xref: /linux/drivers/net/wireless/st/cw1200/scan.c (revision 1fd1dc41724319406b0aff221a352a400b0ddfc5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Scan implementation for ST-Ericsson CW1200 mac80211 drivers
4  *
5  * Copyright (c) 2010, ST-Ericsson
6  * Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
7  */
8 
9 #include <linux/sched.h>
10 #include "cw1200.h"
11 #include "scan.h"
12 #include "sta.h"
13 #include "pm.h"
14 
15 static void cw1200_scan_restart_delayed(struct cw1200_common *priv);
16 
17 static int cw1200_scan_start(struct cw1200_common *priv, struct wsm_scan *scan)
18 {
19 	int ret, i;
20 	int tmo = 2000;
21 
22 	switch (priv->join_status) {
23 	case CW1200_JOIN_STATUS_PRE_STA:
24 	case CW1200_JOIN_STATUS_JOINING:
25 		return -EBUSY;
26 	default:
27 		break;
28 	}
29 
30 	wiphy_dbg(priv->hw->wiphy, "[SCAN] hw req, type %d, %d channels, flags: 0x%x.\n",
31 		  scan->type, scan->num_channels, scan->flags);
32 
33 	for (i = 0; i < scan->num_channels; ++i)
34 		tmo += scan->ch[i].max_chan_time + 10;
35 
36 	cancel_delayed_work_sync(&priv->clear_recent_scan_work);
37 	atomic_set(&priv->scan.in_progress, 1);
38 	atomic_set(&priv->recent_scan, 1);
39 	cw1200_pm_stay_awake(&priv->pm_state, msecs_to_jiffies(tmo));
40 	queue_delayed_work(priv->workqueue, &priv->scan.timeout,
41 			   msecs_to_jiffies(tmo));
42 	ret = wsm_scan(priv, scan);
43 	if (ret) {
44 		atomic_set(&priv->scan.in_progress, 0);
45 		cancel_delayed_work_sync(&priv->scan.timeout);
46 		cw1200_scan_restart_delayed(priv);
47 	}
48 	return ret;
49 }
50 
51 int cw1200_hw_scan(struct ieee80211_hw *hw,
52 		   struct ieee80211_vif *vif,
53 		   struct ieee80211_scan_request *hw_req)
54 {
55 	struct cw1200_common *priv = hw->priv;
56 	struct cfg80211_scan_request *req = &hw_req->req;
57 	struct wsm_template_frame frame = {
58 		.frame_type = WSM_FRAME_TYPE_PROBE_REQUEST,
59 	};
60 	int i, ret;
61 
62 	if (!priv->vif)
63 		return -EINVAL;
64 
65 	/* Scan when P2P_GO corrupt firmware MiniAP mode */
66 	if (priv->join_status == CW1200_JOIN_STATUS_AP)
67 		return -EOPNOTSUPP;
68 
69 	if (req->n_ssids == 1 && !req->ssids[0].ssid_len)
70 		req->n_ssids = 0;
71 
72 	wiphy_dbg(hw->wiphy, "[SCAN] Scan request for %d SSIDs.\n",
73 		  req->n_ssids);
74 
75 	if (req->n_ssids > WSM_SCAN_MAX_NUM_OF_SSIDS)
76 		return -EINVAL;
77 
78 	frame.skb = ieee80211_probereq_get(hw, priv->vif->addr, NULL, 0,
79 		req->ie_len);
80 	if (!frame.skb)
81 		return -ENOMEM;
82 
83 	if (req->ie_len)
84 		skb_put_data(frame.skb, req->ie, req->ie_len);
85 
86 	/* will be unlocked in cw1200_scan_work() */
87 	down(&priv->scan.lock);
88 	mutex_lock(&priv->conf_mutex);
89 
90 	ret = wsm_set_template_frame(priv, &frame);
91 	if (!ret) {
92 		/* Host want to be the probe responder. */
93 		ret = wsm_set_probe_responder(priv, true);
94 	}
95 	if (ret) {
96 		mutex_unlock(&priv->conf_mutex);
97 		up(&priv->scan.lock);
98 		dev_kfree_skb(frame.skb);
99 		return ret;
100 	}
101 
102 	wsm_lock_tx(priv);
103 
104 	BUG_ON(priv->scan.req);
105 	priv->scan.req = req;
106 	priv->scan.n_ssids = 0;
107 	priv->scan.status = 0;
108 	priv->scan.begin = &req->channels[0];
109 	priv->scan.curr = priv->scan.begin;
110 	priv->scan.end = &req->channels[req->n_channels];
111 	priv->scan.output_power = priv->output_power;
112 
113 	for (i = 0; i < req->n_ssids; ++i) {
114 		struct wsm_ssid *dst = &priv->scan.ssids[priv->scan.n_ssids];
115 		memcpy(&dst->ssid[0], req->ssids[i].ssid, sizeof(dst->ssid));
116 		dst->length = req->ssids[i].ssid_len;
117 		++priv->scan.n_ssids;
118 	}
119 
120 	mutex_unlock(&priv->conf_mutex);
121 	dev_kfree_skb(frame.skb);
122 	queue_work(priv->workqueue, &priv->scan.work);
123 	return 0;
124 }
125 
126 void cw1200_scan_work(struct work_struct *work)
127 {
128 	struct cw1200_common *priv = container_of(work, struct cw1200_common,
129 							scan.work);
130 	struct ieee80211_channel **it;
131 	struct wsm_scan scan = {
132 		.type = WSM_SCAN_TYPE_FOREGROUND,
133 		.flags = WSM_SCAN_FLAG_SPLIT_METHOD,
134 	};
135 	bool first_run = (priv->scan.begin == priv->scan.curr &&
136 			  priv->scan.begin != priv->scan.end);
137 	int i;
138 
139 	if (first_run) {
140 		/* Firmware gets crazy if scan request is sent
141 		 * when STA is joined but not yet associated.
142 		 * Force unjoin in this case.
143 		 */
144 		if (cancel_delayed_work_sync(&priv->join_timeout) > 0)
145 			cw1200_join_timeout(&priv->join_timeout.work);
146 	}
147 
148 	mutex_lock(&priv->conf_mutex);
149 
150 	if (first_run) {
151 		if (priv->join_status == CW1200_JOIN_STATUS_STA &&
152 		    !(priv->powersave_mode.mode & WSM_PSM_PS)) {
153 			struct wsm_set_pm pm = priv->powersave_mode;
154 			pm.mode = WSM_PSM_PS;
155 			cw1200_set_pm(priv, &pm);
156 		} else if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
157 			/* FW bug: driver has to restart p2p-dev mode
158 			 * after scan
159 			 */
160 			cw1200_disable_listening(priv);
161 		}
162 	}
163 
164 	if (!priv->scan.req || (priv->scan.curr == priv->scan.end)) {
165 		struct cfg80211_scan_info info = {
166 			.aborted = priv->scan.status ? 1 : 0,
167 		};
168 
169 		if (priv->scan.output_power != priv->output_power)
170 			wsm_set_output_power(priv, priv->output_power * 10);
171 		if (priv->join_status == CW1200_JOIN_STATUS_STA &&
172 		    !(priv->powersave_mode.mode & WSM_PSM_PS))
173 			cw1200_set_pm(priv, &priv->powersave_mode);
174 
175 		if (priv->scan.status < 0)
176 			wiphy_warn(priv->hw->wiphy,
177 				   "[SCAN] Scan failed (%d).\n",
178 				   priv->scan.status);
179 		else if (priv->scan.req)
180 			wiphy_dbg(priv->hw->wiphy,
181 				  "[SCAN] Scan completed.\n");
182 		else
183 			wiphy_dbg(priv->hw->wiphy,
184 				  "[SCAN] Scan canceled.\n");
185 
186 		priv->scan.req = NULL;
187 		cw1200_scan_restart_delayed(priv);
188 		wsm_unlock_tx(priv);
189 		mutex_unlock(&priv->conf_mutex);
190 		ieee80211_scan_completed(priv->hw, &info);
191 		up(&priv->scan.lock);
192 		return;
193 	} else {
194 		struct ieee80211_channel *first = *priv->scan.curr;
195 		for (it = priv->scan.curr + 1, i = 1;
196 		     it != priv->scan.end && i < WSM_SCAN_MAX_NUM_OF_CHANNELS;
197 		     ++it, ++i) {
198 			if ((*it)->band != first->band)
199 				break;
200 			if (((*it)->flags ^ first->flags) &
201 					IEEE80211_CHAN_NO_IR)
202 				break;
203 			if (!(first->flags & IEEE80211_CHAN_NO_IR) &&
204 			    (*it)->max_power != first->max_power)
205 				break;
206 		}
207 		scan.band = first->band;
208 
209 		if (priv->scan.req->no_cck)
210 			scan.max_tx_rate = WSM_TRANSMIT_RATE_6;
211 		else
212 			scan.max_tx_rate = WSM_TRANSMIT_RATE_1;
213 		scan.num_probes =
214 			(first->flags & IEEE80211_CHAN_NO_IR) ? 0 : 2;
215 		scan.num_ssids = priv->scan.n_ssids;
216 		scan.ssids = &priv->scan.ssids[0];
217 		scan.num_channels = it - priv->scan.curr;
218 		/* TODO: Is it optimal? */
219 		scan.probe_delay = 100;
220 		/* It is not stated in WSM specification, however
221 		 * FW team says that driver may not use FG scan
222 		 * when joined.
223 		 */
224 		if (priv->join_status == CW1200_JOIN_STATUS_STA) {
225 			scan.type = WSM_SCAN_TYPE_BACKGROUND;
226 			scan.flags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
227 		}
228 		scan.ch = kzalloc_objs(struct wsm_scan_ch, it - priv->scan.curr);
229 		if (!scan.ch) {
230 			priv->scan.status = -ENOMEM;
231 			goto fail;
232 		}
233 		for (i = 0; i < scan.num_channels; ++i) {
234 			scan.ch[i].number = priv->scan.curr[i]->hw_value;
235 			if (priv->scan.curr[i]->flags & IEEE80211_CHAN_NO_IR) {
236 				scan.ch[i].min_chan_time = 50;
237 				scan.ch[i].max_chan_time = 100;
238 			} else {
239 				scan.ch[i].min_chan_time = 10;
240 				scan.ch[i].max_chan_time = 25;
241 			}
242 		}
243 		if (!(first->flags & IEEE80211_CHAN_NO_IR) &&
244 		    priv->scan.output_power != first->max_power) {
245 			priv->scan.output_power = first->max_power;
246 			wsm_set_output_power(priv,
247 					     priv->scan.output_power * 10);
248 		}
249 		priv->scan.status = cw1200_scan_start(priv, &scan);
250 		kfree(scan.ch);
251 		if (priv->scan.status)
252 			goto fail;
253 		priv->scan.curr = it;
254 	}
255 	mutex_unlock(&priv->conf_mutex);
256 	return;
257 
258 fail:
259 	priv->scan.curr = priv->scan.end;
260 	mutex_unlock(&priv->conf_mutex);
261 	queue_work(priv->workqueue, &priv->scan.work);
262 	return;
263 }
264 
265 static void cw1200_scan_restart_delayed(struct cw1200_common *priv)
266 {
267 	/* FW bug: driver has to restart p2p-dev mode after scan. */
268 	if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
269 		cw1200_enable_listening(priv);
270 		cw1200_update_filtering(priv);
271 	}
272 
273 	if (priv->delayed_unjoin) {
274 		priv->delayed_unjoin = false;
275 		if (queue_work(priv->workqueue, &priv->unjoin_work) <= 0)
276 			wsm_unlock_tx(priv);
277 	} else if (priv->delayed_link_loss) {
278 			wiphy_dbg(priv->hw->wiphy, "[CQM] Requeue BSS loss.\n");
279 			priv->delayed_link_loss = 0;
280 			cw1200_cqm_bssloss_sm(priv, 1, 0, 0);
281 	}
282 }
283 
284 static void cw1200_scan_complete(struct cw1200_common *priv)
285 {
286 	queue_delayed_work(priv->workqueue, &priv->clear_recent_scan_work, HZ);
287 	if (priv->scan.direct_probe) {
288 		wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe complete.\n");
289 		cw1200_scan_restart_delayed(priv);
290 		priv->scan.direct_probe = 0;
291 		up(&priv->scan.lock);
292 		wsm_unlock_tx(priv);
293 	} else {
294 		cw1200_scan_work(&priv->scan.work);
295 	}
296 }
297 
298 void cw1200_scan_failed_cb(struct cw1200_common *priv)
299 {
300 	if (priv->mode == NL80211_IFTYPE_UNSPECIFIED)
301 		/* STA is stopped. */
302 		return;
303 
304 	if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
305 		priv->scan.status = -EIO;
306 		queue_delayed_work(priv->workqueue, &priv->scan.timeout, 0);
307 	}
308 }
309 
310 
311 void cw1200_scan_complete_cb(struct cw1200_common *priv,
312 				struct wsm_scan_complete *arg)
313 {
314 	if (priv->mode == NL80211_IFTYPE_UNSPECIFIED)
315 		/* STA is stopped. */
316 		return;
317 
318 	if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
319 		priv->scan.status = 1;
320 		queue_delayed_work(priv->workqueue, &priv->scan.timeout, 0);
321 	}
322 }
323 
324 void cw1200_clear_recent_scan_work(struct work_struct *work)
325 {
326 	struct cw1200_common *priv =
327 		container_of(work, struct cw1200_common,
328 			     clear_recent_scan_work.work);
329 	atomic_xchg(&priv->recent_scan, 0);
330 }
331 
332 void cw1200_scan_timeout(struct work_struct *work)
333 {
334 	struct cw1200_common *priv =
335 		container_of(work, struct cw1200_common, scan.timeout.work);
336 	if (atomic_xchg(&priv->scan.in_progress, 0)) {
337 		if (priv->scan.status > 0) {
338 			priv->scan.status = 0;
339 		} else if (!priv->scan.status) {
340 			wiphy_warn(priv->hw->wiphy,
341 				   "Timeout waiting for scan complete notification.\n");
342 			priv->scan.status = -ETIMEDOUT;
343 			priv->scan.curr = priv->scan.end;
344 			wsm_stop_scan(priv);
345 		}
346 		cw1200_scan_complete(priv);
347 	}
348 }
349 
350 void cw1200_probe_work(struct work_struct *work)
351 {
352 	struct cw1200_common *priv =
353 		container_of(work, struct cw1200_common, scan.probe_work.work);
354 	u8 queue_id = cw1200_queue_get_queue_id(priv->pending_frame_id);
355 	struct cw1200_queue *queue = &priv->tx_queue[queue_id];
356 	const struct cw1200_txpriv *txpriv;
357 	struct wsm_tx *wsm;
358 	struct wsm_template_frame frame = {
359 		.frame_type = WSM_FRAME_TYPE_PROBE_REQUEST,
360 	};
361 	struct wsm_ssid ssids[1] = {{
362 		.length = 0,
363 	} };
364 	struct wsm_scan_ch ch[1] = {{
365 		.min_chan_time = 0,
366 		.max_chan_time = 10,
367 	} };
368 	struct wsm_scan scan = {
369 		.type = WSM_SCAN_TYPE_FOREGROUND,
370 		.num_probes = 1,
371 		.probe_delay = 0,
372 		.num_channels = 1,
373 		.ssids = ssids,
374 		.ch = ch,
375 	};
376 	u8 *ies;
377 	size_t ies_len;
378 	int ret;
379 
380 	wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe work.\n");
381 
382 	mutex_lock(&priv->conf_mutex);
383 	if (down_trylock(&priv->scan.lock)) {
384 		/* Scan is already in progress. Requeue self. */
385 		schedule();
386 		queue_delayed_work(priv->workqueue, &priv->scan.probe_work,
387 				   msecs_to_jiffies(100));
388 		mutex_unlock(&priv->conf_mutex);
389 		return;
390 	}
391 
392 	/* Make sure we still have a pending probe req */
393 	if (cw1200_queue_get_skb(queue,	priv->pending_frame_id,
394 				 &frame.skb, &txpriv)) {
395 		up(&priv->scan.lock);
396 		mutex_unlock(&priv->conf_mutex);
397 		wsm_unlock_tx(priv);
398 		return;
399 	}
400 	wsm = (struct wsm_tx *)frame.skb->data;
401 	scan.max_tx_rate = wsm->max_tx_rate;
402 	scan.band = (priv->channel->band == NL80211_BAND_5GHZ) ?
403 		WSM_PHY_BAND_5G : WSM_PHY_BAND_2_4G;
404 	if (priv->join_status == CW1200_JOIN_STATUS_STA ||
405 	    priv->join_status == CW1200_JOIN_STATUS_IBSS) {
406 		scan.type = WSM_SCAN_TYPE_BACKGROUND;
407 		scan.flags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
408 	}
409 	ch[0].number = priv->channel->hw_value;
410 
411 	skb_pull(frame.skb, txpriv->offset);
412 
413 	ies = &frame.skb->data[sizeof(struct ieee80211_hdr_3addr)];
414 	ies_len = frame.skb->len - sizeof(struct ieee80211_hdr_3addr);
415 
416 	if (ies_len) {
417 		u8 *ssidie =
418 			(u8 *)cfg80211_find_ie(WLAN_EID_SSID, ies, ies_len);
419 		if (ssidie && ssidie[1] && ssidie[1] <= sizeof(ssids[0].ssid)) {
420 			u8 *nextie = &ssidie[2 + ssidie[1]];
421 			/* Remove SSID from the IE list. It has to be provided
422 			 * as a separate argument in cw1200_scan_start call
423 			 */
424 
425 			/* Store SSID localy */
426 			ssids[0].length = ssidie[1];
427 			memcpy(ssids[0].ssid, &ssidie[2], ssids[0].length);
428 			scan.num_ssids = 1;
429 
430 			/* Remove SSID from IE list */
431 			ssidie[1] = 0;
432 			memmove(&ssidie[2], nextie, &ies[ies_len] - nextie);
433 			skb_trim(frame.skb, frame.skb->len - ssids[0].length);
434 		}
435 	}
436 
437 	/* FW bug: driver has to restart p2p-dev mode after scan */
438 	if (priv->join_status == CW1200_JOIN_STATUS_MONITOR)
439 		cw1200_disable_listening(priv);
440 	ret = wsm_set_template_frame(priv, &frame);
441 	priv->scan.direct_probe = 1;
442 	if (!ret) {
443 		wsm_flush_tx(priv);
444 		ret = cw1200_scan_start(priv, &scan);
445 	}
446 	mutex_unlock(&priv->conf_mutex);
447 
448 	skb_push(frame.skb, txpriv->offset);
449 	if (!ret)
450 		IEEE80211_SKB_CB(frame.skb)->flags |= IEEE80211_TX_STAT_ACK;
451 	BUG_ON(cw1200_queue_remove(queue, priv->pending_frame_id));
452 
453 	if (ret) {
454 		priv->scan.direct_probe = 0;
455 		up(&priv->scan.lock);
456 		wsm_unlock_tx(priv);
457 	}
458 
459 	return;
460 }
461