xref: /linux/net/mac80211/ht.c (revision 9e7c9b8eb719835638ee74d93dccc2173581324c)
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  * Copyright(c) 2020-2022 Intel Corporation
13  */
14 
15 #include <linux/ieee80211.h>
16 #include <linux/export.h>
17 #include <net/mac80211.h>
18 #include "ieee80211_i.h"
19 #include "rate.h"
20 
21 static void __check_htcap_disable(struct ieee80211_ht_cap *ht_capa,
22 				  struct ieee80211_ht_cap *ht_capa_mask,
23 				  struct ieee80211_sta_ht_cap *ht_cap,
24 				  u16 flag)
25 {
26 	__le16 le_flag = cpu_to_le16(flag);
27 	if (ht_capa_mask->cap_info & le_flag) {
28 		if (!(ht_capa->cap_info & le_flag))
29 			ht_cap->cap &= ~flag;
30 	}
31 }
32 
33 static void __check_htcap_enable(struct ieee80211_ht_cap *ht_capa,
34 				  struct ieee80211_ht_cap *ht_capa_mask,
35 				  struct ieee80211_sta_ht_cap *ht_cap,
36 				  u16 flag)
37 {
38 	__le16 le_flag = cpu_to_le16(flag);
39 
40 	if ((ht_capa_mask->cap_info & le_flag) &&
41 	    (ht_capa->cap_info & le_flag))
42 		ht_cap->cap |= flag;
43 }
44 
45 void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
46 				     struct ieee80211_sta_ht_cap *ht_cap)
47 {
48 	struct ieee80211_ht_cap *ht_capa, *ht_capa_mask;
49 	u8 *scaps, *smask;
50 	int i;
51 
52 	if (!ht_cap->ht_supported)
53 		return;
54 
55 	switch (sdata->vif.type) {
56 	case NL80211_IFTYPE_STATION:
57 		ht_capa = &sdata->u.mgd.ht_capa;
58 		ht_capa_mask = &sdata->u.mgd.ht_capa_mask;
59 		break;
60 	case NL80211_IFTYPE_ADHOC:
61 		ht_capa = &sdata->u.ibss.ht_capa;
62 		ht_capa_mask = &sdata->u.ibss.ht_capa_mask;
63 		break;
64 	default:
65 		WARN_ON_ONCE(1);
66 		return;
67 	}
68 
69 	scaps = (u8 *)(&ht_capa->mcs.rx_mask);
70 	smask = (u8 *)(&ht_capa_mask->mcs.rx_mask);
71 
72 	/* NOTE:  If you add more over-rides here, update register_hw
73 	 * ht_capa_mod_mask logic in main.c as well.
74 	 * And, if this method can ever change ht_cap.ht_supported, fix
75 	 * the check in ieee80211_add_ht_ie.
76 	 */
77 
78 	/* check for HT over-rides, MCS rates first. */
79 	for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
80 		u8 m = smask[i];
81 		ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
82 		/* Add back rates that are supported */
83 		ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
84 	}
85 
86 	/* Force removal of HT-40 capabilities? */
87 	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
88 			      IEEE80211_HT_CAP_SUP_WIDTH_20_40);
89 	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
90 			      IEEE80211_HT_CAP_SGI_40);
91 
92 	/* Allow user to disable SGI-20 (SGI-40 is handled above) */
93 	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
94 			      IEEE80211_HT_CAP_SGI_20);
95 
96 	/* Allow user to disable the max-AMSDU bit. */
97 	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
98 			      IEEE80211_HT_CAP_MAX_AMSDU);
99 
100 	/* Allow user to disable LDPC */
101 	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
102 			      IEEE80211_HT_CAP_LDPC_CODING);
103 
104 	/* Allow user to enable 40 MHz intolerant bit. */
105 	__check_htcap_enable(ht_capa, ht_capa_mask, ht_cap,
106 			     IEEE80211_HT_CAP_40MHZ_INTOLERANT);
107 
108 	/* Allow user to enable TX STBC bit  */
109 	__check_htcap_enable(ht_capa, ht_capa_mask, ht_cap,
110 			     IEEE80211_HT_CAP_TX_STBC);
111 
112 	/* Allow user to configure RX STBC bits */
113 	if (ht_capa_mask->cap_info & cpu_to_le16(IEEE80211_HT_CAP_RX_STBC))
114 		ht_cap->cap |= le16_to_cpu(ht_capa->cap_info) &
115 					IEEE80211_HT_CAP_RX_STBC;
116 
117 	/* Allow user to decrease AMPDU factor */
118 	if (ht_capa_mask->ampdu_params_info &
119 	    IEEE80211_HT_AMPDU_PARM_FACTOR) {
120 		u8 n = ht_capa->ampdu_params_info &
121 		       IEEE80211_HT_AMPDU_PARM_FACTOR;
122 		if (n < ht_cap->ampdu_factor)
123 			ht_cap->ampdu_factor = n;
124 	}
125 
126 	/* Allow the user to increase AMPDU density. */
127 	if (ht_capa_mask->ampdu_params_info &
128 	    IEEE80211_HT_AMPDU_PARM_DENSITY) {
129 		u8 n = (ht_capa->ampdu_params_info &
130 			IEEE80211_HT_AMPDU_PARM_DENSITY)
131 			>> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
132 		if (n > ht_cap->ampdu_density)
133 			ht_cap->ampdu_density = n;
134 	}
135 }
136 
137 
138 bool ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
139 				       struct ieee80211_supported_band *sband,
140 				       const struct ieee80211_ht_cap *ht_cap_ie,
141 				       struct link_sta_info *link_sta)
142 {
143 	struct sta_info *sta = link_sta->sta;
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 
150 	memset(&ht_cap, 0, sizeof(ht_cap));
151 
152 	if (!ht_cap_ie || !sband->ht_cap.ht_supported)
153 		goto apply;
154 
155 	ht_cap.ht_supported = true;
156 
157 	own_cap = sband->ht_cap;
158 
159 	/*
160 	 * If user has specified capability over-rides, take care
161 	 * of that if the station we're setting up is the AP or TDLS peer that
162 	 * we advertised a restricted capability set to. Override
163 	 * our own capabilities and then use those below.
164 	 */
165 	if (sdata->vif.type == NL80211_IFTYPE_STATION ||
166 	    sdata->vif.type == NL80211_IFTYPE_ADHOC)
167 		ieee80211_apply_htcap_overrides(sdata, &own_cap);
168 
169 	/*
170 	 * The bits listed in this expression should be
171 	 * the same for the peer and us, if the station
172 	 * advertises more then we can't use those thus
173 	 * we mask them out.
174 	 */
175 	ht_cap.cap = le16_to_cpu(ht_cap_ie->cap_info) &
176 		(own_cap.cap | ~(IEEE80211_HT_CAP_LDPC_CODING |
177 				 IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
178 				 IEEE80211_HT_CAP_GRN_FLD |
179 				 IEEE80211_HT_CAP_SGI_20 |
180 				 IEEE80211_HT_CAP_SGI_40 |
181 				 IEEE80211_HT_CAP_DSSSCCK40));
182 
183 	/*
184 	 * The STBC bits are asymmetric -- if we don't have
185 	 * TX then mask out the peer's RX and vice versa.
186 	 */
187 	if (!(own_cap.cap & IEEE80211_HT_CAP_TX_STBC))
188 		ht_cap.cap &= ~IEEE80211_HT_CAP_RX_STBC;
189 	if (!(own_cap.cap & IEEE80211_HT_CAP_RX_STBC))
190 		ht_cap.cap &= ~IEEE80211_HT_CAP_TX_STBC;
191 
192 	ampdu_info = ht_cap_ie->ampdu_params_info;
193 	ht_cap.ampdu_factor =
194 		ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
195 	ht_cap.ampdu_density =
196 		(ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
197 
198 	/* own MCS TX capabilities */
199 	tx_mcs_set_cap = own_cap.mcs.tx_params;
200 
201 	/* Copy peer MCS TX capabilities, the driver might need them. */
202 	ht_cap.mcs.tx_params = ht_cap_ie->mcs.tx_params;
203 
204 	/* can we TX with MCS rates? */
205 	if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
206 		goto apply;
207 
208 	/* Counting from 0, therefore +1 */
209 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
210 		max_tx_streams =
211 			((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
212 				>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
213 	else
214 		max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
215 
216 	/*
217 	 * 802.11n-2009 20.3.5 / 20.6 says:
218 	 * - indices 0 to 7 and 32 are single spatial stream
219 	 * - 8 to 31 are multiple spatial streams using equal modulation
220 	 *   [8..15 for two streams, 16..23 for three and 24..31 for four]
221 	 * - remainder are multiple spatial streams using unequal modulation
222 	 */
223 	for (i = 0; i < max_tx_streams; i++)
224 		ht_cap.mcs.rx_mask[i] =
225 			own_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
226 
227 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
228 		for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
229 		     i < IEEE80211_HT_MCS_MASK_LEN; i++)
230 			ht_cap.mcs.rx_mask[i] =
231 				own_cap.mcs.rx_mask[i] &
232 					ht_cap_ie->mcs.rx_mask[i];
233 
234 	/* handle MCS rate 32 too */
235 	if (own_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
236 		ht_cap.mcs.rx_mask[32/8] |= 1;
237 
238 	/* set Rx highest rate */
239 	ht_cap.mcs.rx_highest = ht_cap_ie->mcs.rx_highest;
240 
241 	if (ht_cap.cap & IEEE80211_HT_CAP_MAX_AMSDU)
242 		sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_HT_7935;
243 	else
244 		sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_HT_3839;
245 
246  apply:
247 	changed = memcmp(&link_sta->pub->ht_cap, &ht_cap, sizeof(ht_cap));
248 
249 	memcpy(&link_sta->pub->ht_cap, &ht_cap, sizeof(ht_cap));
250 
251 	switch (sdata->vif.link_conf[link_sta->link_id]->chandef.width) {
252 	default:
253 		WARN_ON_ONCE(1);
254 		fallthrough;
255 	case NL80211_CHAN_WIDTH_20_NOHT:
256 	case NL80211_CHAN_WIDTH_20:
257 		bw = IEEE80211_STA_RX_BW_20;
258 		break;
259 	case NL80211_CHAN_WIDTH_40:
260 	case NL80211_CHAN_WIDTH_80:
261 	case NL80211_CHAN_WIDTH_80P80:
262 	case NL80211_CHAN_WIDTH_160:
263 		bw = ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
264 				IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
265 		break;
266 	}
267 
268 	link_sta->pub->bandwidth = bw;
269 
270 	link_sta->cur_max_bandwidth =
271 		ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
272 				IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
273 
274 	if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
275 	    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
276 		enum ieee80211_smps_mode smps_mode;
277 
278 		switch ((ht_cap.cap & IEEE80211_HT_CAP_SM_PS)
279 				>> IEEE80211_HT_CAP_SM_PS_SHIFT) {
280 		case WLAN_HT_CAP_SM_PS_INVALID:
281 		case WLAN_HT_CAP_SM_PS_STATIC:
282 			smps_mode = IEEE80211_SMPS_STATIC;
283 			break;
284 		case WLAN_HT_CAP_SM_PS_DYNAMIC:
285 			smps_mode = IEEE80211_SMPS_DYNAMIC;
286 			break;
287 		case WLAN_HT_CAP_SM_PS_DISABLED:
288 			smps_mode = IEEE80211_SMPS_OFF;
289 			break;
290 		}
291 
292 		if (smps_mode != sta->sta.smps_mode)
293 			changed = true;
294 		sta->sta.smps_mode = smps_mode;
295 	} else {
296 		sta->sta.smps_mode = IEEE80211_SMPS_OFF;
297 	}
298 	return changed;
299 }
300 
301 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta,
302 					 enum ieee80211_agg_stop_reason reason)
303 {
304 	int i;
305 
306 	mutex_lock(&sta->ampdu_mlme.mtx);
307 	for (i = 0; i <  IEEE80211_NUM_TIDS; i++)
308 		___ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
309 						WLAN_REASON_QSTA_LEAVE_QBSS,
310 						reason != AGG_STOP_DESTROY_STA &&
311 						reason != AGG_STOP_PEER_REQUEST);
312 
313 	for (i = 0; i <  IEEE80211_NUM_TIDS; i++)
314 		___ieee80211_stop_tx_ba_session(sta, i, reason);
315 	mutex_unlock(&sta->ampdu_mlme.mtx);
316 
317 	/*
318 	 * In case the tear down is part of a reconfigure due to HW restart
319 	 * request, it is possible that the low level driver requested to stop
320 	 * the BA session, so handle it to properly clean tid_tx data.
321 	 */
322 	if(reason == AGG_STOP_DESTROY_STA) {
323 		cancel_work_sync(&sta->ampdu_mlme.work);
324 
325 		mutex_lock(&sta->ampdu_mlme.mtx);
326 		for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
327 			struct tid_ampdu_tx *tid_tx =
328 				rcu_dereference_protected_tid_tx(sta, i);
329 
330 			if (!tid_tx)
331 				continue;
332 
333 			if (test_and_clear_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state))
334 				ieee80211_stop_tx_ba_cb(sta, i, tid_tx);
335 		}
336 		mutex_unlock(&sta->ampdu_mlme.mtx);
337 	}
338 }
339 
340 void ieee80211_ba_session_work(struct work_struct *work)
341 {
342 	struct sta_info *sta =
343 		container_of(work, struct sta_info, ampdu_mlme.work);
344 	struct tid_ampdu_tx *tid_tx;
345 	bool blocked;
346 	int tid;
347 
348 	/* When this flag is set, new sessions should be blocked. */
349 	blocked = test_sta_flag(sta, WLAN_STA_BLOCK_BA);
350 
351 	mutex_lock(&sta->ampdu_mlme.mtx);
352 	for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
353 		if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
354 			___ieee80211_stop_rx_ba_session(
355 				sta, tid, WLAN_BACK_RECIPIENT,
356 				WLAN_REASON_QSTA_TIMEOUT, true);
357 
358 		if (test_and_clear_bit(tid,
359 				       sta->ampdu_mlme.tid_rx_stop_requested))
360 			___ieee80211_stop_rx_ba_session(
361 				sta, tid, WLAN_BACK_RECIPIENT,
362 				WLAN_REASON_UNSPECIFIED, true);
363 
364 		if (!blocked &&
365 		    test_and_clear_bit(tid,
366 				       sta->ampdu_mlme.tid_rx_manage_offl))
367 			___ieee80211_start_rx_ba_session(sta, 0, 0, 0, 1, tid,
368 							 IEEE80211_MAX_AMPDU_BUF_HT,
369 							 false, true, NULL);
370 
371 		if (test_and_clear_bit(tid + IEEE80211_NUM_TIDS,
372 				       sta->ampdu_mlme.tid_rx_manage_offl))
373 			___ieee80211_stop_rx_ba_session(
374 				sta, tid, WLAN_BACK_RECIPIENT,
375 				0, false);
376 
377 		spin_lock_bh(&sta->lock);
378 
379 		tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
380 		if (!blocked && tid_tx) {
381 			/*
382 			 * Assign it over to the normal tid_tx array
383 			 * where it "goes live".
384 			 */
385 
386 			sta->ampdu_mlme.tid_start_tx[tid] = NULL;
387 			/* could there be a race? */
388 			if (sta->ampdu_mlme.tid_tx[tid])
389 				kfree(tid_tx);
390 			else
391 				ieee80211_assign_tid_tx(sta, tid, tid_tx);
392 			spin_unlock_bh(&sta->lock);
393 
394 			ieee80211_tx_ba_session_handle_start(sta, tid);
395 			continue;
396 		}
397 		spin_unlock_bh(&sta->lock);
398 
399 		tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
400 		if (!tid_tx)
401 			continue;
402 
403 		if (!blocked &&
404 		    test_and_clear_bit(HT_AGG_STATE_START_CB, &tid_tx->state))
405 			ieee80211_start_tx_ba_cb(sta, tid, tid_tx);
406 		if (test_and_clear_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state))
407 			___ieee80211_stop_tx_ba_session(sta, tid,
408 							AGG_STOP_LOCAL_REQUEST);
409 		if (test_and_clear_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state))
410 			ieee80211_stop_tx_ba_cb(sta, tid, tid_tx);
411 	}
412 	mutex_unlock(&sta->ampdu_mlme.mtx);
413 }
414 
415 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
416 			  const u8 *da, u16 tid,
417 			  u16 initiator, u16 reason_code)
418 {
419 	struct ieee80211_local *local = sdata->local;
420 	struct sk_buff *skb;
421 	struct ieee80211_mgmt *mgmt;
422 	u16 params;
423 
424 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
425 	if (!skb)
426 		return;
427 
428 	skb_reserve(skb, local->hw.extra_tx_headroom);
429 	mgmt = skb_put_zero(skb, 24);
430 	memcpy(mgmt->da, da, ETH_ALEN);
431 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
432 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
433 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
434 	    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
435 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
436 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
437 		memcpy(mgmt->bssid, sdata->deflink.u.mgd.bssid, ETH_ALEN);
438 	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
439 		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
440 
441 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
442 					  IEEE80211_STYPE_ACTION);
443 
444 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
445 
446 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
447 	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
448 	params = (u16)(initiator << 11); 	/* bit 11 initiator */
449 	params |= (u16)(tid << 12); 		/* bit 15:12 TID number */
450 
451 	mgmt->u.action.u.delba.params = cpu_to_le16(params);
452 	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
453 
454 	ieee80211_tx_skb(sdata, skb);
455 }
456 
457 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
458 			     struct sta_info *sta,
459 			     struct ieee80211_mgmt *mgmt, size_t len)
460 {
461 	u16 tid, params;
462 	u16 initiator;
463 
464 	params = le16_to_cpu(mgmt->u.action.u.delba.params);
465 	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
466 	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
467 
468 	ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
469 			   mgmt->sa, initiator ? "initiator" : "recipient",
470 			   tid,
471 			   le16_to_cpu(mgmt->u.action.u.delba.reason_code));
472 
473 	if (initiator == WLAN_BACK_INITIATOR)
474 		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
475 					       true);
476 	else
477 		__ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_PEER_REQUEST);
478 }
479 
480 enum nl80211_smps_mode
481 ieee80211_smps_mode_to_smps_mode(enum ieee80211_smps_mode smps)
482 {
483 	switch (smps) {
484 	case IEEE80211_SMPS_OFF:
485 		return NL80211_SMPS_OFF;
486 	case IEEE80211_SMPS_STATIC:
487 		return NL80211_SMPS_STATIC;
488 	case IEEE80211_SMPS_DYNAMIC:
489 		return NL80211_SMPS_DYNAMIC;
490 	default:
491 		return NL80211_SMPS_OFF;
492 	}
493 }
494 
495 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
496 			       enum ieee80211_smps_mode smps, const u8 *da,
497 			       const u8 *bssid)
498 {
499 	struct ieee80211_local *local = sdata->local;
500 	struct sk_buff *skb;
501 	struct ieee80211_mgmt *action_frame;
502 
503 	/* 27 = header + category + action + smps mode */
504 	skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
505 	if (!skb)
506 		return -ENOMEM;
507 
508 	skb_reserve(skb, local->hw.extra_tx_headroom);
509 	action_frame = skb_put(skb, 27);
510 	memcpy(action_frame->da, da, ETH_ALEN);
511 	memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
512 	memcpy(action_frame->bssid, bssid, ETH_ALEN);
513 	action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
514 						  IEEE80211_STYPE_ACTION);
515 	action_frame->u.action.category = WLAN_CATEGORY_HT;
516 	action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
517 	switch (smps) {
518 	case IEEE80211_SMPS_AUTOMATIC:
519 	case IEEE80211_SMPS_NUM_MODES:
520 		WARN_ON(1);
521 		fallthrough;
522 	case IEEE80211_SMPS_OFF:
523 		action_frame->u.action.u.ht_smps.smps_control =
524 				WLAN_HT_SMPS_CONTROL_DISABLED;
525 		break;
526 	case IEEE80211_SMPS_STATIC:
527 		action_frame->u.action.u.ht_smps.smps_control =
528 				WLAN_HT_SMPS_CONTROL_STATIC;
529 		break;
530 	case IEEE80211_SMPS_DYNAMIC:
531 		action_frame->u.action.u.ht_smps.smps_control =
532 				WLAN_HT_SMPS_CONTROL_DYNAMIC;
533 		break;
534 	}
535 
536 	/* we'll do more on status of this frame */
537 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
538 	ieee80211_tx_skb(sdata, skb);
539 
540 	return 0;
541 }
542 
543 void ieee80211_request_smps_mgd_work(struct work_struct *work)
544 {
545 	struct ieee80211_link_data *link =
546 		container_of(work, struct ieee80211_link_data,
547 			     u.mgd.request_smps_work);
548 
549 	sdata_lock(link->sdata);
550 	__ieee80211_request_smps_mgd(link->sdata, link->link_id,
551 				     link->u.mgd.driver_smps_mode);
552 	sdata_unlock(link->sdata);
553 }
554 
555 void ieee80211_request_smps(struct ieee80211_vif *vif, unsigned int link_id,
556 			    enum ieee80211_smps_mode smps_mode)
557 {
558 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
559 	struct ieee80211_link_data *link = sdata->link[link_id];
560 
561 	if (WARN_ON_ONCE(vif->type != NL80211_IFTYPE_STATION))
562 		return;
563 
564 	if (WARN_ON(!link))
565 		return;
566 
567 	if (link->u.mgd.driver_smps_mode == smps_mode)
568 		return;
569 
570 	link->u.mgd.driver_smps_mode = smps_mode;
571 	ieee80211_queue_work(&sdata->local->hw, &link->u.mgd.request_smps_work);
572 }
573 /* this might change ... don't want non-open drivers using it */
574 EXPORT_SYMBOL_GPL(ieee80211_request_smps);
575