net/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         if (WARN_ON_ONCE(!compat)) {
 806                 rcu_read_unlock();
 807                 return;
 808         }
 809
 810         /* TDLS peers can sometimes affect the chandef width */
 811         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 812                 if (!sta->uploaded ||
 813                     !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
 814                     !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
 815                     !sta->tdls_chandef.chan)
 816                         continue;
 817
 818                 compat = cfg80211_chandef_compatible(&sta->tdls_chandef,
 819                                                      compat);
 820                 if (WARN_ON_ONCE(!compat))
 821                         break;
 822         }
 823         rcu_read_unlock();
 824
 825         if (!compat)
 826                 return;
 827
 828         ieee80211_change_chanctx(local, ctx, ctx, compat);
 829 }
 830
 831 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
 832                                            struct ieee80211_chanctx *chanctx)
 833 {
 834         bool radar_enabled;
 835
 836         lockdep_assert_held(&local->chanctx_mtx);
 837         /* for ieee80211_is_radar_required */
 838         lockdep_assert_held(&local->mtx);
 839
 840         radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
 841
 842         if (radar_enabled == chanctx->conf.radar_enabled)
 843                 return;
 844
 845         chanctx->conf.radar_enabled = radar_enabled;
 846
 847         if (!local->use_chanctx) {
 848                 local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
 849                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 850         }
 851
 852         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
 853 }
 854
 855 static int ieee80211_assign_link_chanctx(struct ieee80211_link_data *link,
 856                                          struct ieee80211_chanctx *new_ctx)
 857 {
 858         struct ieee80211_sub_if_data *sdata = link->sdata;
 859         struct ieee80211_local *local = sdata->local;
 860         struct ieee80211_chanctx_conf *conf;
 861         struct ieee80211_chanctx *curr_ctx = NULL;
 862         int ret = 0;
 863
 864         if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
 865                 return -ENOTSUPP;
 866
 867         conf = rcu_dereference_protected(link->conf->chanctx_conf,
 868                                          lockdep_is_held(&local->chanctx_mtx));
 869
 870         if (conf) {
 871                 curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
 872
 873                 drv_unassign_vif_chanctx(local, sdata, link->conf, curr_ctx);
 874                 conf = NULL;
 875                 list_del(&link->assigned_chanctx_list);
 876         }
 877
 878         if (new_ctx) {
 879                 /* recalc considering the link we'll use it for now */
 880                 ieee80211_recalc_chanctx_min_def(local, new_ctx, link);
 881
 882                 ret = drv_assign_vif_chanctx(local, sdata, link->conf, new_ctx);
 883                 if (ret)
 884                         goto out;
 885
 886                 conf = &new_ctx->conf;
 887                 list_add(&link->assigned_chanctx_list,
 888                          &new_ctx->assigned_links);
 889         }
 890
 891 out:
 892         rcu_assign_pointer(link->conf->chanctx_conf, conf);
 893
 894         sdata->vif.cfg.idle = !conf;
 895
 896         if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
 897                 ieee80211_recalc_chanctx_chantype(local, curr_ctx);
 898                 ieee80211_recalc_smps_chanctx(local, curr_ctx);
 899                 ieee80211_recalc_radar_chanctx(local, curr_ctx);
 900                 ieee80211_recalc_chanctx_min_def(local, curr_ctx, NULL);
 901         }
 902
 903         if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
 904                 ieee80211_recalc_txpower(sdata, false);
 905                 ieee80211_recalc_chanctx_min_def(local, new_ctx, NULL);
 906         }
 907
 908         if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
 909             sdata->vif.type != NL80211_IFTYPE_MONITOR)
 910                 ieee80211_vif_cfg_change_notify(sdata, BSS_CHANGED_IDLE);
 911
 912         ieee80211_check_fast_xmit_iface(sdata);
 913
 914         return ret;
 915 }
 916
 917 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
 918                                    struct ieee80211_chanctx *chanctx)
 919 {
 920         struct ieee80211_sub_if_data *sdata;
 921         u8 rx_chains_static, rx_chains_dynamic;
 922
 923         lockdep_assert_held(&local->chanctx_mtx);
 924
 925         rx_chains_static = 1;
 926         rx_chains_dynamic = 1;
 927
 928         rcu_read_lock();
 929         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 930                 u8 needed_static, needed_dynamic;
 931                 unsigned int link_id;
 932
 933                 if (!ieee80211_sdata_running(sdata))
 934                         continue;
 935
 936                 switch (sdata->vif.type) {
 937                 case NL80211_IFTYPE_STATION:
 938                         if (!sdata->u.mgd.associated)
 939                                 continue;
 940                         break;
 941                 case NL80211_IFTYPE_AP:
 942                 case NL80211_IFTYPE_ADHOC:
 943                 case NL80211_IFTYPE_MESH_POINT:
 944                 case NL80211_IFTYPE_OCB:
 945                         break;
 946                 default:
 947                         continue;
 948                 }
 949
 950                 for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
 951                         struct ieee80211_link_data *link;
 952
 953                         link = rcu_dereference(sdata->link[link_id]);
 954
 955                         if (!link)
 956                                 continue;
 957
 958                         if (rcu_access_pointer(link->conf->chanctx_conf) != &chanctx->conf)
 959                                 continue;
 960
 961                         switch (link->smps_mode) {
 962                         default:
 963                                 WARN_ONCE(1, "Invalid SMPS mode %d\n",
 964                                           link->smps_mode);
 965                                 fallthrough;
 966                         case IEEE80211_SMPS_OFF:
 967                                 needed_static = link->needed_rx_chains;
 968                                 needed_dynamic = link->needed_rx_chains;
 969                                 break;
 970                         case IEEE80211_SMPS_DYNAMIC:
 971                                 needed_static = 1;
 972                                 needed_dynamic = link->needed_rx_chains;
 973                                 break;
 974                         case IEEE80211_SMPS_STATIC:
 975                                 needed_static = 1;
 976                                 needed_dynamic = 1;
 977                                 break;
 978                         }
 979
 980                         rx_chains_static = max(rx_chains_static, needed_static);
 981                         rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
 982                 }
 983         }
 984
 985         /* Disable SMPS for the monitor interface */
 986         sdata = rcu_dereference(local->monitor_sdata);
 987         if (sdata &&
 988             rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == &chanctx->conf)
 989                 rx_chains_dynamic = rx_chains_static = local->rx_chains;
 990
 991         rcu_read_unlock();
 992
 993         if (!local->use_chanctx) {
 994                 if (rx_chains_static > 1)
 995                         local->smps_mode = IEEE80211_SMPS_OFF;
 996                 else if (rx_chains_dynamic > 1)
 997                         local->smps_mode = IEEE80211_SMPS_DYNAMIC;
 998                 else
 999                         local->smps_mode = IEEE80211_SMPS_STATIC;
1000                 ieee80211_hw_config(local, 0);
1001         }
1002
1003         if (rx_chains_static == chanctx->conf.rx_chains_static &&
1004             rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
1005                 return;
1006
1007         chanctx->conf.rx_chains_static = rx_chains_static;
1008         chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
1009         drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
1010 }
1011
1012 static void
1013 __ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,
1014                                        bool clear)
1015 {
1016         struct ieee80211_sub_if_data *sdata = link->sdata;
1017         unsigned int link_id = link->link_id;
1018         struct ieee80211_bss_conf *link_conf = link->conf;
1019         struct ieee80211_local *local __maybe_unused = sdata->local;
1020         struct ieee80211_sub_if_data *vlan;
1021         struct ieee80211_chanctx_conf *conf;
1022
1023         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
1024                 return;
1025
1026         lockdep_assert_held(&local->mtx);
1027
1028         /* Check that conf exists, even when clearing this function
1029          * must be called with the AP's channel context still there
1030          * as it would otherwise cause VLANs to have an invalid
1031          * channel context pointer for a while, possibly pointing
1032          * to a channel context that has already been freed.
1033          */
1034         conf = rcu_dereference_protected(link_conf->chanctx_conf,
1035                                          lockdep_is_held(&local->chanctx_mtx));
1036         WARN_ON(!conf);
1037
1038         if (clear)
1039                 conf = NULL;
1040
1041         rcu_read_lock();
1042         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
1043                 struct ieee80211_bss_conf *vlan_conf;
1044
1045                 vlan_conf = rcu_dereference(vlan->vif.link_conf[link_id]);
1046                 if (WARN_ON(!vlan_conf))
1047                         continue;
1048
1049                 rcu_assign_pointer(vlan_conf->chanctx_conf, conf);
1050         }
1051         rcu_read_unlock();
1052 }
1053
1054 void ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,
1055                                           bool clear)
1056 {
1057         struct ieee80211_local *local = link->sdata->local;
1058
1059         mutex_lock(&local->chanctx_mtx);
1060
1061         __ieee80211_link_copy_chanctx_to_vlans(link, clear);
1062
1063         mutex_unlock(&local->chanctx_mtx);
1064 }
1065
1066 int ieee80211_link_unreserve_chanctx(struct ieee80211_link_data *link)
1067 {
1068         struct ieee80211_sub_if_data *sdata = link->sdata;
1069         struct ieee80211_chanctx *ctx = link->reserved_chanctx;
1070
1071         lockdep_assert_held(&sdata->local->chanctx_mtx);
1072
1073         if (WARN_ON(!ctx))
1074                 return -EINVAL;
1075
1076         list_del(&link->reserved_chanctx_list);
1077         link->reserved_chanctx = NULL;
1078
1079         if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
1080                 if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1081                         if (WARN_ON(!ctx->replace_ctx))
1082                                 return -EINVAL;
1083
1084                         WARN_ON(ctx->replace_ctx->replace_state !=
1085                                 IEEE80211_CHANCTX_WILL_BE_REPLACED);
1086                         WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
1087
1088                         ctx->replace_ctx->replace_ctx = NULL;
1089                         ctx->replace_ctx->replace_state =
1090                                         IEEE80211_CHANCTX_REPLACE_NONE;
1091
1092                         list_del_rcu(&ctx->list);
1093                         kfree_rcu(ctx, rcu_head);
1094                 } else {
1095                         ieee80211_free_chanctx(sdata->local, ctx);
1096                 }
1097         }
1098
1099         return 0;
1100 }
1101
1102 int ieee80211_link_reserve_chanctx(struct ieee80211_link_data *link,
1103                                    const struct cfg80211_chan_def *chandef,
1104                                    enum ieee80211_chanctx_mode mode,
1105                                    bool radar_required)
1106 {
1107         struct ieee80211_sub_if_data *sdata = link->sdata;
1108         struct ieee80211_local *local = sdata->local;
1109         struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
1110
1111         lockdep_assert_held(&local->chanctx_mtx);
1112
1113         curr_ctx = ieee80211_link_get_chanctx(link);
1114         if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
1115                 return -ENOTSUPP;
1116
1117         new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
1118         if (!new_ctx) {
1119                 if (ieee80211_can_create_new_chanctx(local)) {
1120                         new_ctx = ieee80211_new_chanctx(local, chandef, mode);
1121                         if (IS_ERR(new_ctx))
1122                                 return PTR_ERR(new_ctx);
1123                 } else {
1124                         if (!curr_ctx ||
1125                             (curr_ctx->replace_state ==
1126                              IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1127                             !list_empty(&curr_ctx->reserved_links)) {
1128                                 /*
1129                                  * Another link already requested this context
1130                                  * for a reservation. Find another one hoping
1131                                  * all links assigned to it will also switch
1132                                  * soon enough.
1133                                  *
1134                                  * TODO: This needs a little more work as some
1135                                  * cases (more than 2 chanctx capable devices)
1136                                  * may fail which could otherwise succeed
1137                                  * provided some channel context juggling was
1138                                  * performed.
1139                                  *
1140                                  * Consider ctx1..3, link1..6, each ctx has 2
1141                                  * links. link1 and link2 from ctx1 request new
1142                                  * different chandefs starting 2 in-place
1143                                  * reserations with ctx4 and ctx5 replacing
1144                                  * ctx1 and ctx2 respectively. Next link5 and
1145                                  * link6 from ctx3 reserve ctx4. If link3 and
1146                                  * link4 remain on ctx2 as they are then this
1147                                  * fails unless `replace_ctx` from ctx5 is
1148                                  * replaced with ctx3.
1149                                  */
1150                                 list_for_each_entry(ctx, &local->chanctx_list,
1151                                                     list) {
1152                                         if (ctx->replace_state !=
1153                                             IEEE80211_CHANCTX_REPLACE_NONE)
1154                                                 continue;
1155
1156                                         if (!list_empty(&ctx->reserved_links))
1157                                                 continue;
1158
1159                                         curr_ctx = ctx;
1160                                         break;
1161                                 }
1162                         }
1163
1164                         /*
1165                          * If that's true then all available contexts already
1166                          * have reservations and cannot be used.
1167                          */
1168                         if (!curr_ctx ||
1169                             (curr_ctx->replace_state ==
1170                              IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1171                             !list_empty(&curr_ctx->reserved_links))
1172                                 return -EBUSY;
1173
1174                         new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
1175                         if (!new_ctx)
1176                                 return -ENOMEM;
1177
1178                         new_ctx->replace_ctx = curr_ctx;
1179                         new_ctx->replace_state =
1180                                         IEEE80211_CHANCTX_REPLACES_OTHER;
1181
1182                         curr_ctx->replace_ctx = new_ctx;
1183                         curr_ctx->replace_state =
1184                                         IEEE80211_CHANCTX_WILL_BE_REPLACED;
1185
1186                         list_add_rcu(&new_ctx->list, &local->chanctx_list);
1187                 }
1188         }
1189
1190         list_add(&link->reserved_chanctx_list, &new_ctx->reserved_links);
1191         link->reserved_chanctx = new_ctx;
1192         link->reserved_chandef = *chandef;
1193         link->reserved_radar_required = radar_required;
1194         link->reserved_ready = false;
1195
1196         return 0;
1197 }
1198
1199 static void
1200 ieee80211_link_chanctx_reservation_complete(struct ieee80211_link_data *link)
1201 {
1202         struct ieee80211_sub_if_data *sdata = link->sdata;
1203
1204         switch (sdata->vif.type) {
1205         case NL80211_IFTYPE_ADHOC:
1206         case NL80211_IFTYPE_AP:
1207         case NL80211_IFTYPE_MESH_POINT:
1208         case NL80211_IFTYPE_OCB:
1209                 ieee80211_queue_work(&sdata->local->hw,
1210                                      &link->csa_finalize_work);
1211                 break;
1212         case NL80211_IFTYPE_STATION:
1213                 wiphy_delayed_work_queue(sdata->local->hw.wiphy,
1214                                          &link->u.mgd.chswitch_work, 0);
1215                 break;
1216         case NL80211_IFTYPE_UNSPECIFIED:
1217         case NL80211_IFTYPE_AP_VLAN:
1218         case NL80211_IFTYPE_WDS:
1219         case NL80211_IFTYPE_MONITOR:
1220         case NL80211_IFTYPE_P2P_CLIENT:
1221         case NL80211_IFTYPE_P2P_GO:
1222         case NL80211_IFTYPE_P2P_DEVICE:
1223         case NL80211_IFTYPE_NAN:
1224         case NUM_NL80211_IFTYPES:
1225                 WARN_ON(1);
1226                 break;
1227         }
1228 }
1229
1230 static void
1231 ieee80211_link_update_chandef(struct ieee80211_link_data *link,
1232                               const struct cfg80211_chan_def *chandef)
1233 {
1234         struct ieee80211_sub_if_data *sdata = link->sdata;
1235         unsigned int link_id = link->link_id;
1236         struct ieee80211_sub_if_data *vlan;
1237
1238         link->conf->chandef = *chandef;
1239
1240         if (sdata->vif.type != NL80211_IFTYPE_AP)
1241                 return;
1242
1243         rcu_read_lock();
1244         list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
1245                 struct ieee80211_bss_conf *vlan_conf;
1246
1247                 vlan_conf = rcu_dereference(vlan->vif.link_conf[link_id]);
1248                 if (WARN_ON(!vlan_conf))
1249                         continue;
1250
1251                 vlan_conf->chandef = *chandef;
1252         }
1253         rcu_read_unlock();
1254 }
1255
1256 static int
1257 ieee80211_link_use_reserved_reassign(struct ieee80211_link_data *link)
1258 {
1259         struct ieee80211_sub_if_data *sdata = link->sdata;
1260         struct ieee80211_bss_conf *link_conf = link->conf;
1261         struct ieee80211_local *local = sdata->local;
1262         struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1263         struct ieee80211_chanctx *old_ctx, *new_ctx;
1264         const struct cfg80211_chan_def *chandef;
1265         u64 changed = 0;
1266         int err;
1267
1268         lockdep_assert_held(&local->mtx);
1269         lockdep_assert_held(&local->chanctx_mtx);
1270
1271         new_ctx = link->reserved_chanctx;
1272         old_ctx = ieee80211_link_get_chanctx(link);
1273
1274         if (WARN_ON(!link->reserved_ready))
1275                 return -EBUSY;
1276
1277         if (WARN_ON(!new_ctx))
1278                 return -EINVAL;
1279
1280         if (WARN_ON(!old_ctx))
1281                 return -EINVAL;
1282
1283         if (WARN_ON(new_ctx->replace_state ==
1284                     IEEE80211_CHANCTX_REPLACES_OTHER))
1285                 return -EINVAL;
1286
1287         chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1288                                 &link->reserved_chandef);
1289         if (WARN_ON(!chandef))
1290                 return -EINVAL;
1291
1292         if (link_conf->chandef.width != link->reserved_chandef.width)
1293                 changed = BSS_CHANGED_BANDWIDTH;
1294
1295         ieee80211_link_update_chandef(link, &link->reserved_chandef);
1296
1297         _ieee80211_change_chanctx(local, new_ctx, old_ctx, chandef, link);
1298
1299         vif_chsw[0].vif = &sdata->vif;
1300         vif_chsw[0].old_ctx = &old_ctx->conf;
1301         vif_chsw[0].new_ctx = &new_ctx->conf;
1302         vif_chsw[0].link_conf = link->conf;
1303
1304         list_del(&link->reserved_chanctx_list);
1305         link->reserved_chanctx = NULL;
1306
1307         err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1308                                      CHANCTX_SWMODE_REASSIGN_VIF);
1309         if (err) {
1310                 if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1311                         ieee80211_free_chanctx(local, new_ctx);
1312
1313                 goto out;
1314         }
1315
1316         list_move(&link->assigned_chanctx_list, &new_ctx->assigned_links);
1317         rcu_assign_pointer(link_conf->chanctx_conf, &new_ctx->conf);
1318
1319         if (sdata->vif.type == NL80211_IFTYPE_AP)
1320                 __ieee80211_link_copy_chanctx_to_vlans(link, false);
1321
1322         ieee80211_check_fast_xmit_iface(sdata);
1323
1324         if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1325                 ieee80211_free_chanctx(local, old_ctx);
1326
1327         ieee80211_recalc_chanctx_min_def(local, new_ctx, NULL);
1328         ieee80211_recalc_smps_chanctx(local, new_ctx);
1329         ieee80211_recalc_radar_chanctx(local, new_ctx);
1330
1331         if (changed)
1332                 ieee80211_link_info_change_notify(sdata, link, changed);
1333
1334 out:
1335         ieee80211_link_chanctx_reservation_complete(link);
1336         return err;
1337 }
1338
1339 static int
1340 ieee80211_link_use_reserved_assign(struct ieee80211_link_data *link)
1341 {
1342         struct ieee80211_sub_if_data *sdata = link->sdata;
1343         struct ieee80211_local *local = sdata->local;
1344         struct ieee80211_chanctx *old_ctx, *new_ctx;
1345         const struct cfg80211_chan_def *chandef;
1346         int err;
1347
1348         old_ctx = ieee80211_link_get_chanctx(link);
1349         new_ctx = link->reserved_chanctx;
1350
1351         if (WARN_ON(!link->reserved_ready))
1352                 return -EINVAL;
1353
1354         if (WARN_ON(old_ctx))
1355                 return -EINVAL;
1356
1357         if (WARN_ON(!new_ctx))
1358                 return -EINVAL;
1359
1360         if (WARN_ON(new_ctx->replace_state ==
1361                     IEEE80211_CHANCTX_REPLACES_OTHER))
1362                 return -EINVAL;
1363
1364         chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1365                                 &link->reserved_chandef);
1366         if (WARN_ON(!chandef))
1367                 return -EINVAL;
1368
1369         ieee80211_change_chanctx(local, new_ctx, new_ctx, chandef);
1370
1371         list_del(&link->reserved_chanctx_list);
1372         link->reserved_chanctx = NULL;
1373
1374         err = ieee80211_assign_link_chanctx(link, new_ctx);
1375         if (err) {
1376                 if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1377                         ieee80211_free_chanctx(local, new_ctx);
1378
1379                 goto out;
1380         }
1381
1382 out:
1383         ieee80211_link_chanctx_reservation_complete(link);
1384         return err;
1385 }
1386
1387 static bool
1388 ieee80211_link_has_in_place_reservation(struct ieee80211_link_data *link)
1389 {
1390         struct ieee80211_sub_if_data *sdata = link->sdata;
1391         struct ieee80211_chanctx *old_ctx, *new_ctx;
1392
1393         lockdep_assert_held(&sdata->local->chanctx_mtx);
1394
1395         new_ctx = link->reserved_chanctx;
1396         old_ctx = ieee80211_link_get_chanctx(link);
1397
1398         if (!old_ctx)
1399                 return false;
1400
1401         if (WARN_ON(!new_ctx))
1402                 return false;
1403
1404         if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1405                 return false;
1406
1407         if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1408                 return false;
1409
1410         return true;
1411 }
1412
1413 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1414                                         struct ieee80211_chanctx *new_ctx)
1415 {
1416         const struct cfg80211_chan_def *chandef;
1417
1418         lockdep_assert_held(&local->mtx);
1419         lockdep_assert_held(&local->chanctx_mtx);
1420
1421         chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1422         if (WARN_ON(!chandef))
1423                 return -EINVAL;
1424
1425         local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1426         local->_oper_chandef = *chandef;
1427         ieee80211_hw_config(local, 0);
1428
1429         return 0;
1430 }
1431
1432 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1433                                       int n_vifs)
1434 {
1435         struct ieee80211_vif_chanctx_switch *vif_chsw;
1436         struct ieee80211_link_data *link;
1437         struct ieee80211_chanctx *ctx, *old_ctx;
1438         int i, err;
1439
1440         lockdep_assert_held(&local->mtx);
1441         lockdep_assert_held(&local->chanctx_mtx);
1442
1443         vif_chsw = kcalloc(n_vifs, sizeof(vif_chsw[0]), GFP_KERNEL);
1444         if (!vif_chsw)
1445                 return -ENOMEM;
1446
1447         i = 0;
1448         list_for_each_entry(ctx, &local->chanctx_list, list) {
1449                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1450                         continue;
1451
1452                 if (WARN_ON(!ctx->replace_ctx)) {
1453                         err = -EINVAL;
1454                         goto out;
1455                 }
1456
1457                 list_for_each_entry(link, &ctx->reserved_links,
1458                                     reserved_chanctx_list) {
1459                         if (!ieee80211_link_has_in_place_reservation(link))
1460                                 continue;
1461
1462                         old_ctx = ieee80211_link_get_chanctx(link);
1463                         vif_chsw[i].vif = &link->sdata->vif;
1464                         vif_chsw[i].old_ctx = &old_ctx->conf;
1465                         vif_chsw[i].new_ctx = &ctx->conf;
1466                         vif_chsw[i].link_conf = link->conf;
1467
1468                         i++;
1469                 }
1470         }
1471
1472         err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1473                                      CHANCTX_SWMODE_SWAP_CONTEXTS);
1474
1475 out:
1476         kfree(vif_chsw);
1477         return err;
1478 }
1479
1480 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1481 {
1482         struct ieee80211_chanctx *ctx;
1483         int err;
1484
1485         lockdep_assert_held(&local->mtx);
1486         lockdep_assert_held(&local->chanctx_mtx);
1487
1488         list_for_each_entry(ctx, &local->chanctx_list, list) {
1489                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1490                         continue;
1491
1492                 if (!list_empty(&ctx->replace_ctx->assigned_links))
1493                         continue;
1494
1495                 ieee80211_del_chanctx(local, ctx->replace_ctx);
1496                 err = ieee80211_add_chanctx(local, ctx);
1497                 if (err)
1498                         goto err;
1499         }
1500
1501         return 0;
1502
1503 err:
1504         WARN_ON(ieee80211_add_chanctx(local, ctx));
1505         list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1506                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1507                         continue;
1508
1509                 if (!list_empty(&ctx->replace_ctx->assigned_links))
1510                         continue;
1511
1512                 ieee80211_del_chanctx(local, ctx);
1513                 WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1514         }
1515
1516         return err;
1517 }
1518
1519 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1520 {
1521         struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1522         struct ieee80211_chanctx *new_ctx = NULL;
1523         int err, n_assigned, n_reserved, n_ready;
1524         int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1525
1526         lockdep_assert_held(&local->mtx);
1527         lockdep_assert_held(&local->chanctx_mtx);
1528
1529         /*
1530          * If there are 2 independent pairs of channel contexts performing
1531          * cross-switch of their vifs this code will still wait until both are
1532          * ready even though it could be possible to switch one before the
1533          * other is ready.
1534          *
1535          * For practical reasons and code simplicity just do a single huge
1536          * switch.
1537          */
1538
1539         /*
1540          * Verify if the reservation is still feasible.
1541          *  - if it's not then disconnect
1542          *  - if it is but not all vifs necessary are ready then defer
1543          */
1544
1545         list_for_each_entry(ctx, &local->chanctx_list, list) {
1546                 struct ieee80211_link_data *link;
1547
1548                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1549                         continue;
1550
1551                 if (WARN_ON(!ctx->replace_ctx)) {
1552                         err = -EINVAL;
1553                         goto err;
1554                 }
1555
1556                 if (!local->use_chanctx)
1557                         new_ctx = ctx;
1558
1559                 n_ctx++;
1560
1561                 n_assigned = 0;
1562                 n_reserved = 0;
1563                 n_ready = 0;
1564
1565                 list_for_each_entry(link, &ctx->replace_ctx->assigned_links,
1566                                     assigned_chanctx_list) {
1567                         n_assigned++;
1568                         if (link->reserved_chanctx) {
1569                                 n_reserved++;
1570                                 if (link->reserved_ready)
1571                                         n_ready++;
1572                         }
1573                 }
1574
1575                 if (n_assigned != n_reserved) {
1576                         if (n_ready == n_reserved) {
1577                                 wiphy_info(local->hw.wiphy,
1578                                            "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1579                                 err = -EBUSY;
1580                                 goto err;
1581                         }
1582
1583                         return -EAGAIN;
1584                 }
1585
1586                 ctx->conf.radar_enabled = false;
1587                 list_for_each_entry(link, &ctx->reserved_links,
1588                                     reserved_chanctx_list) {
1589                         if (ieee80211_link_has_in_place_reservation(link) &&
1590                             !link->reserved_ready)
1591                                 return -EAGAIN;
1592
1593                         old_ctx = ieee80211_link_get_chanctx(link);
1594                         if (old_ctx) {
1595                                 if (old_ctx->replace_state ==
1596                                     IEEE80211_CHANCTX_WILL_BE_REPLACED)
1597                                         n_vifs_switch++;
1598                                 else
1599                                         n_vifs_assign++;
1600                         } else {
1601                                 n_vifs_ctxless++;
1602                         }
1603
1604                         if (link->reserved_radar_required)
1605                                 ctx->conf.radar_enabled = true;
1606                 }
1607         }
1608
1609         if (WARN_ON(n_ctx == 0) ||
1610             WARN_ON(n_vifs_switch == 0 &&
1611                     n_vifs_assign == 0 &&
1612                     n_vifs_ctxless == 0) ||
1613             WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1614             WARN_ON(!new_ctx && !local->use_chanctx)) {
1615                 err = -EINVAL;
1616                 goto err;
1617         }
1618
1619         /*
1620          * All necessary vifs are ready. Perform the switch now depending on
1621          * reservations and driver capabilities.
1622          */
1623
1624         if (local->use_chanctx) {
1625                 if (n_vifs_switch > 0) {
1626                         err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1627                         if (err)
1628                                 goto err;
1629                 }
1630
1631                 if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1632                         err = ieee80211_chsw_switch_ctxs(local);
1633                         if (err)
1634                                 goto err;
1635                 }
1636         } else {
1637                 err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1638                 if (err)
1639                         goto err;
1640         }
1641
1642         /*
1643          * Update all structures, values and pointers to point to new channel
1644          * context(s).
1645          */
1646         list_for_each_entry(ctx, &local->chanctx_list, list) {
1647                 struct ieee80211_link_data *link, *link_tmp;
1648
1649                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1650                         continue;
1651
1652                 if (WARN_ON(!ctx->replace_ctx)) {
1653                         err = -EINVAL;
1654                         goto err;
1655                 }
1656
1657                 list_for_each_entry(link, &ctx->reserved_links,
1658                                     reserved_chanctx_list) {
1659                         struct ieee80211_sub_if_data *sdata = link->sdata;
1660                         struct ieee80211_bss_conf *link_conf = link->conf;
1661                         u64 changed = 0;
1662
1663                         if (!ieee80211_link_has_in_place_reservation(link))
1664                                 continue;
1665
1666                         rcu_assign_pointer(link_conf->chanctx_conf,
1667                                            &ctx->conf);
1668
1669                         if (sdata->vif.type == NL80211_IFTYPE_AP)
1670                                 __ieee80211_link_copy_chanctx_to_vlans(link,
1671                                                                        false);
1672
1673                         ieee80211_check_fast_xmit_iface(sdata);
1674
1675                         link->radar_required = link->reserved_radar_required;
1676
1677                         if (link_conf->chandef.width != link->reserved_chandef.width)
1678                                 changed = BSS_CHANGED_BANDWIDTH;
1679
1680                         ieee80211_link_update_chandef(link, &link->reserved_chandef);
1681                         if (changed)
1682                                 ieee80211_link_info_change_notify(sdata,
1683                                                                   link,
1684                                                                   changed);
1685
1686                         ieee80211_recalc_txpower(sdata, false);
1687                 }
1688
1689                 ieee80211_recalc_chanctx_chantype(local, ctx);
1690                 ieee80211_recalc_smps_chanctx(local, ctx);
1691                 ieee80211_recalc_radar_chanctx(local, ctx);
1692                 ieee80211_recalc_chanctx_min_def(local, ctx, NULL);
1693
1694                 list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1695                                          reserved_chanctx_list) {
1696                         if (ieee80211_link_get_chanctx(link) != ctx)
1697                                 continue;
1698
1699                         list_del(&link->reserved_chanctx_list);
1700                         list_move(&link->assigned_chanctx_list,
1701                                   &ctx->assigned_links);
1702                         link->reserved_chanctx = NULL;
1703
1704                         ieee80211_link_chanctx_reservation_complete(link);
1705                 }
1706
1707                 /*
1708                  * This context might have been a dependency for an already
1709                  * ready re-assign reservation interface that was deferred. Do
1710                  * not propagate error to the caller though. The in-place
1711                  * reservation for originally requested interface has already
1712                  * succeeded at this point.
1713                  */
1714                 list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1715                                          reserved_chanctx_list) {
1716                         if (WARN_ON(ieee80211_link_has_in_place_reservation(link)))
1717                                 continue;
1718
1719                         if (WARN_ON(link->reserved_chanctx != ctx))
1720                                 continue;
1721
1722                         if (!link->reserved_ready)
1723                                 continue;
1724
1725                         if (ieee80211_link_get_chanctx(link))
1726                                 err = ieee80211_link_use_reserved_reassign(link);
1727                         else
1728                                 err = ieee80211_link_use_reserved_assign(link);
1729
1730                         if (err) {
1731                                 link_info(link,
1732                                           "failed to finalize (re-)assign reservation (err=%d)\n",
1733                                           err);
1734                                 ieee80211_link_unreserve_chanctx(link);
1735                                 cfg80211_stop_iface(local->hw.wiphy,
1736                                                     &link->sdata->wdev,
1737                                                     GFP_KERNEL);
1738                         }
1739                 }
1740         }
1741
1742         /*
1743          * Finally free old contexts
1744          */
1745
1746         list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1747                 if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1748                         continue;
1749
1750                 ctx->replace_ctx->replace_ctx = NULL;
1751                 ctx->replace_ctx->replace_state =
1752                                 IEEE80211_CHANCTX_REPLACE_NONE;
1753
1754                 list_del_rcu(&ctx->list);
1755                 kfree_rcu(ctx, rcu_head);
1756         }
1757
1758         return 0;
1759
1760 err:
1761         list_for_each_entry(ctx, &local->chanctx_list, list) {
1762                 struct ieee80211_link_data *link, *link_tmp;
1763
1764                 if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1765                         continue;
1766
1767                 list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1768                                          reserved_chanctx_list) {
1769                         ieee80211_link_unreserve_chanctx(link);
1770                         ieee80211_link_chanctx_reservation_complete(link);
1771                 }
1772         }
1773
1774         return err;
1775 }
1776
1777 static void __ieee80211_link_release_channel(struct ieee80211_link_data *link)
1778 {
1779         struct ieee80211_sub_if_data *sdata = link->sdata;
1780         struct ieee80211_bss_conf *link_conf = link->conf;
1781         struct ieee80211_local *local = sdata->local;
1782         struct ieee80211_chanctx_conf *conf;
1783         struct ieee80211_chanctx *ctx;
1784         bool use_reserved_switch = false;
1785
1786         lockdep_assert_held(&local->chanctx_mtx);
1787
1788         conf = rcu_dereference_protected(link_conf->chanctx_conf,
1789                                          lockdep_is_held(&local->chanctx_mtx));
1790         if (!conf)
1791                 return;
1792
1793         ctx = container_of(conf, struct ieee80211_chanctx, conf);
1794
1795         if (link->reserved_chanctx) {
1796                 if (link->reserved_chanctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER &&
1797                     ieee80211_chanctx_num_reserved(local, link->reserved_chanctx) > 1)
1798                         use_reserved_switch = true;
1799
1800                 ieee80211_link_unreserve_chanctx(link);
1801         }
1802
1803         ieee80211_assign_link_chanctx(link, NULL);
1804         if (ieee80211_chanctx_refcount(local, ctx) == 0)
1805                 ieee80211_free_chanctx(local, ctx);
1806
1807         link->radar_required = false;
1808
1809         /* Unreserving may ready an in-place reservation. */
1810         if (use_reserved_switch)
1811                 ieee80211_vif_use_reserved_switch(local);
1812 }
1813
1814 int ieee80211_link_use_channel(struct ieee80211_link_data *link,
1815                                const struct cfg80211_chan_def *chandef,
1816                                enum ieee80211_chanctx_mode mode)
1817 {
1818         struct ieee80211_sub_if_data *sdata = link->sdata;
1819         struct ieee80211_local *local = sdata->local;
1820         struct ieee80211_chanctx *ctx;
1821         u8 radar_detect_width = 0;
1822         int ret;
1823
1824         lockdep_assert_held(&local->mtx);
1825
1826         if (sdata->vif.active_links &&
1827             !(sdata->vif.active_links & BIT(link->link_id))) {
1828                 ieee80211_link_update_chandef(link, chandef);
1829                 return 0;
1830         }
1831
1832         mutex_lock(&local->chanctx_mtx);
1833
1834         ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1835                                             chandef,
1836                                             sdata->wdev.iftype);
1837         if (ret < 0)
1838                 goto out;
1839         if (ret > 0)
1840                 radar_detect_width = BIT(chandef->width);
1841
1842         link->radar_required = ret;
1843
1844         ret = ieee80211_check_combinations(sdata, chandef, mode,
1845                                            radar_detect_width);
1846         if (ret < 0)
1847                 goto out;
1848
1849         __ieee80211_link_release_channel(link);
1850
1851         ctx = ieee80211_find_chanctx(local, chandef, mode);
1852         if (!ctx)
1853                 ctx = ieee80211_new_chanctx(local, chandef, mode);
1854         if (IS_ERR(ctx)) {
1855                 ret = PTR_ERR(ctx);
1856                 goto out;
1857         }
1858
1859         ieee80211_link_update_chandef(link, chandef);
1860
1861         ret = ieee80211_assign_link_chanctx(link, ctx);
1862         if (ret) {
1863                 /* if assign fails refcount stays the same */
1864                 if (ieee80211_chanctx_refcount(local, ctx) == 0)
1865                         ieee80211_free_chanctx(local, ctx);
1866                 goto out;
1867         }
1868
1869         ieee80211_recalc_smps_chanctx(local, ctx);
1870         ieee80211_recalc_radar_chanctx(local, ctx);
1871  out:
1872         if (ret)
1873                 link->radar_required = false;
1874
1875         mutex_unlock(&local->chanctx_mtx);
1876         return ret;
1877 }
1878
1879 int ieee80211_link_use_reserved_context(struct ieee80211_link_data *link)
1880 {
1881         struct ieee80211_sub_if_data *sdata = link->sdata;
1882         struct ieee80211_local *local = sdata->local;
1883         struct ieee80211_chanctx *new_ctx;
1884         struct ieee80211_chanctx *old_ctx;
1885         int err;
1886
1887         lockdep_assert_held(&local->mtx);
1888         lockdep_assert_held(&local->chanctx_mtx);
1889
1890         new_ctx = link->reserved_chanctx;
1891         old_ctx = ieee80211_link_get_chanctx(link);
1892
1893         if (WARN_ON(!new_ctx))
1894                 return -EINVAL;
1895
1896         if (WARN_ON(new_ctx->replace_state ==
1897                     IEEE80211_CHANCTX_WILL_BE_REPLACED))
1898                 return -EINVAL;
1899
1900         if (WARN_ON(link->reserved_ready))
1901                 return -EINVAL;
1902
1903         link->reserved_ready = true;
1904
1905         if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1906                 if (old_ctx)
1907                         return ieee80211_link_use_reserved_reassign(link);
1908
1909                 return ieee80211_link_use_reserved_assign(link);
1910         }
1911
1912         /*
1913          * In-place reservation may need to be finalized now either if:
1914          *  a) sdata is taking part in the swapping itself and is the last one
1915          *  b) sdata has switched with a re-assign reservation to an existing
1916          *     context readying in-place switching of old_ctx
1917          *
1918          * In case of (b) do not propagate the error up because the requested
1919          * sdata already switched successfully. Just spill an extra warning.
1920          * The ieee80211_vif_use_reserved_switch() already stops all necessary
1921          * interfaces upon failure.
1922          */
1923         if ((old_ctx &&
1924              old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1925             new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1926                 err = ieee80211_vif_use_reserved_switch(local);
1927                 if (err && err != -EAGAIN) {
1928                         if (new_ctx->replace_state ==
1929                             IEEE80211_CHANCTX_REPLACES_OTHER)
1930                                 return err;
1931
1932                         wiphy_info(local->hw.wiphy,
1933                                    "depending in-place reservation failed (err=%d)\n",
1934                                    err);
1935                 }
1936         }
1937
1938         return 0;
1939 }
1940
1941 int ieee80211_link_change_bandwidth(struct ieee80211_link_data *link,
1942                                     const struct cfg80211_chan_def *chandef,
1943                                     u64 *changed)
1944 {
1945         struct ieee80211_sub_if_data *sdata = link->sdata;
1946         struct ieee80211_bss_conf *link_conf = link->conf;
1947         struct ieee80211_local *local = sdata->local;
1948         struct ieee80211_chanctx_conf *conf;
1949         struct ieee80211_chanctx *ctx;
1950         const struct cfg80211_chan_def *compat;
1951         int ret;
1952
1953         if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1954                                      IEEE80211_CHAN_DISABLED))
1955                 return -EINVAL;
1956
1957         mutex_lock(&local->chanctx_mtx);
1958         if (cfg80211_chandef_identical(chandef, &link_conf->chandef)) {
1959                 ret = 0;
1960                 goto out;
1961         }
1962
1963         if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1964             link_conf->chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1965                 ret = -EINVAL;
1966                 goto out;
1967         }
1968
1969         conf = rcu_dereference_protected(link_conf->chanctx_conf,
1970                                          lockdep_is_held(&local->chanctx_mtx));
1971         if (!conf) {
1972                 ret = -EINVAL;
1973                 goto out;
1974         }
1975
1976         ctx = container_of(conf, struct ieee80211_chanctx, conf);
1977
1978         compat = cfg80211_chandef_compatible(&conf->def, chandef);
1979         if (!compat) {
1980                 ret = -EINVAL;
1981                 goto out;
1982         }
1983
1984         switch (ctx->replace_state) {
1985         case IEEE80211_CHANCTX_REPLACE_NONE:
1986                 if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1987                         ret = -EBUSY;
1988                         goto out;
1989                 }
1990                 break;
1991         case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1992                 /* TODO: Perhaps the bandwidth change could be treated as a
1993                  * reservation itself? */
1994                 ret = -EBUSY;
1995                 goto out;
1996         case IEEE80211_CHANCTX_REPLACES_OTHER:
1997                 /* channel context that is going to replace another channel
1998                  * context doesn't really exist and shouldn't be assigned
1999                  * anywhere yet */
2000                 WARN_ON(1);
2001                 break;
2002         }
2003
2004         ieee80211_link_update_chandef(link, chandef);
2005
2006         ieee80211_recalc_chanctx_chantype(local, ctx);
2007
2008         *changed |= BSS_CHANGED_BANDWIDTH;
2009         ret = 0;
2010  out:
2011         mutex_unlock(&local->chanctx_mtx);
2012         return ret;
2013 }
2014
2015 void ieee80211_link_release_channel(struct ieee80211_link_data *link)
2016 {
2017         struct ieee80211_sub_if_data *sdata = link->sdata;
2018
2019         mutex_lock(&sdata->local->chanctx_mtx);
2020         if (rcu_access_pointer(link->conf->chanctx_conf)) {
2021                 lockdep_assert_held(&sdata->local->mtx);
2022                 __ieee80211_link_release_channel(link);
2023         }
2024         mutex_unlock(&sdata->local->chanctx_mtx);
2025 }
2026
2027 void ieee80211_link_vlan_copy_chanctx(struct ieee80211_link_data *link)
2028 {
2029         struct ieee80211_sub_if_data *sdata = link->sdata;
2030         unsigned int link_id = link->link_id;
2031         struct ieee80211_bss_conf *link_conf = link->conf;
2032         struct ieee80211_bss_conf *ap_conf;
2033         struct ieee80211_local *local = sdata->local;
2034         struct ieee80211_sub_if_data *ap;
2035         struct ieee80211_chanctx_conf *conf;
2036
2037         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
2038                 return;
2039
2040         ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
2041
2042         mutex_lock(&local->chanctx_mtx);
2043
2044         rcu_read_lock();
2045         ap_conf = rcu_dereference(ap->vif.link_conf[link_id]);
2046         conf = rcu_dereference_protected(ap_conf->chanctx_conf,
2047                                          lockdep_is_held(&local->chanctx_mtx));
2048         rcu_assign_pointer(link_conf->chanctx_conf, conf);
2049         rcu_read_unlock();
2050         mutex_unlock(&local->chanctx_mtx);
2051 }
2052
2053 void ieee80211_iter_chan_contexts_atomic(
2054         struct ieee80211_hw *hw,
2055         void (*iter)(struct ieee80211_hw *hw,
2056                      struct ieee80211_chanctx_conf *chanctx_conf,
2057                      void *data),
2058         void *iter_data)
2059 {
2060         struct ieee80211_local *local = hw_to_local(hw);
2061         struct ieee80211_chanctx *ctx;
2062
2063         rcu_read_lock();
2064         list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
2065                 if (ctx->driver_present)
2066                         iter(hw, &ctx->conf, iter_data);
2067         rcu_read_unlock();
2068 }
2069 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);