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 */
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 */
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  */
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
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 
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 
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 
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 *
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->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->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 
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 
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 
260 int mt7601u_conf_tx(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
261 		    u16 queue, const struct ieee80211_tx_queue_params *params)
262 {
263 	struct mt7601u_dev *dev = hw->priv;
264 	u8 cw_min = 5, cw_max = 10, hw_q = q2hwq(queue);
265 	u32 val;
266 
267 	/* TODO: should we do funny things with the parameters?
268 	 *	 See what mt7601u_set_default_edca() used to do in init.c.
269 	 */
270 
271 	if (params->cw_min)
272 		cw_min = fls(params->cw_min);
273 	if (params->cw_max)
274 		cw_max = fls(params->cw_max);
275 
276 	WARN_ON(params->txop > 0xff);
277 	WARN_ON(params->aifs > 0xf);
278 	WARN_ON(cw_min > 0xf);
279 	WARN_ON(cw_max > 0xf);
280 
281 	val = FIELD_PREP(MT_EDCA_CFG_AIFSN, params->aifs) |
282 	      FIELD_PREP(MT_EDCA_CFG_CWMIN, cw_min) |
283 	      FIELD_PREP(MT_EDCA_CFG_CWMAX, cw_max);
284 	/* TODO: based on user-controlled EnableTxBurst var vendor drv sets
285 	 *	 a really long txop on AC0 (see connect.c:2009) but only on
286 	 *	 connect? When not connected should be 0.
287 	 */
288 	if (!hw_q)
289 		val |= 0x60;
290 	else
291 		val |= FIELD_PREP(MT_EDCA_CFG_TXOP, params->txop);
292 	mt76_wr(dev, MT_EDCA_CFG_AC(hw_q), val);
293 
294 	val = mt76_rr(dev, MT_WMM_TXOP(hw_q));
295 	val &= ~(MT_WMM_TXOP_MASK << MT_WMM_TXOP_SHIFT(hw_q));
296 	val |= params->txop << MT_WMM_TXOP_SHIFT(hw_q);
297 	mt76_wr(dev, MT_WMM_TXOP(hw_q), val);
298 
299 	val = mt76_rr(dev, MT_WMM_AIFSN);
300 	val &= ~(MT_WMM_AIFSN_MASK << MT_WMM_AIFSN_SHIFT(hw_q));
301 	val |= params->aifs << MT_WMM_AIFSN_SHIFT(hw_q);
302 	mt76_wr(dev, MT_WMM_AIFSN, val);
303 
304 	val = mt76_rr(dev, MT_WMM_CWMIN);
305 	val &= ~(MT_WMM_CWMIN_MASK << MT_WMM_CWMIN_SHIFT(hw_q));
306 	val |= cw_min << MT_WMM_CWMIN_SHIFT(hw_q);
307 	mt76_wr(dev, MT_WMM_CWMIN, val);
308 
309 	val = mt76_rr(dev, MT_WMM_CWMAX);
310 	val &= ~(MT_WMM_CWMAX_MASK << MT_WMM_CWMAX_SHIFT(hw_q));
311 	val |= cw_max << MT_WMM_CWMAX_SHIFT(hw_q);
312 	mt76_wr(dev, MT_WMM_CWMAX, val);
313 
314 	return 0;
315 }
316