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
17void wfx_tx_lock(struct wfx_dev *wdev)
18{
19	atomic_inc(&wdev->tx_lock);
20}
21
22void 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
31void 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
54void wfx_tx_lock_flush(struct wfx_dev *wdev)
55{
56	wfx_tx_lock(wdev);
57	wfx_tx_flush(wdev);
58}
59
60void 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
76bool 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
83void 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
93static 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
106void 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
115void 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
128void 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
147struct 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
177void 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
202unsigned 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
210bool 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
226static int wfx_tx_queue_get_weight(struct wfx_queue *queue)
227{
228	return atomic_read(&queue->pending_frames) * queue->priority;
229}
230
231static 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
307struct 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