xref: /linux/drivers/net/wireless/st/cw1200/scan.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
1 /*
2  * Scan implementation for ST-Ericsson CW1200 mac80211 drivers
3  *
4  * Copyright (c) 2010, ST-Ericsson
5  * Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #include <linux/sched.h>
13 #include "cw1200.h"
14 #include "scan.h"
15 #include "sta.h"
16 #include "pm.h"
17 
18 static void cw1200_scan_restart_delayed(struct cw1200_common *priv);
19 
20 static int cw1200_scan_start(struct cw1200_common *priv, struct wsm_scan *scan)
21 {
22 	int ret, i;
23 	int tmo = 2000;
24 
25 	switch (priv->join_status) {
26 	case CW1200_JOIN_STATUS_PRE_STA:
27 	case CW1200_JOIN_STATUS_JOINING:
28 		return -EBUSY;
29 	default:
30 		break;
31 	}
32 
33 	wiphy_dbg(priv->hw->wiphy, "[SCAN] hw req, type %d, %d channels, flags: 0x%x.\n",
34 		  scan->type, scan->num_channels, scan->flags);
35 
36 	for (i = 0; i < scan->num_channels; ++i)
37 		tmo += scan->ch[i].max_chan_time + 10;
38 
39 	cancel_delayed_work_sync(&priv->clear_recent_scan_work);
40 	atomic_set(&priv->scan.in_progress, 1);
41 	atomic_set(&priv->recent_scan, 1);
42 	cw1200_pm_stay_awake(&priv->pm_state, msecs_to_jiffies(tmo));
43 	queue_delayed_work(priv->workqueue, &priv->scan.timeout,
44 			   msecs_to_jiffies(tmo));
45 	ret = wsm_scan(priv, scan);
46 	if (ret) {
47 		atomic_set(&priv->scan.in_progress, 0);
48 		cancel_delayed_work_sync(&priv->scan.timeout);
49 		cw1200_scan_restart_delayed(priv);
50 	}
51 	return ret;
52 }
53 
54 int cw1200_hw_scan(struct ieee80211_hw *hw,
55 		   struct ieee80211_vif *vif,
56 		   struct ieee80211_scan_request *hw_req)
57 {
58 	struct cw1200_common *priv = hw->priv;
59 	struct cfg80211_scan_request *req = &hw_req->req;
60 	struct wsm_template_frame frame = {
61 		.frame_type = WSM_FRAME_TYPE_PROBE_REQUEST,
62 	};
63 	int i, ret;
64 
65 	if (!priv->vif)
66 		return -EINVAL;
67 
68 	/* Scan when P2P_GO corrupt firmware MiniAP mode */
69 	if (priv->join_status == CW1200_JOIN_STATUS_AP)
70 		return -EOPNOTSUPP;
71 
72 	if (req->n_ssids == 1 && !req->ssids[0].ssid_len)
73 		req->n_ssids = 0;
74 
75 	wiphy_dbg(hw->wiphy, "[SCAN] Scan request for %d SSIDs.\n",
76 		  req->n_ssids);
77 
78 	if (req->n_ssids > WSM_SCAN_MAX_NUM_OF_SSIDS)
79 		return -EINVAL;
80 
81 	frame.skb = ieee80211_probereq_get(hw, priv->vif->addr, NULL, 0,
82 		req->ie_len);
83 	if (!frame.skb)
84 		return -ENOMEM;
85 
86 	if (req->ie_len)
87 		memcpy(skb_put(frame.skb, req->ie_len), req->ie, req->ie_len);
88 
89 	/* will be unlocked in cw1200_scan_work() */
90 	down(&priv->scan.lock);
91 	mutex_lock(&priv->conf_mutex);
92 
93 	ret = wsm_set_template_frame(priv, &frame);
94 	if (!ret) {
95 		/* Host want to be the probe responder. */
96 		ret = wsm_set_probe_responder(priv, true);
97 	}
98 	if (ret) {
99 		mutex_unlock(&priv->conf_mutex);
100 		up(&priv->scan.lock);
101 		dev_kfree_skb(frame.skb);
102 		return ret;
103 	}
104 
105 	wsm_lock_tx(priv);
106 
107 	BUG_ON(priv->scan.req);
108 	priv->scan.req = req;
109 	priv->scan.n_ssids = 0;
110 	priv->scan.status = 0;
111 	priv->scan.begin = &req->channels[0];
112 	priv->scan.curr = priv->scan.begin;
113 	priv->scan.end = &req->channels[req->n_channels];
114 	priv->scan.output_power = priv->output_power;
115 
116 	for (i = 0; i < req->n_ssids; ++i) {
117 		struct wsm_ssid *dst = &priv->scan.ssids[priv->scan.n_ssids];
118 		memcpy(&dst->ssid[0], req->ssids[i].ssid, sizeof(dst->ssid));
119 		dst->length = req->ssids[i].ssid_len;
120 		++priv->scan.n_ssids;
121 	}
122 
123 	mutex_unlock(&priv->conf_mutex);
124 
125 	if (frame.skb)
126 		dev_kfree_skb(frame.skb);
127 	queue_work(priv->workqueue, &priv->scan.work);
128 	return 0;
129 }
130 
131 void cw1200_scan_work(struct work_struct *work)
132 {
133 	struct cw1200_common *priv = container_of(work, struct cw1200_common,
134 							scan.work);
135 	struct ieee80211_channel **it;
136 	struct wsm_scan scan = {
137 		.type = WSM_SCAN_TYPE_FOREGROUND,
138 		.flags = WSM_SCAN_FLAG_SPLIT_METHOD,
139 	};
140 	bool first_run = (priv->scan.begin == priv->scan.curr &&
141 			  priv->scan.begin != priv->scan.end);
142 	int i;
143 
144 	if (first_run) {
145 		/* Firmware gets crazy if scan request is sent
146 		 * when STA is joined but not yet associated.
147 		 * Force unjoin in this case.
148 		 */
149 		if (cancel_delayed_work_sync(&priv->join_timeout) > 0)
150 			cw1200_join_timeout(&priv->join_timeout.work);
151 	}
152 
153 	mutex_lock(&priv->conf_mutex);
154 
155 	if (first_run) {
156 		if (priv->join_status == CW1200_JOIN_STATUS_STA &&
157 		    !(priv->powersave_mode.mode & WSM_PSM_PS)) {
158 			struct wsm_set_pm pm = priv->powersave_mode;
159 			pm.mode = WSM_PSM_PS;
160 			cw1200_set_pm(priv, &pm);
161 		} else if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
162 			/* FW bug: driver has to restart p2p-dev mode
163 			 * after scan
164 			 */
165 			cw1200_disable_listening(priv);
166 		}
167 	}
168 
169 	if (!priv->scan.req || (priv->scan.curr == priv->scan.end)) {
170 		if (priv->scan.output_power != priv->output_power)
171 			wsm_set_output_power(priv, priv->output_power * 10);
172 		if (priv->join_status == CW1200_JOIN_STATUS_STA &&
173 		    !(priv->powersave_mode.mode & WSM_PSM_PS))
174 			cw1200_set_pm(priv, &priv->powersave_mode);
175 
176 		if (priv->scan.status < 0)
177 			wiphy_warn(priv->hw->wiphy,
178 				   "[SCAN] Scan failed (%d).\n",
179 				   priv->scan.status);
180 		else if (priv->scan.req)
181 			wiphy_dbg(priv->hw->wiphy,
182 				  "[SCAN] Scan completed.\n");
183 		else
184 			wiphy_dbg(priv->hw->wiphy,
185 				  "[SCAN] Scan canceled.\n");
186 
187 		priv->scan.req = NULL;
188 		cw1200_scan_restart_delayed(priv);
189 		wsm_unlock_tx(priv);
190 		mutex_unlock(&priv->conf_mutex);
191 		ieee80211_scan_completed(priv->hw, priv->scan.status ? 1 : 0);
192 		up(&priv->scan.lock);
193 		return;
194 	} else {
195 		struct ieee80211_channel *first = *priv->scan.curr;
196 		for (it = priv->scan.curr + 1, i = 1;
197 		     it != priv->scan.end && i < WSM_SCAN_MAX_NUM_OF_CHANNELS;
198 		     ++it, ++i) {
199 			if ((*it)->band != first->band)
200 				break;
201 			if (((*it)->flags ^ first->flags) &
202 					IEEE80211_CHAN_NO_IR)
203 				break;
204 			if (!(first->flags & IEEE80211_CHAN_NO_IR) &&
205 			    (*it)->max_power != first->max_power)
206 				break;
207 		}
208 		scan.band = first->band;
209 
210 		if (priv->scan.req->no_cck)
211 			scan.max_tx_rate = WSM_TRANSMIT_RATE_6;
212 		else
213 			scan.max_tx_rate = WSM_TRANSMIT_RATE_1;
214 		scan.num_probes =
215 			(first->flags & IEEE80211_CHAN_NO_IR) ? 0 : 2;
216 		scan.num_ssids = priv->scan.n_ssids;
217 		scan.ssids = &priv->scan.ssids[0];
218 		scan.num_channels = it - priv->scan.curr;
219 		/* TODO: Is it optimal? */
220 		scan.probe_delay = 100;
221 		/* It is not stated in WSM specification, however
222 		 * FW team says that driver may not use FG scan
223 		 * when joined.
224 		 */
225 		if (priv->join_status == CW1200_JOIN_STATUS_STA) {
226 			scan.type = WSM_SCAN_TYPE_BACKGROUND;
227 			scan.flags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
228 		}
229 		scan.ch = kzalloc(
230 			sizeof(struct wsm_scan_ch) * (it - priv->scan.curr),
231 			GFP_KERNEL);
232 		if (!scan.ch) {
233 			priv->scan.status = -ENOMEM;
234 			goto fail;
235 		}
236 		for (i = 0; i < scan.num_channels; ++i) {
237 			scan.ch[i].number = priv->scan.curr[i]->hw_value;
238 			if (priv->scan.curr[i]->flags & IEEE80211_CHAN_NO_IR) {
239 				scan.ch[i].min_chan_time = 50;
240 				scan.ch[i].max_chan_time = 100;
241 			} else {
242 				scan.ch[i].min_chan_time = 10;
243 				scan.ch[i].max_chan_time = 25;
244 			}
245 		}
246 		if (!(first->flags & IEEE80211_CHAN_NO_IR) &&
247 		    priv->scan.output_power != first->max_power) {
248 			priv->scan.output_power = first->max_power;
249 			wsm_set_output_power(priv,
250 					     priv->scan.output_power * 10);
251 		}
252 		priv->scan.status = cw1200_scan_start(priv, &scan);
253 		kfree(scan.ch);
254 		if (priv->scan.status)
255 			goto fail;
256 		priv->scan.curr = it;
257 	}
258 	mutex_unlock(&priv->conf_mutex);
259 	return;
260 
261 fail:
262 	priv->scan.curr = priv->scan.end;
263 	mutex_unlock(&priv->conf_mutex);
264 	queue_work(priv->workqueue, &priv->scan.work);
265 	return;
266 }
267 
268 static void cw1200_scan_restart_delayed(struct cw1200_common *priv)
269 {
270 	/* FW bug: driver has to restart p2p-dev mode after scan. */
271 	if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
272 		cw1200_enable_listening(priv);
273 		cw1200_update_filtering(priv);
274 	}
275 
276 	if (priv->delayed_unjoin) {
277 		priv->delayed_unjoin = false;
278 		if (queue_work(priv->workqueue, &priv->unjoin_work) <= 0)
279 			wsm_unlock_tx(priv);
280 	} else if (priv->delayed_link_loss) {
281 			wiphy_dbg(priv->hw->wiphy, "[CQM] Requeue BSS loss.\n");
282 			priv->delayed_link_loss = 0;
283 			cw1200_cqm_bssloss_sm(priv, 1, 0, 0);
284 	}
285 }
286 
287 static void cw1200_scan_complete(struct cw1200_common *priv)
288 {
289 	queue_delayed_work(priv->workqueue, &priv->clear_recent_scan_work, HZ);
290 	if (priv->scan.direct_probe) {
291 		wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe complete.\n");
292 		cw1200_scan_restart_delayed(priv);
293 		priv->scan.direct_probe = 0;
294 		up(&priv->scan.lock);
295 		wsm_unlock_tx(priv);
296 	} else {
297 		cw1200_scan_work(&priv->scan.work);
298 	}
299 }
300 
301 void cw1200_scan_failed_cb(struct cw1200_common *priv)
302 {
303 	if (priv->mode == NL80211_IFTYPE_UNSPECIFIED)
304 		/* STA is stopped. */
305 		return;
306 
307 	if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
308 		priv->scan.status = -EIO;
309 		queue_delayed_work(priv->workqueue, &priv->scan.timeout, 0);
310 	}
311 }
312 
313 
314 void cw1200_scan_complete_cb(struct cw1200_common *priv,
315 				struct wsm_scan_complete *arg)
316 {
317 	if (priv->mode == NL80211_IFTYPE_UNSPECIFIED)
318 		/* STA is stopped. */
319 		return;
320 
321 	if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
322 		priv->scan.status = 1;
323 		queue_delayed_work(priv->workqueue, &priv->scan.timeout, 0);
324 	}
325 }
326 
327 void cw1200_clear_recent_scan_work(struct work_struct *work)
328 {
329 	struct cw1200_common *priv =
330 		container_of(work, struct cw1200_common,
331 			     clear_recent_scan_work.work);
332 	atomic_xchg(&priv->recent_scan, 0);
333 }
334 
335 void cw1200_scan_timeout(struct work_struct *work)
336 {
337 	struct cw1200_common *priv =
338 		container_of(work, struct cw1200_common, scan.timeout.work);
339 	if (atomic_xchg(&priv->scan.in_progress, 0)) {
340 		if (priv->scan.status > 0) {
341 			priv->scan.status = 0;
342 		} else if (!priv->scan.status) {
343 			wiphy_warn(priv->hw->wiphy,
344 				   "Timeout waiting for scan complete notification.\n");
345 			priv->scan.status = -ETIMEDOUT;
346 			priv->scan.curr = priv->scan.end;
347 			wsm_stop_scan(priv);
348 		}
349 		cw1200_scan_complete(priv);
350 	}
351 }
352 
353 void cw1200_probe_work(struct work_struct *work)
354 {
355 	struct cw1200_common *priv =
356 		container_of(work, struct cw1200_common, scan.probe_work.work);
357 	u8 queue_id = cw1200_queue_get_queue_id(priv->pending_frame_id);
358 	struct cw1200_queue *queue = &priv->tx_queue[queue_id];
359 	const struct cw1200_txpriv *txpriv;
360 	struct wsm_tx *wsm;
361 	struct wsm_template_frame frame = {
362 		.frame_type = WSM_FRAME_TYPE_PROBE_REQUEST,
363 	};
364 	struct wsm_ssid ssids[1] = {{
365 		.length = 0,
366 	} };
367 	struct wsm_scan_ch ch[1] = {{
368 		.min_chan_time = 0,
369 		.max_chan_time = 10,
370 	} };
371 	struct wsm_scan scan = {
372 		.type = WSM_SCAN_TYPE_FOREGROUND,
373 		.num_probes = 1,
374 		.probe_delay = 0,
375 		.num_channels = 1,
376 		.ssids = ssids,
377 		.ch = ch,
378 	};
379 	u8 *ies;
380 	size_t ies_len;
381 	int ret;
382 
383 	wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe work.\n");
384 
385 	mutex_lock(&priv->conf_mutex);
386 	if (down_trylock(&priv->scan.lock)) {
387 		/* Scan is already in progress. Requeue self. */
388 		schedule();
389 		queue_delayed_work(priv->workqueue, &priv->scan.probe_work,
390 				   msecs_to_jiffies(100));
391 		mutex_unlock(&priv->conf_mutex);
392 		return;
393 	}
394 
395 	/* Make sure we still have a pending probe req */
396 	if (cw1200_queue_get_skb(queue,	priv->pending_frame_id,
397 				 &frame.skb, &txpriv)) {
398 		up(&priv->scan.lock);
399 		mutex_unlock(&priv->conf_mutex);
400 		wsm_unlock_tx(priv);
401 		return;
402 	}
403 	wsm = (struct wsm_tx *)frame.skb->data;
404 	scan.max_tx_rate = wsm->max_tx_rate;
405 	scan.band = (priv->channel->band == IEEE80211_BAND_5GHZ) ?
406 		WSM_PHY_BAND_5G : WSM_PHY_BAND_2_4G;
407 	if (priv->join_status == CW1200_JOIN_STATUS_STA ||
408 	    priv->join_status == CW1200_JOIN_STATUS_IBSS) {
409 		scan.type = WSM_SCAN_TYPE_BACKGROUND;
410 		scan.flags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
411 	}
412 	ch[0].number = priv->channel->hw_value;
413 
414 	skb_pull(frame.skb, txpriv->offset);
415 
416 	ies = &frame.skb->data[sizeof(struct ieee80211_hdr_3addr)];
417 	ies_len = frame.skb->len - sizeof(struct ieee80211_hdr_3addr);
418 
419 	if (ies_len) {
420 		u8 *ssidie =
421 			(u8 *)cfg80211_find_ie(WLAN_EID_SSID, ies, ies_len);
422 		if (ssidie && ssidie[1] && ssidie[1] <= sizeof(ssids[0].ssid)) {
423 			u8 *nextie = &ssidie[2 + ssidie[1]];
424 			/* Remove SSID from the IE list. It has to be provided
425 			 * as a separate argument in cw1200_scan_start call
426 			 */
427 
428 			/* Store SSID localy */
429 			ssids[0].length = ssidie[1];
430 			memcpy(ssids[0].ssid, &ssidie[2], ssids[0].length);
431 			scan.num_ssids = 1;
432 
433 			/* Remove SSID from IE list */
434 			ssidie[1] = 0;
435 			memmove(&ssidie[2], nextie, &ies[ies_len] - nextie);
436 			skb_trim(frame.skb, frame.skb->len - ssids[0].length);
437 		}
438 	}
439 
440 	/* FW bug: driver has to restart p2p-dev mode after scan */
441 	if (priv->join_status == CW1200_JOIN_STATUS_MONITOR)
442 		cw1200_disable_listening(priv);
443 	ret = wsm_set_template_frame(priv, &frame);
444 	priv->scan.direct_probe = 1;
445 	if (!ret) {
446 		wsm_flush_tx(priv);
447 		ret = cw1200_scan_start(priv, &scan);
448 	}
449 	mutex_unlock(&priv->conf_mutex);
450 
451 	skb_push(frame.skb, txpriv->offset);
452 	if (!ret)
453 		IEEE80211_SKB_CB(frame.skb)->flags |= IEEE80211_TX_STAT_ACK;
454 	BUG_ON(cw1200_queue_remove(queue, priv->pending_frame_id));
455 
456 	if (ret) {
457 		priv->scan.direct_probe = 0;
458 		up(&priv->scan.lock);
459 		wsm_unlock_tx(priv);
460 	}
461 
462 	return;
463 }
464