xref: /openbmc/linux/net/mac80211/airtime.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: ISC
2 /*
3  * Copyright (C) 2019 Felix Fietkau <nbd@nbd.name>
4  */
5 
6 #include <net/mac80211.h>
7 #include "ieee80211_i.h"
8 #include "sta_info.h"
9 
10 #define AVG_PKT_SIZE	1024
11 
12 /* Number of bits for an average sized packet */
13 #define MCS_NBITS (AVG_PKT_SIZE << 3)
14 
15 /* Number of kilo-symbols (symbols * 1024) for a packet with (bps) bits per
16  * symbol. We use k-symbols to avoid rounding in the _TIME macros below.
17  */
18 #define MCS_N_KSYMS(bps) DIV_ROUND_UP(MCS_NBITS << 10, (bps))
19 
20 /* Transmission time (in 1024 * usec) for a packet containing (ksyms) * 1024
21  * symbols.
22  */
23 #define MCS_SYMBOL_TIME(sgi, ksyms)					\
24 	(sgi ?								\
25 	  ((ksyms) * 4 * 18) / 20 :		/* 3.6 us per sym */	\
26 	  ((ksyms) * 4)			/* 4.0 us per sym */	\
27 	)
28 
29 /* Transmit duration for the raw data part of an average sized packet */
30 #define MCS_DURATION(streams, sgi, bps) \
31 	((u32)MCS_SYMBOL_TIME(sgi, MCS_N_KSYMS((streams) * (bps))))
32 
33 #define MCS_DURATION_S(shift, streams, sgi, bps)		\
34 	((u16)((MCS_DURATION(streams, sgi, bps) >> shift)))
35 
36 /* These should match the values in enum nl80211_he_gi */
37 #define HE_GI_08 0
38 #define HE_GI_16 1
39 #define HE_GI_32 2
40 
41 /* Transmission time (1024 usec) for a packet containing (ksyms) * k-symbols */
42 #define HE_SYMBOL_TIME(gi, ksyms)					\
43 	(gi == HE_GI_08 ?						\
44 	 ((ksyms) * 16 * 17) / 20 :		/* 13.6 us per sym */	\
45 	 (gi == HE_GI_16 ?						\
46 	  ((ksyms) * 16 * 18) / 20 :		/* 14.4 us per sym */	\
47 	  ((ksyms) * 16)			/* 16.0 us per sym */	\
48 	 ))
49 
50 /* Transmit duration for the raw data part of an average sized packet */
51 #define HE_DURATION(streams, gi, bps) \
52 	((u32)HE_SYMBOL_TIME(gi, MCS_N_KSYMS((streams) * (bps))))
53 
54 #define HE_DURATION_S(shift, streams, gi, bps)		\
55 	(HE_DURATION(streams, gi, bps) >> shift)
56 
57 #define BW_20			0
58 #define BW_40			1
59 #define BW_80			2
60 #define BW_160			3
61 
62 /*
63  * Define group sort order: HT40 -> SGI -> #streams
64  */
65 #define IEEE80211_MAX_STREAMS		4
66 #define IEEE80211_HT_STREAM_GROUPS	4 /* BW(=2) * SGI(=2) */
67 #define IEEE80211_VHT_STREAM_GROUPS	8 /* BW(=4) * SGI(=2) */
68 
69 #define IEEE80211_HE_MAX_STREAMS	8
70 #define IEEE80211_HE_STREAM_GROUPS	12 /* BW(=4) * GI(=3) */
71 
72 #define IEEE80211_HT_GROUPS_NB	(IEEE80211_MAX_STREAMS *	\
73 				 IEEE80211_HT_STREAM_GROUPS)
74 #define IEEE80211_VHT_GROUPS_NB	(IEEE80211_MAX_STREAMS *	\
75 					 IEEE80211_VHT_STREAM_GROUPS)
76 #define IEEE80211_HE_GROUPS_NB	(IEEE80211_HE_MAX_STREAMS *	\
77 				 IEEE80211_HE_STREAM_GROUPS)
78 #define IEEE80211_GROUPS_NB	(IEEE80211_HT_GROUPS_NB +	\
79 				 IEEE80211_VHT_GROUPS_NB +	\
80 				 IEEE80211_HE_GROUPS_NB)
81 
82 #define IEEE80211_HT_GROUP_0	0
83 #define IEEE80211_VHT_GROUP_0	(IEEE80211_HT_GROUP_0 + IEEE80211_HT_GROUPS_NB)
84 #define IEEE80211_HE_GROUP_0	(IEEE80211_VHT_GROUP_0 + IEEE80211_VHT_GROUPS_NB)
85 
86 #define MCS_GROUP_RATES		12
87 
88 #define HT_GROUP_IDX(_streams, _sgi, _ht40)	\
89 	IEEE80211_HT_GROUP_0 +			\
90 	IEEE80211_MAX_STREAMS * 2 * _ht40 +	\
91 	IEEE80211_MAX_STREAMS * _sgi +		\
92 	_streams - 1
93 
94 #define _MAX(a, b) (((a)>(b))?(a):(b))
95 
96 #define GROUP_SHIFT(duration)						\
97 	_MAX(0, 16 - __builtin_clz(duration))
98 
99 /* MCS rate information for an MCS group */
100 #define __MCS_GROUP(_streams, _sgi, _ht40, _s)				\
101 	[HT_GROUP_IDX(_streams, _sgi, _ht40)] = {			\
102 	.shift = _s,							\
103 	.duration = {							\
104 		MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 54 : 26),	\
105 		MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 108 : 52),	\
106 		MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 162 : 78),	\
107 		MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 216 : 104),	\
108 		MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 324 : 156),	\
109 		MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 432 : 208),	\
110 		MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 486 : 234),	\
111 		MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 540 : 260)	\
112 	}								\
113 }
114 
115 #define MCS_GROUP_SHIFT(_streams, _sgi, _ht40)				\
116 	GROUP_SHIFT(MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26))
117 
118 #define MCS_GROUP(_streams, _sgi, _ht40)				\
119 	__MCS_GROUP(_streams, _sgi, _ht40,				\
120 		    MCS_GROUP_SHIFT(_streams, _sgi, _ht40))
121 
122 #define VHT_GROUP_IDX(_streams, _sgi, _bw)				\
123 	(IEEE80211_VHT_GROUP_0 +					\
124 	 IEEE80211_MAX_STREAMS * 2 * (_bw) +				\
125 	 IEEE80211_MAX_STREAMS * (_sgi) +				\
126 	 (_streams) - 1)
127 
128 #define BW2VBPS(_bw, r4, r3, r2, r1)					\
129 	(_bw == BW_160 ? r4 : _bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
130 
131 #define __VHT_GROUP(_streams, _sgi, _bw, _s)				\
132 	[VHT_GROUP_IDX(_streams, _sgi, _bw)] = {			\
133 	.shift = _s,							\
134 	.duration = {							\
135 		MCS_DURATION_S(_s, _streams, _sgi,			\
136 			       BW2VBPS(_bw,  234,  117,  54,  26)),	\
137 		MCS_DURATION_S(_s, _streams, _sgi,			\
138 			       BW2VBPS(_bw,  468,  234, 108,  52)),	\
139 		MCS_DURATION_S(_s, _streams, _sgi,			\
140 			       BW2VBPS(_bw,  702,  351, 162,  78)),	\
141 		MCS_DURATION_S(_s, _streams, _sgi,			\
142 			       BW2VBPS(_bw,  936,  468, 216, 104)),	\
143 		MCS_DURATION_S(_s, _streams, _sgi,			\
144 			       BW2VBPS(_bw, 1404,  702, 324, 156)),	\
145 		MCS_DURATION_S(_s, _streams, _sgi,			\
146 			       BW2VBPS(_bw, 1872,  936, 432, 208)),	\
147 		MCS_DURATION_S(_s, _streams, _sgi,			\
148 			       BW2VBPS(_bw, 2106, 1053, 486, 234)),	\
149 		MCS_DURATION_S(_s, _streams, _sgi,			\
150 			       BW2VBPS(_bw, 2340, 1170, 540, 260)),	\
151 		MCS_DURATION_S(_s, _streams, _sgi,			\
152 			       BW2VBPS(_bw, 2808, 1404, 648, 312)),	\
153 		MCS_DURATION_S(_s, _streams, _sgi,			\
154 			       BW2VBPS(_bw, 3120, 1560, 720, 346))	\
155         }								\
156 }
157 
158 #define VHT_GROUP_SHIFT(_streams, _sgi, _bw)				\
159 	GROUP_SHIFT(MCS_DURATION(_streams, _sgi,			\
160 				 BW2VBPS(_bw, 243, 117,  54,  26)))
161 
162 #define VHT_GROUP(_streams, _sgi, _bw)					\
163 	__VHT_GROUP(_streams, _sgi, _bw,				\
164 		    VHT_GROUP_SHIFT(_streams, _sgi, _bw))
165 
166 
167 #define HE_GROUP_IDX(_streams, _gi, _bw)				\
168 	(IEEE80211_HE_GROUP_0 +					\
169 	 IEEE80211_HE_MAX_STREAMS * 3 * (_bw) +			\
170 	 IEEE80211_HE_MAX_STREAMS * (_gi) +				\
171 	 (_streams) - 1)
172 
173 #define __HE_GROUP(_streams, _gi, _bw, _s)				\
174 	[HE_GROUP_IDX(_streams, _gi, _bw)] = {			\
175 	.shift = _s,							\
176 	.duration = {							\
177 		HE_DURATION_S(_s, _streams, _gi,			\
178 			      BW2VBPS(_bw,   979,  489,  230,  115)),	\
179 		HE_DURATION_S(_s, _streams, _gi,			\
180 			      BW2VBPS(_bw,  1958,  979,  475,  230)),	\
181 		HE_DURATION_S(_s, _streams, _gi,			\
182 			      BW2VBPS(_bw,  2937, 1468,  705,  345)),	\
183 		HE_DURATION_S(_s, _streams, _gi,			\
184 			      BW2VBPS(_bw,  3916, 1958,  936,  475)),	\
185 		HE_DURATION_S(_s, _streams, _gi,			\
186 			      BW2VBPS(_bw,  5875, 2937, 1411,  705)),	\
187 		HE_DURATION_S(_s, _streams, _gi,			\
188 			      BW2VBPS(_bw,  7833, 3916, 1872,  936)),	\
189 		HE_DURATION_S(_s, _streams, _gi,			\
190 			      BW2VBPS(_bw,  8827, 4406, 2102, 1051)),	\
191 		HE_DURATION_S(_s, _streams, _gi,			\
192 			      BW2VBPS(_bw,  9806, 4896, 2347, 1166)),	\
193 		HE_DURATION_S(_s, _streams, _gi,			\
194 			      BW2VBPS(_bw, 11764, 5875, 2808, 1411)),	\
195 		HE_DURATION_S(_s, _streams, _gi,			\
196 			      BW2VBPS(_bw, 13060, 6523, 3124, 1555)),	\
197 		HE_DURATION_S(_s, _streams, _gi,			\
198 			      BW2VBPS(_bw, 14702, 7344, 3513, 1756)),	\
199 		HE_DURATION_S(_s, _streams, _gi,			\
200 			      BW2VBPS(_bw, 16329, 8164, 3902, 1944))	\
201         }								\
202 }
203 
204 #define HE_GROUP_SHIFT(_streams, _gi, _bw)				\
205 	GROUP_SHIFT(HE_DURATION(_streams, _gi,			\
206 				BW2VBPS(_bw,   979,  489,  230,  115)))
207 
208 #define HE_GROUP(_streams, _gi, _bw)					\
209 	__HE_GROUP(_streams, _gi, _bw,				\
210 		   HE_GROUP_SHIFT(_streams, _gi, _bw))
211 struct mcs_group {
212 	u8 shift;
213 	u16 duration[MCS_GROUP_RATES];
214 };
215 
216 static const struct mcs_group airtime_mcs_groups[] = {
217 	MCS_GROUP(1, 0, BW_20),
218 	MCS_GROUP(2, 0, BW_20),
219 	MCS_GROUP(3, 0, BW_20),
220 	MCS_GROUP(4, 0, BW_20),
221 
222 	MCS_GROUP(1, 1, BW_20),
223 	MCS_GROUP(2, 1, BW_20),
224 	MCS_GROUP(3, 1, BW_20),
225 	MCS_GROUP(4, 1, BW_20),
226 
227 	MCS_GROUP(1, 0, BW_40),
228 	MCS_GROUP(2, 0, BW_40),
229 	MCS_GROUP(3, 0, BW_40),
230 	MCS_GROUP(4, 0, BW_40),
231 
232 	MCS_GROUP(1, 1, BW_40),
233 	MCS_GROUP(2, 1, BW_40),
234 	MCS_GROUP(3, 1, BW_40),
235 	MCS_GROUP(4, 1, BW_40),
236 
237 	VHT_GROUP(1, 0, BW_20),
238 	VHT_GROUP(2, 0, BW_20),
239 	VHT_GROUP(3, 0, BW_20),
240 	VHT_GROUP(4, 0, BW_20),
241 
242 	VHT_GROUP(1, 1, BW_20),
243 	VHT_GROUP(2, 1, BW_20),
244 	VHT_GROUP(3, 1, BW_20),
245 	VHT_GROUP(4, 1, BW_20),
246 
247 	VHT_GROUP(1, 0, BW_40),
248 	VHT_GROUP(2, 0, BW_40),
249 	VHT_GROUP(3, 0, BW_40),
250 	VHT_GROUP(4, 0, BW_40),
251 
252 	VHT_GROUP(1, 1, BW_40),
253 	VHT_GROUP(2, 1, BW_40),
254 	VHT_GROUP(3, 1, BW_40),
255 	VHT_GROUP(4, 1, BW_40),
256 
257 	VHT_GROUP(1, 0, BW_80),
258 	VHT_GROUP(2, 0, BW_80),
259 	VHT_GROUP(3, 0, BW_80),
260 	VHT_GROUP(4, 0, BW_80),
261 
262 	VHT_GROUP(1, 1, BW_80),
263 	VHT_GROUP(2, 1, BW_80),
264 	VHT_GROUP(3, 1, BW_80),
265 	VHT_GROUP(4, 1, BW_80),
266 
267 	VHT_GROUP(1, 0, BW_160),
268 	VHT_GROUP(2, 0, BW_160),
269 	VHT_GROUP(3, 0, BW_160),
270 	VHT_GROUP(4, 0, BW_160),
271 
272 	VHT_GROUP(1, 1, BW_160),
273 	VHT_GROUP(2, 1, BW_160),
274 	VHT_GROUP(3, 1, BW_160),
275 	VHT_GROUP(4, 1, BW_160),
276 
277 	HE_GROUP(1, HE_GI_08, BW_20),
278 	HE_GROUP(2, HE_GI_08, BW_20),
279 	HE_GROUP(3, HE_GI_08, BW_20),
280 	HE_GROUP(4, HE_GI_08, BW_20),
281 	HE_GROUP(5, HE_GI_08, BW_20),
282 	HE_GROUP(6, HE_GI_08, BW_20),
283 	HE_GROUP(7, HE_GI_08, BW_20),
284 	HE_GROUP(8, HE_GI_08, BW_20),
285 
286 	HE_GROUP(1, HE_GI_16, BW_20),
287 	HE_GROUP(2, HE_GI_16, BW_20),
288 	HE_GROUP(3, HE_GI_16, BW_20),
289 	HE_GROUP(4, HE_GI_16, BW_20),
290 	HE_GROUP(5, HE_GI_16, BW_20),
291 	HE_GROUP(6, HE_GI_16, BW_20),
292 	HE_GROUP(7, HE_GI_16, BW_20),
293 	HE_GROUP(8, HE_GI_16, BW_20),
294 
295 	HE_GROUP(1, HE_GI_32, BW_20),
296 	HE_GROUP(2, HE_GI_32, BW_20),
297 	HE_GROUP(3, HE_GI_32, BW_20),
298 	HE_GROUP(4, HE_GI_32, BW_20),
299 	HE_GROUP(5, HE_GI_32, BW_20),
300 	HE_GROUP(6, HE_GI_32, BW_20),
301 	HE_GROUP(7, HE_GI_32, BW_20),
302 	HE_GROUP(8, HE_GI_32, BW_20),
303 
304 	HE_GROUP(1, HE_GI_08, BW_40),
305 	HE_GROUP(2, HE_GI_08, BW_40),
306 	HE_GROUP(3, HE_GI_08, BW_40),
307 	HE_GROUP(4, HE_GI_08, BW_40),
308 	HE_GROUP(5, HE_GI_08, BW_40),
309 	HE_GROUP(6, HE_GI_08, BW_40),
310 	HE_GROUP(7, HE_GI_08, BW_40),
311 	HE_GROUP(8, HE_GI_08, BW_40),
312 
313 	HE_GROUP(1, HE_GI_16, BW_40),
314 	HE_GROUP(2, HE_GI_16, BW_40),
315 	HE_GROUP(3, HE_GI_16, BW_40),
316 	HE_GROUP(4, HE_GI_16, BW_40),
317 	HE_GROUP(5, HE_GI_16, BW_40),
318 	HE_GROUP(6, HE_GI_16, BW_40),
319 	HE_GROUP(7, HE_GI_16, BW_40),
320 	HE_GROUP(8, HE_GI_16, BW_40),
321 
322 	HE_GROUP(1, HE_GI_32, BW_40),
323 	HE_GROUP(2, HE_GI_32, BW_40),
324 	HE_GROUP(3, HE_GI_32, BW_40),
325 	HE_GROUP(4, HE_GI_32, BW_40),
326 	HE_GROUP(5, HE_GI_32, BW_40),
327 	HE_GROUP(6, HE_GI_32, BW_40),
328 	HE_GROUP(7, HE_GI_32, BW_40),
329 	HE_GROUP(8, HE_GI_32, BW_40),
330 
331 	HE_GROUP(1, HE_GI_08, BW_80),
332 	HE_GROUP(2, HE_GI_08, BW_80),
333 	HE_GROUP(3, HE_GI_08, BW_80),
334 	HE_GROUP(4, HE_GI_08, BW_80),
335 	HE_GROUP(5, HE_GI_08, BW_80),
336 	HE_GROUP(6, HE_GI_08, BW_80),
337 	HE_GROUP(7, HE_GI_08, BW_80),
338 	HE_GROUP(8, HE_GI_08, BW_80),
339 
340 	HE_GROUP(1, HE_GI_16, BW_80),
341 	HE_GROUP(2, HE_GI_16, BW_80),
342 	HE_GROUP(3, HE_GI_16, BW_80),
343 	HE_GROUP(4, HE_GI_16, BW_80),
344 	HE_GROUP(5, HE_GI_16, BW_80),
345 	HE_GROUP(6, HE_GI_16, BW_80),
346 	HE_GROUP(7, HE_GI_16, BW_80),
347 	HE_GROUP(8, HE_GI_16, BW_80),
348 
349 	HE_GROUP(1, HE_GI_32, BW_80),
350 	HE_GROUP(2, HE_GI_32, BW_80),
351 	HE_GROUP(3, HE_GI_32, BW_80),
352 	HE_GROUP(4, HE_GI_32, BW_80),
353 	HE_GROUP(5, HE_GI_32, BW_80),
354 	HE_GROUP(6, HE_GI_32, BW_80),
355 	HE_GROUP(7, HE_GI_32, BW_80),
356 	HE_GROUP(8, HE_GI_32, BW_80),
357 
358 	HE_GROUP(1, HE_GI_08, BW_160),
359 	HE_GROUP(2, HE_GI_08, BW_160),
360 	HE_GROUP(3, HE_GI_08, BW_160),
361 	HE_GROUP(4, HE_GI_08, BW_160),
362 	HE_GROUP(5, HE_GI_08, BW_160),
363 	HE_GROUP(6, HE_GI_08, BW_160),
364 	HE_GROUP(7, HE_GI_08, BW_160),
365 	HE_GROUP(8, HE_GI_08, BW_160),
366 
367 	HE_GROUP(1, HE_GI_16, BW_160),
368 	HE_GROUP(2, HE_GI_16, BW_160),
369 	HE_GROUP(3, HE_GI_16, BW_160),
370 	HE_GROUP(4, HE_GI_16, BW_160),
371 	HE_GROUP(5, HE_GI_16, BW_160),
372 	HE_GROUP(6, HE_GI_16, BW_160),
373 	HE_GROUP(7, HE_GI_16, BW_160),
374 	HE_GROUP(8, HE_GI_16, BW_160),
375 
376 	HE_GROUP(1, HE_GI_32, BW_160),
377 	HE_GROUP(2, HE_GI_32, BW_160),
378 	HE_GROUP(3, HE_GI_32, BW_160),
379 	HE_GROUP(4, HE_GI_32, BW_160),
380 	HE_GROUP(5, HE_GI_32, BW_160),
381 	HE_GROUP(6, HE_GI_32, BW_160),
382 	HE_GROUP(7, HE_GI_32, BW_160),
383 	HE_GROUP(8, HE_GI_32, BW_160),
384 };
385 
386 static u32
387 ieee80211_calc_legacy_rate_duration(u16 bitrate, bool short_pre,
388 				    bool cck, int len)
389 {
390 	u32 duration;
391 
392 	if (cck) {
393 		duration = 144 + 48; /* preamble + PLCP */
394 		if (short_pre)
395 			duration >>= 1;
396 
397 		duration += 10; /* SIFS */
398 	} else {
399 		duration = 20 + 16; /* premable + SIFS */
400 	}
401 
402 	len <<= 3;
403 	duration += (len * 10) / bitrate;
404 
405 	return duration;
406 }
407 
408 u32 ieee80211_calc_rx_airtime(struct ieee80211_hw *hw,
409 			      struct ieee80211_rx_status *status,
410 			      int len)
411 {
412 	struct ieee80211_supported_band *sband;
413 	const struct ieee80211_rate *rate;
414 	bool sgi = status->enc_flags & RX_ENC_FLAG_SHORT_GI;
415 	bool sp = status->enc_flags & RX_ENC_FLAG_SHORTPRE;
416 	int bw, streams;
417 	int group, idx;
418 	u32 duration;
419 	bool cck;
420 
421 	switch (status->bw) {
422 	case RATE_INFO_BW_20:
423 		bw = BW_20;
424 		break;
425 	case RATE_INFO_BW_40:
426 		bw = BW_40;
427 		break;
428 	case RATE_INFO_BW_80:
429 		bw = BW_80;
430 		break;
431 	case RATE_INFO_BW_160:
432 		bw = BW_160;
433 		break;
434 	default:
435 		WARN_ON_ONCE(1);
436 		return 0;
437 	}
438 
439 	switch (status->encoding) {
440 	case RX_ENC_LEGACY:
441 		if (WARN_ON_ONCE(status->band > NL80211_BAND_5GHZ))
442 			return 0;
443 
444 		sband = hw->wiphy->bands[status->band];
445 		if (!sband || status->rate_idx >= sband->n_bitrates)
446 			return 0;
447 
448 		rate = &sband->bitrates[status->rate_idx];
449 		cck = rate->flags & IEEE80211_RATE_MANDATORY_B;
450 
451 		return ieee80211_calc_legacy_rate_duration(rate->bitrate, sp,
452 							   cck, len);
453 
454 	case RX_ENC_VHT:
455 		streams = status->nss;
456 		idx = status->rate_idx;
457 		group = VHT_GROUP_IDX(streams, sgi, bw);
458 		break;
459 	case RX_ENC_HT:
460 		streams = ((status->rate_idx >> 3) & 3) + 1;
461 		idx = status->rate_idx & 7;
462 		group = HT_GROUP_IDX(streams, sgi, bw);
463 		break;
464 	case RX_ENC_HE:
465 		streams = status->nss;
466 		idx = status->rate_idx;
467 		group = HE_GROUP_IDX(streams, status->he_gi, bw);
468 		break;
469 	default:
470 		WARN_ON_ONCE(1);
471 		return 0;
472 	}
473 
474 	if (WARN_ON_ONCE((status->encoding != RX_ENC_HE && streams > 4) ||
475 			 (status->encoding == RX_ENC_HE && streams > 8)))
476 		return 0;
477 
478 	duration = airtime_mcs_groups[group].duration[idx];
479 	duration <<= airtime_mcs_groups[group].shift;
480 	duration *= len;
481 	duration /= AVG_PKT_SIZE;
482 	duration /= 1024;
483 
484 	duration += 36 + (streams << 2);
485 
486 	return duration;
487 }
488 EXPORT_SYMBOL_GPL(ieee80211_calc_rx_airtime);
489 
490 static u32 ieee80211_calc_tx_airtime_rate(struct ieee80211_hw *hw,
491 					  struct ieee80211_tx_rate *rate,
492 					  u8 band, int len)
493 {
494 	struct ieee80211_rx_status stat = {
495 		.band = band,
496 	};
497 
498 	if (rate->idx < 0 || !rate->count)
499 		return 0;
500 
501 	if (rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH)
502 		stat.bw = RATE_INFO_BW_80;
503 	else if (rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
504 		stat.bw = RATE_INFO_BW_40;
505 	else
506 		stat.bw = RATE_INFO_BW_20;
507 
508 	stat.enc_flags = 0;
509 	if (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
510 		stat.enc_flags |= RX_ENC_FLAG_SHORTPRE;
511 	if (rate->flags & IEEE80211_TX_RC_SHORT_GI)
512 		stat.enc_flags |= RX_ENC_FLAG_SHORT_GI;
513 
514 	stat.rate_idx = rate->idx;
515 	if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
516 		stat.encoding = RX_ENC_VHT;
517 		stat.rate_idx = ieee80211_rate_get_vht_mcs(rate);
518 		stat.nss = ieee80211_rate_get_vht_nss(rate);
519 	} else if (rate->flags & IEEE80211_TX_RC_MCS) {
520 		stat.encoding = RX_ENC_HT;
521 	} else {
522 		stat.encoding = RX_ENC_LEGACY;
523 	}
524 
525 	return ieee80211_calc_rx_airtime(hw, &stat, len);
526 }
527 
528 u32 ieee80211_calc_tx_airtime(struct ieee80211_hw *hw,
529 			      struct ieee80211_tx_info *info,
530 			      int len)
531 {
532 	u32 duration = 0;
533 	int i;
534 
535 	for (i = 0; i < ARRAY_SIZE(info->status.rates); i++) {
536 		struct ieee80211_tx_rate *rate = &info->status.rates[i];
537 		u32 cur_duration;
538 
539 		cur_duration = ieee80211_calc_tx_airtime_rate(hw, rate,
540 							      info->band, len);
541 		if (!cur_duration)
542 			break;
543 
544 		duration += cur_duration * rate->count;
545 	}
546 
547 	return duration;
548 }
549 EXPORT_SYMBOL_GPL(ieee80211_calc_tx_airtime);
550 
551 u32 ieee80211_calc_expected_tx_airtime(struct ieee80211_hw *hw,
552 				       struct ieee80211_vif *vif,
553 				       struct ieee80211_sta *pubsta,
554 				       int len)
555 {
556 	struct ieee80211_supported_band *sband;
557 	struct ieee80211_chanctx_conf *conf;
558 	int rateidx, shift = 0;
559 	bool cck, short_pream;
560 	u32 basic_rates;
561 	u8 band = 0;
562 	u16 rate;
563 
564 	len += 38; /* Ethernet header length */
565 
566 	conf = rcu_dereference(vif->chanctx_conf);
567 	if (conf) {
568 		band = conf->def.chan->band;
569 		shift = ieee80211_chandef_get_shift(&conf->def);
570 	}
571 
572 	if (pubsta) {
573 		struct sta_info *sta = container_of(pubsta, struct sta_info,
574 						    sta);
575 
576 		return ieee80211_calc_tx_airtime_rate(hw,
577 						      &sta->tx_stats.last_rate,
578 						      band, len);
579 	}
580 
581 	if (!conf)
582 		return 0;
583 
584 	/* No station to get latest rate from, so calculate the worst-case
585 	 * duration using the lowest configured basic rate.
586 	 */
587 	sband = hw->wiphy->bands[band];
588 
589 	basic_rates = vif->bss_conf.basic_rates;
590 	short_pream = vif->bss_conf.use_short_preamble;
591 
592 	rateidx = basic_rates ? ffs(basic_rates) - 1 : 0;
593 	rate = sband->bitrates[rateidx].bitrate << shift;
594 	cck = sband->bitrates[rateidx].flags & IEEE80211_RATE_MANDATORY_B;
595 
596 	return ieee80211_calc_legacy_rate_duration(rate, short_pream, cck, len);
597 }
598