xref: /linux/net/mac80211/vht.c (revision 2dbc0838bcf24ca59cabc3130cf3b1d6809cdcd4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * VHT handling
4  *
5  * Portions of this file
6  * Copyright(c) 2015 - 2016 Intel Deutschland GmbH
7  * Copyright (C) 2018 Intel Corporation
8  */
9 
10 #include <linux/ieee80211.h>
11 #include <linux/export.h>
12 #include <net/mac80211.h>
13 #include "ieee80211_i.h"
14 #include "rate.h"
15 
16 
17 static void __check_vhtcap_disable(struct ieee80211_sub_if_data *sdata,
18 				   struct ieee80211_sta_vht_cap *vht_cap,
19 				   u32 flag)
20 {
21 	__le32 le_flag = cpu_to_le32(flag);
22 
23 	if (sdata->u.mgd.vht_capa_mask.vht_cap_info & le_flag &&
24 	    !(sdata->u.mgd.vht_capa.vht_cap_info & le_flag))
25 		vht_cap->cap &= ~flag;
26 }
27 
28 void ieee80211_apply_vhtcap_overrides(struct ieee80211_sub_if_data *sdata,
29 				      struct ieee80211_sta_vht_cap *vht_cap)
30 {
31 	int i;
32 	u16 rxmcs_mask, rxmcs_cap, rxmcs_n, txmcs_mask, txmcs_cap, txmcs_n;
33 
34 	if (!vht_cap->vht_supported)
35 		return;
36 
37 	if (sdata->vif.type != NL80211_IFTYPE_STATION)
38 		return;
39 
40 	__check_vhtcap_disable(sdata, vht_cap,
41 			       IEEE80211_VHT_CAP_RXLDPC);
42 	__check_vhtcap_disable(sdata, vht_cap,
43 			       IEEE80211_VHT_CAP_SHORT_GI_80);
44 	__check_vhtcap_disable(sdata, vht_cap,
45 			       IEEE80211_VHT_CAP_SHORT_GI_160);
46 	__check_vhtcap_disable(sdata, vht_cap,
47 			       IEEE80211_VHT_CAP_TXSTBC);
48 	__check_vhtcap_disable(sdata, vht_cap,
49 			       IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE);
50 	__check_vhtcap_disable(sdata, vht_cap,
51 			       IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE);
52 	__check_vhtcap_disable(sdata, vht_cap,
53 			       IEEE80211_VHT_CAP_RX_ANTENNA_PATTERN);
54 	__check_vhtcap_disable(sdata, vht_cap,
55 			       IEEE80211_VHT_CAP_TX_ANTENNA_PATTERN);
56 
57 	/* Allow user to decrease AMPDU length exponent */
58 	if (sdata->u.mgd.vht_capa_mask.vht_cap_info &
59 	    cpu_to_le32(IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK)) {
60 		u32 cap, n;
61 
62 		n = le32_to_cpu(sdata->u.mgd.vht_capa.vht_cap_info) &
63 			IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
64 		n >>= IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_SHIFT;
65 		cap = vht_cap->cap & IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
66 		cap >>= IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_SHIFT;
67 
68 		if (n < cap) {
69 			vht_cap->cap &=
70 				~IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
71 			vht_cap->cap |=
72 				n << IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_SHIFT;
73 		}
74 	}
75 
76 	/* Allow the user to decrease MCSes */
77 	rxmcs_mask =
78 		le16_to_cpu(sdata->u.mgd.vht_capa_mask.supp_mcs.rx_mcs_map);
79 	rxmcs_n = le16_to_cpu(sdata->u.mgd.vht_capa.supp_mcs.rx_mcs_map);
80 	rxmcs_n &= rxmcs_mask;
81 	rxmcs_cap = le16_to_cpu(vht_cap->vht_mcs.rx_mcs_map);
82 
83 	txmcs_mask =
84 		le16_to_cpu(sdata->u.mgd.vht_capa_mask.supp_mcs.tx_mcs_map);
85 	txmcs_n = le16_to_cpu(sdata->u.mgd.vht_capa.supp_mcs.tx_mcs_map);
86 	txmcs_n &= txmcs_mask;
87 	txmcs_cap = le16_to_cpu(vht_cap->vht_mcs.tx_mcs_map);
88 	for (i = 0; i < 8; i++) {
89 		u8 m, n, c;
90 
91 		m = (rxmcs_mask >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
92 		n = (rxmcs_n >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
93 		c = (rxmcs_cap >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
94 
95 		if (m && ((c != IEEE80211_VHT_MCS_NOT_SUPPORTED && n < c) ||
96 			  n == IEEE80211_VHT_MCS_NOT_SUPPORTED)) {
97 			rxmcs_cap &= ~(3 << 2*i);
98 			rxmcs_cap |= (rxmcs_n & (3 << 2*i));
99 		}
100 
101 		m = (txmcs_mask >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
102 		n = (txmcs_n >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
103 		c = (txmcs_cap >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
104 
105 		if (m && ((c != IEEE80211_VHT_MCS_NOT_SUPPORTED && n < c) ||
106 			  n == IEEE80211_VHT_MCS_NOT_SUPPORTED)) {
107 			txmcs_cap &= ~(3 << 2*i);
108 			txmcs_cap |= (txmcs_n & (3 << 2*i));
109 		}
110 	}
111 	vht_cap->vht_mcs.rx_mcs_map = cpu_to_le16(rxmcs_cap);
112 	vht_cap->vht_mcs.tx_mcs_map = cpu_to_le16(txmcs_cap);
113 }
114 
115 void
116 ieee80211_vht_cap_ie_to_sta_vht_cap(struct ieee80211_sub_if_data *sdata,
117 				    struct ieee80211_supported_band *sband,
118 				    const struct ieee80211_vht_cap *vht_cap_ie,
119 				    struct sta_info *sta)
120 {
121 	struct ieee80211_sta_vht_cap *vht_cap = &sta->sta.vht_cap;
122 	struct ieee80211_sta_vht_cap own_cap;
123 	u32 cap_info, i;
124 	bool have_80mhz;
125 
126 	memset(vht_cap, 0, sizeof(*vht_cap));
127 
128 	if (!sta->sta.ht_cap.ht_supported)
129 		return;
130 
131 	if (!vht_cap_ie || !sband->vht_cap.vht_supported)
132 		return;
133 
134 	/* Allow VHT if at least one channel on the sband supports 80 MHz */
135 	have_80mhz = false;
136 	for (i = 0; i < sband->n_channels; i++) {
137 		if (sband->channels[i].flags & (IEEE80211_CHAN_DISABLED |
138 						IEEE80211_CHAN_NO_80MHZ))
139 			continue;
140 
141 		have_80mhz = true;
142 		break;
143 	}
144 
145 	if (!have_80mhz)
146 		return;
147 
148 	/*
149 	 * A VHT STA must support 40 MHz, but if we verify that here
150 	 * then we break a few things - some APs (e.g. Netgear R6300v2
151 	 * and others based on the BCM4360 chipset) will unset this
152 	 * capability bit when operating in 20 MHz.
153 	 */
154 
155 	vht_cap->vht_supported = true;
156 
157 	own_cap = sband->vht_cap;
158 	/*
159 	 * If user has specified capability overrides, take care
160 	 * of that if the station we're setting up is the AP 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 	    !test_sta_flag(sta, WLAN_STA_TDLS_PEER))
166 		ieee80211_apply_vhtcap_overrides(sdata, &own_cap);
167 
168 	/* take some capabilities as-is */
169 	cap_info = le32_to_cpu(vht_cap_ie->vht_cap_info);
170 	vht_cap->cap = cap_info;
171 	vht_cap->cap &= IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_3895 |
172 			IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_7991 |
173 			IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_11454 |
174 			IEEE80211_VHT_CAP_RXLDPC |
175 			IEEE80211_VHT_CAP_VHT_TXOP_PS |
176 			IEEE80211_VHT_CAP_HTC_VHT |
177 			IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK |
178 			IEEE80211_VHT_CAP_VHT_LINK_ADAPTATION_VHT_UNSOL_MFB |
179 			IEEE80211_VHT_CAP_VHT_LINK_ADAPTATION_VHT_MRQ_MFB |
180 			IEEE80211_VHT_CAP_RX_ANTENNA_PATTERN |
181 			IEEE80211_VHT_CAP_TX_ANTENNA_PATTERN;
182 
183 	/* and some based on our own capabilities */
184 	switch (own_cap.cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK) {
185 	case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ:
186 		vht_cap->cap |= cap_info &
187 				IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ;
188 		break;
189 	case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ:
190 		vht_cap->cap |= cap_info &
191 				IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
192 		break;
193 	default:
194 		/* nothing */
195 		break;
196 	}
197 
198 	/* symmetric capabilities */
199 	vht_cap->cap |= cap_info & own_cap.cap &
200 			(IEEE80211_VHT_CAP_SHORT_GI_80 |
201 			 IEEE80211_VHT_CAP_SHORT_GI_160);
202 
203 	/* remaining ones */
204 	if (own_cap.cap & IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE)
205 		vht_cap->cap |= cap_info &
206 				(IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE |
207 				 IEEE80211_VHT_CAP_SOUNDING_DIMENSIONS_MASK);
208 
209 	if (own_cap.cap & IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE)
210 		vht_cap->cap |= cap_info &
211 				(IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE |
212 				 IEEE80211_VHT_CAP_BEAMFORMEE_STS_MASK);
213 
214 	if (own_cap.cap & IEEE80211_VHT_CAP_MU_BEAMFORMER_CAPABLE)
215 		vht_cap->cap |= cap_info &
216 				IEEE80211_VHT_CAP_MU_BEAMFORMEE_CAPABLE;
217 
218 	if (own_cap.cap & IEEE80211_VHT_CAP_MU_BEAMFORMEE_CAPABLE)
219 		vht_cap->cap |= cap_info &
220 				IEEE80211_VHT_CAP_MU_BEAMFORMER_CAPABLE;
221 
222 	if (own_cap.cap & IEEE80211_VHT_CAP_TXSTBC)
223 		vht_cap->cap |= cap_info & IEEE80211_VHT_CAP_RXSTBC_MASK;
224 
225 	if (own_cap.cap & IEEE80211_VHT_CAP_RXSTBC_MASK)
226 		vht_cap->cap |= cap_info & IEEE80211_VHT_CAP_TXSTBC;
227 
228 	/* Copy peer MCS info, the driver might need them. */
229 	memcpy(&vht_cap->vht_mcs, &vht_cap_ie->supp_mcs,
230 	       sizeof(struct ieee80211_vht_mcs_info));
231 
232 	/* copy EXT_NSS_BW Support value or remove the capability */
233 	if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_VHT_EXT_NSS_BW))
234 		vht_cap->cap |= (cap_info & IEEE80211_VHT_CAP_EXT_NSS_BW_MASK);
235 	else
236 		vht_cap->vht_mcs.tx_highest &=
237 			~cpu_to_le16(IEEE80211_VHT_EXT_NSS_BW_CAPABLE);
238 
239 	/* but also restrict MCSes */
240 	for (i = 0; i < 8; i++) {
241 		u16 own_rx, own_tx, peer_rx, peer_tx;
242 
243 		own_rx = le16_to_cpu(own_cap.vht_mcs.rx_mcs_map);
244 		own_rx = (own_rx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
245 
246 		own_tx = le16_to_cpu(own_cap.vht_mcs.tx_mcs_map);
247 		own_tx = (own_tx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
248 
249 		peer_rx = le16_to_cpu(vht_cap->vht_mcs.rx_mcs_map);
250 		peer_rx = (peer_rx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
251 
252 		peer_tx = le16_to_cpu(vht_cap->vht_mcs.tx_mcs_map);
253 		peer_tx = (peer_tx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
254 
255 		if (peer_tx != IEEE80211_VHT_MCS_NOT_SUPPORTED) {
256 			if (own_rx == IEEE80211_VHT_MCS_NOT_SUPPORTED)
257 				peer_tx = IEEE80211_VHT_MCS_NOT_SUPPORTED;
258 			else if (own_rx < peer_tx)
259 				peer_tx = own_rx;
260 		}
261 
262 		if (peer_rx != IEEE80211_VHT_MCS_NOT_SUPPORTED) {
263 			if (own_tx == IEEE80211_VHT_MCS_NOT_SUPPORTED)
264 				peer_rx = IEEE80211_VHT_MCS_NOT_SUPPORTED;
265 			else if (own_tx < peer_rx)
266 				peer_rx = own_tx;
267 		}
268 
269 		vht_cap->vht_mcs.rx_mcs_map &=
270 			~cpu_to_le16(IEEE80211_VHT_MCS_NOT_SUPPORTED << i * 2);
271 		vht_cap->vht_mcs.rx_mcs_map |= cpu_to_le16(peer_rx << i * 2);
272 
273 		vht_cap->vht_mcs.tx_mcs_map &=
274 			~cpu_to_le16(IEEE80211_VHT_MCS_NOT_SUPPORTED << i * 2);
275 		vht_cap->vht_mcs.tx_mcs_map |= cpu_to_le16(peer_tx << i * 2);
276 	}
277 
278 	/*
279 	 * This is a workaround for VHT-enabled STAs which break the spec
280 	 * and have the VHT-MCS Rx map filled in with value 3 for all eight
281 	 * spacial streams, an example is AR9462.
282 	 *
283 	 * As per spec, in section 22.1.1 Introduction to the VHT PHY
284 	 * A VHT STA shall support at least single spactial stream VHT-MCSs
285 	 * 0 to 7 (transmit and receive) in all supported channel widths.
286 	 */
287 	if (vht_cap->vht_mcs.rx_mcs_map == cpu_to_le16(0xFFFF)) {
288 		vht_cap->vht_supported = false;
289 		sdata_info(sdata, "Ignoring VHT IE from %pM due to invalid rx_mcs_map\n",
290 			   sta->addr);
291 		return;
292 	}
293 
294 	/* finally set up the bandwidth */
295 	switch (vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK) {
296 	case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ:
297 	case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ:
298 		sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_160;
299 		break;
300 	default:
301 		sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_80;
302 
303 		if (!(vht_cap->vht_mcs.tx_highest &
304 				cpu_to_le16(IEEE80211_VHT_EXT_NSS_BW_CAPABLE)))
305 			break;
306 
307 		/*
308 		 * If this is non-zero, then it does support 160 MHz after all,
309 		 * in one form or the other. We don't distinguish here (or even
310 		 * above) between 160 and 80+80 yet.
311 		 */
312 		if (cap_info & IEEE80211_VHT_CAP_EXT_NSS_BW_MASK)
313 			sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_160;
314 	}
315 
316 	sta->sta.bandwidth = ieee80211_sta_cur_vht_bw(sta);
317 
318 	/* If HT IE reported 3839 bytes only, stay with that size. */
319 	if (sta->sta.max_amsdu_len == IEEE80211_MAX_MPDU_LEN_HT_3839)
320 		return;
321 
322 	switch (vht_cap->cap & IEEE80211_VHT_CAP_MAX_MPDU_MASK) {
323 	case IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_11454:
324 		sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_VHT_11454;
325 		break;
326 	case IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_7991:
327 		sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_VHT_7991;
328 		break;
329 	case IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_3895:
330 	default:
331 		sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_VHT_3895;
332 		break;
333 	}
334 }
335 
336 enum ieee80211_sta_rx_bandwidth ieee80211_sta_cap_rx_bw(struct sta_info *sta)
337 {
338 	struct ieee80211_sta_vht_cap *vht_cap = &sta->sta.vht_cap;
339 	u32 cap_width;
340 
341 	if (!vht_cap->vht_supported)
342 		return sta->sta.ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
343 				IEEE80211_STA_RX_BW_40 :
344 				IEEE80211_STA_RX_BW_20;
345 
346 	cap_width = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
347 
348 	if (cap_width == IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ ||
349 	    cap_width == IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
350 		return IEEE80211_STA_RX_BW_160;
351 
352 	return IEEE80211_STA_RX_BW_80;
353 }
354 
355 enum nl80211_chan_width ieee80211_sta_cap_chan_bw(struct sta_info *sta)
356 {
357 	struct ieee80211_sta_vht_cap *vht_cap = &sta->sta.vht_cap;
358 	u32 cap_width;
359 
360 	if (!vht_cap->vht_supported) {
361 		if (!sta->sta.ht_cap.ht_supported)
362 			return NL80211_CHAN_WIDTH_20_NOHT;
363 
364 		return sta->sta.ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
365 				NL80211_CHAN_WIDTH_40 : NL80211_CHAN_WIDTH_20;
366 	}
367 
368 	cap_width = vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
369 
370 	if (cap_width == IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ)
371 		return NL80211_CHAN_WIDTH_160;
372 	else if (cap_width == IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ)
373 		return NL80211_CHAN_WIDTH_80P80;
374 
375 	return NL80211_CHAN_WIDTH_80;
376 }
377 
378 enum nl80211_chan_width
379 ieee80211_sta_rx_bw_to_chan_width(struct sta_info *sta)
380 {
381 	enum ieee80211_sta_rx_bandwidth cur_bw = sta->sta.bandwidth;
382 	struct ieee80211_sta_vht_cap *vht_cap = &sta->sta.vht_cap;
383 	u32 cap_width;
384 
385 	switch (cur_bw) {
386 	case IEEE80211_STA_RX_BW_20:
387 		if (!sta->sta.ht_cap.ht_supported)
388 			return NL80211_CHAN_WIDTH_20_NOHT;
389 		else
390 			return NL80211_CHAN_WIDTH_20;
391 	case IEEE80211_STA_RX_BW_40:
392 		return NL80211_CHAN_WIDTH_40;
393 	case IEEE80211_STA_RX_BW_80:
394 		return NL80211_CHAN_WIDTH_80;
395 	case IEEE80211_STA_RX_BW_160:
396 		cap_width =
397 			vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
398 
399 		if (cap_width == IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ)
400 			return NL80211_CHAN_WIDTH_160;
401 
402 		return NL80211_CHAN_WIDTH_80P80;
403 	default:
404 		return NL80211_CHAN_WIDTH_20;
405 	}
406 }
407 
408 enum ieee80211_sta_rx_bandwidth
409 ieee80211_chan_width_to_rx_bw(enum nl80211_chan_width width)
410 {
411 	switch (width) {
412 	case NL80211_CHAN_WIDTH_20_NOHT:
413 	case NL80211_CHAN_WIDTH_20:
414 		return IEEE80211_STA_RX_BW_20;
415 	case NL80211_CHAN_WIDTH_40:
416 		return IEEE80211_STA_RX_BW_40;
417 	case NL80211_CHAN_WIDTH_80:
418 		return IEEE80211_STA_RX_BW_80;
419 	case NL80211_CHAN_WIDTH_160:
420 	case NL80211_CHAN_WIDTH_80P80:
421 		return IEEE80211_STA_RX_BW_160;
422 	default:
423 		WARN_ON_ONCE(1);
424 		return IEEE80211_STA_RX_BW_20;
425 	}
426 }
427 
428 enum ieee80211_sta_rx_bandwidth ieee80211_sta_cur_vht_bw(struct sta_info *sta)
429 {
430 	struct ieee80211_sub_if_data *sdata = sta->sdata;
431 	enum ieee80211_sta_rx_bandwidth bw;
432 	enum nl80211_chan_width bss_width = sdata->vif.bss_conf.chandef.width;
433 
434 	bw = ieee80211_sta_cap_rx_bw(sta);
435 	bw = min(bw, sta->cur_max_bandwidth);
436 
437 	/* Don't consider AP's bandwidth for TDLS peers, section 11.23.1 of
438 	 * IEEE80211-2016 specification makes higher bandwidth operation
439 	 * possible on the TDLS link if the peers have wider bandwidth
440 	 * capability.
441 	 */
442 	if (test_sta_flag(sta, WLAN_STA_TDLS_PEER) &&
443 	    test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW))
444 		return bw;
445 
446 	bw = min(bw, ieee80211_chan_width_to_rx_bw(bss_width));
447 
448 	return bw;
449 }
450 
451 void ieee80211_sta_set_rx_nss(struct sta_info *sta)
452 {
453 	u8 ht_rx_nss = 0, vht_rx_nss = 0;
454 
455 	/* if we received a notification already don't overwrite it */
456 	if (sta->sta.rx_nss)
457 		return;
458 
459 	if (sta->sta.ht_cap.ht_supported) {
460 		if (sta->sta.ht_cap.mcs.rx_mask[0])
461 			ht_rx_nss++;
462 		if (sta->sta.ht_cap.mcs.rx_mask[1])
463 			ht_rx_nss++;
464 		if (sta->sta.ht_cap.mcs.rx_mask[2])
465 			ht_rx_nss++;
466 		if (sta->sta.ht_cap.mcs.rx_mask[3])
467 			ht_rx_nss++;
468 		/* FIXME: consider rx_highest? */
469 	}
470 
471 	if (sta->sta.vht_cap.vht_supported) {
472 		int i;
473 		u16 rx_mcs_map;
474 
475 		rx_mcs_map = le16_to_cpu(sta->sta.vht_cap.vht_mcs.rx_mcs_map);
476 
477 		for (i = 7; i >= 0; i--) {
478 			u8 mcs = (rx_mcs_map >> (2 * i)) & 3;
479 
480 			if (mcs != IEEE80211_VHT_MCS_NOT_SUPPORTED) {
481 				vht_rx_nss = i + 1;
482 				break;
483 			}
484 		}
485 		/* FIXME: consider rx_highest? */
486 	}
487 
488 	ht_rx_nss = max(ht_rx_nss, vht_rx_nss);
489 	sta->sta.rx_nss = max_t(u8, 1, ht_rx_nss);
490 }
491 
492 u32 __ieee80211_vht_handle_opmode(struct ieee80211_sub_if_data *sdata,
493 				  struct sta_info *sta, u8 opmode,
494 				  enum nl80211_band band)
495 {
496 	enum ieee80211_sta_rx_bandwidth new_bw;
497 	struct sta_opmode_info sta_opmode = {};
498 	u32 changed = 0;
499 	u8 nss;
500 
501 	/* ignore - no support for BF yet */
502 	if (opmode & IEEE80211_OPMODE_NOTIF_RX_NSS_TYPE_BF)
503 		return 0;
504 
505 	nss = opmode & IEEE80211_OPMODE_NOTIF_RX_NSS_MASK;
506 	nss >>= IEEE80211_OPMODE_NOTIF_RX_NSS_SHIFT;
507 	nss += 1;
508 
509 	if (sta->sta.rx_nss != nss) {
510 		sta->sta.rx_nss = nss;
511 		sta_opmode.rx_nss = nss;
512 		changed |= IEEE80211_RC_NSS_CHANGED;
513 		sta_opmode.changed |= STA_OPMODE_N_SS_CHANGED;
514 	}
515 
516 	switch (opmode & IEEE80211_OPMODE_NOTIF_CHANWIDTH_MASK) {
517 	case IEEE80211_OPMODE_NOTIF_CHANWIDTH_20MHZ:
518 		sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_20;
519 		break;
520 	case IEEE80211_OPMODE_NOTIF_CHANWIDTH_40MHZ:
521 		sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_40;
522 		break;
523 	case IEEE80211_OPMODE_NOTIF_CHANWIDTH_80MHZ:
524 		sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_80;
525 		break;
526 	case IEEE80211_OPMODE_NOTIF_CHANWIDTH_160MHZ:
527 		sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_160;
528 		break;
529 	}
530 
531 	new_bw = ieee80211_sta_cur_vht_bw(sta);
532 	if (new_bw != sta->sta.bandwidth) {
533 		sta->sta.bandwidth = new_bw;
534 		sta_opmode.bw = ieee80211_sta_rx_bw_to_chan_width(sta);
535 		changed |= IEEE80211_RC_BW_CHANGED;
536 		sta_opmode.changed |= STA_OPMODE_MAX_BW_CHANGED;
537 	}
538 
539 	if (sta_opmode.changed)
540 		cfg80211_sta_opmode_change_notify(sdata->dev, sta->addr,
541 						  &sta_opmode, GFP_KERNEL);
542 
543 	return changed;
544 }
545 
546 void ieee80211_process_mu_groups(struct ieee80211_sub_if_data *sdata,
547 				 struct ieee80211_mgmt *mgmt)
548 {
549 	struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
550 
551 	if (!sdata->vif.mu_mimo_owner)
552 		return;
553 
554 	if (!memcmp(mgmt->u.action.u.vht_group_notif.position,
555 		    bss_conf->mu_group.position, WLAN_USER_POSITION_LEN) &&
556 	    !memcmp(mgmt->u.action.u.vht_group_notif.membership,
557 		    bss_conf->mu_group.membership, WLAN_MEMBERSHIP_LEN))
558 		return;
559 
560 	memcpy(bss_conf->mu_group.membership,
561 	       mgmt->u.action.u.vht_group_notif.membership,
562 	       WLAN_MEMBERSHIP_LEN);
563 	memcpy(bss_conf->mu_group.position,
564 	       mgmt->u.action.u.vht_group_notif.position,
565 	       WLAN_USER_POSITION_LEN);
566 
567 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_MU_GROUPS);
568 }
569 
570 void ieee80211_update_mu_groups(struct ieee80211_vif *vif,
571 				const u8 *membership, const u8 *position)
572 {
573 	struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
574 
575 	if (WARN_ON_ONCE(!vif->mu_mimo_owner))
576 		return;
577 
578 	memcpy(bss_conf->mu_group.membership, membership, WLAN_MEMBERSHIP_LEN);
579 	memcpy(bss_conf->mu_group.position, position, WLAN_USER_POSITION_LEN);
580 }
581 EXPORT_SYMBOL_GPL(ieee80211_update_mu_groups);
582 
583 void ieee80211_vht_handle_opmode(struct ieee80211_sub_if_data *sdata,
584 				 struct sta_info *sta, u8 opmode,
585 				 enum nl80211_band band)
586 {
587 	struct ieee80211_local *local = sdata->local;
588 	struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
589 
590 	u32 changed = __ieee80211_vht_handle_opmode(sdata, sta, opmode, band);
591 
592 	if (changed > 0) {
593 		ieee80211_recalc_min_chandef(sdata);
594 		rate_control_rate_update(local, sband, sta, changed);
595 	}
596 }
597 
598 void ieee80211_get_vht_mask_from_cap(__le16 vht_cap,
599 				     u16 vht_mask[NL80211_VHT_NSS_MAX])
600 {
601 	int i;
602 	u16 mask, cap = le16_to_cpu(vht_cap);
603 
604 	for (i = 0; i < NL80211_VHT_NSS_MAX; i++) {
605 		mask = (cap >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
606 		switch (mask) {
607 		case IEEE80211_VHT_MCS_SUPPORT_0_7:
608 			vht_mask[i] = 0x00FF;
609 			break;
610 		case IEEE80211_VHT_MCS_SUPPORT_0_8:
611 			vht_mask[i] = 0x01FF;
612 			break;
613 		case IEEE80211_VHT_MCS_SUPPORT_0_9:
614 			vht_mask[i] = 0x03FF;
615 			break;
616 		case IEEE80211_VHT_MCS_NOT_SUPPORTED:
617 		default:
618 			vht_mask[i] = 0;
619 			break;
620 		}
621 	}
622 }
623