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 		wvif->tx_queue[i].priority = priorities[i];
72 	}
73 }
74 
75 bool wfx_tx_queue_empty(struct wfx_vif *wvif, struct wfx_queue *queue)
76 {
77 	return skb_queue_empty_lockless(&queue->normal) && skb_queue_empty_lockless(&queue->cab);
78 }
79 
80 void wfx_tx_queues_check_empty(struct wfx_vif *wvif)
81 {
82 	int i;
83 
84 	for (i = 0; i < IEEE80211_NUM_ACS; ++i) {
85 		WARN_ON(atomic_read(&wvif->tx_queue[i].pending_frames));
86 		WARN_ON(!wfx_tx_queue_empty(wvif, &wvif->tx_queue[i]));
87 	}
88 }
89 
90 static void __wfx_tx_queue_drop(struct wfx_vif *wvif,
91 				struct sk_buff_head *skb_queue, struct sk_buff_head *dropped)
92 {
93 	struct sk_buff *skb, *tmp;
94 
95 	spin_lock_bh(&skb_queue->lock);
96 	skb_queue_walk_safe(skb_queue, skb, tmp) {
97 		__skb_unlink(skb, skb_queue);
98 		skb_queue_head(dropped, skb);
99 	}
100 	spin_unlock_bh(&skb_queue->lock);
101 }
102 
103 void wfx_tx_queue_drop(struct wfx_vif *wvif, struct wfx_queue *queue,
104 		       struct sk_buff_head *dropped)
105 {
106 	__wfx_tx_queue_drop(wvif, &queue->cab, dropped);
107 	__wfx_tx_queue_drop(wvif, &queue->normal, dropped);
108 	wake_up(&wvif->wdev->tx_dequeue);
109 }
110 
111 void wfx_tx_queues_put(struct wfx_vif *wvif, struct sk_buff *skb)
112 {
113 	struct wfx_queue *queue = &wvif->tx_queue[skb_get_queue_mapping(skb)];
114 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
115 
116 	if (tx_info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM)
117 		skb_queue_tail(&queue->cab, skb);
118 	else
119 		skb_queue_tail(&queue->normal, skb);
120 }
121 
122 void wfx_pending_drop(struct wfx_dev *wdev, struct sk_buff_head *dropped)
123 {
124 	struct wfx_queue *queue;
125 	struct wfx_vif *wvif;
126 	struct wfx_hif_msg *hif;
127 	struct sk_buff *skb;
128 
129 	WARN(!wdev->chip_frozen, "%s should only be used to recover a frozen device", __func__);
130 	while ((skb = skb_dequeue(&wdev->tx_pending)) != NULL) {
131 		hif = (struct wfx_hif_msg *)skb->data;
132 		wvif = wdev_to_wvif(wdev, hif->interface);
133 		if (wvif) {
134 			queue = &wvif->tx_queue[skb_get_queue_mapping(skb)];
135 			WARN_ON(skb_get_queue_mapping(skb) > 3);
136 			WARN_ON(!atomic_read(&queue->pending_frames));
137 			atomic_dec(&queue->pending_frames);
138 		}
139 		skb_queue_head(dropped, skb);
140 	}
141 }
142 
143 struct sk_buff *wfx_pending_get(struct wfx_dev *wdev, u32 packet_id)
144 {
145 	struct wfx_queue *queue;
146 	struct wfx_hif_req_tx *req;
147 	struct wfx_vif *wvif;
148 	struct wfx_hif_msg *hif;
149 	struct sk_buff *skb;
150 
151 	spin_lock_bh(&wdev->tx_pending.lock);
152 	skb_queue_walk(&wdev->tx_pending, skb) {
153 		hif = (struct wfx_hif_msg *)skb->data;
154 		req = (struct wfx_hif_req_tx *)hif->body;
155 		if (req->packet_id != packet_id)
156 			continue;
157 		spin_unlock_bh(&wdev->tx_pending.lock);
158 		wvif = wdev_to_wvif(wdev, hif->interface);
159 		if (wvif) {
160 			queue = &wvif->tx_queue[skb_get_queue_mapping(skb)];
161 			WARN_ON(skb_get_queue_mapping(skb) > 3);
162 			WARN_ON(!atomic_read(&queue->pending_frames));
163 			atomic_dec(&queue->pending_frames);
164 		}
165 		skb_unlink(skb, &wdev->tx_pending);
166 		return skb;
167 	}
168 	spin_unlock_bh(&wdev->tx_pending.lock);
169 	WARN(1, "cannot find packet in pending queue");
170 	return NULL;
171 }
172 
173 void wfx_pending_dump_old_frames(struct wfx_dev *wdev, unsigned int limit_ms)
174 {
175 	ktime_t now = ktime_get();
176 	struct wfx_tx_priv *tx_priv;
177 	struct wfx_hif_req_tx *req;
178 	struct sk_buff *skb;
179 	bool first = true;
180 
181 	spin_lock_bh(&wdev->tx_pending.lock);
182 	skb_queue_walk(&wdev->tx_pending, skb) {
183 		tx_priv = wfx_skb_tx_priv(skb);
184 		req = wfx_skb_txreq(skb);
185 		if (ktime_after(now, ktime_add_ms(tx_priv->xmit_timestamp, limit_ms))) {
186 			if (first) {
187 				dev_info(wdev->dev, "frames stuck in firmware since %dms or more:\n",
188 					 limit_ms);
189 				first = false;
190 			}
191 			dev_info(wdev->dev, "   id %08x sent %lldms ago\n",
192 				 req->packet_id, ktime_ms_delta(now, tx_priv->xmit_timestamp));
193 		}
194 	}
195 	spin_unlock_bh(&wdev->tx_pending.lock);
196 }
197 
198 unsigned int wfx_pending_get_pkt_us_delay(struct wfx_dev *wdev, struct sk_buff *skb)
199 {
200 	ktime_t now = ktime_get();
201 	struct wfx_tx_priv *tx_priv = wfx_skb_tx_priv(skb);
202 
203 	return ktime_us_delta(now, tx_priv->xmit_timestamp);
204 }
205 
206 bool wfx_tx_queues_has_cab(struct wfx_vif *wvif)
207 {
208 	struct ieee80211_vif *vif = wvif_to_vif(wvif);
209 	int i;
210 
211 	if (vif->type != NL80211_IFTYPE_AP)
212 		return false;
213 	for (i = 0; i < IEEE80211_NUM_ACS; ++i)
214 		/* Note: since only AP can have mcast frames in queue and only one vif can be AP,
215 		 * all queued frames has same interface id
216 		 */
217 		if (!skb_queue_empty_lockless(&wvif->tx_queue[i].cab))
218 			return true;
219 	return false;
220 }
221 
222 static int wfx_tx_queue_get_weight(struct wfx_queue *queue)
223 {
224 	return atomic_read(&queue->pending_frames) * queue->priority;
225 }
226 
227 static struct sk_buff *wfx_tx_queues_get_skb(struct wfx_dev *wdev)
228 {
229 	struct wfx_queue *queues[IEEE80211_NUM_ACS * ARRAY_SIZE(wdev->vif)];
230 	int i, j, num_queues = 0;
231 	struct wfx_vif *wvif;
232 	struct wfx_hif_msg *hif;
233 	struct sk_buff *skb;
234 
235 	/* sort the queues */
236 	wvif = NULL;
237 	while ((wvif = wvif_iterate(wdev, wvif)) != NULL) {
238 		for (i = 0; i < IEEE80211_NUM_ACS; i++) {
239 			WARN_ON(num_queues >= ARRAY_SIZE(queues));
240 			queues[num_queues] = &wvif->tx_queue[i];
241 			for (j = num_queues; j > 0; j--)
242 				if (wfx_tx_queue_get_weight(queues[j]) <
243 				    wfx_tx_queue_get_weight(queues[j - 1]))
244 					swap(queues[j - 1], queues[j]);
245 			num_queues++;
246 		}
247 	}
248 
249 	wvif = NULL;
250 	while ((wvif = wvif_iterate(wdev, wvif)) != NULL) {
251 		if (!wvif->after_dtim_tx_allowed)
252 			continue;
253 		for (i = 0; i < num_queues; i++) {
254 			skb = skb_dequeue(&queues[i]->cab);
255 			if (!skb)
256 				continue;
257 			/* Note: since only AP can have mcast frames in queue and only one vif can
258 			 * be AP, all queued frames has same interface id
259 			 */
260 			hif = (struct wfx_hif_msg *)skb->data;
261 			WARN_ON(hif->interface != wvif->id);
262 			WARN_ON(queues[i] != &wvif->tx_queue[skb_get_queue_mapping(skb)]);
263 			atomic_inc(&queues[i]->pending_frames);
264 			trace_queues_stats(wdev, queues[i]);
265 			return skb;
266 		}
267 		/* No more multicast to sent */
268 		wvif->after_dtim_tx_allowed = false;
269 		schedule_work(&wvif->update_tim_work);
270 	}
271 
272 	for (i = 0; i < num_queues; i++) {
273 		skb = skb_dequeue(&queues[i]->normal);
274 		if (skb) {
275 			atomic_inc(&queues[i]->pending_frames);
276 			trace_queues_stats(wdev, queues[i]);
277 			return skb;
278 		}
279 	}
280 	return NULL;
281 }
282 
283 struct wfx_hif_msg *wfx_tx_queues_get(struct wfx_dev *wdev)
284 {
285 	struct wfx_tx_priv *tx_priv;
286 	struct sk_buff *skb;
287 
288 	if (atomic_read(&wdev->tx_lock))
289 		return NULL;
290 	skb = wfx_tx_queues_get_skb(wdev);
291 	if (!skb)
292 		return NULL;
293 	skb_queue_tail(&wdev->tx_pending, skb);
294 	wake_up(&wdev->tx_dequeue);
295 	tx_priv = wfx_skb_tx_priv(skb);
296 	tx_priv->xmit_timestamp = ktime_get();
297 	return (struct wfx_hif_msg *)skb->data;
298 }
299