1 // SPDX-License-Identifier: ISC
2 /*
3  * Copyright (C) 2016 Felix Fietkau <nbd@nbd.name>
4  */
5 
6 #include "mt76.h"
7 
8 static struct mt76_txwi_cache *
9 mt76_alloc_txwi(struct mt76_dev *dev)
10 {
11 	struct mt76_txwi_cache *t;
12 	dma_addr_t addr;
13 	u8 *txwi;
14 	int size;
15 
16 	size = L1_CACHE_ALIGN(dev->drv->txwi_size + sizeof(*t));
17 	txwi = devm_kzalloc(dev->dev, size, GFP_ATOMIC);
18 	if (!txwi)
19 		return NULL;
20 
21 	addr = dma_map_single(dev->dev, txwi, dev->drv->txwi_size,
22 			      DMA_TO_DEVICE);
23 	t = (struct mt76_txwi_cache *)(txwi + dev->drv->txwi_size);
24 	t->dma_addr = addr;
25 
26 	return t;
27 }
28 
29 static struct mt76_txwi_cache *
30 __mt76_get_txwi(struct mt76_dev *dev)
31 {
32 	struct mt76_txwi_cache *t = NULL;
33 
34 	spin_lock_bh(&dev->lock);
35 	if (!list_empty(&dev->txwi_cache)) {
36 		t = list_first_entry(&dev->txwi_cache, struct mt76_txwi_cache,
37 				     list);
38 		list_del(&t->list);
39 	}
40 	spin_unlock_bh(&dev->lock);
41 
42 	return t;
43 }
44 
45 struct mt76_txwi_cache *
46 mt76_get_txwi(struct mt76_dev *dev)
47 {
48 	struct mt76_txwi_cache *t = __mt76_get_txwi(dev);
49 
50 	if (t)
51 		return t;
52 
53 	return mt76_alloc_txwi(dev);
54 }
55 
56 void
57 mt76_put_txwi(struct mt76_dev *dev, struct mt76_txwi_cache *t)
58 {
59 	if (!t)
60 		return;
61 
62 	spin_lock_bh(&dev->lock);
63 	list_add(&t->list, &dev->txwi_cache);
64 	spin_unlock_bh(&dev->lock);
65 }
66 EXPORT_SYMBOL_GPL(mt76_put_txwi);
67 
68 void mt76_tx_free(struct mt76_dev *dev)
69 {
70 	struct mt76_txwi_cache *t;
71 
72 	while ((t = __mt76_get_txwi(dev)) != NULL)
73 		dma_unmap_single(dev->dev, t->dma_addr, dev->drv->txwi_size,
74 				 DMA_TO_DEVICE);
75 }
76 
77 static int
78 mt76_txq_get_qid(struct ieee80211_txq *txq)
79 {
80 	if (!txq->sta)
81 		return MT_TXQ_BE;
82 
83 	return txq->ac;
84 }
85 
86 static void
87 mt76_check_agg_ssn(struct mt76_txq *mtxq, struct sk_buff *skb)
88 {
89 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
90 
91 	if (!ieee80211_is_data_qos(hdr->frame_control) ||
92 	    !ieee80211_is_data_present(hdr->frame_control))
93 		return;
94 
95 	mtxq->agg_ssn = le16_to_cpu(hdr->seq_ctrl) + 0x10;
96 }
97 
98 void
99 mt76_tx_status_lock(struct mt76_dev *dev, struct sk_buff_head *list)
100 		   __acquires(&dev->status_list.lock)
101 {
102 	__skb_queue_head_init(list);
103 	spin_lock_bh(&dev->status_list.lock);
104 }
105 EXPORT_SYMBOL_GPL(mt76_tx_status_lock);
106 
107 void
108 mt76_tx_status_unlock(struct mt76_dev *dev, struct sk_buff_head *list)
109 		      __releases(&dev->status_list.lock)
110 {
111 	struct ieee80211_hw *hw;
112 	struct sk_buff *skb;
113 
114 	spin_unlock_bh(&dev->status_list.lock);
115 
116 	while ((skb = __skb_dequeue(list)) != NULL) {
117 		hw = mt76_tx_status_get_hw(dev, skb);
118 		ieee80211_tx_status(hw, skb);
119 	}
120 
121 }
122 EXPORT_SYMBOL_GPL(mt76_tx_status_unlock);
123 
124 static void
125 __mt76_tx_status_skb_done(struct mt76_dev *dev, struct sk_buff *skb, u8 flags,
126 			  struct sk_buff_head *list)
127 {
128 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
129 	struct mt76_tx_cb *cb = mt76_tx_skb_cb(skb);
130 	u8 done = MT_TX_CB_DMA_DONE | MT_TX_CB_TXS_DONE;
131 
132 	flags |= cb->flags;
133 	cb->flags = flags;
134 
135 	if ((flags & done) != done)
136 		return;
137 
138 	__skb_unlink(skb, &dev->status_list);
139 
140 	/* Tx status can be unreliable. if it fails, mark the frame as ACKed */
141 	if (flags & MT_TX_CB_TXS_FAILED) {
142 		ieee80211_tx_info_clear_status(info);
143 		info->status.rates[0].idx = -1;
144 		info->flags |= IEEE80211_TX_STAT_ACK;
145 	}
146 
147 	__skb_queue_tail(list, skb);
148 }
149 
150 void
151 mt76_tx_status_skb_done(struct mt76_dev *dev, struct sk_buff *skb,
152 			struct sk_buff_head *list)
153 {
154 	__mt76_tx_status_skb_done(dev, skb, MT_TX_CB_TXS_DONE, list);
155 }
156 EXPORT_SYMBOL_GPL(mt76_tx_status_skb_done);
157 
158 int
159 mt76_tx_status_skb_add(struct mt76_dev *dev, struct mt76_wcid *wcid,
160 		       struct sk_buff *skb)
161 {
162 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
163 	struct mt76_tx_cb *cb = mt76_tx_skb_cb(skb);
164 	int pid;
165 
166 	if (!wcid)
167 		return MT_PACKET_ID_NO_ACK;
168 
169 	if (info->flags & IEEE80211_TX_CTL_NO_ACK)
170 		return MT_PACKET_ID_NO_ACK;
171 
172 	if (!(info->flags & (IEEE80211_TX_CTL_REQ_TX_STATUS |
173 			     IEEE80211_TX_CTL_RATE_CTRL_PROBE)))
174 		return MT_PACKET_ID_NO_SKB;
175 
176 	spin_lock_bh(&dev->status_list.lock);
177 
178 	memset(cb, 0, sizeof(*cb));
179 	wcid->packet_id = (wcid->packet_id + 1) & MT_PACKET_ID_MASK;
180 	if (wcid->packet_id == MT_PACKET_ID_NO_ACK ||
181 	    wcid->packet_id == MT_PACKET_ID_NO_SKB)
182 		wcid->packet_id = MT_PACKET_ID_FIRST;
183 
184 	pid = wcid->packet_id;
185 	cb->wcid = wcid->idx;
186 	cb->pktid = pid;
187 	cb->jiffies = jiffies;
188 
189 	__skb_queue_tail(&dev->status_list, skb);
190 	spin_unlock_bh(&dev->status_list.lock);
191 
192 	return pid;
193 }
194 EXPORT_SYMBOL_GPL(mt76_tx_status_skb_add);
195 
196 struct sk_buff *
197 mt76_tx_status_skb_get(struct mt76_dev *dev, struct mt76_wcid *wcid, int pktid,
198 		       struct sk_buff_head *list)
199 {
200 	struct sk_buff *skb, *tmp;
201 
202 	skb_queue_walk_safe(&dev->status_list, skb, tmp) {
203 		struct mt76_tx_cb *cb = mt76_tx_skb_cb(skb);
204 
205 		if (wcid && cb->wcid != wcid->idx)
206 			continue;
207 
208 		if (cb->pktid == pktid)
209 			return skb;
210 
211 		if (pktid >= 0 && !time_after(jiffies, cb->jiffies +
212 					      MT_TX_STATUS_SKB_TIMEOUT))
213 			continue;
214 
215 		__mt76_tx_status_skb_done(dev, skb, MT_TX_CB_TXS_FAILED |
216 						    MT_TX_CB_TXS_DONE, list);
217 	}
218 
219 	return NULL;
220 }
221 EXPORT_SYMBOL_GPL(mt76_tx_status_skb_get);
222 
223 void
224 mt76_tx_status_check(struct mt76_dev *dev, struct mt76_wcid *wcid, bool flush)
225 {
226 	struct sk_buff_head list;
227 
228 	mt76_tx_status_lock(dev, &list);
229 	mt76_tx_status_skb_get(dev, wcid, flush ? -1 : 0, &list);
230 	mt76_tx_status_unlock(dev, &list);
231 }
232 EXPORT_SYMBOL_GPL(mt76_tx_status_check);
233 
234 void mt76_tx_complete_skb(struct mt76_dev *dev, struct sk_buff *skb)
235 {
236 	struct ieee80211_hw *hw;
237 	struct sk_buff_head list;
238 
239 	if (!skb->prev) {
240 		hw = mt76_tx_status_get_hw(dev, skb);
241 		ieee80211_free_txskb(hw, skb);
242 		return;
243 	}
244 
245 	mt76_tx_status_lock(dev, &list);
246 	__mt76_tx_status_skb_done(dev, skb, MT_TX_CB_DMA_DONE, &list);
247 	mt76_tx_status_unlock(dev, &list);
248 }
249 EXPORT_SYMBOL_GPL(mt76_tx_complete_skb);
250 
251 void
252 mt76_tx(struct mt76_phy *phy, struct ieee80211_sta *sta,
253 	struct mt76_wcid *wcid, struct sk_buff *skb)
254 {
255 	struct mt76_dev *dev = phy->dev;
256 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
257 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
258 	struct mt76_queue *q;
259 	int qid = skb_get_queue_mapping(skb);
260 	bool ext_phy = phy != &dev->phy;
261 
262 	if (WARN_ON(qid >= MT_TXQ_PSD)) {
263 		qid = MT_TXQ_BE;
264 		skb_set_queue_mapping(skb, qid);
265 	}
266 
267 	if (!(wcid->tx_info & MT_WCID_TX_INFO_SET))
268 		ieee80211_get_tx_rates(info->control.vif, sta, skb,
269 				       info->control.rates, 1);
270 
271 	if (sta && ieee80211_is_data_qos(hdr->frame_control)) {
272 		struct ieee80211_txq *txq;
273 		struct mt76_txq *mtxq;
274 		u8 tid;
275 
276 		tid = skb->priority & IEEE80211_QOS_CTL_TID_MASK;
277 		txq = sta->txq[tid];
278 		mtxq = (struct mt76_txq *)txq->drv_priv;
279 
280 		if (mtxq->aggr)
281 			mt76_check_agg_ssn(mtxq, skb);
282 	}
283 
284 	if (ext_phy)
285 		info->hw_queue |= MT_TX_HW_QUEUE_EXT_PHY;
286 
287 	q = dev->q_tx[qid].q;
288 
289 	spin_lock_bh(&q->lock);
290 	dev->queue_ops->tx_queue_skb(dev, qid, skb, wcid, sta);
291 	dev->queue_ops->kick(dev, q);
292 
293 	if (q->queued > q->ndesc - 8 && !q->stopped) {
294 		ieee80211_stop_queue(phy->hw, skb_get_queue_mapping(skb));
295 		q->stopped = true;
296 	}
297 
298 	spin_unlock_bh(&q->lock);
299 }
300 EXPORT_SYMBOL_GPL(mt76_tx);
301 
302 static struct sk_buff *
303 mt76_txq_dequeue(struct mt76_phy *phy, struct mt76_txq *mtxq, bool ps)
304 {
305 	struct ieee80211_txq *txq = mtxq_to_txq(mtxq);
306 	struct ieee80211_tx_info *info;
307 	bool ext_phy = phy != &phy->dev->phy;
308 	struct sk_buff *skb;
309 
310 	skb = skb_dequeue(&mtxq->retry_q);
311 	if (skb) {
312 		u8 tid = skb->priority & IEEE80211_QOS_CTL_TID_MASK;
313 
314 		if (ps && skb_queue_empty(&mtxq->retry_q))
315 			ieee80211_sta_set_buffered(txq->sta, tid, false);
316 
317 		return skb;
318 	}
319 
320 	skb = ieee80211_tx_dequeue(phy->hw, txq);
321 	if (!skb)
322 		return NULL;
323 
324 	info = IEEE80211_SKB_CB(skb);
325 	if (ext_phy)
326 		info->hw_queue |= MT_TX_HW_QUEUE_EXT_PHY;
327 
328 	return skb;
329 }
330 
331 static void
332 mt76_queue_ps_skb(struct mt76_dev *dev, struct ieee80211_sta *sta,
333 		  struct sk_buff *skb, bool last)
334 {
335 	struct mt76_wcid *wcid = (struct mt76_wcid *)sta->drv_priv;
336 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
337 
338 	info->control.flags |= IEEE80211_TX_CTRL_PS_RESPONSE;
339 	if (last)
340 		info->flags |= IEEE80211_TX_STATUS_EOSP |
341 			       IEEE80211_TX_CTL_REQ_TX_STATUS;
342 
343 	mt76_skb_set_moredata(skb, !last);
344 	dev->queue_ops->tx_queue_skb(dev, MT_TXQ_PSD, skb, wcid, sta);
345 }
346 
347 void
348 mt76_release_buffered_frames(struct ieee80211_hw *hw, struct ieee80211_sta *sta,
349 			     u16 tids, int nframes,
350 			     enum ieee80211_frame_release_type reason,
351 			     bool more_data)
352 {
353 	struct mt76_phy *phy = hw->priv;
354 	struct mt76_dev *dev = phy->dev;
355 	struct sk_buff *last_skb = NULL;
356 	struct mt76_queue *hwq = dev->q_tx[MT_TXQ_PSD].q;
357 	int i;
358 
359 	spin_lock_bh(&hwq->lock);
360 	for (i = 0; tids && nframes; i++, tids >>= 1) {
361 		struct ieee80211_txq *txq = sta->txq[i];
362 		struct mt76_txq *mtxq = (struct mt76_txq *)txq->drv_priv;
363 		struct sk_buff *skb;
364 
365 		if (!(tids & 1))
366 			continue;
367 
368 		do {
369 			skb = mt76_txq_dequeue(phy, mtxq, true);
370 			if (!skb)
371 				break;
372 
373 			if (mtxq->aggr)
374 				mt76_check_agg_ssn(mtxq, skb);
375 
376 			nframes--;
377 			if (last_skb)
378 				mt76_queue_ps_skb(dev, sta, last_skb, false);
379 
380 			last_skb = skb;
381 		} while (nframes);
382 	}
383 
384 	if (last_skb) {
385 		mt76_queue_ps_skb(dev, sta, last_skb, true);
386 		dev->queue_ops->kick(dev, hwq);
387 	} else {
388 		ieee80211_sta_eosp(sta);
389 	}
390 
391 	spin_unlock_bh(&hwq->lock);
392 }
393 EXPORT_SYMBOL_GPL(mt76_release_buffered_frames);
394 
395 static int
396 mt76_txq_send_burst(struct mt76_phy *phy, struct mt76_sw_queue *sq,
397 		    struct mt76_txq *mtxq)
398 {
399 	struct mt76_dev *dev = phy->dev;
400 	struct ieee80211_txq *txq = mtxq_to_txq(mtxq);
401 	enum mt76_txq_id qid = mt76_txq_get_qid(txq);
402 	struct mt76_wcid *wcid = mtxq->wcid;
403 	struct mt76_queue *hwq = sq->q;
404 	struct ieee80211_tx_info *info;
405 	struct sk_buff *skb;
406 	int n_frames = 1, limit;
407 	struct ieee80211_tx_rate tx_rate;
408 	bool ampdu;
409 	bool probe;
410 	int idx;
411 
412 	if (test_bit(MT_WCID_FLAG_PS, &wcid->flags))
413 		return 0;
414 
415 	skb = mt76_txq_dequeue(phy, mtxq, false);
416 	if (!skb)
417 		return 0;
418 
419 	info = IEEE80211_SKB_CB(skb);
420 	if (!(wcid->tx_info & MT_WCID_TX_INFO_SET))
421 		ieee80211_get_tx_rates(txq->vif, txq->sta, skb,
422 				       info->control.rates, 1);
423 	tx_rate = info->control.rates[0];
424 
425 	probe = (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE);
426 	ampdu = IEEE80211_SKB_CB(skb)->flags & IEEE80211_TX_CTL_AMPDU;
427 	limit = ampdu ? 16 : 3;
428 
429 	if (ampdu)
430 		mt76_check_agg_ssn(mtxq, skb);
431 
432 	idx = dev->queue_ops->tx_queue_skb(dev, qid, skb, wcid, txq->sta);
433 
434 	if (idx < 0)
435 		return idx;
436 
437 	do {
438 		bool cur_ampdu;
439 
440 		if (probe)
441 			break;
442 
443 		if (test_bit(MT76_RESET, &phy->state))
444 			return -EBUSY;
445 
446 		skb = mt76_txq_dequeue(phy, mtxq, false);
447 		if (!skb)
448 			break;
449 
450 		info = IEEE80211_SKB_CB(skb);
451 		cur_ampdu = info->flags & IEEE80211_TX_CTL_AMPDU;
452 
453 		if (ampdu != cur_ampdu ||
454 		    (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)) {
455 			skb_queue_tail(&mtxq->retry_q, skb);
456 			break;
457 		}
458 
459 		info->control.rates[0] = tx_rate;
460 
461 		if (cur_ampdu)
462 			mt76_check_agg_ssn(mtxq, skb);
463 
464 		idx = dev->queue_ops->tx_queue_skb(dev, qid, skb, wcid,
465 						   txq->sta);
466 		if (idx < 0)
467 			return idx;
468 
469 		n_frames++;
470 	} while (n_frames < limit);
471 
472 	if (!probe) {
473 		hwq->entry[idx].qid = sq - dev->q_tx;
474 		hwq->entry[idx].schedule = true;
475 		sq->swq_queued++;
476 	}
477 
478 	dev->queue_ops->kick(dev, hwq);
479 
480 	return n_frames;
481 }
482 
483 static int
484 mt76_txq_schedule_list(struct mt76_phy *phy, enum mt76_txq_id qid)
485 {
486 	struct mt76_dev *dev = phy->dev;
487 	struct mt76_sw_queue *sq = &dev->q_tx[qid];
488 	struct mt76_queue *hwq = sq->q;
489 	struct ieee80211_txq *txq;
490 	struct mt76_txq *mtxq;
491 	struct mt76_wcid *wcid;
492 	int ret = 0;
493 
494 	spin_lock_bh(&hwq->lock);
495 	while (1) {
496 		if (sq->swq_queued >= 4)
497 			break;
498 
499 		if (test_bit(MT76_RESET, &phy->state)) {
500 			ret = -EBUSY;
501 			break;
502 		}
503 
504 		txq = ieee80211_next_txq(phy->hw, qid);
505 		if (!txq)
506 			break;
507 
508 		mtxq = (struct mt76_txq *)txq->drv_priv;
509 		wcid = mtxq->wcid;
510 		if (wcid && test_bit(MT_WCID_FLAG_PS, &wcid->flags))
511 			continue;
512 
513 		if (mtxq->send_bar && mtxq->aggr) {
514 			struct ieee80211_txq *txq = mtxq_to_txq(mtxq);
515 			struct ieee80211_sta *sta = txq->sta;
516 			struct ieee80211_vif *vif = txq->vif;
517 			u16 agg_ssn = mtxq->agg_ssn;
518 			u8 tid = txq->tid;
519 
520 			mtxq->send_bar = false;
521 			spin_unlock_bh(&hwq->lock);
522 			ieee80211_send_bar(vif, sta->addr, tid, agg_ssn);
523 			spin_lock_bh(&hwq->lock);
524 		}
525 
526 		ret += mt76_txq_send_burst(phy, sq, mtxq);
527 		ieee80211_return_txq(phy->hw, txq,
528 				     !skb_queue_empty(&mtxq->retry_q));
529 	}
530 	spin_unlock_bh(&hwq->lock);
531 
532 	return ret;
533 }
534 
535 void mt76_txq_schedule(struct mt76_phy *phy, enum mt76_txq_id qid)
536 {
537 	struct mt76_dev *dev = phy->dev;
538 	struct mt76_sw_queue *sq = &dev->q_tx[qid];
539 	int len;
540 
541 	if (qid >= 4)
542 		return;
543 
544 	if (sq->swq_queued >= 4)
545 		return;
546 
547 	rcu_read_lock();
548 
549 	do {
550 		ieee80211_txq_schedule_start(phy->hw, qid);
551 		len = mt76_txq_schedule_list(phy, qid);
552 		ieee80211_txq_schedule_end(phy->hw, qid);
553 	} while (len > 0);
554 
555 	rcu_read_unlock();
556 }
557 EXPORT_SYMBOL_GPL(mt76_txq_schedule);
558 
559 void mt76_txq_schedule_all(struct mt76_phy *phy)
560 {
561 	int i;
562 
563 	for (i = 0; i <= MT_TXQ_BK; i++)
564 		mt76_txq_schedule(phy, i);
565 }
566 EXPORT_SYMBOL_GPL(mt76_txq_schedule_all);
567 
568 void mt76_tx_tasklet(unsigned long data)
569 {
570 	struct mt76_dev *dev = (struct mt76_dev *)data;
571 
572 	mt76_txq_schedule_all(&dev->phy);
573 	if (dev->phy2)
574 		mt76_txq_schedule_all(dev->phy2);
575 }
576 
577 void mt76_stop_tx_queues(struct mt76_dev *dev, struct ieee80211_sta *sta,
578 			 bool send_bar)
579 {
580 	int i;
581 
582 	for (i = 0; i < ARRAY_SIZE(sta->txq); i++) {
583 		struct ieee80211_txq *txq = sta->txq[i];
584 		struct mt76_queue *hwq;
585 		struct mt76_txq *mtxq;
586 
587 		if (!txq)
588 			continue;
589 
590 		mtxq = (struct mt76_txq *)txq->drv_priv;
591 		hwq = mtxq->swq->q;
592 
593 		spin_lock_bh(&hwq->lock);
594 		mtxq->send_bar = mtxq->aggr && send_bar;
595 		spin_unlock_bh(&hwq->lock);
596 	}
597 }
598 EXPORT_SYMBOL_GPL(mt76_stop_tx_queues);
599 
600 void mt76_wake_tx_queue(struct ieee80211_hw *hw, struct ieee80211_txq *txq)
601 {
602 	struct mt76_phy *phy = hw->priv;
603 	struct mt76_dev *dev = phy->dev;
604 
605 	if (!test_bit(MT76_STATE_RUNNING, &phy->state))
606 		return;
607 
608 	tasklet_schedule(&dev->tx_tasklet);
609 }
610 EXPORT_SYMBOL_GPL(mt76_wake_tx_queue);
611 
612 void mt76_txq_remove(struct mt76_dev *dev, struct ieee80211_txq *txq)
613 {
614 	struct ieee80211_hw *hw;
615 	struct mt76_txq *mtxq;
616 	struct sk_buff *skb;
617 
618 	if (!txq)
619 		return;
620 
621 	mtxq = (struct mt76_txq *)txq->drv_priv;
622 
623 	while ((skb = skb_dequeue(&mtxq->retry_q)) != NULL) {
624 		hw = mt76_tx_status_get_hw(dev, skb);
625 		ieee80211_free_txskb(hw, skb);
626 	}
627 }
628 EXPORT_SYMBOL_GPL(mt76_txq_remove);
629 
630 void mt76_txq_init(struct mt76_dev *dev, struct ieee80211_txq *txq)
631 {
632 	struct mt76_txq *mtxq = (struct mt76_txq *)txq->drv_priv;
633 
634 	skb_queue_head_init(&mtxq->retry_q);
635 
636 	mtxq->swq = &dev->q_tx[mt76_txq_get_qid(txq)];
637 }
638 EXPORT_SYMBOL_GPL(mt76_txq_init);
639 
640 u8 mt76_ac_to_hwq(u8 ac)
641 {
642 	static const u8 wmm_queue_map[] = {
643 		[IEEE80211_AC_BE] = 0,
644 		[IEEE80211_AC_BK] = 1,
645 		[IEEE80211_AC_VI] = 2,
646 		[IEEE80211_AC_VO] = 3,
647 	};
648 
649 	if (WARN_ON(ac >= IEEE80211_NUM_ACS))
650 		return 0;
651 
652 	return wmm_queue_map[ac];
653 }
654 EXPORT_SYMBOL_GPL(mt76_ac_to_hwq);
655