xref: /openbmc/linux/drivers/net/wireless/mediatek/mt76/tx.c (revision 8631f940b81bf0da3d375fce166d381fa8c47bb2)
1 /*
2  * Copyright (C) 2016 Felix Fietkau <nbd@nbd.name>
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "mt76.h"
18 
19 static struct mt76_txwi_cache *
20 mt76_alloc_txwi(struct mt76_dev *dev)
21 {
22 	struct mt76_txwi_cache *t;
23 	dma_addr_t addr;
24 	int size;
25 
26 	size = (sizeof(*t) + L1_CACHE_BYTES - 1) & ~(L1_CACHE_BYTES - 1);
27 	t = devm_kzalloc(dev->dev, size, GFP_ATOMIC);
28 	if (!t)
29 		return NULL;
30 
31 	addr = dma_map_single(dev->dev, &t->txwi, sizeof(t->txwi),
32 			      DMA_TO_DEVICE);
33 	t->dma_addr = addr;
34 
35 	return t;
36 }
37 
38 static struct mt76_txwi_cache *
39 __mt76_get_txwi(struct mt76_dev *dev)
40 {
41 	struct mt76_txwi_cache *t = NULL;
42 
43 	spin_lock_bh(&dev->lock);
44 	if (!list_empty(&dev->txwi_cache)) {
45 		t = list_first_entry(&dev->txwi_cache, struct mt76_txwi_cache,
46 				     list);
47 		list_del(&t->list);
48 	}
49 	spin_unlock_bh(&dev->lock);
50 
51 	return t;
52 }
53 
54 struct mt76_txwi_cache *
55 mt76_get_txwi(struct mt76_dev *dev)
56 {
57 	struct mt76_txwi_cache *t = __mt76_get_txwi(dev);
58 
59 	if (t)
60 		return t;
61 
62 	return mt76_alloc_txwi(dev);
63 }
64 
65 void
66 mt76_put_txwi(struct mt76_dev *dev, struct mt76_txwi_cache *t)
67 {
68 	if (!t)
69 		return;
70 
71 	spin_lock_bh(&dev->lock);
72 	list_add(&t->list, &dev->txwi_cache);
73 	spin_unlock_bh(&dev->lock);
74 }
75 
76 void mt76_tx_free(struct mt76_dev *dev)
77 {
78 	struct mt76_txwi_cache *t;
79 
80 	while ((t = __mt76_get_txwi(dev)) != NULL)
81 		dma_unmap_single(dev->dev, t->dma_addr, sizeof(t->txwi),
82 				 DMA_TO_DEVICE);
83 }
84 
85 static int
86 mt76_txq_get_qid(struct ieee80211_txq *txq)
87 {
88 	if (!txq->sta)
89 		return MT_TXQ_BE;
90 
91 	return txq->ac;
92 }
93 
94 static void
95 mt76_check_agg_ssn(struct mt76_txq *mtxq, struct sk_buff *skb)
96 {
97 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
98 
99 	if (!ieee80211_is_data_qos(hdr->frame_control) ||
100 	    !ieee80211_is_data_present(hdr->frame_control))
101 		return;
102 
103 	mtxq->agg_ssn = le16_to_cpu(hdr->seq_ctrl) + 0x10;
104 }
105 
106 void
107 mt76_tx_status_lock(struct mt76_dev *dev, struct sk_buff_head *list)
108 		   __acquires(&dev->status_list.lock)
109 {
110 	__skb_queue_head_init(list);
111 	spin_lock_bh(&dev->status_list.lock);
112 	__acquire(&dev->status_list.lock);
113 }
114 EXPORT_SYMBOL_GPL(mt76_tx_status_lock);
115 
116 void
117 mt76_tx_status_unlock(struct mt76_dev *dev, struct sk_buff_head *list)
118 		      __releases(&dev->status_list.unlock)
119 {
120 	struct sk_buff *skb;
121 
122 	spin_unlock_bh(&dev->status_list.lock);
123 	__release(&dev->status_list.unlock);
124 
125 	while ((skb = __skb_dequeue(list)) != NULL)
126 		ieee80211_tx_status(dev->hw, skb);
127 }
128 EXPORT_SYMBOL_GPL(mt76_tx_status_unlock);
129 
130 static void
131 __mt76_tx_status_skb_done(struct mt76_dev *dev, struct sk_buff *skb, u8 flags,
132 			  struct sk_buff_head *list)
133 {
134 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
135 	struct mt76_tx_cb *cb = mt76_tx_skb_cb(skb);
136 	u8 done = MT_TX_CB_DMA_DONE | MT_TX_CB_TXS_DONE;
137 
138 	flags |= cb->flags;
139 	cb->flags = flags;
140 
141 	if ((flags & done) != done)
142 		return;
143 
144 	__skb_unlink(skb, &dev->status_list);
145 
146 	/* Tx status can be unreliable. if it fails, mark the frame as ACKed */
147 	if (flags & MT_TX_CB_TXS_FAILED) {
148 		ieee80211_tx_info_clear_status(info);
149 		info->status.rates[0].idx = -1;
150 		info->flags |= IEEE80211_TX_STAT_ACK;
151 	}
152 
153 	__skb_queue_tail(list, skb);
154 }
155 
156 void
157 mt76_tx_status_skb_done(struct mt76_dev *dev, struct sk_buff *skb,
158 			struct sk_buff_head *list)
159 {
160 	__mt76_tx_status_skb_done(dev, skb, MT_TX_CB_TXS_DONE, list);
161 }
162 EXPORT_SYMBOL_GPL(mt76_tx_status_skb_done);
163 
164 int
165 mt76_tx_status_skb_add(struct mt76_dev *dev, struct mt76_wcid *wcid,
166 		       struct sk_buff *skb)
167 {
168 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
169 	struct mt76_tx_cb *cb = mt76_tx_skb_cb(skb);
170 	int pid;
171 
172 	if (!wcid)
173 		return 0;
174 
175 	if (info->flags & IEEE80211_TX_CTL_NO_ACK)
176 		return MT_PACKET_ID_NO_ACK;
177 
178 	if (!(info->flags & (IEEE80211_TX_CTL_REQ_TX_STATUS |
179 			     IEEE80211_TX_CTL_RATE_CTRL_PROBE)))
180 		return 0;
181 
182 	spin_lock_bh(&dev->status_list.lock);
183 
184 	memset(cb, 0, sizeof(*cb));
185 	wcid->packet_id = (wcid->packet_id + 1) & MT_PACKET_ID_MASK;
186 	if (!wcid->packet_id || wcid->packet_id == MT_PACKET_ID_NO_ACK)
187 		wcid->packet_id = 1;
188 
189 	pid = wcid->packet_id;
190 	cb->wcid = wcid->idx;
191 	cb->pktid = pid;
192 	cb->jiffies = jiffies;
193 
194 	__skb_queue_tail(&dev->status_list, skb);
195 	spin_unlock_bh(&dev->status_list.lock);
196 
197 	return pid;
198 }
199 EXPORT_SYMBOL_GPL(mt76_tx_status_skb_add);
200 
201 struct sk_buff *
202 mt76_tx_status_skb_get(struct mt76_dev *dev, struct mt76_wcid *wcid, int pktid,
203 		       struct sk_buff_head *list)
204 {
205 	struct sk_buff *skb, *tmp;
206 
207 	if (pktid == MT_PACKET_ID_NO_ACK)
208 		return NULL;
209 
210 	skb_queue_walk_safe(&dev->status_list, skb, tmp) {
211 		struct mt76_tx_cb *cb = mt76_tx_skb_cb(skb);
212 
213 		if (wcid && cb->wcid != wcid->idx)
214 			continue;
215 
216 		if (cb->pktid == pktid)
217 			return skb;
218 
219 		if (!pktid &&
220 		    !time_after(jiffies, cb->jiffies + MT_TX_STATUS_SKB_TIMEOUT))
221 			continue;
222 
223 		__mt76_tx_status_skb_done(dev, skb, MT_TX_CB_TXS_FAILED |
224 						    MT_TX_CB_TXS_DONE, list);
225 	}
226 
227 	return NULL;
228 }
229 EXPORT_SYMBOL_GPL(mt76_tx_status_skb_get);
230 
231 void
232 mt76_tx_status_check(struct mt76_dev *dev, struct mt76_wcid *wcid, bool flush)
233 {
234 	struct sk_buff_head list;
235 
236 	mt76_tx_status_lock(dev, &list);
237 	mt76_tx_status_skb_get(dev, wcid, flush ? -1 : 0, &list);
238 	mt76_tx_status_unlock(dev, &list);
239 }
240 EXPORT_SYMBOL_GPL(mt76_tx_status_check);
241 
242 void mt76_tx_complete_skb(struct mt76_dev *dev, struct sk_buff *skb)
243 {
244 	struct sk_buff_head list;
245 
246 	if (!skb->prev) {
247 		ieee80211_free_txskb(dev->hw, skb);
248 		return;
249 	}
250 
251 	mt76_tx_status_lock(dev, &list);
252 	__mt76_tx_status_skb_done(dev, skb, MT_TX_CB_DMA_DONE, &list);
253 	mt76_tx_status_unlock(dev, &list);
254 }
255 EXPORT_SYMBOL_GPL(mt76_tx_complete_skb);
256 
257 void
258 mt76_tx(struct mt76_dev *dev, struct ieee80211_sta *sta,
259 	struct mt76_wcid *wcid, struct sk_buff *skb)
260 {
261 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
262 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
263 	struct mt76_queue *q;
264 	int qid = skb_get_queue_mapping(skb);
265 
266 	if (WARN_ON(qid >= MT_TXQ_PSD)) {
267 		qid = MT_TXQ_BE;
268 		skb_set_queue_mapping(skb, qid);
269 	}
270 
271 	if (!wcid->tx_rate_set)
272 		ieee80211_get_tx_rates(info->control.vif, sta, skb,
273 				       info->control.rates, 1);
274 
275 	if (sta && ieee80211_is_data_qos(hdr->frame_control)) {
276 		struct ieee80211_txq *txq;
277 		struct mt76_txq *mtxq;
278 		u8 tid;
279 
280 		tid = skb->priority & IEEE80211_QOS_CTL_TID_MASK;
281 		txq = sta->txq[tid];
282 		mtxq = (struct mt76_txq *) txq->drv_priv;
283 
284 		if (mtxq->aggr)
285 			mt76_check_agg_ssn(mtxq, skb);
286 	}
287 
288 	q = &dev->q_tx[qid];
289 
290 	spin_lock_bh(&q->lock);
291 	dev->queue_ops->tx_queue_skb(dev, q, skb, wcid, sta);
292 	dev->queue_ops->kick(dev, q);
293 
294 	if (q->queued > q->ndesc - 8)
295 		ieee80211_stop_queue(dev->hw, skb_get_queue_mapping(skb));
296 	spin_unlock_bh(&q->lock);
297 }
298 EXPORT_SYMBOL_GPL(mt76_tx);
299 
300 static struct sk_buff *
301 mt76_txq_dequeue(struct mt76_dev *dev, struct mt76_txq *mtxq, bool ps)
302 {
303 	struct ieee80211_txq *txq = mtxq_to_txq(mtxq);
304 	struct sk_buff *skb;
305 
306 	skb = skb_dequeue(&mtxq->retry_q);
307 	if (skb) {
308 		u8 tid = skb->priority & IEEE80211_QOS_CTL_TID_MASK;
309 
310 		if (ps && skb_queue_empty(&mtxq->retry_q))
311 			ieee80211_sta_set_buffered(txq->sta, tid, false);
312 
313 		return skb;
314 	}
315 
316 	skb = ieee80211_tx_dequeue(dev->hw, txq);
317 	if (!skb)
318 		return NULL;
319 
320 	return skb;
321 }
322 
323 static void
324 mt76_queue_ps_skb(struct mt76_dev *dev, struct ieee80211_sta *sta,
325 		  struct sk_buff *skb, bool last)
326 {
327 	struct mt76_wcid *wcid = (struct mt76_wcid *) sta->drv_priv;
328 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
329 	struct mt76_queue *hwq = &dev->q_tx[MT_TXQ_PSD];
330 
331 	info->control.flags |= IEEE80211_TX_CTRL_PS_RESPONSE;
332 	if (last)
333 		info->flags |= IEEE80211_TX_STATUS_EOSP;
334 
335 	mt76_skb_set_moredata(skb, !last);
336 	dev->queue_ops->tx_queue_skb(dev, hwq, skb, wcid, sta);
337 }
338 
339 void
340 mt76_release_buffered_frames(struct ieee80211_hw *hw, struct ieee80211_sta *sta,
341 			     u16 tids, int nframes,
342 			     enum ieee80211_frame_release_type reason,
343 			     bool more_data)
344 {
345 	struct mt76_dev *dev = hw->priv;
346 	struct sk_buff *last_skb = NULL;
347 	struct mt76_queue *hwq = &dev->q_tx[MT_TXQ_PSD];
348 	int i;
349 
350 	spin_lock_bh(&hwq->lock);
351 	for (i = 0; tids && nframes; i++, tids >>= 1) {
352 		struct ieee80211_txq *txq = sta->txq[i];
353 		struct mt76_txq *mtxq = (struct mt76_txq *) txq->drv_priv;
354 		struct sk_buff *skb;
355 
356 		if (!(tids & 1))
357 			continue;
358 
359 		do {
360 			skb = mt76_txq_dequeue(dev, mtxq, true);
361 			if (!skb)
362 				break;
363 
364 			if (mtxq->aggr)
365 				mt76_check_agg_ssn(mtxq, skb);
366 
367 			nframes--;
368 			if (last_skb)
369 				mt76_queue_ps_skb(dev, sta, last_skb, false);
370 
371 			last_skb = skb;
372 		} while (nframes);
373 	}
374 
375 	if (last_skb) {
376 		mt76_queue_ps_skb(dev, sta, last_skb, true);
377 		dev->queue_ops->kick(dev, hwq);
378 	}
379 	spin_unlock_bh(&hwq->lock);
380 }
381 EXPORT_SYMBOL_GPL(mt76_release_buffered_frames);
382 
383 static int
384 mt76_txq_send_burst(struct mt76_dev *dev, struct mt76_queue *hwq,
385 		    struct mt76_txq *mtxq, bool *empty)
386 {
387 	struct ieee80211_txq *txq = mtxq_to_txq(mtxq);
388 	struct ieee80211_tx_info *info;
389 	struct mt76_wcid *wcid = mtxq->wcid;
390 	struct sk_buff *skb;
391 	int n_frames = 1, limit;
392 	struct ieee80211_tx_rate tx_rate;
393 	bool ampdu;
394 	bool probe;
395 	int idx;
396 
397 	skb = mt76_txq_dequeue(dev, mtxq, false);
398 	if (!skb) {
399 		*empty = true;
400 		return 0;
401 	}
402 
403 	info = IEEE80211_SKB_CB(skb);
404 	if (!wcid->tx_rate_set)
405 		ieee80211_get_tx_rates(txq->vif, txq->sta, skb,
406 				       info->control.rates, 1);
407 	tx_rate = info->control.rates[0];
408 
409 	probe = (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE);
410 	ampdu = IEEE80211_SKB_CB(skb)->flags & IEEE80211_TX_CTL_AMPDU;
411 	limit = ampdu ? 16 : 3;
412 
413 	if (ampdu)
414 		mt76_check_agg_ssn(mtxq, skb);
415 
416 	idx = dev->queue_ops->tx_queue_skb(dev, hwq, skb, wcid, txq->sta);
417 
418 	if (idx < 0)
419 		return idx;
420 
421 	do {
422 		bool cur_ampdu;
423 
424 		if (probe)
425 			break;
426 
427 		if (test_bit(MT76_OFFCHANNEL, &dev->state) ||
428 		    test_bit(MT76_RESET, &dev->state))
429 			return -EBUSY;
430 
431 		skb = mt76_txq_dequeue(dev, mtxq, false);
432 		if (!skb) {
433 			*empty = true;
434 			break;
435 		}
436 
437 		info = IEEE80211_SKB_CB(skb);
438 		cur_ampdu = info->flags & IEEE80211_TX_CTL_AMPDU;
439 
440 		if (ampdu != cur_ampdu ||
441 		    (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)) {
442 			skb_queue_tail(&mtxq->retry_q, skb);
443 			break;
444 		}
445 
446 		info->control.rates[0] = tx_rate;
447 
448 		if (cur_ampdu)
449 			mt76_check_agg_ssn(mtxq, skb);
450 
451 		idx = dev->queue_ops->tx_queue_skb(dev, hwq, skb, wcid,
452 						   txq->sta);
453 		if (idx < 0)
454 			return idx;
455 
456 		n_frames++;
457 	} while (n_frames < limit);
458 
459 	if (!probe) {
460 		hwq->swq_queued++;
461 		hwq->entry[idx].schedule = true;
462 	}
463 
464 	dev->queue_ops->kick(dev, hwq);
465 
466 	return n_frames;
467 }
468 
469 static int
470 mt76_txq_schedule_list(struct mt76_dev *dev, struct mt76_queue *hwq)
471 {
472 	struct mt76_txq *mtxq, *mtxq_last;
473 	int len = 0;
474 
475 restart:
476 	mtxq_last = list_last_entry(&hwq->swq, struct mt76_txq, list);
477 	while (!list_empty(&hwq->swq)) {
478 		bool empty = false;
479 		int cur;
480 
481 		if (test_bit(MT76_OFFCHANNEL, &dev->state) ||
482 		    test_bit(MT76_RESET, &dev->state))
483 			return -EBUSY;
484 
485 		mtxq = list_first_entry(&hwq->swq, struct mt76_txq, list);
486 		if (mtxq->send_bar && mtxq->aggr) {
487 			struct ieee80211_txq *txq = mtxq_to_txq(mtxq);
488 			struct ieee80211_sta *sta = txq->sta;
489 			struct ieee80211_vif *vif = txq->vif;
490 			u16 agg_ssn = mtxq->agg_ssn;
491 			u8 tid = txq->tid;
492 
493 			mtxq->send_bar = false;
494 			spin_unlock_bh(&hwq->lock);
495 			ieee80211_send_bar(vif, sta->addr, tid, agg_ssn);
496 			spin_lock_bh(&hwq->lock);
497 			goto restart;
498 		}
499 
500 		list_del_init(&mtxq->list);
501 
502 		cur = mt76_txq_send_burst(dev, hwq, mtxq, &empty);
503 		if (!empty)
504 			list_add_tail(&mtxq->list, &hwq->swq);
505 
506 		if (cur < 0)
507 			return cur;
508 
509 		len += cur;
510 
511 		if (mtxq == mtxq_last)
512 			break;
513 	}
514 
515 	return len;
516 }
517 
518 void mt76_txq_schedule(struct mt76_dev *dev, struct mt76_queue *hwq)
519 {
520 	int len;
521 
522 	rcu_read_lock();
523 	do {
524 		if (hwq->swq_queued >= 4 || list_empty(&hwq->swq))
525 			break;
526 
527 		len = mt76_txq_schedule_list(dev, hwq);
528 	} while (len > 0);
529 	rcu_read_unlock();
530 }
531 EXPORT_SYMBOL_GPL(mt76_txq_schedule);
532 
533 void mt76_txq_schedule_all(struct mt76_dev *dev)
534 {
535 	int i;
536 
537 	for (i = 0; i <= MT_TXQ_BK; i++) {
538 		struct mt76_queue *q = &dev->q_tx[i];
539 
540 		spin_lock_bh(&q->lock);
541 		mt76_txq_schedule(dev, q);
542 		spin_unlock_bh(&q->lock);
543 	}
544 }
545 EXPORT_SYMBOL_GPL(mt76_txq_schedule_all);
546 
547 void mt76_stop_tx_queues(struct mt76_dev *dev, struct ieee80211_sta *sta,
548 			 bool send_bar)
549 {
550 	int i;
551 
552 	for (i = 0; i < ARRAY_SIZE(sta->txq); i++) {
553 		struct ieee80211_txq *txq = sta->txq[i];
554 		struct mt76_txq *mtxq;
555 
556 		if (!txq)
557 			continue;
558 
559 		mtxq = (struct mt76_txq *)txq->drv_priv;
560 
561 		spin_lock_bh(&mtxq->hwq->lock);
562 		mtxq->send_bar = mtxq->aggr && send_bar;
563 		if (!list_empty(&mtxq->list))
564 			list_del_init(&mtxq->list);
565 		spin_unlock_bh(&mtxq->hwq->lock);
566 	}
567 }
568 EXPORT_SYMBOL_GPL(mt76_stop_tx_queues);
569 
570 void mt76_wake_tx_queue(struct ieee80211_hw *hw, struct ieee80211_txq *txq)
571 {
572 	struct mt76_dev *dev = hw->priv;
573 	struct mt76_txq *mtxq = (struct mt76_txq *) txq->drv_priv;
574 	struct mt76_queue *hwq = mtxq->hwq;
575 
576 	spin_lock_bh(&hwq->lock);
577 	if (list_empty(&mtxq->list))
578 		list_add_tail(&mtxq->list, &hwq->swq);
579 	mt76_txq_schedule(dev, hwq);
580 	spin_unlock_bh(&hwq->lock);
581 }
582 EXPORT_SYMBOL_GPL(mt76_wake_tx_queue);
583 
584 void mt76_txq_remove(struct mt76_dev *dev, struct ieee80211_txq *txq)
585 {
586 	struct mt76_txq *mtxq;
587 	struct mt76_queue *hwq;
588 	struct sk_buff *skb;
589 
590 	if (!txq)
591 		return;
592 
593 	mtxq = (struct mt76_txq *) txq->drv_priv;
594 	hwq = mtxq->hwq;
595 
596 	spin_lock_bh(&hwq->lock);
597 	if (!list_empty(&mtxq->list))
598 		list_del_init(&mtxq->list);
599 	spin_unlock_bh(&hwq->lock);
600 
601 	while ((skb = skb_dequeue(&mtxq->retry_q)) != NULL)
602 		ieee80211_free_txskb(dev->hw, skb);
603 }
604 EXPORT_SYMBOL_GPL(mt76_txq_remove);
605 
606 void mt76_txq_init(struct mt76_dev *dev, struct ieee80211_txq *txq)
607 {
608 	struct mt76_txq *mtxq = (struct mt76_txq *) txq->drv_priv;
609 
610 	INIT_LIST_HEAD(&mtxq->list);
611 	skb_queue_head_init(&mtxq->retry_q);
612 
613 	mtxq->hwq = &dev->q_tx[mt76_txq_get_qid(txq)];
614 }
615 EXPORT_SYMBOL_GPL(mt76_txq_init);
616 
617 u8 mt76_ac_to_hwq(u8 ac)
618 {
619 	static const u8 wmm_queue_map[] = {
620 		[IEEE80211_AC_BE] = 0,
621 		[IEEE80211_AC_BK] = 1,
622 		[IEEE80211_AC_VI] = 2,
623 		[IEEE80211_AC_VO] = 3,
624 	};
625 
626 	if (WARN_ON(ac >= IEEE80211_NUM_ACS))
627 		return 0;
628 
629 	return wmm_queue_map[ac];
630 }
631 EXPORT_SYMBOL_GPL(mt76_ac_to_hwq);
632