net/mac80211/ht.c

   1 /*
   2  * HT handling
   3  *
   4  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   5  * Copyright 2002-2005, Instant802 Networks, Inc.
   6  * Copyright 2005-2006, Devicescape Software, Inc.
   7  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   8  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
   9  * Copyright 2007-2010, Intel Corporation
  10  * Copyright 2017       Intel Deutschland GmbH
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License version 2 as
  14  * published by the Free Software Foundation.
  15  */
  16
  17 #include <linux/ieee80211.h>
  18 #include <linux/export.h>
  19 #include <net/mac80211.h>
  20 #include "ieee80211_i.h"
  21 #include "rate.h"
  22
  23 static void __check_htcap_disable(struct ieee80211_ht_cap *ht_capa,
  24                                   struct ieee80211_ht_cap *ht_capa_mask,
  25                                   struct ieee80211_sta_ht_cap *ht_cap,
  26                                   u16 flag)
  27 {
  28         __le16 le_flag = cpu_to_le16(flag);
  29         if (ht_capa_mask->cap_info & le_flag) {
  30                 if (!(ht_capa->cap_info & le_flag))
  31                         ht_cap->cap &= ~flag;
  32         }
  33 }
  34
  35 static void __check_htcap_enable(struct ieee80211_ht_cap *ht_capa,
  36                                   struct ieee80211_ht_cap *ht_capa_mask,
  37                                   struct ieee80211_sta_ht_cap *ht_cap,
  38                                   u16 flag)
  39 {
  40         __le16 le_flag = cpu_to_le16(flag);
  41
  42         if ((ht_capa_mask->cap_info & le_flag) &&
  43             (ht_capa->cap_info & le_flag))
  44                 ht_cap->cap |= flag;
  45 }
  46
  47 void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
  48                                      struct ieee80211_sta_ht_cap *ht_cap)
  49 {
  50         struct ieee80211_ht_cap *ht_capa, *ht_capa_mask;
  51         u8 *scaps, *smask;
  52         int i;
  53
  54         if (!ht_cap->ht_supported)
  55                 return;
  56
  57         switch (sdata->vif.type) {
  58         case NL80211_IFTYPE_STATION:
  59                 ht_capa = &sdata->u.mgd.ht_capa;
  60                 ht_capa_mask = &sdata->u.mgd.ht_capa_mask;
  61                 break;
  62         case NL80211_IFTYPE_ADHOC:
  63                 ht_capa = &sdata->u.ibss.ht_capa;
  64                 ht_capa_mask = &sdata->u.ibss.ht_capa_mask;
  65                 break;
  66         default:
  67                 WARN_ON_ONCE(1);
  68                 return;
  69         }
  70
  71         scaps = (u8 *)(&ht_capa->mcs.rx_mask);
  72         smask = (u8 *)(&ht_capa_mask->mcs.rx_mask);
  73
  74         /* NOTE:  If you add more over-rides here, update register_hw
  75          * ht_capa_mod_mask logic in main.c as well.
  76          * And, if this method can ever change ht_cap.ht_supported, fix
  77          * the check in ieee80211_add_ht_ie.
  78          */
  79
  80         /* check for HT over-rides, MCS rates first. */
  81         for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
  82                 u8 m = smask[i];
  83                 ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
  84                 /* Add back rates that are supported */
  85                 ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
  86         }
  87
  88         /* Force removal of HT-40 capabilities? */
  89         __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
  90                               IEEE80211_HT_CAP_SUP_WIDTH_20_40);
  91         __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
  92                               IEEE80211_HT_CAP_SGI_40);
  93
  94         /* Allow user to disable SGI-20 (SGI-40 is handled above) */
  95         __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
  96                               IEEE80211_HT_CAP_SGI_20);
  97
  98         /* Allow user to disable the max-AMSDU bit. */
  99         __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
 100                               IEEE80211_HT_CAP_MAX_AMSDU);
 101
 102         /* Allow user to disable LDPC */
 103         __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
 104                               IEEE80211_HT_CAP_LDPC_CODING);
 105
 106         /* Allow user to enable 40 MHz intolerant bit. */
 107         __check_htcap_enable(ht_capa, ht_capa_mask, ht_cap,
 108                              IEEE80211_HT_CAP_40MHZ_INTOLERANT);
 109
 110         /* Allow user to enable TX STBC bit  */
 111         __check_htcap_enable(ht_capa, ht_capa_mask, ht_cap,
 112                              IEEE80211_HT_CAP_TX_STBC);
 113
 114         /* Allow user to configure RX STBC bits */
 115         if (ht_capa_mask->cap_info & IEEE80211_HT_CAP_RX_STBC)
 116                 ht_cap->cap |= ht_capa->cap_info & IEEE80211_HT_CAP_RX_STBC;
 117
 118         /* Allow user to decrease AMPDU factor */
 119         if (ht_capa_mask->ampdu_params_info &
 120             IEEE80211_HT_AMPDU_PARM_FACTOR) {
 121                 u8 n = ht_capa->ampdu_params_info &
 122                        IEEE80211_HT_AMPDU_PARM_FACTOR;
 123                 if (n < ht_cap->ampdu_factor)
 124                         ht_cap->ampdu_factor = n;
 125         }
 126
 127         /* Allow the user to increase AMPDU density. */
 128         if (ht_capa_mask->ampdu_params_info &
 129             IEEE80211_HT_AMPDU_PARM_DENSITY) {
 130                 u8 n = (ht_capa->ampdu_params_info &
 131                         IEEE80211_HT_AMPDU_PARM_DENSITY)
 132                         >> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
 133                 if (n > ht_cap->ampdu_density)
 134                         ht_cap->ampdu_density = n;
 135         }
 136 }
 137
 138
 139 bool ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
 140                                        struct ieee80211_supported_band *sband,
 141                                        const struct ieee80211_ht_cap *ht_cap_ie,
 142                                        struct sta_info *sta)
 143 {
 144         struct ieee80211_sta_ht_cap ht_cap, own_cap;
 145         u8 ampdu_info, tx_mcs_set_cap;
 146         int i, max_tx_streams;
 147         bool changed;
 148         enum ieee80211_sta_rx_bandwidth bw;
 149         enum ieee80211_smps_mode smps_mode;
 150
 151         memset(&ht_cap, 0, sizeof(ht_cap));
 152
 153         if (!ht_cap_ie || !sband->ht_cap.ht_supported)
 154                 goto apply;
 155
 156         ht_cap.ht_supported = true;
 157
 158         own_cap = sband->ht_cap;
 159
 160         /*
 161          * If user has specified capability over-rides, take care
 162          * of that if the station we're setting up is the AP or TDLS peer that
 163          * we advertised a restricted capability set to. Override
 164          * our own capabilities and then use those below.
 165          */
 166         if (sdata->vif.type == NL80211_IFTYPE_STATION ||
 167             sdata->vif.type == NL80211_IFTYPE_ADHOC)
 168                 ieee80211_apply_htcap_overrides(sdata, &own_cap);
 169
 170         /*
 171          * The bits listed in this expression should be
 172          * the same for the peer and us, if the station
 173          * advertises more then we can't use those thus
 174          * we mask them out.
 175          */
 176         ht_cap.cap = le16_to_cpu(ht_cap_ie->cap_info) &
 177                 (own_cap.cap | ~(IEEE80211_HT_CAP_LDPC_CODING |
 178                                  IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
 179                                  IEEE80211_HT_CAP_GRN_FLD |
 180                                  IEEE80211_HT_CAP_SGI_20 |
 181                                  IEEE80211_HT_CAP_SGI_40 |
 182                                  IEEE80211_HT_CAP_DSSSCCK40));
 183
 184         /*
 185          * The STBC bits are asymmetric -- if we don't have
 186          * TX then mask out the peer's RX and vice versa.
 187          */
 188         if (!(own_cap.cap & IEEE80211_HT_CAP_TX_STBC))
 189                 ht_cap.cap &= ~IEEE80211_HT_CAP_RX_STBC;
 190         if (!(own_cap.cap & IEEE80211_HT_CAP_RX_STBC))
 191                 ht_cap.cap &= ~IEEE80211_HT_CAP_TX_STBC;
 192
 193         ampdu_info = ht_cap_ie->ampdu_params_info;
 194         ht_cap.ampdu_factor =
 195                 ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
 196         ht_cap.ampdu_density =
 197                 (ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
 198
 199         /* own MCS TX capabilities */
 200         tx_mcs_set_cap = own_cap.mcs.tx_params;
 201
 202         /* Copy peer MCS TX capabilities, the driver might need them. */
 203         ht_cap.mcs.tx_params = ht_cap_ie->mcs.tx_params;
 204
 205         /* can we TX with MCS rates? */
 206         if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
 207                 goto apply;
 208
 209         /* Counting from 0, therefore +1 */
 210         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
 211                 max_tx_streams =
 212                         ((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
 213                                 >> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
 214         else
 215                 max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
 216
 217         /*
 218          * 802.11n-2009 20.3.5 / 20.6 says:
 219          * - indices 0 to 7 and 32 are single spatial stream
 220          * - 8 to 31 are multiple spatial streams using equal modulation
 221          *   [8..15 for two streams, 16..23 for three and 24..31 for four]
 222          * - remainder are multiple spatial streams using unequal modulation
 223          */
 224         for (i = 0; i < max_tx_streams; i++)
 225                 ht_cap.mcs.rx_mask[i] =
 226                         own_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
 227
 228         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
 229                 for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
 230                      i < IEEE80211_HT_MCS_MASK_LEN; i++)
 231                         ht_cap.mcs.rx_mask[i] =
 232                                 own_cap.mcs.rx_mask[i] &
 233                                         ht_cap_ie->mcs.rx_mask[i];
 234
 235         /* handle MCS rate 32 too */
 236         if (own_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
 237                 ht_cap.mcs.rx_mask[32/8] |= 1;
 238
 239         /* set Rx highest rate */
 240         ht_cap.mcs.rx_highest = ht_cap_ie->mcs.rx_highest;
 241
 242         if (ht_cap.cap & IEEE80211_HT_CAP_MAX_AMSDU)
 243                 sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_HT_7935;
 244         else
 245                 sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_HT_3839;
 246
 247  apply:
 248         changed = memcmp(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
 249
 250         memcpy(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
 251
 252         switch (sdata->vif.bss_conf.chandef.width) {
 253         default:
 254                 WARN_ON_ONCE(1);
 255                 /* fall through */
 256         case NL80211_CHAN_WIDTH_20_NOHT:
 257         case NL80211_CHAN_WIDTH_20:
 258                 bw = IEEE80211_STA_RX_BW_20;
 259                 break;
 260         case NL80211_CHAN_WIDTH_40:
 261         case NL80211_CHAN_WIDTH_80:
 262         case NL80211_CHAN_WIDTH_80P80:
 263         case NL80211_CHAN_WIDTH_160:
 264                 bw = ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
 265                                 IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
 266                 break;
 267         }
 268
 269         sta->sta.bandwidth = bw;
 270
 271         sta->cur_max_bandwidth =
 272                 ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
 273                                 IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
 274
 275         switch ((ht_cap.cap & IEEE80211_HT_CAP_SM_PS)
 276                         >> IEEE80211_HT_CAP_SM_PS_SHIFT) {
 277         case WLAN_HT_CAP_SM_PS_INVALID:
 278         case WLAN_HT_CAP_SM_PS_STATIC:
 279                 smps_mode = IEEE80211_SMPS_STATIC;
 280                 break;
 281         case WLAN_HT_CAP_SM_PS_DYNAMIC:
 282                 smps_mode = IEEE80211_SMPS_DYNAMIC;
 283                 break;
 284         case WLAN_HT_CAP_SM_PS_DISABLED:
 285                 smps_mode = IEEE80211_SMPS_OFF;
 286                 break;
 287         }
 288
 289         if (smps_mode != sta->sta.smps_mode)
 290                 changed = true;
 291         sta->sta.smps_mode = smps_mode;
 292
 293         return changed;
 294 }
 295
 296 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta,
 297                                          enum ieee80211_agg_stop_reason reason)
 298 {
 299         int i;
 300
 301         mutex_lock(&sta->ampdu_mlme.mtx);
 302         for (i = 0; i <  IEEE80211_NUM_TIDS; i++)
 303                 ___ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
 304                                                 WLAN_REASON_QSTA_LEAVE_QBSS,
 305                                                 reason != AGG_STOP_DESTROY_STA &&
 306                                                 reason != AGG_STOP_PEER_REQUEST);
 307
 308         for (i = 0; i <  IEEE80211_NUM_TIDS; i++)
 309                 ___ieee80211_stop_tx_ba_session(sta, i, reason);
 310         mutex_unlock(&sta->ampdu_mlme.mtx);
 311
 312         /*
 313          * In case the tear down is part of a reconfigure due to HW restart
 314          * request, it is possible that the low level driver requested to stop
 315          * the BA session, so handle it to properly clean tid_tx data.
 316          */
 317         if(reason == AGG_STOP_DESTROY_STA) {
 318                 cancel_work_sync(&sta->ampdu_mlme.work);
 319
 320                 mutex_lock(&sta->ampdu_mlme.mtx);
 321                 for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
 322                         struct tid_ampdu_tx *tid_tx =
 323                                 rcu_dereference_protected_tid_tx(sta, i);
 324
 325                         if (!tid_tx)
 326                                 continue;
 327
 328                         if (test_and_clear_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state))
 329                                 ieee80211_stop_tx_ba_cb(sta, i, tid_tx);
 330                 }
 331                 mutex_unlock(&sta->ampdu_mlme.mtx);
 332         }
 333 }
 334
 335 void ieee80211_ba_session_work(struct work_struct *work)
 336 {
 337         struct sta_info *sta =
 338                 container_of(work, struct sta_info, ampdu_mlme.work);
 339         struct tid_ampdu_tx *tid_tx;
 340         bool blocked;
 341         int tid;
 342
 343         /* When this flag is set, new sessions should be blocked. */
 344         blocked = test_sta_flag(sta, WLAN_STA_BLOCK_BA);
 345
 346         mutex_lock(&sta->ampdu_mlme.mtx);
 347         for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
 348                 if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
 349                         ___ieee80211_stop_rx_ba_session(
 350                                 sta, tid, WLAN_BACK_RECIPIENT,
 351                                 WLAN_REASON_QSTA_TIMEOUT, true);
 352
 353                 if (test_and_clear_bit(tid,
 354                                        sta->ampdu_mlme.tid_rx_stop_requested))
 355                         ___ieee80211_stop_rx_ba_session(
 356                                 sta, tid, WLAN_BACK_RECIPIENT,
 357                                 WLAN_REASON_UNSPECIFIED, true);
 358
 359                 if (!blocked &&
 360                     test_and_clear_bit(tid,
 361                                        sta->ampdu_mlme.tid_rx_manage_offl))
 362                         ___ieee80211_start_rx_ba_session(sta, 0, 0, 0, 1, tid,
 363                                                          IEEE80211_MAX_AMPDU_BUF_HT,
 364                                                          false, true);
 365
 366                 if (test_and_clear_bit(tid + IEEE80211_NUM_TIDS,
 367                                        sta->ampdu_mlme.tid_rx_manage_offl))
 368                         ___ieee80211_stop_rx_ba_session(
 369                                 sta, tid, WLAN_BACK_RECIPIENT,
 370                                 0, false);
 371
 372                 spin_lock_bh(&sta->lock);
 373
 374                 tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
 375                 if (!blocked && tid_tx) {
 376                         /*
 377                          * Assign it over to the normal tid_tx array
 378                          * where it "goes live".
 379                          */
 380
 381                         sta->ampdu_mlme.tid_start_tx[tid] = NULL;
 382                         /* could there be a race? */
 383                         if (sta->ampdu_mlme.tid_tx[tid])
 384                                 kfree(tid_tx);
 385                         else
 386                                 ieee80211_assign_tid_tx(sta, tid, tid_tx);
 387                         spin_unlock_bh(&sta->lock);
 388
 389                         ieee80211_tx_ba_session_handle_start(sta, tid);
 390                         continue;
 391                 }
 392                 spin_unlock_bh(&sta->lock);
 393
 394                 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 395                 if (!tid_tx)
 396                         continue;
 397
 398                 if (!blocked &&
 399                     test_and_clear_bit(HT_AGG_STATE_START_CB, &tid_tx->state))
 400                         ieee80211_start_tx_ba_cb(sta, tid, tid_tx);
 401                 if (test_and_clear_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state))
 402                         ___ieee80211_stop_tx_ba_session(sta, tid,
 403                                                         AGG_STOP_LOCAL_REQUEST);
 404                 if (test_and_clear_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state))
 405                         ieee80211_stop_tx_ba_cb(sta, tid, tid_tx);
 406         }
 407         mutex_unlock(&sta->ampdu_mlme.mtx);
 408 }
 409
 410 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
 411                           const u8 *da, u16 tid,
 412                           u16 initiator, u16 reason_code)
 413 {
 414         struct ieee80211_local *local = sdata->local;
 415         struct sk_buff *skb;
 416         struct ieee80211_mgmt *mgmt;
 417         u16 params;
 418
 419         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 420         if (!skb)
 421                 return;
 422
 423         skb_reserve(skb, local->hw.extra_tx_headroom);
 424         mgmt = skb_put_zero(skb, 24);
 425         memcpy(mgmt->da, da, ETH_ALEN);
 426         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 427         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 428             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
 429             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 430                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 431         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 432                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 433         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 434                 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 435
 436         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 437                                           IEEE80211_STYPE_ACTION);
 438
 439         skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
 440
 441         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 442         mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
 443         params = (u16)(initiator << 11);        /* bit 11 initiator */
 444         params |= (u16)(tid << 12);             /* bit 15:12 TID number */
 445
 446         mgmt->u.action.u.delba.params = cpu_to_le16(params);
 447         mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
 448
 449         ieee80211_tx_skb(sdata, skb);
 450 }
 451
 452 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
 453                              struct sta_info *sta,
 454                              struct ieee80211_mgmt *mgmt, size_t len)
 455 {
 456         u16 tid, params;
 457         u16 initiator;
 458
 459         params = le16_to_cpu(mgmt->u.action.u.delba.params);
 460         tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
 461         initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
 462
 463         ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
 464                            mgmt->sa, initiator ? "initiator" : "recipient",
 465                            tid,
 466                            le16_to_cpu(mgmt->u.action.u.delba.reason_code));
 467
 468         if (initiator == WLAN_BACK_INITIATOR)
 469                 __ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
 470                                                true);
 471         else
 472                 __ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_PEER_REQUEST);
 473 }
 474
 475 enum nl80211_smps_mode
 476 ieee80211_smps_mode_to_smps_mode(enum ieee80211_smps_mode smps)
 477 {
 478         switch (smps) {
 479         case IEEE80211_SMPS_OFF:
 480                 return NL80211_SMPS_OFF;
 481         case IEEE80211_SMPS_STATIC:
 482                 return NL80211_SMPS_STATIC;
 483         case IEEE80211_SMPS_DYNAMIC:
 484                 return NL80211_SMPS_DYNAMIC;
 485         default:
 486                 return NL80211_SMPS_OFF;
 487         }
 488 }
 489
 490 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
 491                                enum ieee80211_smps_mode smps, const u8 *da,
 492                                const u8 *bssid)
 493 {
 494         struct ieee80211_local *local = sdata->local;
 495         struct sk_buff *skb;
 496         struct ieee80211_mgmt *action_frame;
 497
 498         /* 27 = header + category + action + smps mode */
 499         skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
 500         if (!skb)
 501                 return -ENOMEM;
 502
 503         skb_reserve(skb, local->hw.extra_tx_headroom);
 504         action_frame = skb_put(skb, 27);
 505         memcpy(action_frame->da, da, ETH_ALEN);
 506         memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
 507         memcpy(action_frame->bssid, bssid, ETH_ALEN);
 508         action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 509                                                   IEEE80211_STYPE_ACTION);
 510         action_frame->u.action.category = WLAN_CATEGORY_HT;
 511         action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
 512         switch (smps) {
 513         case IEEE80211_SMPS_AUTOMATIC:
 514         case IEEE80211_SMPS_NUM_MODES:
 515                 WARN_ON(1);
 516                 /* fall through */
 517         case IEEE80211_SMPS_OFF:
 518                 action_frame->u.action.u.ht_smps.smps_control =
 519                                 WLAN_HT_SMPS_CONTROL_DISABLED;
 520                 break;
 521         case IEEE80211_SMPS_STATIC:
 522                 action_frame->u.action.u.ht_smps.smps_control =
 523                                 WLAN_HT_SMPS_CONTROL_STATIC;
 524                 break;
 525         case IEEE80211_SMPS_DYNAMIC:
 526                 action_frame->u.action.u.ht_smps.smps_control =
 527                                 WLAN_HT_SMPS_CONTROL_DYNAMIC;
 528                 break;
 529         }
 530
 531         /* we'll do more on status of this frame */
 532         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 533         ieee80211_tx_skb(sdata, skb);
 534
 535         return 0;
 536 }
 537
 538 void ieee80211_request_smps_mgd_work(struct work_struct *work)
 539 {
 540         struct ieee80211_sub_if_data *sdata =
 541                 container_of(work, struct ieee80211_sub_if_data,
 542                              u.mgd.request_smps_work);
 543
 544         sdata_lock(sdata);
 545         __ieee80211_request_smps_mgd(sdata, sdata->u.mgd.driver_smps_mode);
 546         sdata_unlock(sdata);
 547 }
 548
 549 void ieee80211_request_smps_ap_work(struct work_struct *work)
 550 {
 551         struct ieee80211_sub_if_data *sdata =
 552                 container_of(work, struct ieee80211_sub_if_data,
 553                              u.ap.request_smps_work);
 554
 555         sdata_lock(sdata);
 556         if (sdata_dereference(sdata->u.ap.beacon, sdata))
 557                 __ieee80211_request_smps_ap(sdata,
 558                                             sdata->u.ap.driver_smps_mode);
 559         sdata_unlock(sdata);
 560 }
 561
 562 void ieee80211_request_smps(struct ieee80211_vif *vif,
 563                             enum ieee80211_smps_mode smps_mode)
 564 {
 565         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 566
 567         if (WARN_ON_ONCE(vif->type != NL80211_IFTYPE_STATION &&
 568                          vif->type != NL80211_IFTYPE_AP))
 569                 return;
 570
 571         if (vif->type == NL80211_IFTYPE_STATION) {
 572                 if (sdata->u.mgd.driver_smps_mode == smps_mode)
 573                         return;
 574                 sdata->u.mgd.driver_smps_mode = smps_mode;
 575                 ieee80211_queue_work(&sdata->local->hw,
 576                                      &sdata->u.mgd.request_smps_work);
 577         } else {
 578                 /* AUTOMATIC is meaningless in AP mode */
 579                 if (WARN_ON_ONCE(smps_mode == IEEE80211_SMPS_AUTOMATIC))
 580                         return;
 581                 if (sdata->u.ap.driver_smps_mode == smps_mode)
 582                         return;
 583                 sdata->u.ap.driver_smps_mode = smps_mode;
 584                 ieee80211_queue_work(&sdata->local->hw,
 585                                      &sdata->u.ap.request_smps_work);
 586         }
 587 }
 588 /* this might change ... don't want non-open drivers using it */
 589 EXPORT_SYMBOL_GPL(ieee80211_request_smps);