xref: /linux/drivers/net/wireless/silabs/wfx/queue.c (revision 4e94ddfe2aab72139acb8d5372fac9e6c3f3e383)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Queue between the tx operation and the bh workqueue.
4  *
5  * Copyright (c) 2017-2020, Silicon Laboratories, Inc.
6  * Copyright (c) 2010, ST-Ericsson
7  */
8 #include <linux/sched.h>
9 #include <net/mac80211.h>
10 
11 #include "queue.h"
12 #include "wfx.h"
13 #include "sta.h"
14 #include "data_tx.h"
15 #include "traces.h"
16 
17 void wfx_tx_lock(struct wfx_dev *wdev)
18 {
19 	atomic_inc(&wdev->tx_lock);
20 }
21 
22 void wfx_tx_unlock(struct wfx_dev *wdev)
23 {
24 	int tx_lock = atomic_dec_return(&wdev->tx_lock);
25 
26 	WARN(tx_lock < 0, "inconsistent tx_lock value");
27 	if (!tx_lock)
28 		wfx_bh_request_tx(wdev);
29 }
30 
31 void wfx_tx_flush(struct wfx_dev *wdev)
32 {
33 	int ret;
34 
35 	/* Do not wait for any reply if chip is frozen */
36 	if (wdev->chip_frozen)
37 		return;
38 
39 	wfx_tx_lock(wdev);
40 	mutex_lock(&wdev->hif_cmd.lock);
41 	ret = wait_event_timeout(wdev->hif.tx_buffers_empty, !wdev->hif.tx_buffers_used,
42 				 msecs_to_jiffies(3000));
43 	if (!ret) {
44 		dev_warn(wdev->dev, "cannot flush tx buffers (%d still busy)\n",
45 			 wdev->hif.tx_buffers_used);
46 		wfx_pending_dump_old_frames(wdev, 3000);
47 		/* FIXME: drop pending frames here */
48 		wdev->chip_frozen = true;
49 	}
50 	mutex_unlock(&wdev->hif_cmd.lock);
51 	wfx_tx_unlock(wdev);
52 }
53 
54 void wfx_tx_lock_flush(struct wfx_dev *wdev)
55 {
56 	wfx_tx_lock(wdev);
57 	wfx_tx_flush(wdev);
58 }
59 
60 void wfx_tx_queues_init(struct wfx_vif *wvif)
61 {
62 	/* The device is in charge to respect the details of the QoS parameters. The driver just
63 	 * ensure that it roughtly respect the priorities to avoid any shortage.
64 	 */
65 	const int priorities[IEEE80211_NUM_ACS] = { 1, 2, 64, 128 };
66 	int i;
67 
68 	for (i = 0; i < IEEE80211_NUM_ACS; ++i) {
69 		skb_queue_head_init(&wvif->tx_queue[i].normal);
70 		skb_queue_head_init(&wvif->tx_queue[i].cab);
71 		skb_queue_head_init(&wvif->tx_queue[i].offchan);
72 		wvif->tx_queue[i].priority = priorities[i];
73 	}
74 }
75 
76 bool wfx_tx_queue_empty(struct wfx_vif *wvif, struct wfx_queue *queue)
77 {
78 	return skb_queue_empty_lockless(&queue->normal) &&
79 	       skb_queue_empty_lockless(&queue->cab) &&
80 	       skb_queue_empty_lockless(&queue->offchan);
81 }
82 
83 void wfx_tx_queues_check_empty(struct wfx_vif *wvif)
84 {
85 	int i;
86 
87 	for (i = 0; i < IEEE80211_NUM_ACS; ++i) {
88 		WARN_ON(atomic_read(&wvif->tx_queue[i].pending_frames));
89 		WARN_ON(!wfx_tx_queue_empty(wvif, &wvif->tx_queue[i]));
90 	}
91 }
92 
93 static void __wfx_tx_queue_drop(struct wfx_vif *wvif,
94 				struct sk_buff_head *skb_queue, struct sk_buff_head *dropped)
95 {
96 	struct sk_buff *skb, *tmp;
97 
98 	spin_lock_bh(&skb_queue->lock);
99 	skb_queue_walk_safe(skb_queue, skb, tmp) {
100 		__skb_unlink(skb, skb_queue);
101 		skb_queue_head(dropped, skb);
102 	}
103 	spin_unlock_bh(&skb_queue->lock);
104 }
105 
106 void wfx_tx_queue_drop(struct wfx_vif *wvif, struct wfx_queue *queue,
107 		       struct sk_buff_head *dropped)
108 {
109 	__wfx_tx_queue_drop(wvif, &queue->normal, dropped);
110 	__wfx_tx_queue_drop(wvif, &queue->cab, dropped);
111 	__wfx_tx_queue_drop(wvif, &queue->offchan, dropped);
112 	wake_up(&wvif->wdev->tx_dequeue);
113 }
114 
115 void wfx_tx_queues_put(struct wfx_vif *wvif, struct sk_buff *skb)
116 {
117 	struct wfx_queue *queue = &wvif->tx_queue[skb_get_queue_mapping(skb)];
118 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
119 
120 	if (tx_info->flags & IEEE80211_TX_CTL_TX_OFFCHAN)
121 		skb_queue_tail(&queue->offchan, skb);
122 	else if (tx_info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM)
123 		skb_queue_tail(&queue->cab, skb);
124 	else
125 		skb_queue_tail(&queue->normal, skb);
126 }
127 
128 void wfx_pending_drop(struct wfx_dev *wdev, struct sk_buff_head *dropped)
129 {
130 	struct wfx_queue *queue;
131 	struct wfx_vif *wvif;
132 	struct sk_buff *skb;
133 
134 	WARN(!wdev->chip_frozen, "%s should only be used to recover a frozen device", __func__);
135 	while ((skb = skb_dequeue(&wdev->tx_pending)) != NULL) {
136 		wvif = wfx_skb_wvif(wdev, skb);
137 		if (wvif) {
138 			queue = &wvif->tx_queue[skb_get_queue_mapping(skb)];
139 			WARN_ON(skb_get_queue_mapping(skb) > 3);
140 			WARN_ON(!atomic_read(&queue->pending_frames));
141 			atomic_dec(&queue->pending_frames);
142 		}
143 		skb_queue_head(dropped, skb);
144 	}
145 }
146 
147 struct sk_buff *wfx_pending_get(struct wfx_dev *wdev, u32 packet_id)
148 {
149 	struct wfx_queue *queue;
150 	struct wfx_hif_req_tx *req;
151 	struct wfx_vif *wvif;
152 	struct wfx_hif_msg *hif;
153 	struct sk_buff *skb;
154 
155 	spin_lock_bh(&wdev->tx_pending.lock);
156 	skb_queue_walk(&wdev->tx_pending, skb) {
157 		hif = (struct wfx_hif_msg *)skb->data;
158 		req = (struct wfx_hif_req_tx *)hif->body;
159 		if (req->packet_id != packet_id)
160 			continue;
161 		spin_unlock_bh(&wdev->tx_pending.lock);
162 		wvif = wfx_skb_wvif(wdev, skb);
163 		if (wvif) {
164 			queue = &wvif->tx_queue[skb_get_queue_mapping(skb)];
165 			WARN_ON(skb_get_queue_mapping(skb) > 3);
166 			WARN_ON(!atomic_read(&queue->pending_frames));
167 			atomic_dec(&queue->pending_frames);
168 		}
169 		skb_unlink(skb, &wdev->tx_pending);
170 		return skb;
171 	}
172 	spin_unlock_bh(&wdev->tx_pending.lock);
173 	WARN(1, "cannot find packet in pending queue");
174 	return NULL;
175 }
176 
177 void wfx_pending_dump_old_frames(struct wfx_dev *wdev, unsigned int limit_ms)
178 {
179 	ktime_t now = ktime_get();
180 	struct wfx_tx_priv *tx_priv;
181 	struct wfx_hif_req_tx *req;
182 	struct sk_buff *skb;
183 	bool first = true;
184 
185 	spin_lock_bh(&wdev->tx_pending.lock);
186 	skb_queue_walk(&wdev->tx_pending, skb) {
187 		tx_priv = wfx_skb_tx_priv(skb);
188 		req = wfx_skb_txreq(skb);
189 		if (ktime_after(now, ktime_add_ms(tx_priv->xmit_timestamp, limit_ms))) {
190 			if (first) {
191 				dev_info(wdev->dev, "frames stuck in firmware since %dms or more:\n",
192 					 limit_ms);
193 				first = false;
194 			}
195 			dev_info(wdev->dev, "   id %08x sent %lldms ago\n",
196 				 req->packet_id, ktime_ms_delta(now, tx_priv->xmit_timestamp));
197 		}
198 	}
199 	spin_unlock_bh(&wdev->tx_pending.lock);
200 }
201 
202 unsigned int wfx_pending_get_pkt_us_delay(struct wfx_dev *wdev, struct sk_buff *skb)
203 {
204 	ktime_t now = ktime_get();
205 	struct wfx_tx_priv *tx_priv = wfx_skb_tx_priv(skb);
206 
207 	return ktime_us_delta(now, tx_priv->xmit_timestamp);
208 }
209 
210 bool wfx_tx_queues_has_cab(struct wfx_vif *wvif)
211 {
212 	struct ieee80211_vif *vif = wvif_to_vif(wvif);
213 	int i;
214 
215 	if (vif->type != NL80211_IFTYPE_AP)
216 		return false;
217 	for (i = 0; i < IEEE80211_NUM_ACS; ++i)
218 		/* Note: since only AP can have mcast frames in queue and only one vif can be AP,
219 		 * all queued frames has same interface id
220 		 */
221 		if (!skb_queue_empty_lockless(&wvif->tx_queue[i].cab))
222 			return true;
223 	return false;
224 }
225 
226 static int wfx_tx_queue_get_weight(struct wfx_queue *queue)
227 {
228 	return atomic_read(&queue->pending_frames) * queue->priority;
229 }
230 
231 static struct sk_buff *wfx_tx_queues_get_skb(struct wfx_dev *wdev)
232 {
233 	struct wfx_queue *queues[IEEE80211_NUM_ACS * ARRAY_SIZE(wdev->vif)];
234 	int i, j, num_queues = 0;
235 	struct wfx_vif *wvif;
236 	struct wfx_hif_msg *hif;
237 	struct sk_buff *skb;
238 
239 	/* sort the queues */
240 	wvif = NULL;
241 	while ((wvif = wvif_iterate(wdev, wvif)) != NULL) {
242 		for (i = 0; i < IEEE80211_NUM_ACS; i++) {
243 			WARN_ON(num_queues >= ARRAY_SIZE(queues));
244 			queues[num_queues] = &wvif->tx_queue[i];
245 			for (j = num_queues; j > 0; j--)
246 				if (wfx_tx_queue_get_weight(queues[j]) <
247 				    wfx_tx_queue_get_weight(queues[j - 1]))
248 					swap(queues[j - 1], queues[j]);
249 			num_queues++;
250 		}
251 	}
252 
253 	wvif = NULL;
254 	while ((wvif = wvif_iterate(wdev, wvif)) != NULL) {
255 		for (i = 0; i < num_queues; i++) {
256 			skb = skb_dequeue(&queues[i]->offchan);
257 			if (!skb)
258 				continue;
259 			hif = (struct wfx_hif_msg *)skb->data;
260 			/* Offchan frames are assigned to a special interface.
261 			 * The only interface allowed to send data during scan.
262 			 */
263 			WARN_ON(hif->interface != 2);
264 			atomic_inc(&queues[i]->pending_frames);
265 			trace_queues_stats(wdev, queues[i]);
266 			return skb;
267 		}
268 	}
269 
270 	if (mutex_is_locked(&wdev->scan_lock))
271 		return NULL;
272 
273 	wvif = NULL;
274 	while ((wvif = wvif_iterate(wdev, wvif)) != NULL) {
275 		if (!wvif->after_dtim_tx_allowed)
276 			continue;
277 		for (i = 0; i < num_queues; i++) {
278 			skb = skb_dequeue(&queues[i]->cab);
279 			if (!skb)
280 				continue;
281 			/* Note: since only AP can have mcast frames in queue and only one vif can
282 			 * be AP, all queued frames has same interface id
283 			 */
284 			hif = (struct wfx_hif_msg *)skb->data;
285 			WARN_ON(hif->interface != wvif->id);
286 			WARN_ON(queues[i] != &wvif->tx_queue[skb_get_queue_mapping(skb)]);
287 			atomic_inc(&queues[i]->pending_frames);
288 			trace_queues_stats(wdev, queues[i]);
289 			return skb;
290 		}
291 		/* No more multicast to sent */
292 		wvif->after_dtim_tx_allowed = false;
293 		schedule_work(&wvif->update_tim_work);
294 	}
295 
296 	for (i = 0; i < num_queues; i++) {
297 		skb = skb_dequeue(&queues[i]->normal);
298 		if (skb) {
299 			atomic_inc(&queues[i]->pending_frames);
300 			trace_queues_stats(wdev, queues[i]);
301 			return skb;
302 		}
303 	}
304 	return NULL;
305 }
306 
307 struct wfx_hif_msg *wfx_tx_queues_get(struct wfx_dev *wdev)
308 {
309 	struct wfx_tx_priv *tx_priv;
310 	struct sk_buff *skb;
311 
312 	if (atomic_read(&wdev->tx_lock))
313 		return NULL;
314 	skb = wfx_tx_queues_get_skb(wdev);
315 	if (!skb)
316 		return NULL;
317 	skb_queue_tail(&wdev->tx_pending, skb);
318 	wake_up(&wdev->tx_dequeue);
319 	tx_priv = wfx_skb_tx_priv(skb);
320 	tx_priv->xmit_timestamp = ktime_get();
321 	return (struct wfx_hif_msg *)skb->data;
322 }
323