summaryrefslogtreecommitdiff
path: root/drivers/net/wireless/mediatek/mt76/agg-rx.c
blob: 73c8b2805c978cb688e73bbd72156078eb98a492 (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
/*
 * Copyright (C) 2018 Felix Fietkau <nbd@nbd.name>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#include "mt76.h"

#define REORDER_TIMEOUT (HZ / 10)

static void
mt76_aggr_release(struct mt76_rx_tid *tid, struct sk_buff_head *frames, int idx)
{
	struct sk_buff *skb;

	tid->head = ieee80211_sn_inc(tid->head);

	skb = tid->reorder_buf[idx];
	if (!skb)
		return;

	tid->reorder_buf[idx] = NULL;
	tid->nframes--;
	__skb_queue_tail(frames, skb);
}

static void
mt76_rx_aggr_release_frames(struct mt76_rx_tid *tid, struct sk_buff_head *frames,
			 u16 head)
{
	int idx;

	while (ieee80211_sn_less(tid->head, head)) {
		idx = tid->head % tid->size;
		mt76_aggr_release(tid, frames, idx);
	}
}

static void
mt76_rx_aggr_release_head(struct mt76_rx_tid *tid, struct sk_buff_head *frames)
{
	int idx = tid->head % tid->size;

	while (tid->reorder_buf[idx]) {
		mt76_aggr_release(tid, frames, idx);
		idx = tid->head % tid->size;
	}
}

static void
mt76_rx_aggr_check_release(struct mt76_rx_tid *tid, struct sk_buff_head *frames)
{
	struct mt76_rx_status *status;
	struct sk_buff *skb;
	int start, idx, nframes;

	if (!tid->nframes)
		return;

	mt76_rx_aggr_release_head(tid, frames);

	start = tid->head % tid->size;
	nframes = tid->nframes;

	for (idx = (tid->head + 1) % tid->size;
	     idx != start && nframes;
	     idx = (idx + 1) % tid->size) {

		skb = tid->reorder_buf[idx];
		if (!skb)
			continue;

		nframes--;
		status = (struct mt76_rx_status *) skb->cb;
		if (!time_after(jiffies, status->reorder_time +
					 REORDER_TIMEOUT))
			continue;

		mt76_rx_aggr_release_frames(tid, frames, status->seqno);
	}

	mt76_rx_aggr_release_head(tid, frames);
}

static void
mt76_rx_aggr_reorder_work(struct work_struct *work)
{
	struct mt76_rx_tid *tid = container_of(work, struct mt76_rx_tid,
					       reorder_work.work);
	struct mt76_dev *dev = tid->dev;
	struct sk_buff_head frames;
	int nframes;

	__skb_queue_head_init(&frames);

	local_bh_disable();
	rcu_read_lock();

	spin_lock(&tid->lock);
	mt76_rx_aggr_check_release(tid, &frames);
	nframes = tid->nframes;
	spin_unlock(&tid->lock);

	if (nframes)
		ieee80211_queue_delayed_work(tid->dev->hw, &tid->reorder_work,
					     REORDER_TIMEOUT);
	mt76_rx_complete(dev, &frames, NULL);

	rcu_read_unlock();
	local_bh_enable();
}

static void
mt76_rx_aggr_check_ctl(struct sk_buff *skb, struct sk_buff_head *frames)
{
	struct mt76_rx_status *status = (struct mt76_rx_status *) skb->cb;
	struct ieee80211_bar *bar = (struct ieee80211_bar *) skb->data;
	struct mt76_wcid *wcid = status->wcid;
	struct mt76_rx_tid *tid;
	u16 seqno;

	if (!ieee80211_is_ctl(bar->frame_control))
		return;

	if (!ieee80211_is_back_req(bar->frame_control))
		return;

	status->tid = le16_to_cpu(bar->control) >> 12;
	seqno = le16_to_cpu(bar->start_seq_num) >> 4;
	tid = rcu_dereference(wcid->aggr[status->tid]);
	if (!tid)
		return;

	spin_lock_bh(&tid->lock);
	mt76_rx_aggr_release_frames(tid, frames, seqno);
	mt76_rx_aggr_release_head(tid, frames);
	spin_unlock_bh(&tid->lock);
}

void mt76_rx_aggr_reorder(struct sk_buff *skb, struct sk_buff_head *frames)
{
	struct mt76_rx_status *status = (struct mt76_rx_status *) skb->cb;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	struct mt76_wcid *wcid = status->wcid;
	struct ieee80211_sta *sta;
	struct mt76_rx_tid *tid;
	bool sn_less;
	u16 seqno, head, size;
	u8 ackp, idx;

	__skb_queue_tail(frames, skb);

	sta = wcid_to_sta(wcid);
	if (!sta)
		return;

	if (!status->aggr) {
		mt76_rx_aggr_check_ctl(skb, frames);
		return;
	}

	/* not part of a BA session */
	ackp = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_ACK_POLICY_MASK;
	if (ackp != IEEE80211_QOS_CTL_ACK_POLICY_BLOCKACK &&
	    ackp != IEEE80211_QOS_CTL_ACK_POLICY_NORMAL)
		return;

	tid = rcu_dereference(wcid->aggr[status->tid]);
	if (!tid)
		return;

	status->flag |= RX_FLAG_DUP_VALIDATED;
	spin_lock_bh(&tid->lock);

	if (tid->stopped)
		goto out;

	head = tid->head;
	seqno = status->seqno;
	size = tid->size;
	sn_less = ieee80211_sn_less(seqno, head);

	if (!tid->started) {
		if (sn_less)
			goto out;

		tid->started = true;
	}

	if (sn_less) {
		__skb_unlink(skb, frames);
		dev_kfree_skb(skb);
		goto out;
	}

	if (seqno == head) {
		tid->head = ieee80211_sn_inc(head);
		if (tid->nframes)
			mt76_rx_aggr_release_head(tid, frames);
		goto out;
	}

	__skb_unlink(skb, frames);

	/*
	 * Frame sequence number exceeds buffering window, free up some space
	 * by releasing previous frames
	 */
	if (!ieee80211_sn_less(seqno, head + size)) {
		head = ieee80211_sn_inc(ieee80211_sn_sub(seqno, size));
		mt76_rx_aggr_release_frames(tid, frames, head);
	}

	idx = seqno % size;

	/* Discard if the current slot is already in use */
	if (tid->reorder_buf[idx]) {
		dev_kfree_skb(skb);
		goto out;
	}

	status->reorder_time = jiffies;
	tid->reorder_buf[idx] = skb;
	tid->nframes++;
	mt76_rx_aggr_release_head(tid, frames);

	ieee80211_queue_delayed_work(tid->dev->hw, &tid->reorder_work, REORDER_TIMEOUT);

out:
	spin_unlock_bh(&tid->lock);
}

int mt76_rx_aggr_start(struct mt76_dev *dev, struct mt76_wcid *wcid, u8 tidno,
		       u16 ssn, u8 size)
{
	struct mt76_rx_tid *tid;

	mt76_rx_aggr_stop(dev, wcid, tidno);

	tid = kzalloc(struct_size(tid, reorder_buf, size), GFP_KERNEL);
	if (!tid)
		return -ENOMEM;

	tid->dev = dev;
	tid->head = ssn;
	tid->size = size;
	INIT_DELAYED_WORK(&tid->reorder_work, mt76_rx_aggr_reorder_work);
	spin_lock_init(&tid->lock);

	rcu_assign_pointer(wcid->aggr[tidno], tid);

	return 0;
}
EXPORT_SYMBOL_GPL(mt76_rx_aggr_start);

static void mt76_rx_aggr_shutdown(struct mt76_dev *dev, struct mt76_rx_tid *tid)
{
	u8 size = tid->size;
	int i;

	cancel_delayed_work(&tid->reorder_work);

	spin_lock_bh(&tid->lock);

	tid->stopped = true;
	for (i = 0; tid->nframes && i < size; i++) {
		struct sk_buff *skb = tid->reorder_buf[i];

		if (!skb)
			continue;

		tid->nframes--;
		dev_kfree_skb(skb);
	}

	spin_unlock_bh(&tid->lock);
}

void mt76_rx_aggr_stop(struct mt76_dev *dev, struct mt76_wcid *wcid, u8 tidno)
{
	struct mt76_rx_tid *tid;

	rcu_read_lock();

	tid = rcu_dereference(wcid->aggr[tidno]);
	if (tid) {
		rcu_assign_pointer(wcid->aggr[tidno], NULL);
		mt76_rx_aggr_shutdown(dev, tid);
		kfree_rcu(tid, rcu_head);
	}

	rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(mt76_rx_aggr_stop);