xref: /linux/drivers/net/wireless/mediatek/mt76/tx.c (revision b7d3826c2ed6c3e626e7ae796c5df2c0d2551c6a)
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 		return;
101 
102 	mtxq->agg_ssn = le16_to_cpu(hdr->seq_ctrl) + 0x10;
103 }
104 
105 void
106 mt76_tx(struct mt76_dev *dev, struct ieee80211_sta *sta,
107 	struct mt76_wcid *wcid, struct sk_buff *skb)
108 {
109 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
110 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
111 	struct mt76_queue *q;
112 	int qid = skb_get_queue_mapping(skb);
113 
114 	if (WARN_ON(qid >= MT_TXQ_PSD)) {
115 		qid = MT_TXQ_BE;
116 		skb_set_queue_mapping(skb, qid);
117 	}
118 
119 	if (!wcid->tx_rate_set)
120 		ieee80211_get_tx_rates(info->control.vif, sta, skb,
121 				       info->control.rates, 1);
122 
123 	if (sta && ieee80211_is_data_qos(hdr->frame_control)) {
124 		struct ieee80211_txq *txq;
125 		struct mt76_txq *mtxq;
126 		u8 tid;
127 
128 		tid = skb->priority & IEEE80211_QOS_CTL_TID_MASK;
129 		txq = sta->txq[tid];
130 		mtxq = (struct mt76_txq *) txq->drv_priv;
131 
132 		if (mtxq->aggr)
133 			mt76_check_agg_ssn(mtxq, skb);
134 	}
135 
136 	q = &dev->q_tx[qid];
137 
138 	spin_lock_bh(&q->lock);
139 	dev->queue_ops->tx_queue_skb(dev, q, skb, wcid, sta);
140 	dev->queue_ops->kick(dev, q);
141 
142 	if (q->queued > q->ndesc - 8)
143 		ieee80211_stop_queue(dev->hw, skb_get_queue_mapping(skb));
144 	spin_unlock_bh(&q->lock);
145 }
146 EXPORT_SYMBOL_GPL(mt76_tx);
147 
148 static struct sk_buff *
149 mt76_txq_dequeue(struct mt76_dev *dev, struct mt76_txq *mtxq, bool ps)
150 {
151 	struct ieee80211_txq *txq = mtxq_to_txq(mtxq);
152 	struct sk_buff *skb;
153 
154 	skb = skb_dequeue(&mtxq->retry_q);
155 	if (skb) {
156 		u8 tid = skb->priority & IEEE80211_QOS_CTL_TID_MASK;
157 
158 		if (ps && skb_queue_empty(&mtxq->retry_q))
159 			ieee80211_sta_set_buffered(txq->sta, tid, false);
160 
161 		return skb;
162 	}
163 
164 	skb = ieee80211_tx_dequeue(dev->hw, txq);
165 	if (!skb)
166 		return NULL;
167 
168 	return skb;
169 }
170 
171 static void
172 mt76_queue_ps_skb(struct mt76_dev *dev, struct ieee80211_sta *sta,
173 		  struct sk_buff *skb, bool last)
174 {
175 	struct mt76_wcid *wcid = (struct mt76_wcid *) sta->drv_priv;
176 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
177 	struct mt76_queue *hwq = &dev->q_tx[MT_TXQ_PSD];
178 
179 	info->control.flags |= IEEE80211_TX_CTRL_PS_RESPONSE;
180 	if (last)
181 		info->flags |= IEEE80211_TX_STATUS_EOSP;
182 
183 	mt76_skb_set_moredata(skb, !last);
184 	dev->queue_ops->tx_queue_skb(dev, hwq, skb, wcid, sta);
185 }
186 
187 void
188 mt76_release_buffered_frames(struct ieee80211_hw *hw, struct ieee80211_sta *sta,
189 			     u16 tids, int nframes,
190 			     enum ieee80211_frame_release_type reason,
191 			     bool more_data)
192 {
193 	struct mt76_dev *dev = hw->priv;
194 	struct sk_buff *last_skb = NULL;
195 	struct mt76_queue *hwq = &dev->q_tx[MT_TXQ_PSD];
196 	int i;
197 
198 	spin_lock_bh(&hwq->lock);
199 	for (i = 0; tids && nframes; i++, tids >>= 1) {
200 		struct ieee80211_txq *txq = sta->txq[i];
201 		struct mt76_txq *mtxq = (struct mt76_txq *) txq->drv_priv;
202 		struct sk_buff *skb;
203 
204 		if (!(tids & 1))
205 			continue;
206 
207 		do {
208 			skb = mt76_txq_dequeue(dev, mtxq, true);
209 			if (!skb)
210 				break;
211 
212 			if (mtxq->aggr)
213 				mt76_check_agg_ssn(mtxq, skb);
214 
215 			nframes--;
216 			if (last_skb)
217 				mt76_queue_ps_skb(dev, sta, last_skb, false);
218 
219 			last_skb = skb;
220 		} while (nframes);
221 	}
222 
223 	if (last_skb) {
224 		mt76_queue_ps_skb(dev, sta, last_skb, true);
225 		dev->queue_ops->kick(dev, hwq);
226 	}
227 	spin_unlock_bh(&hwq->lock);
228 }
229 EXPORT_SYMBOL_GPL(mt76_release_buffered_frames);
230 
231 static int
232 mt76_txq_send_burst(struct mt76_dev *dev, struct mt76_queue *hwq,
233 		    struct mt76_txq *mtxq, bool *empty)
234 {
235 	struct ieee80211_txq *txq = mtxq_to_txq(mtxq);
236 	struct ieee80211_tx_info *info;
237 	struct mt76_wcid *wcid = mtxq->wcid;
238 	struct sk_buff *skb;
239 	int n_frames = 1, limit;
240 	struct ieee80211_tx_rate tx_rate;
241 	bool ampdu;
242 	bool probe;
243 	int idx;
244 
245 	skb = mt76_txq_dequeue(dev, mtxq, false);
246 	if (!skb) {
247 		*empty = true;
248 		return 0;
249 	}
250 
251 	info = IEEE80211_SKB_CB(skb);
252 	if (!wcid->tx_rate_set)
253 		ieee80211_get_tx_rates(txq->vif, txq->sta, skb,
254 				       info->control.rates, 1);
255 	tx_rate = info->control.rates[0];
256 
257 	probe = (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE);
258 	ampdu = IEEE80211_SKB_CB(skb)->flags & IEEE80211_TX_CTL_AMPDU;
259 	limit = ampdu ? 16 : 3;
260 
261 	if (ampdu)
262 		mt76_check_agg_ssn(mtxq, skb);
263 
264 	idx = dev->queue_ops->tx_queue_skb(dev, hwq, skb, wcid, txq->sta);
265 
266 	if (idx < 0)
267 		return idx;
268 
269 	do {
270 		bool cur_ampdu;
271 
272 		if (probe)
273 			break;
274 
275 		if (test_bit(MT76_OFFCHANNEL, &dev->state) ||
276 		    test_bit(MT76_RESET, &dev->state))
277 			return -EBUSY;
278 
279 		skb = mt76_txq_dequeue(dev, mtxq, false);
280 		if (!skb) {
281 			*empty = true;
282 			break;
283 		}
284 
285 		info = IEEE80211_SKB_CB(skb);
286 		cur_ampdu = info->flags & IEEE80211_TX_CTL_AMPDU;
287 
288 		if (ampdu != cur_ampdu ||
289 		    (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)) {
290 			skb_queue_tail(&mtxq->retry_q, skb);
291 			break;
292 		}
293 
294 		info->control.rates[0] = tx_rate;
295 
296 		if (cur_ampdu)
297 			mt76_check_agg_ssn(mtxq, skb);
298 
299 		idx = dev->queue_ops->tx_queue_skb(dev, hwq, skb, wcid,
300 						   txq->sta);
301 		if (idx < 0)
302 			return idx;
303 
304 		n_frames++;
305 	} while (n_frames < limit);
306 
307 	if (!probe) {
308 		hwq->swq_queued++;
309 		hwq->entry[idx].schedule = true;
310 	}
311 
312 	dev->queue_ops->kick(dev, hwq);
313 
314 	return n_frames;
315 }
316 
317 static int
318 mt76_txq_schedule_list(struct mt76_dev *dev, struct mt76_queue *hwq)
319 {
320 	struct mt76_txq *mtxq, *mtxq_last;
321 	int len = 0;
322 
323 restart:
324 	mtxq_last = list_last_entry(&hwq->swq, struct mt76_txq, list);
325 	while (!list_empty(&hwq->swq)) {
326 		bool empty = false;
327 		int cur;
328 
329 		if (test_bit(MT76_OFFCHANNEL, &dev->state) ||
330 		    test_bit(MT76_RESET, &dev->state))
331 			return -EBUSY;
332 
333 		mtxq = list_first_entry(&hwq->swq, struct mt76_txq, list);
334 		if (mtxq->send_bar && mtxq->aggr) {
335 			struct ieee80211_txq *txq = mtxq_to_txq(mtxq);
336 			struct ieee80211_sta *sta = txq->sta;
337 			struct ieee80211_vif *vif = txq->vif;
338 			u16 agg_ssn = mtxq->agg_ssn;
339 			u8 tid = txq->tid;
340 
341 			mtxq->send_bar = false;
342 			spin_unlock_bh(&hwq->lock);
343 			ieee80211_send_bar(vif, sta->addr, tid, agg_ssn);
344 			spin_lock_bh(&hwq->lock);
345 			goto restart;
346 		}
347 
348 		list_del_init(&mtxq->list);
349 
350 		cur = mt76_txq_send_burst(dev, hwq, mtxq, &empty);
351 		if (!empty)
352 			list_add_tail(&mtxq->list, &hwq->swq);
353 
354 		if (cur < 0)
355 			return cur;
356 
357 		len += cur;
358 
359 		if (mtxq == mtxq_last)
360 			break;
361 	}
362 
363 	return len;
364 }
365 
366 void mt76_txq_schedule(struct mt76_dev *dev, struct mt76_queue *hwq)
367 {
368 	int len;
369 
370 	rcu_read_lock();
371 	do {
372 		if (hwq->swq_queued >= 4 || list_empty(&hwq->swq))
373 			break;
374 
375 		len = mt76_txq_schedule_list(dev, hwq);
376 	} while (len > 0);
377 	rcu_read_unlock();
378 }
379 EXPORT_SYMBOL_GPL(mt76_txq_schedule);
380 
381 void mt76_txq_schedule_all(struct mt76_dev *dev)
382 {
383 	int i;
384 
385 	for (i = 0; i <= MT_TXQ_BK; i++) {
386 		struct mt76_queue *q = &dev->q_tx[i];
387 
388 		spin_lock_bh(&q->lock);
389 		mt76_txq_schedule(dev, q);
390 		spin_unlock_bh(&q->lock);
391 	}
392 }
393 EXPORT_SYMBOL_GPL(mt76_txq_schedule_all);
394 
395 void mt76_stop_tx_queues(struct mt76_dev *dev, struct ieee80211_sta *sta,
396 			 bool send_bar)
397 {
398 	int i;
399 
400 	for (i = 0; i < ARRAY_SIZE(sta->txq); i++) {
401 		struct ieee80211_txq *txq = sta->txq[i];
402 		struct mt76_txq *mtxq = (struct mt76_txq *) txq->drv_priv;
403 
404 		spin_lock_bh(&mtxq->hwq->lock);
405 		mtxq->send_bar = mtxq->aggr && send_bar;
406 		if (!list_empty(&mtxq->list))
407 			list_del_init(&mtxq->list);
408 		spin_unlock_bh(&mtxq->hwq->lock);
409 	}
410 }
411 EXPORT_SYMBOL_GPL(mt76_stop_tx_queues);
412 
413 void mt76_wake_tx_queue(struct ieee80211_hw *hw, struct ieee80211_txq *txq)
414 {
415 	struct mt76_dev *dev = hw->priv;
416 	struct mt76_txq *mtxq = (struct mt76_txq *) txq->drv_priv;
417 	struct mt76_queue *hwq = mtxq->hwq;
418 
419 	spin_lock_bh(&hwq->lock);
420 	if (list_empty(&mtxq->list))
421 		list_add_tail(&mtxq->list, &hwq->swq);
422 	mt76_txq_schedule(dev, hwq);
423 	spin_unlock_bh(&hwq->lock);
424 }
425 EXPORT_SYMBOL_GPL(mt76_wake_tx_queue);
426 
427 void mt76_txq_remove(struct mt76_dev *dev, struct ieee80211_txq *txq)
428 {
429 	struct mt76_txq *mtxq;
430 	struct mt76_queue *hwq;
431 	struct sk_buff *skb;
432 
433 	if (!txq)
434 		return;
435 
436 	mtxq = (struct mt76_txq *) txq->drv_priv;
437 	hwq = mtxq->hwq;
438 
439 	spin_lock_bh(&hwq->lock);
440 	if (!list_empty(&mtxq->list))
441 		list_del(&mtxq->list);
442 	spin_unlock_bh(&hwq->lock);
443 
444 	while ((skb = skb_dequeue(&mtxq->retry_q)) != NULL)
445 		ieee80211_free_txskb(dev->hw, skb);
446 }
447 EXPORT_SYMBOL_GPL(mt76_txq_remove);
448 
449 void mt76_txq_init(struct mt76_dev *dev, struct ieee80211_txq *txq)
450 {
451 	struct mt76_txq *mtxq = (struct mt76_txq *) txq->drv_priv;
452 
453 	INIT_LIST_HEAD(&mtxq->list);
454 	skb_queue_head_init(&mtxq->retry_q);
455 
456 	mtxq->hwq = &dev->q_tx[mt76_txq_get_qid(txq)];
457 }
458 EXPORT_SYMBOL_GPL(mt76_txq_init);
459 
460 u8 mt76_ac_to_hwq(u8 ac)
461 {
462 	static const u8 wmm_queue_map[] = {
463 		[IEEE80211_AC_BE] = 0,
464 		[IEEE80211_AC_BK] = 1,
465 		[IEEE80211_AC_VI] = 2,
466 		[IEEE80211_AC_VO] = 3,
467 	};
468 
469 	if (WARN_ON(ac >= IEEE80211_NUM_ACS))
470 		return 0;
471 
472 	return wmm_queue_map[ac];
473 }
474 EXPORT_SYMBOL_GPL(mt76_ac_to_hwq);
475