ctx))
1715                                 continue;
1716
1717                         if (!link->reserved_ready)
1718                                 continue;
1719
1720                         if (ieee80211_link_get_chanctx(link))
1721                                 err = ieee80211_link_use_reserved_reassign(link);
1722                         else
1723                                 err = ieee80211_link_use_reserved_assign(link);
1724
1725                         if (err) {
1726                                 link_info(link,
1727                                           "failed to finalize (re-)assign reservation (err=%d)\n",
1728                                           err);
1729                                 ieee80211_link_unreserve_chanctx(link);
1730                                 cfg80211_stop_iface(local->hw.wiphy,
1731                                                     &link->sdata->wdev,
1732                                                     GFP_KERNEL);
1733                         }
1734                 }
1735         }
1736
1737         /*
1738          * Finally free old contexts
1739          */
1740
1741         list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1742                 if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1743                         continue;
1744
1745                 ctx->replace_ctx->replace_ctx = NULL;
1746                 ctx->replace_ctx->replace_state =
1747                                 IEEE80211_CHANCTX_REPLACE_NONE;
1748
1749                 list_del_rcu(&ctx->list);
1750                 kfree_rcu(ctx, rcu_head);
1751         }
1752
1753         return 0;
1754
1755 err:
1756         list_for_each_entry(ctx, &local->chanctx_list, list) {
1757                 struct ieee80211_link_data *link, *link_tmp;
1758
1759                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1760                         continue;
1761
1762                 list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1763                                          reserved_chanctx_list) {
1764                         ieee80211_link_unreserve_chanctx(link);
1765                         ieee80211_link_chanctx_reservation_complete(link);
1766                 }
1767         }
1768
1769         return err;
1770 }
1771
1772 static void __ieee80211_link_release_channel(struct ieee80211_link_data *link)
1773 {
1774         struct ieee80211_sub_if_data *sdata = link->sdata;
1775         struct ieee80211_bss_conf *link_conf = link->conf;
1776         struct ieee80211_local *local = sdata->local;
1777         struct ieee80211_chanctx_conf *conf;
1778         struct ieee80211_chanctx *ctx;
1779         bool use_reserved_switch = false;
1780
1781         lockdep_assert_held(&local->chanctx_mtx);
1782
1783         conf = rcu_dereference_protected(link_conf->chanctx_conf,
1784                                          lockdep_is_held(&local->chanctx_mtx));
1785         if (!conf)
1786                 return;
1787
1788         ctx = container_of(conf, struct ieee80211_chanctx, conf);
1789
1790         if (link->reserved_chanctx) {
1791                 if (link->reserved_chanctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER &&
1792                     ieee80211_chanctx_num_reserved(local, link->reserved_chanctx) > 1)
1793                         use_reserved_switch = true;
1794
1795                 ieee80211_link_unreserve_chanctx(link);
1796         }
1797
1798         ieee80211_assign_link_chanctx(link, NULL);
1799         if (ieee80211_chanctx_refcount(local, ctx) == 0)
1800                 ieee80211_free_chanctx(local, ctx);
1801
1802         link->radar_required = false;
1803
1804         /* Unreserving may ready an in-place reservation. */
1805         if (use_reserved_switch)
1806                 ieee80211_vif_use_reserved_switch(local);
1807 }
1808
1809 int ieee80211_link_use_channel(struct ieee80211_link_data *link,
1810                                const struct cfg80211_chan_def *chandef,
1811                                enum ieee80211_chanctx_mode mode)
1812 {
1813         struct ieee80211_sub_if_data *sdata = link->sdata;
1814         struct ieee80211_local *local = sdata->local;
1815         struct ieee80211_chanctx *ctx;
1816         u8 radar_detect_width = 0;
1817         int ret;
1818
1819         lockdep_assert_held(&local->mtx);
1820
1821         if (sdata->vif.active_links &&
1822             !(sdata->vif.active_links & BIT(link->link_id))) {
1823                 ieee80211_link_update_chandef(link, chandef);
1824                 return 0;
1825         }
1826
1827         mutex_lock(&local->chanctx_mtx);
1828
1829         ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1830                                             chandef,
1831                                             sdata->wdev.iftype);
1832         if (ret < 0)
1833                 goto out;
1834         if (ret > 0)
1835                 radar_detect_width = BIT(chandef->width);
1836
1837         link->radar_required = ret;
1838
1839         ret = ieee80211_check_combinations(sdata, chandef, mode,
1840                                            radar_detect_width);
1841         if (ret < 0)
1842                 goto out;
1843
1844         __ieee80211_link_release_channel(link);
1845
1846         ctx = ieee80211_find_chanctx(local, chandef, mode);
1847         if (!ctx)
1848                 ctx = ieee80211_new_chanctx(local, chandef, mode);
1849         if (IS_ERR(ctx)) {
1850                 ret = PTR_ERR(ctx);
1851                 goto out;
1852         }
1853
1854         ieee80211_link_update_chandef(link, chandef);
1855
1856         ret = ieee80211_assign_link_chanctx(link, ctx);
1857         if (ret) {
1858                 /* if assign fails refcount stays the same */
1859                 if (ieee80211_chanctx_refcount(local, ctx) == 0)
1860                         ieee80211_free_chanctx(local, ctx);
1861                 goto out;
1862         }
1863
1864         ieee80211_recalc_smps_chanctx(local, ctx);
1865         ieee80211_recalc_radar_chanctx(local, ctx);
1866  out:
1867         if (ret)
1868                 link->radar_required = false;
1869
1870         mutex_unlock(&local->chanctx_mtx);
1871         return ret;
1872 }
1873
1874 int ieee80211_link_use_reserved_context(struct ieee80211_link_data *link)
1875 {
1876         struct ieee80211_sub_if_data *sdata = link->sdata;
1877         struct ieee80211_local *local = sdata->local;
1878         struct ieee80211_chanctx *new_ctx;
1879         struct ieee80211_chanctx *old_ctx;
1880         int err;
1881
1882         lockdep_assert_held(&local->mtx);
1883         lockdep_assert_held(&local->chanctx_mtx);
1884
1885         new_ctx = link->reserved_chanctx;
1886         old_ctx = ieee80211_link_get_chanctx(link);
1887
1888         if (WARN_ON(!new_ctx))
1889                 return -EINVAL;
1890
1891         if (WARN_ON(new_ctx->replace_state ==
1892                     IEEE80211_CHANCTX_WILL_BE_REPLACED))
1893                 return -EINVAL;
1894
1895         if (WARN_ON(link->reserved_ready))
1896                 return -EINVAL;
1897
1898         link->reserved_ready = true;
1899
1900         if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1901                 if (old_ctx)
1902                         return ieee80211_link_use_reserved_reassign(link);
1903
1904                 return ieee80211_link_use_reserved_assign(link);
1905         }
1906
1907         /*
1908          * In-place reservation may need to be finalized now either if:
1909          *  a) sdata is taking part in the swapping itself and is the last one
1910          *  b) sdata has switched with a re-assign reservation to an existing
1911          *     context readying in-place switching of old_ctx
1912          *
1913          * In case of (b) do not propagate the error up because the requested
1914          * sdata already switched successfully. Just spill an extra warning.
1915          * The ieee80211_vif_use_reserved_switch() already stops all necessary
1916          * interfaces upon failure.
1917          */
1918         if ((old_ctx &&
1919              old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1920             new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1921                 err = ieee80211_vif_use_reserved_switch(local);
1922                 if (err && err != -EAGAIN) {
1923                         if (new_ctx->replace_state ==
1924                             IEEE80211_CHANCTX_REPLACES_OTHER)
1925                                 return err;
1926
1927                         wiphy_info(local->hw.wiphy,
1928                                    "depending in-place reservation failed (err=%d)\n",
1929                                    err);
1930                 }
1931         }
1932
1933         return 0;
1934 }
1935
1936 int ieee80211_link_change_bandwidth(struct ieee80211_link_data *link,
1937                                     const struct cfg80211_chan_def *chandef,
1938                                     u32 *changed)
1939 {
1940         struct ieee80211_sub_if_data *sdata = link->sdata;
1941         struct ieee80211_bss_conf *link_conf = link->conf;
1942         struct ieee80211_local *local = sdata->local;
1943         struct ieee80211_chanctx_conf *conf;
1944         struct ieee80211_chanctx *ctx;
1945         const struct cfg80211_chan_def *compat;
1946         int ret;
1947
1948         if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1949                                      IEEE80211_CHAN_DISABLED))
1950                 return -EINVAL;
1951
1952         mutex_lock(&local->chanctx_mtx);
1953         if (cfg80211_chandef_identical(chandef, &link_conf->chandef)) {
1954                 ret = 0;
1955                 goto out;
1956         }
1957
1958         if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1959             link_conf->chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1960                 ret = -EINVAL;
1961                 goto out;
1962         }
1963
1964         conf = rcu_dereference_protected(link_conf->chanctx_conf,
1965                                          lockdep_is_held(&local->chanctx_mtx));
1966         if (!conf) {
1967                 ret = -EINVAL;
1968                 goto out;
1969         }
1970
1971         ctx = container_of(conf, struct ieee80211_chanctx, conf);
1972
1973         compat = cfg80211_chandef_compatible(&conf->def, chandef);
1974         if (!compat) {
1975                 ret = -EINVAL;
1976                 goto out;
1977         }
1978
1979         switch (ctx->replace_state) {
1980         case IEEE80211_CHANCTX_REPLACE_NONE:
1981                 if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1982                         ret = -EBUSY;
1983                         goto out;
1984                 }
1985                 break;
1986         case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1987                 /* TODO: Perhaps the bandwidth change could be treated as a
1988                  * reservation itself? */
1989                 ret = -EBUSY;
1990                 goto out;
1991         case IEEE80211_CHANCTX_REPLACES_OTHER:
1992                 /* channel context that is going to replace another channel
1993                  * context doesn't really exist and shouldn't be assigned
1994                  * anywhere yet */
1995                 WARN_ON(1);
1996                 break;
1997         }
1998
1999         ieee80211_link_update_chandef(link, chandef);
2000
2001         ieee80211_recalc_chanctx_chantype(local, ctx);
2002
2003         *changed |= BSS_CHANGED_BANDWIDTH;
2004         ret = 0;
2005  out:
2006         mutex_unlock(&local->chanctx_mtx);
2007         return ret;
2008 }
2009
2010 void ieee80211_link_release_channel(struct ieee80211_link_data *link)
2011 {
2012         struct ieee80211_sub_if_data *sdata = link->sdata;
2013
2014         mutex_lock(&sdata->local->chanctx_mtx);
2015         if (rcu_access_pointer(link->conf->chanctx_conf)) {
2016                 lockdep_assert_held(&sdata->local->mtx);
2017                 __ieee80211_link_release_channel(link);
2018         }
2019         mutex_unlock(&sdata->local->chanctx_mtx);
2020 }
2021
2022 void ieee80211_link_vlan_copy_chanctx(struct ieee80211_link_data *link)
2023 {
2024         struct ieee80211_sub_if_data *sdata = link->sdata;
2025         unsigned int link_id = link->link_id;
2026         struct ieee80211_bss_conf *link_conf = link->conf;
2027         struct ieee80211_bss_conf *ap_conf;
2028         struct ieee80211_local *local = sdata->local;
2029         struct ieee80211_sub_if_data *ap;
2030         struct ieee80211_chanctx_conf *conf;
2031
2032         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
2033                 return;
2034
2035         ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
2036
2037         mutex_lock(&local->chanctx_mtx);
2038
2039         rcu_read_lock();
2040         ap_conf = rcu_dereference(ap->vif.link_conf[link_id]);
2041         conf = rcu_dereference_protected(ap_conf->chanctx_conf,
2042                                          lockdep_is_held(&local->chanctx_mtx));
2043         rcu_assign_pointer(link_conf->chanctx_conf, conf);
2044         rcu_read_unlock();
2045         mutex_unlock(&local->chanctx_mtx);
2046 }
2047
2048 void ieee80211_iter_chan_contexts_atomic(
2049         struct ieee80211_hw *hw,
2050         void (*iter)(struct ieee80211_hw *hw,
2051                      struct ieee80211_chanctx_conf *chanctx_conf,
2052                      void *data),
2053         void *iter_data)
2054 {
2055         struct ieee80211_local *local = hw_to_local(hw);
2056         struct ieee80211_chanctx *ctx;
2057
2058         rcu_read_lock();
2059         list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
2060                 if (ctx->driver_present)
2061                         iter(hw, &ctx->conf, iter_data);
2062         rcu_read_unlock();
2063 }
2064 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);