net/mac80211/ht.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * HT handling
   4  *
   5  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   6  * Copyright 2002-2005, Instant802 Networks, Inc.
   7  * Copyright 2005-2006, Devicescape Software, Inc.
   8  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   9  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
  10  * Copyright 2007-2010, Intel Corporation
  11  * Copyright 2017       Intel Deutschland GmbH
  12  */
  13
  14 #include <linux/ieee80211.h>
  15 #include <linux/export.h>
  16 #include <net/mac80211.h>
  17 #include "ieee80211_i.h"
  18 #include "rate.h"
  19
  20 static void __check_htcap_disable(struct ieee80211_ht_cap *ht_capa,
  21                                   struct ieee80211_ht_cap *ht_capa_mask,
  22                                   struct ieee80211_sta_ht_cap *ht_cap,
  23                                   u16 flag)
  24 {
  25         __le16 le_flag = cpu_to_le16(flag);
  26         if (ht_capa_mask->cap_info & le_flag) {
  27                 if (!(ht_capa->cap_info & le_flag))
  28                         ht_cap->cap &= ~flag;
  29         }
  30 }
  31
  32 static void __check_htcap_enable(struct ieee80211_ht_cap *ht_capa,
  33                                   struct ieee80211_ht_cap *ht_capa_mask,
  34                                   struct ieee80211_sta_ht_cap *ht_cap,
  35                                   u16 flag)
  36 {
  37         __le16 le_flag = cpu_to_le16(flag);
  38
  39         if ((ht_capa_mask->cap_info & le_flag) &&
  40             (ht_capa->cap_info & le_flag))
  41                 ht_cap->cap |= flag;
  42 }
  43
  44 void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
  45                                      struct ieee80211_sta_ht_cap *ht_cap)
  46 {
  47         struct ieee80211_ht_cap *ht_capa, *ht_capa_mask;
  48         u8 *scaps, *smask;
  49         int i;
  50
  51         if (!ht_cap->ht_supported)
  52                 return;
  53
  54         switch (sdata->vif.type) {
  55         case NL80211_IFTYPE_STATION:
  56                 ht_capa = &sdata->u.mgd.ht_capa;
  57                 ht_capa_mask = &sdata->u.mgd.ht_capa_mask;
  58                 break;
  59         case NL80211_IFTYPE_ADHOC:
  60                 ht_capa = &sdata->u.ibss.ht_capa;
  61                 ht_capa_mask = &sdata->u.ibss.ht_capa_mask;
  62                 break;
  63         default:
  64                 WARN_ON_ONCE(1);
  65                 return;
  66         }
  67
  68         scaps = (u8 *)(&ht_capa->mcs.rx_mask);
  69         smask = (u8 *)(&ht_capa_mask->mcs.rx_mask);
  70
  71         /* NOTE:  If you add more over-rides here, update register_hw
  72          * ht_capa_mod_mask logic in main.c as well.
  73          * And, if this method can ever change ht_cap.ht_supported, fix
  74          * the check in ieee80211_add_ht_ie.
  75          */
  76
  77         /* check for HT over-rides, MCS rates first. */
  78         for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
  79                 u8 m = smask[i];
  80                 ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
  81                 /* Add back rates that are supported */
  82                 ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
  83         }
  84
  85         /* Force removal of HT-40 capabilities? */
  86         __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
  87                               IEEE80211_HT_CAP_SUP_WIDTH_20_40);
  88         __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
  89                               IEEE80211_HT_CAP_SGI_40);
  90
  91         /* Allow user to disable SGI-20 (SGI-40 is handled above) */
  92         __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
  93                               IEEE80211_HT_CAP_SGI_20);
  94
  95         /* Allow user to disable the max-AMSDU bit. */
  96         __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
  97                               IEEE80211_HT_CAP_MAX_AMSDU);
  98
  99         /* Allow user to disable LDPC */
 100         __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
 101                               IEEE80211_HT_CAP_LDPC_CODING);
 102
 103         /* Allow user to enable 40 MHz intolerant bit. */
 104         __check_htcap_enable(ht_capa, ht_capa_mask, ht_cap,
 105                              IEEE80211_HT_CAP_40MHZ_INTOLERANT);
 106
 107         /* Allow user to enable TX STBC bit  */
 108         __check_htcap_enable(ht_capa, ht_capa_mask, ht_cap,
 109                              IEEE80211_HT_CAP_TX_STBC);
 110
 111         /* Allow user to configure RX STBC bits */
 112         if (ht_capa_mask->cap_info & cpu_to_le16(IEEE80211_HT_CAP_RX_STBC))
 113                 ht_cap->cap |= le16_to_cpu(ht_capa->cap_info) &
 114                                         IEEE80211_HT_CAP_RX_STBC;
 115
 116         /* Allow user to decrease AMPDU factor */
 117         if (ht_capa_mask->ampdu_params_info &
 118             IEEE80211_HT_AMPDU_PARM_FACTOR) {
 119                 u8 n = ht_capa->ampdu_params_info &
 120                        IEEE80211_HT_AMPDU_PARM_FACTOR;
 121                 if (n < ht_cap->ampdu_factor)
 122                         ht_cap->ampdu_factor = n;
 123         }
 124
 125         /* Allow the user to increase AMPDU density. */
 126         if (ht_capa_mask->ampdu_params_info &
 127             IEEE80211_HT_AMPDU_PARM_DENSITY) {
 128                 u8 n = (ht_capa->ampdu_params_info &
 129                         IEEE80211_HT_AMPDU_PARM_DENSITY)
 130                         >> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
 131                 if (n > ht_cap->ampdu_density)
 132                         ht_cap->ampdu_density = n;
 133         }
 134 }
 135
 136
 137 bool ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
 138                                        struct ieee80211_supported_band *sband,
 139                                        const struct ieee80211_ht_cap *ht_cap_ie,
 140                                        struct sta_info *sta)
 141 {
 142         struct ieee80211_sta_ht_cap ht_cap, own_cap;
 143         u8 ampdu_info, tx_mcs_set_cap;
 144         int i, max_tx_streams;
 145         bool changed;
 146         enum ieee80211_sta_rx_bandwidth bw;
 147         enum ieee80211_smps_mode smps_mode;
 148
 149         memset(&ht_cap, 0, sizeof(ht_cap));
 150
 151         if (!ht_cap_ie || !sband->ht_cap.ht_supported)
 152                 goto apply;
 153
 154         ht_cap.ht_supported = true;
 155
 156         own_cap = sband->ht_cap;
 157
 158         /*
 159          * If user has specified capability over-rides, take care
 160          * of that if the station we're setting up is the AP or TDLS peer that
 161          * we advertised a restricted capability set to. Override
 162          * our own capabilities and then use those below.
 163          */
 164         if (sdata->vif.type == NL80211_IFTYPE_STATION ||
 165             sdata->vif.type == NL80211_IFTYPE_ADHOC)
 166                 ieee80211_apply_htcap_overrides(sdata, &own_cap);
 167
 168         /*
 169          * The bits listed in this expression should be
 170          * the same for the peer and us, if the station
 171          * advertises more then we can't use those thus
 172          * we mask them out.
 173          */
 174         ht_cap.cap = le16_to_cpu(ht_cap_ie->cap_info) &
 175                 (own_cap.cap | ~(IEEE80211_HT_CAP_LDPC_CODING |
 176                                  IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
 177                                  IEEE80211_HT_CAP_GRN_FLD |
 178                                  IEEE80211_HT_CAP_SGI_20 |
 179                                  IEEE80211_HT_CAP_SGI_40 |
 180                                  IEEE80211_HT_CAP_DSSSCCK40));
 181
 182         /*
 183          * The STBC bits are asymmetric -- if we don't have
 184          * TX then mask out the peer's RX and vice versa.
 185          */
 186         if (!(own_cap.cap & IEEE80211_HT_CAP_TX_STBC))
 187                 ht_cap.cap &= ~IEEE80211_HT_CAP_RX_STBC;
 188         if (!(own_cap.cap & IEEE80211_HT_CAP_RX_STBC))
 189                 ht_cap.cap &= ~IEEE80211_HT_CAP_TX_STBC;
 190
 191         ampdu_info = ht_cap_ie->ampdu_params_info;
 192         ht_cap.ampdu_factor =
 193                 ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
 194         ht_cap.ampdu_density =
 195                 (ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
 196
 197         /* own MCS TX capabilities */
 198         tx_mcs_set_cap = own_cap.mcs.tx_params;
 199
 200         /* Copy peer MCS TX capabilities, the driver might need them. */
 201         ht_cap.mcs.tx_params = ht_cap_ie->mcs.tx_params;
 202
 203         /* can we TX with MCS rates? */
 204         if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
 205                 goto apply;
 206
 207         /* Counting from 0, therefore +1 */
 208         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
 209                 max_tx_streams =
 210                         ((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
 211                                 >> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
 212         else
 213                 max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
 214
 215         /*
 216          * 802.11n-2009 20.3.5 / 20.6 says:
 217          * - indices 0 to 7 and 32 are single spatial stream
 218          * - 8 to 31 are multiple spatial streams using equal modulation
 219          *   [8..15 for two streams, 16..23 for three and 24..31 for four]
 220          * - remainder are multiple spatial streams using unequal modulation
 221          */
 222         for (i = 0; i < max_tx_streams; i++)
 223                 ht_cap.mcs.rx_mask[i] =
 224                         own_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
 225
 226         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
 227                 for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
 228                      i < IEEE80211_HT_MCS_MASK_LEN; i++)
 229                         ht_cap.mcs.rx_mask[i] =
 230                                 own_cap.mcs.rx_mask[i] &
 231                                         ht_cap_ie->mcs.rx_mask[i];
 232
 233         /* handle MCS rate 32 too */
 234         if (own_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
 235                 ht_cap.mcs.rx_mask[32/8] |= 1;
 236
 237         /* set Rx highest rate */
 238         ht_cap.mcs.rx_highest = ht_cap_ie->mcs.rx_highest;
 239
 240         if (ht_cap.cap & IEEE80211_HT_CAP_MAX_AMSDU)
 241                 sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_HT_7935;
 242         else
 243                 sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_HT_3839;
 244
 245  apply:
 246         changed = memcmp(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
 247
 248         memcpy(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
 249
 250         switch (sdata->vif.bss_conf.chandef.width) {
 251         default:
 252                 WARN_ON_ONCE(1);
 253                 /* fall through */
 254         case NL80211_CHAN_WIDTH_20_NOHT:
 255         case NL80211_CHAN_WIDTH_20:
 256                 bw = IEEE80211_STA_RX_BW_20;
 257                 break;
 258         case NL80211_CHAN_WIDTH_40:
 259         case NL80211_CHAN_WIDTH_80:
 260         case NL80211_CHAN_WIDTH_80P80:
 261         case NL80211_CHAN_WIDTH_160:
 262                 bw = ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
 263                                 IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
 264                 break;
 265         }
 266
 267         sta->sta.bandwidth = bw;
 268
 269         sta->cur_max_bandwidth =
 270                 ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
 271                                 IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
 272
 273         switch ((ht_cap.cap & IEEE80211_HT_CAP_SM_PS)
 274                         >> IEEE80211_HT_CAP_SM_PS_SHIFT) {
 275         case WLAN_HT_CAP_SM_PS_INVALID:
 276         case WLAN_HT_CAP_SM_PS_STATIC:
 277                 smps_mode = IEEE80211_SMPS_STATIC;
 278                 break;
 279         case WLAN_HT_CAP_SM_PS_DYNAMIC:
 280                 smps_mode = IEEE80211_SMPS_DYNAMIC;
 281                 break;
 282         case WLAN_HT_CAP_SM_PS_DISABLED:
 283                 smps_mode = IEEE80211_SMPS_OFF;
 284                 break;
 285         }
 286
 287         if (smps_mode != sta->sta.smps_mode)
 288                 changed = true;
 289         sta->sta.smps_mode = smps_mode;
 290
 291         return changed;
 292 }
 293
 294 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta,
 295                                          enum ieee80211_agg_stop_reason reason)
 296 {
 297         int i;
 298
 299         mutex_lock(&sta->ampdu_mlme.mtx);
 300         for (i = 0; i <  IEEE80211_NUM_TIDS; i++)
 301                 ___ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
 302                                                 WLAN_REASON_QSTA_LEAVE_QBSS,
 303                                                 reason != AGG_STOP_DESTROY_STA &&
 304                                                 reason != AGG_STOP_PEER_REQUEST);
 305
 306         for (i = 0; i <  IEEE80211_NUM_TIDS; i++)
 307                 ___ieee80211_stop_tx_ba_session(sta, i, reason);
 308         mutex_unlock(&sta->ampdu_mlme.mtx);
 309
 310         /*
 311          * In case the tear down is part of a reconfigure due to HW restart
 312          * request, it is possible that the low level driver requested to stop
 313          * the BA session, so handle it to properly clean tid_tx data.
 314          */
 315         if(reason == AGG_STOP_DESTROY_STA) {
 316                 cancel_work_sync(&sta->ampdu_mlme.work);
 317
 318                 mutex_lock(&sta->ampdu_mlme.mtx);
 319                 for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
 320                         struct tid_ampdu_tx *tid_tx =
 321                                 rcu_dereference_protected_tid_tx(sta, i);
 322
 323                         if (!tid_tx)
 324                                 continue;
 325
 326                         if (test_and_clear_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state))
 327                                 ieee80211_stop_tx_ba_cb(sta, i, tid_tx);
 328                 }
 329                 mutex_unlock(&sta->ampdu_mlme.mtx);
 330         }
 331 }
 332
 333 void ieee80211_ba_session_work(struct work_struct *work)
 334 {
 335         struct sta_info *sta =
 336                 container_of(work, struct sta_info, ampdu_mlme.work);
 337         struct tid_ampdu_tx *tid_tx;
 338         bool blocked;
 339         int tid;
 340
 341         /* When this flag is set, new sessions should be blocked. */
 342         blocked = test_sta_flag(sta, WLAN_STA_BLOCK_BA);
 343
 344         mutex_lock(&sta->ampdu_mlme.mtx);
 345         for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
 346                 if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
 347                         ___ieee80211_stop_rx_ba_session(
 348                                 sta, tid, WLAN_BACK_RECIPIENT,
 349                                 WLAN_REASON_QSTA_TIMEOUT, true);
 350
 351                 if (test_and_clear_bit(tid,
 352                                        sta->ampdu_mlme.tid_rx_stop_requested))
 353                         ___ieee80211_stop_rx_ba_session(
 354                                 sta, tid, WLAN_BACK_RECIPIENT,
 355                                 WLAN_REASON_UNSPECIFIED, true);
 356
 357                 if (!blocked &&
 358                     test_and_clear_bit(tid,
 359                                        sta->ampdu_mlme.tid_rx_manage_offl))
 360                         ___ieee80211_start_rx_ba_session(sta, 0, 0, 0, 1, tid,
 361                                                          IEEE80211_MAX_AMPDU_BUF_HT,
 362                                                          false, true);
 363
 364                 if (test_and_clear_bit(tid + IEEE80211_NUM_TIDS,
 365                                        sta->ampdu_mlme.tid_rx_manage_offl))
 366                         ___ieee80211_stop_rx_ba_session(
 367                                 sta, tid, WLAN_BACK_RECIPIENT,
 368                                 0, false);
 369
 370                 spin_lock_bh(&sta->lock);
 371
 372                 tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
 373                 if (!blocked && tid_tx) {
 374                         /*
 375                          * Assign it over to the normal tid_tx array
 376                          * where it "goes live".
 377                          */
 378
 379                         sta->ampdu_mlme.tid_start_tx[tid] = NULL;
 380                         /* could there be a race? */
 381                         if (sta->ampdu_mlme.tid_tx[tid])
 382                                 kfree(tid_tx);
 383                         else
 384                                 ieee80211_assign_tid_tx(sta, tid, tid_tx);
 385                         spin_unlock_bh(&sta->lock);
 386
 387                         ieee80211_tx_ba_session_handle_start(sta, tid);
 388                         continue;
 389                 }
 390                 spin_unlock_bh(&sta->lock);
 391
 392                 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 393                 if (!tid_tx)
 394                         continue;
 395
 396                 if (!blocked &&
 397                     test_and_clear_bit(HT_AGG_STATE_START_CB, &tid_tx->state))
 398                         ieee80211_start_tx_ba_cb(sta, tid, tid_tx);
 399                 if (test_and_clear_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state))
 400                         ___ieee80211_stop_tx_ba_session(sta, tid,
 401                                                         AGG_STOP_LOCAL_REQUEST);
 402                 if (test_and_clear_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state))
 403                         ieee80211_stop_tx_ba_cb(sta, tid, tid_tx);
 404         }
 405         mutex_unlock(&sta->ampdu_mlme.mtx);
 406 }
 407
 408 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
 409                           const u8 *da, u16 tid,
 410                           u16 initiator, u16 reason_code)
 411 {
 412         struct ieee80211_local *local = sdata->local;
 413         struct sk_buff *skb;
 414         struct ieee80211_mgmt *mgmt;
 415         u16 params;
 416
 417         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 418         if (!skb)
 419                 return;
 420
 421         skb_reserve(skb, local->hw.extra_tx_headroom);
 422         mgmt = skb_put_zero(skb, 24);
 423         memcpy(mgmt->da, da, ETH_ALEN);
 424         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 425         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 426             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
 427             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 428                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 429         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 430                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 431         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 432                 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 433
 434         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 435                                           IEEE80211_STYPE_ACTION);
 436
 437         skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
 438
 439         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 440         mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
 441         params = (u16)(initiator << 11);        /* bit 11 initiator */
 442         params |= (u16)(tid << 12);             /* bit 15:12 TID number */
 443
 444         mgmt->u.action.u.delba.params = cpu_to_le16(params);
 445         mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
 446
 447         ieee80211_tx_skb(sdata, skb);
 448 }
 449
 450 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
 451                              struct sta_info *sta,
 452                              struct ieee80211_mgmt *mgmt, size_t len)
 453 {
 454         u16 tid, params;
 455         u16 initiator;
 456
 457         params = le16_to_cpu(mgmt->u.action.u.delba.params);
 458         tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
 459         initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
 460
 461         ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
 462                            mgmt->sa, initiator ? "initiator" : "recipient",
 463                            tid,
 464                            le16_to_cpu(mgmt->u.action.u.delba.reason_code));
 465
 466         if (initiator == WLAN_BACK_INITIATOR)
 467                 __ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
 468                                                true);
 469         else
 470                 __ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_PEER_REQUEST);
 471 }
 472
 473 enum nl80211_smps_mode
 474 ieee80211_smps_mode_to_smps_mode(enum ieee80211_smps_mode smps)
 475 {
 476         switch (smps) {
 477         case IEEE80211_SMPS_OFF:
 478                 return NL80211_SMPS_OFF;
 479         case IEEE80211_SMPS_STATIC:
 480                 return NL80211_SMPS_STATIC;
 481         case IEEE80211_SMPS_DYNAMIC:
 482                 return NL80211_SMPS_DYNAMIC;
 483         default:
 484                 return NL80211_SMPS_OFF;
 485         }
 486 }
 487
 488 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
 489                                enum ieee80211_smps_mode smps, const u8 *da,
 490                                const u8 *bssid)
 491 {
 492         struct ieee80211_local *local = sdata->local;
 493         struct sk_buff *skb;
 494         struct ieee80211_mgmt *action_frame;
 495
 496         /* 27 = header + category + action + smps mode */
 497         skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
 498         if (!skb)
 499                 return -ENOMEM;
 500
 501         skb_reserve(skb, local->hw.extra_tx_headroom);
 502         action_frame = skb_put(skb, 27);
 503         memcpy(action_frame->da, da, ETH_ALEN);
 504         memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
 505         memcpy(action_frame->bssid, bssid, ETH_ALEN);
 506         action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 507                                                   IEEE80211_STYPE_ACTION);
 508         action_frame->u.action.category = WLAN_CATEGORY_HT;
 509         action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
 510         switch (smps) {
 511         case IEEE80211_SMPS_AUTOMATIC:
 512         case IEEE80211_SMPS_NUM_MODES:
 513                 WARN_ON(1);
 514                 /* fall through */
 515         case IEEE80211_SMPS_OFF:
 516                 action_frame->u.action.u.ht_smps.smps_control =
 517                                 WLAN_HT_SMPS_CONTROL_DISABLED;
 518                 break;
 519         case IEEE80211_SMPS_STATIC:
 520                 action_frame->u.action.u.ht_smps.smps_control =
 521                                 WLAN_HT_SMPS_CONTROL_STATIC;
 522                 break;
 523         case IEEE80211_SMPS_DYNAMIC:
 524                 action_frame->u.action.u.ht_smps.smps_control =
 525                                 WLAN_HT_SMPS_CONTROL_DYNAMIC;
 526                 break;
 527         }
 528
 529         /* we'll do more on status of this frame */
 530         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 531         ieee80211_tx_skb(sdata, skb);
 532
 533         return 0;
 534 }
 535
 536 void ieee80211_request_smps_mgd_work(struct work_struct *work)
 537 {
 538         struct ieee80211_sub_if_data *sdata =
 539                 container_of(work, struct ieee80211_sub_if_data,
 540                              u.mgd.request_smps_work);
 541
 542         sdata_lock(sdata);
 543         __ieee80211_request_smps_mgd(sdata, sdata->u.mgd.driver_smps_mode);
 544         sdata_unlock(sdata);
 545 }
 546
 547 void ieee80211_request_smps_ap_work(struct work_struct *work)
 548 {
 549         struct ieee80211_sub_if_data *sdata =
 550                 container_of(work, struct ieee80211_sub_if_data,
 551                              u.ap.request_smps_work);
 552
 553         sdata_lock(sdata);
 554         if (sdata_dereference(sdata->u.ap.beacon, sdata))
 555                 __ieee80211_request_smps_ap(sdata,
 556                                             sdata->u.ap.driver_smps_mode);
 557         sdata_unlock(sdata);
 558 }
 559
 560 void ieee80211_request_smps(struct ieee80211_vif *vif,
 561                             enum ieee80211_smps_mode smps_mode)
 562 {
 563         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 564
 565         if (WARN_ON_ONCE(vif->type != NL80211_IFTYPE_STATION &&
 566                          vif->type != NL80211_IFTYPE_AP))
 567                 return;
 568
 569         if (vif->type == NL80211_IFTYPE_STATION) {
 570                 if (sdata->u.mgd.driver_smps_mode == smps_mode)
 571                         return;
 572                 sdata->u.mgd.driver_smps_mode = smps_mode;
 573                 ieee80211_queue_work(&sdata->local->hw,
 574                                      &sdata->u.mgd.request_smps_work);
 575         } else {
 576                 /* AUTOMATIC is meaningless in AP mode */
 577                 if (WARN_ON_ONCE(smps_mode == IEEE80211_SMPS_AUTOMATIC))
 578                         return;
 579                 if (sdata->u.ap.driver_smps_mode == smps_mode)
 580                         return;
 581                 sdata->u.ap.driver_smps_mode = smps_mode;
 582                 ieee80211_queue_work(&sdata->local->hw,
 583                                      &sdata->u.ap.request_smps_work);
 584         }
 585 }
 586 /* this might change ... don't want non-open drivers using it */
 587 EXPORT_SYMBOL_GPL(ieee80211_request_smps);