summaryrefslogtreecommitdiff
path: root/drivers/net/wireless/mediatek/mt7601u/tx.c
blob: 0be2080ceab387ef9e21c1849b1e96e4eb635309 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
/*
 * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
 * Copyright (C) 2015 Jakub Kicinski <kubakici@wp.pl>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

#include "mt7601u.h"
#include "trace.h"

enum mt76_txq_id {
	MT_TXQ_VO = IEEE80211_AC_VO,
	MT_TXQ_VI = IEEE80211_AC_VI,
	MT_TXQ_BE = IEEE80211_AC_BE,
	MT_TXQ_BK = IEEE80211_AC_BK,
	MT_TXQ_PSD,
	MT_TXQ_MCU,
	__MT_TXQ_MAX
};

/* Hardware uses mirrored order of queues with Q0 having the highest priority */
static u8 q2hwq(u8 q)
{
	return q ^ 0x3;
}

/* Take mac80211 Q id from the skb and translate it to hardware Q id */
static u8 skb2q(struct sk_buff *skb)
{
	int qid = skb_get_queue_mapping(skb);

	if (WARN_ON(qid >= MT_TXQ_PSD)) {
		qid = MT_TXQ_BE;
		skb_set_queue_mapping(skb, qid);
	}

	return q2hwq(qid);
}

/* Note: TX retry reporting is a bit broken.
 *	 Retries are reported only once per AMPDU and often come a frame early
 *	 i.e. they are reported in the last status preceding the AMPDU. Apart
 *	 from the fact that it's hard to know the length of the AMPDU (which is
 *	 required to know to how many consecutive frames retries should be
 *	 applied), if status comes early on full FIFO it gets lost and retries
 *	 of the whole AMPDU become invisible.
 *	 As a work-around encode the desired rate in PKT_ID of TX descriptor
 *	 and based on that guess the retries (every rate is tried once).
 *	 Only downside here is that for MCS0 we have to rely solely on
 *	 transmission failures as no retries can ever be reported.
 *	 Not having to read EXT_FIFO has a nice effect of doubling the number
 *	 of reports which can be fetched.
 *	 Also the vendor driver never uses the EXT_FIFO register so it may be
 *	 undertested.
 */
static u8 mt7601u_tx_pktid_enc(struct mt7601u_dev *dev, u8 rate, bool is_probe)
{
	u8 encoded = (rate + 1) + is_probe *  8;

	/* Because PKT_ID 0 disables status reporting only 15 values are
	 * available but 16 are needed (8 MCS * 2 for encoding is_probe)
	 * - we need to cram together two rates. MCS0 and MCS7 with is_probe
	 * share PKT_ID 9.
	 */
	if (is_probe && rate == 7)
		return encoded - 7;

	return encoded;
}

static void
mt7601u_tx_pktid_dec(struct mt7601u_dev *dev, struct mt76_tx_status *stat)
{
	u8 req_rate = stat->pktid;
	u8 eff_rate = stat->rate & 0x7;

	req_rate -= 1;

	if (req_rate > 7) {
		stat->is_probe = true;
		req_rate -= 8;

		/* Decide between MCS0 and MCS7 which share pktid 9 */
		if (!req_rate && eff_rate)
			req_rate = 7;
	}

	stat->retry = req_rate - eff_rate;
}

static void mt7601u_tx_skb_remove_dma_overhead(struct sk_buff *skb,
					       struct ieee80211_tx_info *info)
{
	int pkt_len = (unsigned long)info->status.status_driver_data[0];

	skb_pull(skb, sizeof(struct mt76_txwi) + 4);
	if (ieee80211_get_hdrlen_from_skb(skb) % 4)
		mt76_remove_hdr_pad(skb);

	skb_trim(skb, pkt_len);
}

void mt7601u_tx_status(struct mt7601u_dev *dev, struct sk_buff *skb)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

	mt7601u_tx_skb_remove_dma_overhead(skb, info);

	ieee80211_tx_info_clear_status(info);
	info->status.rates[0].idx = -1;
	info->flags |= IEEE80211_TX_STAT_ACK;
	ieee80211_tx_status(dev->hw, skb);
}

static int mt7601u_skb_rooms(struct mt7601u_dev *dev, struct sk_buff *skb)
{
	int hdr_len = ieee80211_get_hdrlen_from_skb(skb);
	u32 need_head;

	need_head = sizeof(struct mt76_txwi) + 4;
	if (hdr_len % 4)
		need_head += 2;

	return skb_cow(skb, need_head);
}

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)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_tx_rate *rate = &info->control.rates[0];
	struct mt76_txwi *txwi;
	unsigned long flags;
	bool is_probe;
	u32 pkt_id;
	u16 rate_ctl;
	u8 nss;

	txwi = (struct mt76_txwi *)skb_push(skb, sizeof(struct mt76_txwi));
	memset(txwi, 0, sizeof(*txwi));

	if (!wcid->tx_rate_set)
		ieee80211_get_tx_rates(info->control.vif, sta, skb,
				       info->control.rates, 1);

	spin_lock_irqsave(&dev->lock, flags);
	if (rate->idx < 0 || !rate->count)
		rate_ctl = wcid->tx_rate;
	else
		rate_ctl = mt76_mac_tx_rate_val(dev, rate, &nss);
	spin_unlock_irqrestore(&dev->lock, flags);
	txwi->rate_ctl = cpu_to_le16(rate_ctl);

	if (!(info->flags & IEEE80211_TX_CTL_NO_ACK))
		txwi->ack_ctl |= MT_TXWI_ACK_CTL_REQ;
	if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ)
		txwi->ack_ctl |= MT_TXWI_ACK_CTL_NSEQ;

	if ((info->flags & IEEE80211_TX_CTL_AMPDU) && sta) {
		u8 ba_size = IEEE80211_MIN_AMPDU_BUF;

		ba_size <<= sta->ht_cap.ampdu_factor;
		ba_size = min_t(int, 63, ba_size);
		if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
			ba_size = 0;
		txwi->ack_ctl |= MT76_SET(MT_TXWI_ACK_CTL_BA_WINDOW, ba_size);

		txwi->flags = cpu_to_le16(MT_TXWI_FLAGS_AMPDU |
					  MT76_SET(MT_TXWI_FLAGS_MPDU_DENSITY,
						   sta->ht_cap.ampdu_density));
		if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
			txwi->flags = 0;
	}

	txwi->wcid = wcid->idx;

	is_probe = !!(info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE);
	pkt_id = mt7601u_tx_pktid_enc(dev, rate_ctl & 0x7, is_probe);
	pkt_len |= MT76_SET(MT_TXWI_LEN_PKTID, pkt_id);
	txwi->len_ctl = cpu_to_le16(pkt_len);

	return txwi;
}

void mt7601u_tx(struct ieee80211_hw *hw, struct ieee80211_tx_control *control,
		struct sk_buff *skb)
{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct mt7601u_dev *dev = hw->priv;
	struct ieee80211_vif *vif = info->control.vif;
	struct ieee80211_sta *sta = control->sta;
	struct mt76_sta *msta = NULL;
	struct mt76_wcid *wcid = dev->mon_wcid;
	struct mt76_txwi *txwi;
	int pkt_len = skb->len;
	int hw_q = skb2q(skb);

	BUILD_BUG_ON(ARRAY_SIZE(info->status.status_driver_data) < 1);
	info->status.status_driver_data[0] = (void *)(unsigned long)pkt_len;

	if (mt7601u_skb_rooms(dev, skb) || mt76_insert_hdr_pad(skb)) {
		ieee80211_free_txskb(dev->hw, skb);
		return;
	}

	if (sta) {
		msta = (struct mt76_sta *) sta->drv_priv;
		wcid = &msta->wcid;
	} else if (vif) {
		struct mt76_vif *mvif = (struct mt76_vif *)vif->drv_priv;

		wcid = &mvif->group_wcid;
	}

	txwi = mt7601u_push_txwi(dev, skb, sta, wcid, pkt_len);

	if (mt7601u_dma_enqueue_tx(dev, skb, wcid, hw_q))
		return;

	trace_mt_tx(dev, skb, msta, txwi);
}

void mt7601u_tx_stat(struct work_struct *work)
{
	struct mt7601u_dev *dev = container_of(work, struct mt7601u_dev,
					       stat_work.work);
	struct mt76_tx_status stat;
	unsigned long flags;
	int cleaned = 0;

	while (!test_bit(MT7601U_STATE_REMOVED, &dev->state)) {
		stat = mt7601u_mac_fetch_tx_status(dev);
		if (!stat.valid)
			break;

		mt7601u_tx_pktid_dec(dev, &stat);
		mt76_send_tx_status(dev, &stat);

		cleaned++;
	}
	trace_mt_tx_status_cleaned(dev, cleaned);

	spin_lock_irqsave(&dev->tx_lock, flags);
	if (cleaned)
		queue_delayed_work(dev->stat_wq, &dev->stat_work,
				   msecs_to_jiffies(10));
	else if (test_and_clear_bit(MT7601U_STATE_MORE_STATS, &dev->state))
		queue_delayed_work(dev->stat_wq, &dev->stat_work,
				   msecs_to_jiffies(20));
	else
		clear_bit(MT7601U_STATE_READING_STATS, &dev->state);
	spin_unlock_irqrestore(&dev->tx_lock, flags);
}

int mt7601u_conf_tx(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
		    u16 queue, const struct ieee80211_tx_queue_params *params)
{
	struct mt7601u_dev *dev = hw->priv;
	u8 cw_min = 5, cw_max = 10, hw_q = q2hwq(queue);
	u32 val;

	/* TODO: should we do funny things with the parameters?
	 *	 See what mt7601u_set_default_edca() used to do in init.c.
	 */

	if (params->cw_min)
		cw_min = fls(params->cw_min);
	if (params->cw_max)
		cw_max = fls(params->cw_max);

	WARN_ON(params->txop > 0xff);
	WARN_ON(params->aifs > 0xf);
	WARN_ON(cw_min > 0xf);
	WARN_ON(cw_max > 0xf);

	val = MT76_SET(MT_EDCA_CFG_AIFSN, params->aifs) |
	      MT76_SET(MT_EDCA_CFG_CWMIN, cw_min) |
	      MT76_SET(MT_EDCA_CFG_CWMAX, cw_max);
	/* TODO: based on user-controlled EnableTxBurst var vendor drv sets
	 *	 a really long txop on AC0 (see connect.c:2009) but only on
	 *	 connect? When not connected should be 0.
	 */
	if (!hw_q)
		val |= 0x60;
	else
		val |= MT76_SET(MT_EDCA_CFG_TXOP, params->txop);
	mt76_wr(dev, MT_EDCA_CFG_AC(hw_q), val);

	val = mt76_rr(dev, MT_WMM_TXOP(hw_q));
	val &= ~(MT_WMM_TXOP_MASK << MT_WMM_TXOP_SHIFT(hw_q));
	val |= params->txop << MT_WMM_TXOP_SHIFT(hw_q);
	mt76_wr(dev, MT_WMM_TXOP(hw_q), val);

	val = mt76_rr(dev, MT_WMM_AIFSN);
	val &= ~(MT_WMM_AIFSN_MASK << MT_WMM_AIFSN_SHIFT(hw_q));
	val |= params->aifs << MT_WMM_AIFSN_SHIFT(hw_q);
	mt76_wr(dev, MT_WMM_AIFSN, val);

	val = mt76_rr(dev, MT_WMM_CWMIN);
	val &= ~(MT_WMM_CWMIN_MASK << MT_WMM_CWMIN_SHIFT(hw_q));
	val |= cw_min << MT_WMM_CWMIN_SHIFT(hw_q);
	mt76_wr(dev, MT_WMM_CWMIN, val);

	val = mt76_rr(dev, MT_WMM_CWMAX);
	val &= ~(MT_WMM_CWMAX_MASK << MT_WMM_CWMAX_SHIFT(hw_q));
	val |= cw_max << MT_WMM_CWMAX_SHIFT(hw_q);
	mt76_wr(dev, MT_WMM_CWMAX, val);

	return 0;
}