1/*
2 * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
3 * Copyright (C) 2015 Jakub Kicinski <kubakici@wp.pl>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2
7 * as published by the Free Software Foundation
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 */
14
15#include "mt7601u.h"
16#include "trace.h"
17
18enum mt76_txq_id {
19	MT_TXQ_VO = IEEE80211_AC_VO,
20	MT_TXQ_VI = IEEE80211_AC_VI,
21	MT_TXQ_BE = IEEE80211_AC_BE,
22	MT_TXQ_BK = IEEE80211_AC_BK,
23	MT_TXQ_PSD,
24	MT_TXQ_MCU,
25	__MT_TXQ_MAX
26};
27
28/* Hardware uses mirrored order of queues with Q0 having the highest priority */
29static u8 q2hwq(u8 q)
30{
31	return q ^ 0x3;
32}
33
34/* Take mac80211 Q id from the skb and translate it to hardware Q id */
35static u8 skb2q(struct sk_buff *skb)
36{
37	int qid = skb_get_queue_mapping(skb);
38
39	if (WARN_ON(qid >= MT_TXQ_PSD)) {
40		qid = MT_TXQ_BE;
41		skb_set_queue_mapping(skb, qid);
42	}
43
44	return q2hwq(qid);
45}
46
47/* Note: TX retry reporting is a bit broken.
48 *	 Retries are reported only once per AMPDU and often come a frame early
49 *	 i.e. they are reported in the last status preceding the AMPDU. Apart
50 *	 from the fact that it's hard to know the length of the AMPDU (which is
51 *	 required to know to how many consecutive frames retries should be
52 *	 applied), if status comes early on full FIFO it gets lost and retries
53 *	 of the whole AMPDU become invisible.
54 *	 As a work-around encode the desired rate in PKT_ID of TX descriptor
55 *	 and based on that guess the retries (every rate is tried once).
56 *	 Only downside here is that for MCS0 we have to rely solely on
57 *	 transmission failures as no retries can ever be reported.
58 *	 Not having to read EXT_FIFO has a nice effect of doubling the number
59 *	 of reports which can be fetched.
60 *	 Also the vendor driver never uses the EXT_FIFO register so it may be
61 *	 undertested.
62 */
63static u8 mt7601u_tx_pktid_enc(struct mt7601u_dev *dev, u8 rate, bool is_probe)
64{
65	u8 encoded = (rate + 1) + is_probe *  8;
66
67	/* Because PKT_ID 0 disables status reporting only 15 values are
68	 * available but 16 are needed (8 MCS * 2 for encoding is_probe)
69	 * - we need to cram together two rates. MCS0 and MCS7 with is_probe
70	 * share PKT_ID 9.
71	 */
72	if (is_probe && rate == 7)
73		return encoded - 7;
74
75	return encoded;
76}
77
78static void
79mt7601u_tx_pktid_dec(struct mt7601u_dev *dev, struct mt76_tx_status *stat)
80{
81	u8 req_rate = stat->pktid;
82	u8 eff_rate = stat->rate & 0x7;
83
84	req_rate -= 1;
85
86	if (req_rate > 7) {
87		stat->is_probe = true;
88		req_rate -= 8;
89
90		/* Decide between MCS0 and MCS7 which share pktid 9 */
91		if (!req_rate && eff_rate)
92			req_rate = 7;
93	}
94
95	stat->retry = req_rate - eff_rate;
96}
97
98static void mt7601u_tx_skb_remove_dma_overhead(struct sk_buff *skb,
99					       struct ieee80211_tx_info *info)
100{
101	int pkt_len = (unsigned long)info->status.status_driver_data[0];
102
103	skb_pull(skb, sizeof(struct mt76_txwi) + 4);
104	if (ieee80211_get_hdrlen_from_skb(skb) % 4)
105		mt76_remove_hdr_pad(skb);
106
107	skb_trim(skb, pkt_len);
108}
109
110void mt7601u_tx_status(struct mt7601u_dev *dev, struct sk_buff *skb)
111{
112	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
113
114	mt7601u_tx_skb_remove_dma_overhead(skb, info);
115
116	ieee80211_tx_info_clear_status(info);
117	info->status.rates[0].idx = -1;
118	info->flags |= IEEE80211_TX_STAT_ACK;
119
120	spin_lock(&dev->mac_lock);
121	ieee80211_tx_status(dev->hw, skb);
122	spin_unlock(&dev->mac_lock);
123}
124
125static int mt7601u_skb_rooms(struct mt7601u_dev *dev, struct sk_buff *skb)
126{
127	int hdr_len = ieee80211_get_hdrlen_from_skb(skb);
128	u32 need_head;
129
130	need_head = sizeof(struct mt76_txwi) + 4;
131	if (hdr_len % 4)
132		need_head += 2;
133
134	return skb_cow(skb, need_head);
135}
136
137static struct mt76_txwi *
138mt7601u_push_txwi(struct mt7601u_dev *dev, struct sk_buff *skb,
139		  struct ieee80211_sta *sta, struct mt76_wcid *wcid,
140		  int pkt_len)
141{
142	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
143	struct ieee80211_tx_rate *rate = &info->control.rates[0];
144	struct mt76_txwi *txwi;
145	unsigned long flags;
146	bool is_probe;
147	u32 pkt_id;
148	u16 rate_ctl;
149	u8 nss;
150
151	txwi = (struct mt76_txwi *)skb_push(skb, sizeof(struct mt76_txwi));
152	memset(txwi, 0, sizeof(*txwi));
153
154	if (!wcid->tx_rate_set)
155		ieee80211_get_tx_rates(info->control.vif, sta, skb,
156				       info->control.rates, 1);
157
158	spin_lock_irqsave(&dev->lock, flags);
159	if (rate->idx < 0 || !rate->count)
160		rate_ctl = wcid->tx_rate;
161	else
162		rate_ctl = mt76_mac_tx_rate_val(dev, rate, &nss);
163	spin_unlock_irqrestore(&dev->lock, flags);
164	txwi->rate_ctl = cpu_to_le16(rate_ctl);
165
166	if (!(info->flags & IEEE80211_TX_CTL_NO_ACK))
167		txwi->ack_ctl |= MT_TXWI_ACK_CTL_REQ;
168	if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ)
169		txwi->ack_ctl |= MT_TXWI_ACK_CTL_NSEQ;
170
171	if ((info->flags & IEEE80211_TX_CTL_AMPDU) && sta) {
172		u8 ba_size = IEEE80211_MIN_AMPDU_BUF;
173
174		ba_size <<= sta->ht_cap.ampdu_factor;
175		ba_size = min_t(int, 63, ba_size);
176		if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
177			ba_size = 0;
178		txwi->ack_ctl |= MT76_SET(MT_TXWI_ACK_CTL_BA_WINDOW, ba_size);
179
180		txwi->flags = cpu_to_le16(MT_TXWI_FLAGS_AMPDU |
181					  MT76_SET(MT_TXWI_FLAGS_MPDU_DENSITY,
182						   sta->ht_cap.ampdu_density));
183		if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
184			txwi->flags = 0;
185	}
186
187	txwi->wcid = wcid->idx;
188
189	is_probe = !!(info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE);
190	pkt_id = mt7601u_tx_pktid_enc(dev, rate_ctl & 0x7, is_probe);
191	pkt_len |= MT76_SET(MT_TXWI_LEN_PKTID, pkt_id);
192	txwi->len_ctl = cpu_to_le16(pkt_len);
193
194	return txwi;
195}
196
197void mt7601u_tx(struct ieee80211_hw *hw, struct ieee80211_tx_control *control,
198		struct sk_buff *skb)
199{
200	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
201	struct mt7601u_dev *dev = hw->priv;
202	struct ieee80211_vif *vif = info->control.vif;
203	struct ieee80211_sta *sta = control->sta;
204	struct mt76_sta *msta = NULL;
205	struct mt76_wcid *wcid = dev->mon_wcid;
206	struct mt76_txwi *txwi;
207	int pkt_len = skb->len;
208	int hw_q = skb2q(skb);
209
210	BUILD_BUG_ON(ARRAY_SIZE(info->status.status_driver_data) < 1);
211	info->status.status_driver_data[0] = (void *)(unsigned long)pkt_len;
212
213	if (mt7601u_skb_rooms(dev, skb) || mt76_insert_hdr_pad(skb)) {
214		ieee80211_free_txskb(dev->hw, skb);
215		return;
216	}
217
218	if (sta) {
219		msta = (struct mt76_sta *) sta->drv_priv;
220		wcid = &msta->wcid;
221	} else if (vif) {
222		struct mt76_vif *mvif = (struct mt76_vif *)vif->drv_priv;
223
224		wcid = &mvif->group_wcid;
225	}
226
227	txwi = mt7601u_push_txwi(dev, skb, sta, wcid, pkt_len);
228
229	if (mt7601u_dma_enqueue_tx(dev, skb, wcid, hw_q))
230		return;
231
232	trace_mt_tx(dev, skb, msta, txwi);
233}
234
235void mt7601u_tx_stat(struct work_struct *work)
236{
237	struct mt7601u_dev *dev = container_of(work, struct mt7601u_dev,
238					       stat_work.work);
239	struct mt76_tx_status stat;
240	unsigned long flags;
241	int cleaned = 0;
242
243	while (!test_bit(MT7601U_STATE_REMOVED, &dev->state)) {
244		stat = mt7601u_mac_fetch_tx_status(dev);
245		if (!stat.valid)
246			break;
247
248		mt7601u_tx_pktid_dec(dev, &stat);
249		mt76_send_tx_status(dev, &stat);
250
251		cleaned++;
252	}
253	trace_mt_tx_status_cleaned(dev, cleaned);
254
255	spin_lock_irqsave(&dev->tx_lock, flags);
256	if (cleaned)
257		queue_delayed_work(dev->stat_wq, &dev->stat_work,
258				   msecs_to_jiffies(10));
259	else if (test_and_clear_bit(MT7601U_STATE_MORE_STATS, &dev->state))
260		queue_delayed_work(dev->stat_wq, &dev->stat_work,
261				   msecs_to_jiffies(20));
262	else
263		clear_bit(MT7601U_STATE_READING_STATS, &dev->state);
264	spin_unlock_irqrestore(&dev->tx_lock, flags);
265}
266
267int mt7601u_conf_tx(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
268		    u16 queue, const struct ieee80211_tx_queue_params *params)
269{
270	struct mt7601u_dev *dev = hw->priv;
271	u8 cw_min = 5, cw_max = 10, hw_q = q2hwq(queue);
272	u32 val;
273
274	/* TODO: should we do funny things with the parameters?
275	 *	 See what mt7601u_set_default_edca() used to do in init.c.
276	 */
277
278	if (params->cw_min)
279		cw_min = fls(params->cw_min);
280	if (params->cw_max)
281		cw_max = fls(params->cw_max);
282
283	WARN_ON(params->txop > 0xff);
284	WARN_ON(params->aifs > 0xf);
285	WARN_ON(cw_min > 0xf);
286	WARN_ON(cw_max > 0xf);
287
288	val = MT76_SET(MT_EDCA_CFG_AIFSN, params->aifs) |
289	      MT76_SET(MT_EDCA_CFG_CWMIN, cw_min) |
290	      MT76_SET(MT_EDCA_CFG_CWMAX, cw_max);
291	/* TODO: based on user-controlled EnableTxBurst var vendor drv sets
292	 *	 a really long txop on AC0 (see connect.c:2009) but only on
293	 *	 connect? When not connected should be 0.
294	 */
295	if (!hw_q)
296		val |= 0x60;
297	else
298		val |= MT76_SET(MT_EDCA_CFG_TXOP, params->txop);
299	mt76_wr(dev, MT_EDCA_CFG_AC(hw_q), val);
300
301	val = mt76_rr(dev, MT_WMM_TXOP(hw_q));
302	val &= ~(MT_WMM_TXOP_MASK << MT_WMM_TXOP_SHIFT(hw_q));
303	val |= params->txop << MT_WMM_TXOP_SHIFT(hw_q);
304	mt76_wr(dev, MT_WMM_TXOP(hw_q), val);
305
306	val = mt76_rr(dev, MT_WMM_AIFSN);
307	val &= ~(MT_WMM_AIFSN_MASK << MT_WMM_AIFSN_SHIFT(hw_q));
308	val |= params->aifs << MT_WMM_AIFSN_SHIFT(hw_q);
309	mt76_wr(dev, MT_WMM_AIFSN, val);
310
311	val = mt76_rr(dev, MT_WMM_CWMIN);
312	val &= ~(MT_WMM_CWMIN_MASK << MT_WMM_CWMIN_SHIFT(hw_q));
313	val |= cw_min << MT_WMM_CWMIN_SHIFT(hw_q);
314	mt76_wr(dev, MT_WMM_CWMIN, val);
315
316	val = mt76_rr(dev, MT_WMM_CWMAX);
317	val &= ~(MT_WMM_CWMAX_MASK << MT_WMM_CWMAX_SHIFT(hw_q));
318	val |= cw_max << MT_WMM_CWMAX_SHIFT(hw_q);
319	mt76_wr(dev, MT_WMM_CWMAX, val);
320
321	return 0;
322}
323