1  // SPDX-License-Identifier: GPL-2.0-only
2  /*
3   * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
4   * Copyright (C) 2015 Jakub Kicinski <kubakici@wp.pl>
5   */
6  
7  #include "mt7601u.h"
8  #include "trace.h"
9  
10  enum mt76_txq_id {
11  	MT_TXQ_VO = IEEE80211_AC_VO,
12  	MT_TXQ_VI = IEEE80211_AC_VI,
13  	MT_TXQ_BE = IEEE80211_AC_BE,
14  	MT_TXQ_BK = IEEE80211_AC_BK,
15  	MT_TXQ_PSD,
16  	MT_TXQ_MCU,
17  	__MT_TXQ_MAX
18  };
19  
20  /* Hardware uses mirrored order of queues with Q0 having the highest priority */
q2hwq(u8 q)21  static u8 q2hwq(u8 q)
22  {
23  	return q ^ 0x3;
24  }
25  
26  /* Take mac80211 Q id from the skb and translate it to hardware Q id */
skb2q(struct sk_buff * skb)27  static u8 skb2q(struct sk_buff *skb)
28  {
29  	int qid = skb_get_queue_mapping(skb);
30  
31  	if (WARN_ON(qid >= MT_TXQ_PSD)) {
32  		qid = MT_TXQ_BE;
33  		skb_set_queue_mapping(skb, qid);
34  	}
35  
36  	return q2hwq(qid);
37  }
38  
39  /* Note: TX retry reporting is a bit broken.
40   *	 Retries are reported only once per AMPDU and often come a frame early
41   *	 i.e. they are reported in the last status preceding the AMPDU. Apart
42   *	 from the fact that it's hard to know the length of the AMPDU (which is
43   *	 required to know to how many consecutive frames retries should be
44   *	 applied), if status comes early on full FIFO it gets lost and retries
45   *	 of the whole AMPDU become invisible.
46   *	 As a work-around encode the desired rate in PKT_ID of TX descriptor
47   *	 and based on that guess the retries (every rate is tried once).
48   *	 Only downside here is that for MCS0 we have to rely solely on
49   *	 transmission failures as no retries can ever be reported.
50   *	 Not having to read EXT_FIFO has a nice effect of doubling the number
51   *	 of reports which can be fetched.
52   *	 Also the vendor driver never uses the EXT_FIFO register so it may be
53   *	 undertested.
54   */
mt7601u_tx_pktid_enc(struct mt7601u_dev * dev,u8 rate,bool is_probe)55  static u8 mt7601u_tx_pktid_enc(struct mt7601u_dev *dev, u8 rate, bool is_probe)
56  {
57  	u8 encoded = (rate + 1) + is_probe *  8;
58  
59  	/* Because PKT_ID 0 disables status reporting only 15 values are
60  	 * available but 16 are needed (8 MCS * 2 for encoding is_probe)
61  	 * - we need to cram together two rates. MCS0 and MCS7 with is_probe
62  	 * share PKT_ID 9.
63  	 */
64  	if (is_probe && rate == 7)
65  		return encoded - 7;
66  
67  	return encoded;
68  }
69  
70  static void
mt7601u_tx_pktid_dec(struct mt7601u_dev * dev,struct mt76_tx_status * stat)71  mt7601u_tx_pktid_dec(struct mt7601u_dev *dev, struct mt76_tx_status *stat)
72  {
73  	u8 req_rate = stat->pktid;
74  	u8 eff_rate = stat->rate & 0x7;
75  
76  	req_rate -= 1;
77  
78  	if (req_rate > 7) {
79  		stat->is_probe = true;
80  		req_rate -= 8;
81  
82  		/* Decide between MCS0 and MCS7 which share pktid 9 */
83  		if (!req_rate && eff_rate)
84  			req_rate = 7;
85  	}
86  
87  	stat->retry = req_rate - eff_rate;
88  }
89  
mt7601u_tx_skb_remove_dma_overhead(struct sk_buff * skb,struct ieee80211_tx_info * info)90  static void mt7601u_tx_skb_remove_dma_overhead(struct sk_buff *skb,
91  					       struct ieee80211_tx_info *info)
92  {
93  	int pkt_len = (unsigned long)info->status.status_driver_data[0];
94  
95  	skb_pull(skb, sizeof(struct mt76_txwi) + 4);
96  	if (ieee80211_get_hdrlen_from_skb(skb) % 4)
97  		mt76_remove_hdr_pad(skb);
98  
99  	skb_trim(skb, pkt_len);
100  }
101  
mt7601u_tx_status(struct mt7601u_dev * dev,struct sk_buff * skb)102  void mt7601u_tx_status(struct mt7601u_dev *dev, struct sk_buff *skb)
103  {
104  	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
105  
106  	mt7601u_tx_skb_remove_dma_overhead(skb, info);
107  
108  	ieee80211_tx_info_clear_status(info);
109  	info->status.rates[0].idx = -1;
110  	info->flags |= IEEE80211_TX_STAT_ACK;
111  
112  	spin_lock_bh(&dev->mac_lock);
113  	ieee80211_tx_status(dev->hw, skb);
114  	spin_unlock_bh(&dev->mac_lock);
115  }
116  
mt7601u_skb_rooms(struct mt7601u_dev * dev,struct sk_buff * skb)117  static int mt7601u_skb_rooms(struct mt7601u_dev *dev, struct sk_buff *skb)
118  {
119  	int hdr_len = ieee80211_get_hdrlen_from_skb(skb);
120  	u32 need_head;
121  
122  	need_head = sizeof(struct mt76_txwi) + 4;
123  	if (hdr_len % 4)
124  		need_head += 2;
125  
126  	return skb_cow(skb, need_head);
127  }
128  
129  static struct mt76_txwi *
mt7601u_push_txwi(struct mt7601u_dev * dev,struct sk_buff * skb,struct ieee80211_sta * sta,struct mt76_wcid * wcid,int pkt_len)130  mt7601u_push_txwi(struct mt7601u_dev *dev, struct sk_buff *skb,
131  		  struct ieee80211_sta *sta, struct mt76_wcid *wcid,
132  		  int pkt_len)
133  {
134  	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
135  	struct ieee80211_tx_rate *rate = &info->control.rates[0];
136  	struct mt76_txwi *txwi;
137  	unsigned long flags;
138  	bool is_probe;
139  	u32 pkt_id;
140  	u16 rate_ctl;
141  	u8 nss;
142  
143  	txwi = skb_push(skb, sizeof(struct mt76_txwi));
144  	memset(txwi, 0, sizeof(*txwi));
145  
146  	if (!wcid->tx_rate_set)
147  		ieee80211_get_tx_rates(info->control.vif, sta, skb,
148  				       info->control.rates, 1);
149  
150  	spin_lock_irqsave(&dev->lock, flags);
151  	if (rate->idx < 0 || !rate->count)
152  		rate_ctl = wcid->tx_rate;
153  	else
154  		rate_ctl = mt76_mac_tx_rate_val(dev, rate, &nss);
155  	spin_unlock_irqrestore(&dev->lock, flags);
156  	txwi->rate_ctl = cpu_to_le16(rate_ctl);
157  
158  	if (!(info->flags & IEEE80211_TX_CTL_NO_ACK))
159  		txwi->ack_ctl |= MT_TXWI_ACK_CTL_REQ;
160  	if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ)
161  		txwi->ack_ctl |= MT_TXWI_ACK_CTL_NSEQ;
162  
163  	if ((info->flags & IEEE80211_TX_CTL_AMPDU) && sta) {
164  		u8 ba_size = IEEE80211_MIN_AMPDU_BUF;
165  
166  		ba_size <<= sta->deflink.ht_cap.ampdu_factor;
167  		ba_size = min_t(int, 63, ba_size);
168  		if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
169  			ba_size = 0;
170  		txwi->ack_ctl |= FIELD_PREP(MT_TXWI_ACK_CTL_BA_WINDOW, ba_size);
171  
172  		txwi->flags =
173  			cpu_to_le16(MT_TXWI_FLAGS_AMPDU |
174  				    FIELD_PREP(MT_TXWI_FLAGS_MPDU_DENSITY,
175  					       sta->deflink.ht_cap.ampdu_density));
176  		if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
177  			txwi->flags = 0;
178  	}
179  
180  	txwi->wcid = wcid->idx;
181  
182  	is_probe = !!(info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE);
183  	pkt_id = mt7601u_tx_pktid_enc(dev, rate_ctl & 0x7, is_probe);
184  	pkt_len |= FIELD_PREP(MT_TXWI_LEN_PKTID, pkt_id);
185  	txwi->len_ctl = cpu_to_le16(pkt_len);
186  
187  	return txwi;
188  }
189  
mt7601u_tx(struct ieee80211_hw * hw,struct ieee80211_tx_control * control,struct sk_buff * skb)190  void mt7601u_tx(struct ieee80211_hw *hw, struct ieee80211_tx_control *control,
191  		struct sk_buff *skb)
192  {
193  	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
194  	struct mt7601u_dev *dev = hw->priv;
195  	struct ieee80211_vif *vif = info->control.vif;
196  	struct ieee80211_sta *sta = control->sta;
197  	struct mt76_sta *msta = NULL;
198  	struct mt76_wcid *wcid = dev->mon_wcid;
199  	struct mt76_txwi *txwi;
200  	int pkt_len = skb->len;
201  	int hw_q = skb2q(skb);
202  
203  	BUILD_BUG_ON(ARRAY_SIZE(info->status.status_driver_data) < 1);
204  	info->status.status_driver_data[0] = (void *)(unsigned long)pkt_len;
205  
206  	if (mt7601u_skb_rooms(dev, skb) || mt76_insert_hdr_pad(skb)) {
207  		ieee80211_free_txskb(dev->hw, skb);
208  		return;
209  	}
210  
211  	if (sta) {
212  		msta = (struct mt76_sta *) sta->drv_priv;
213  		wcid = &msta->wcid;
214  	} else if (vif) {
215  		struct mt76_vif *mvif = (struct mt76_vif *)vif->drv_priv;
216  
217  		wcid = &mvif->group_wcid;
218  	}
219  
220  	txwi = mt7601u_push_txwi(dev, skb, sta, wcid, pkt_len);
221  
222  	if (mt7601u_dma_enqueue_tx(dev, skb, wcid, hw_q))
223  		return;
224  
225  	trace_mt_tx(dev, skb, msta, txwi);
226  }
227  
mt7601u_tx_stat(struct work_struct * work)228  void mt7601u_tx_stat(struct work_struct *work)
229  {
230  	struct mt7601u_dev *dev = container_of(work, struct mt7601u_dev,
231  					       stat_work.work);
232  	struct mt76_tx_status stat;
233  	unsigned long flags;
234  	int cleaned = 0;
235  
236  	while (!test_bit(MT7601U_STATE_REMOVED, &dev->state)) {
237  		stat = mt7601u_mac_fetch_tx_status(dev);
238  		if (!stat.valid)
239  			break;
240  
241  		mt7601u_tx_pktid_dec(dev, &stat);
242  		mt76_send_tx_status(dev, &stat);
243  
244  		cleaned++;
245  	}
246  	trace_mt_tx_status_cleaned(dev, cleaned);
247  
248  	spin_lock_irqsave(&dev->tx_lock, flags);
249  	if (cleaned)
250  		queue_delayed_work(dev->stat_wq, &dev->stat_work,
251  				   msecs_to_jiffies(10));
252  	else if (test_and_clear_bit(MT7601U_STATE_MORE_STATS, &dev->state))
253  		queue_delayed_work(dev->stat_wq, &dev->stat_work,
254  				   msecs_to_jiffies(20));
255  	else
256  		clear_bit(MT7601U_STATE_READING_STATS, &dev->state);
257  	spin_unlock_irqrestore(&dev->tx_lock, flags);
258  }
259  
mt7601u_conf_tx(struct ieee80211_hw * hw,struct ieee80211_vif * vif,unsigned int link_id,u16 queue,const struct ieee80211_tx_queue_params * params)260  int mt7601u_conf_tx(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
261  		    unsigned int link_id, u16 queue,
262  		    const struct ieee80211_tx_queue_params *params)
263  {
264  	struct mt7601u_dev *dev = hw->priv;
265  	u8 cw_min = 5, cw_max = 10, hw_q = q2hwq(queue);
266  	u32 val;
267  
268  	/* TODO: should we do funny things with the parameters?
269  	 *	 See what mt7601u_set_default_edca() used to do in init.c.
270  	 */
271  
272  	if (params->cw_min)
273  		cw_min = fls(params->cw_min);
274  	if (params->cw_max)
275  		cw_max = fls(params->cw_max);
276  
277  	WARN_ON(params->txop > 0xff);
278  	WARN_ON(params->aifs > 0xf);
279  	WARN_ON(cw_min > 0xf);
280  	WARN_ON(cw_max > 0xf);
281  
282  	val = FIELD_PREP(MT_EDCA_CFG_AIFSN, params->aifs) |
283  	      FIELD_PREP(MT_EDCA_CFG_CWMIN, cw_min) |
284  	      FIELD_PREP(MT_EDCA_CFG_CWMAX, cw_max);
285  	/* TODO: based on user-controlled EnableTxBurst var vendor drv sets
286  	 *	 a really long txop on AC0 (see connect.c:2009) but only on
287  	 *	 connect? When not connected should be 0.
288  	 */
289  	if (!hw_q)
290  		val |= 0x60;
291  	else
292  		val |= FIELD_PREP(MT_EDCA_CFG_TXOP, params->txop);
293  	mt76_wr(dev, MT_EDCA_CFG_AC(hw_q), val);
294  
295  	val = mt76_rr(dev, MT_WMM_TXOP(hw_q));
296  	val &= ~(MT_WMM_TXOP_MASK << MT_WMM_TXOP_SHIFT(hw_q));
297  	val |= params->txop << MT_WMM_TXOP_SHIFT(hw_q);
298  	mt76_wr(dev, MT_WMM_TXOP(hw_q), val);
299  
300  	val = mt76_rr(dev, MT_WMM_AIFSN);
301  	val &= ~(MT_WMM_AIFSN_MASK << MT_WMM_AIFSN_SHIFT(hw_q));
302  	val |= params->aifs << MT_WMM_AIFSN_SHIFT(hw_q);
303  	mt76_wr(dev, MT_WMM_AIFSN, val);
304  
305  	val = mt76_rr(dev, MT_WMM_CWMIN);
306  	val &= ~(MT_WMM_CWMIN_MASK << MT_WMM_CWMIN_SHIFT(hw_q));
307  	val |= cw_min << MT_WMM_CWMIN_SHIFT(hw_q);
308  	mt76_wr(dev, MT_WMM_CWMIN, val);
309  
310  	val = mt76_rr(dev, MT_WMM_CWMAX);
311  	val &= ~(MT_WMM_CWMAX_MASK << MT_WMM_CWMAX_SHIFT(hw_q));
312  	val |= cw_max << MT_WMM_CWMAX_SHIFT(hw_q);
313  	mt76_wr(dev, MT_WMM_CWMAX, val);
314  
315  	return 0;
316  }
317