1 /******************************************************************************
2  *
3  * GPL LICENSE SUMMARY
4  *
5  * Copyright(c) 2008 - 2014 Intel Corporation. All rights reserved.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of version 2 of the GNU General Public License as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
19  * USA
20  *
21  * The full GNU General Public License is included in this distribution
22  * in the file called COPYING.
23  *
24  * Contact Information:
25  *  Intel Linux Wireless <linuxwifi@intel.com>
26  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
27  *****************************************************************************/
28 #include <linux/slab.h>
29 #include <linux/types.h>
30 #include <linux/etherdevice.h>
31 #include <net/mac80211.h>
32 
33 #include "dev.h"
34 #include "agn.h"
35 
36 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
37  * sending probe req.  This should be set long enough to hear probe responses
38  * from more than one AP.  */
39 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
40 #define IWL_ACTIVE_DWELL_TIME_52    (20)
41 
42 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
43 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
44 
45 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
46  * Must be set longer than active dwell time.
47  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
48 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
49 #define IWL_PASSIVE_DWELL_TIME_52   (10)
50 #define IWL_PASSIVE_DWELL_BASE      (100)
51 #define IWL_CHANNEL_TUNE_TIME       5
52 #define MAX_SCAN_CHANNEL	    50
53 
54 /* For reset radio, need minimal dwell time only */
55 #define IWL_RADIO_RESET_DWELL_TIME	5
56 
57 static int iwl_send_scan_abort(struct iwl_priv *priv)
58 {
59 	int ret;
60 	struct iwl_host_cmd cmd = {
61 		.id = REPLY_SCAN_ABORT_CMD,
62 		.flags = CMD_WANT_SKB,
63 	};
64 	__le32 *status;
65 
66 	/* Exit instantly with error when device is not ready
67 	 * to receive scan abort command or it does not perform
68 	 * hardware scan currently */
69 	if (!test_bit(STATUS_READY, &priv->status) ||
70 	    !test_bit(STATUS_SCAN_HW, &priv->status) ||
71 	    test_bit(STATUS_FW_ERROR, &priv->status))
72 		return -EIO;
73 
74 	ret = iwl_dvm_send_cmd(priv, &cmd);
75 	if (ret)
76 		return ret;
77 
78 	status = (void *)cmd.resp_pkt->data;
79 	if (*status != CAN_ABORT_STATUS) {
80 		/* The scan abort will return 1 for success or
81 		 * 2 for "failure".  A failure condition can be
82 		 * due to simply not being in an active scan which
83 		 * can occur if we send the scan abort before we
84 		 * the microcode has notified us that a scan is
85 		 * completed. */
86 		IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n",
87 			       le32_to_cpu(*status));
88 		ret = -EIO;
89 	}
90 
91 	iwl_free_resp(&cmd);
92 	return ret;
93 }
94 
95 static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
96 {
97 	struct cfg80211_scan_info info = {
98 		.aborted = aborted,
99 	};
100 
101 	/* check if scan was requested from mac80211 */
102 	if (priv->scan_request) {
103 		IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
104 		ieee80211_scan_completed(priv->hw, &info);
105 	}
106 
107 	priv->scan_type = IWL_SCAN_NORMAL;
108 	priv->scan_vif = NULL;
109 	priv->scan_request = NULL;
110 }
111 
112 static void iwl_process_scan_complete(struct iwl_priv *priv)
113 {
114 	bool aborted;
115 
116 	lockdep_assert_held(&priv->mutex);
117 
118 	if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->status))
119 		return;
120 
121 	IWL_DEBUG_SCAN(priv, "Completed scan.\n");
122 
123 	cancel_delayed_work(&priv->scan_check);
124 
125 	aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
126 	if (aborted)
127 		IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
128 
129 	if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
130 		IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
131 		goto out_settings;
132 	}
133 
134 	if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
135 		int err;
136 
137 		/* Check if mac80211 requested scan during our internal scan */
138 		if (priv->scan_request == NULL)
139 			goto out_complete;
140 
141 		/* If so request a new scan */
142 		err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
143 					priv->scan_request->channels[0]->band);
144 		if (err) {
145 			IWL_DEBUG_SCAN(priv,
146 				"failed to initiate pending scan: %d\n", err);
147 			aborted = true;
148 			goto out_complete;
149 		}
150 
151 		return;
152 	}
153 
154 out_complete:
155 	iwl_complete_scan(priv, aborted);
156 
157 out_settings:
158 	/* Can we still talk to firmware ? */
159 	if (!iwl_is_ready_rf(priv))
160 		return;
161 
162 	iwlagn_post_scan(priv);
163 }
164 
165 void iwl_force_scan_end(struct iwl_priv *priv)
166 {
167 	lockdep_assert_held(&priv->mutex);
168 
169 	if (!test_bit(STATUS_SCANNING, &priv->status)) {
170 		IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
171 		return;
172 	}
173 
174 	IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
175 	clear_bit(STATUS_SCANNING, &priv->status);
176 	clear_bit(STATUS_SCAN_HW, &priv->status);
177 	clear_bit(STATUS_SCAN_ABORTING, &priv->status);
178 	clear_bit(STATUS_SCAN_COMPLETE, &priv->status);
179 	iwl_complete_scan(priv, true);
180 }
181 
182 static void iwl_do_scan_abort(struct iwl_priv *priv)
183 {
184 	int ret;
185 
186 	lockdep_assert_held(&priv->mutex);
187 
188 	if (!test_bit(STATUS_SCANNING, &priv->status)) {
189 		IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
190 		return;
191 	}
192 
193 	if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
194 		IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
195 		return;
196 	}
197 
198 	ret = iwl_send_scan_abort(priv);
199 	if (ret) {
200 		IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
201 		iwl_force_scan_end(priv);
202 	} else
203 		IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
204 }
205 
206 /**
207  * iwl_scan_cancel - Cancel any currently executing HW scan
208  */
209 int iwl_scan_cancel(struct iwl_priv *priv)
210 {
211 	IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
212 	queue_work(priv->workqueue, &priv->abort_scan);
213 	return 0;
214 }
215 
216 /**
217  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
218  * @ms: amount of time to wait (in milliseconds) for scan to abort
219  *
220  */
221 void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
222 {
223 	unsigned long timeout = jiffies + msecs_to_jiffies(ms);
224 
225 	lockdep_assert_held(&priv->mutex);
226 
227 	IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
228 
229 	iwl_do_scan_abort(priv);
230 
231 	while (time_before_eq(jiffies, timeout)) {
232 		if (!test_bit(STATUS_SCAN_HW, &priv->status))
233 			goto finished;
234 		msleep(20);
235 	}
236 
237 	return;
238 
239  finished:
240 	/*
241 	 * Now STATUS_SCAN_HW is clear. This means that the
242 	 * device finished, but the background work is going
243 	 * to execute at best as soon as we release the mutex.
244 	 * Since we need to be able to issue a new scan right
245 	 * after this function returns, run the complete here.
246 	 * The STATUS_SCAN_COMPLETE bit will then be cleared
247 	 * and prevent the background work from "completing"
248 	 * a possible new scan.
249 	 */
250 	iwl_process_scan_complete(priv);
251 }
252 
253 /* Service response to REPLY_SCAN_CMD (0x80) */
254 static void iwl_rx_reply_scan(struct iwl_priv *priv,
255 			      struct iwl_rx_cmd_buffer *rxb)
256 {
257 #ifdef CONFIG_IWLWIFI_DEBUG
258 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
259 	struct iwl_scanreq_notification *notif = (void *)pkt->data;
260 
261 	IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
262 #endif
263 }
264 
265 /* Service SCAN_START_NOTIFICATION (0x82) */
266 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
267 				    struct iwl_rx_cmd_buffer *rxb)
268 {
269 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
270 	struct iwl_scanstart_notification *notif = (void *)pkt->data;
271 
272 	priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
273 	IWL_DEBUG_SCAN(priv, "Scan start: "
274 		       "%d [802.11%s] "
275 		       "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
276 		       notif->channel,
277 		       notif->band ? "bg" : "a",
278 		       le32_to_cpu(notif->tsf_high),
279 		       le32_to_cpu(notif->tsf_low),
280 		       notif->status, notif->beacon_timer);
281 }
282 
283 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
284 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
285 				      struct iwl_rx_cmd_buffer *rxb)
286 {
287 #ifdef CONFIG_IWLWIFI_DEBUG
288 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
289 	struct iwl_scanresults_notification *notif = (void *)pkt->data;
290 
291 	IWL_DEBUG_SCAN(priv, "Scan ch.res: "
292 		       "%d [802.11%s] "
293 		       "probe status: %u:%u "
294 		       "(TSF: 0x%08X:%08X) - %d "
295 		       "elapsed=%lu usec\n",
296 		       notif->channel,
297 		       notif->band ? "bg" : "a",
298 		       notif->probe_status, notif->num_probe_not_sent,
299 		       le32_to_cpu(notif->tsf_high),
300 		       le32_to_cpu(notif->tsf_low),
301 		       le32_to_cpu(notif->statistics[0]),
302 		       le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
303 #endif
304 }
305 
306 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
307 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
308 				       struct iwl_rx_cmd_buffer *rxb)
309 {
310 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
311 	struct iwl_scancomplete_notification *scan_notif = (void *)pkt->data;
312 
313 	IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
314 		       scan_notif->scanned_channels,
315 		       scan_notif->tsf_low,
316 		       scan_notif->tsf_high, scan_notif->status);
317 
318 	IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
319 		       (priv->scan_band == NL80211_BAND_2GHZ) ? "2.4" : "5.2",
320 		       jiffies_to_msecs(jiffies - priv->scan_start));
321 
322 	/*
323 	 * When aborting, we run the scan completed background work inline
324 	 * and the background work must then do nothing. The SCAN_COMPLETE
325 	 * bit helps implement that logic and thus needs to be set before
326 	 * queueing the work. Also, since the scan abort waits for SCAN_HW
327 	 * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
328 	 * to avoid a race there.
329 	 */
330 	set_bit(STATUS_SCAN_COMPLETE, &priv->status);
331 	clear_bit(STATUS_SCAN_HW, &priv->status);
332 	queue_work(priv->workqueue, &priv->scan_completed);
333 
334 	if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
335 	    iwl_advanced_bt_coexist(priv) &&
336 	    priv->bt_status != scan_notif->bt_status) {
337 		if (scan_notif->bt_status) {
338 			/* BT on */
339 			if (!priv->bt_ch_announce)
340 				priv->bt_traffic_load =
341 					IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
342 			/*
343 			 * otherwise, no traffic load information provided
344 			 * no changes made
345 			 */
346 		} else {
347 			/* BT off */
348 			priv->bt_traffic_load =
349 				IWL_BT_COEX_TRAFFIC_LOAD_NONE;
350 		}
351 		priv->bt_status = scan_notif->bt_status;
352 		queue_work(priv->workqueue,
353 			   &priv->bt_traffic_change_work);
354 	}
355 }
356 
357 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
358 {
359 	/* scan handlers */
360 	priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
361 	priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
362 	priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
363 					iwl_rx_scan_results_notif;
364 	priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
365 					iwl_rx_scan_complete_notif;
366 }
367 
368 static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
369 				     enum nl80211_band band, u8 n_probes)
370 {
371 	if (band == NL80211_BAND_5GHZ)
372 		return IWL_ACTIVE_DWELL_TIME_52 +
373 			IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
374 	else
375 		return IWL_ACTIVE_DWELL_TIME_24 +
376 			IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
377 }
378 
379 static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
380 {
381 	struct iwl_rxon_context *ctx;
382 	int limits[NUM_IWL_RXON_CTX] = {};
383 	int n_active = 0;
384 	u16 limit;
385 
386 	BUILD_BUG_ON(NUM_IWL_RXON_CTX != 2);
387 
388 	/*
389 	 * If we're associated, we clamp the dwell time 98%
390 	 * of the beacon interval (minus 2 * channel tune time)
391 	 * If both contexts are active, we have to restrict to
392 	 * 1/2 of the minimum of them, because they might be in
393 	 * lock-step with the time inbetween only half of what
394 	 * time we'd have in each of them.
395 	 */
396 	for_each_context(priv, ctx) {
397 		switch (ctx->staging.dev_type) {
398 		case RXON_DEV_TYPE_P2P:
399 			/* no timing constraints */
400 			continue;
401 		case RXON_DEV_TYPE_ESS:
402 		default:
403 			/* timing constraints if associated */
404 			if (!iwl_is_associated_ctx(ctx))
405 				continue;
406 			break;
407 		case RXON_DEV_TYPE_CP:
408 		case RXON_DEV_TYPE_2STA:
409 			/*
410 			 * These seem to always have timers for TBTT
411 			 * active in uCode even when not associated yet.
412 			 */
413 			break;
414 		}
415 
416 		limits[n_active++] = ctx->beacon_int ?: IWL_PASSIVE_DWELL_BASE;
417 	}
418 
419 	switch (n_active) {
420 	case 0:
421 		return dwell_time;
422 	case 2:
423 		limit = (limits[1] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
424 		limit /= 2;
425 		dwell_time = min(limit, dwell_time);
426 		/* fall through to limit further */
427 	case 1:
428 		limit = (limits[0] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
429 		limit /= n_active;
430 		return min(limit, dwell_time);
431 	default:
432 		WARN_ON_ONCE(1);
433 		return dwell_time;
434 	}
435 }
436 
437 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
438 				      enum nl80211_band band)
439 {
440 	u16 passive = (band == NL80211_BAND_2GHZ) ?
441 	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
442 	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
443 
444 	return iwl_limit_dwell(priv, passive);
445 }
446 
447 /* Return valid, unused, channel for a passive scan to reset the RF */
448 static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
449 					enum nl80211_band band)
450 {
451 	struct ieee80211_supported_band *sband = priv->hw->wiphy->bands[band];
452 	struct iwl_rxon_context *ctx;
453 	int i;
454 
455 	for (i = 0; i < sband->n_channels; i++) {
456 		bool busy = false;
457 
458 		for_each_context(priv, ctx) {
459 			busy = sband->channels[i].hw_value ==
460 				le16_to_cpu(ctx->staging.channel);
461 			if (busy)
462 				break;
463 		}
464 
465 		if (busy)
466 			continue;
467 
468 		if (!(sband->channels[i].flags & IEEE80211_CHAN_DISABLED))
469 			return sband->channels[i].hw_value;
470 	}
471 
472 	return 0;
473 }
474 
475 static int iwl_get_channel_for_reset_scan(struct iwl_priv *priv,
476 					  struct ieee80211_vif *vif,
477 					  enum nl80211_band band,
478 					  struct iwl_scan_channel *scan_ch)
479 {
480 	const struct ieee80211_supported_band *sband;
481 	u16 channel;
482 
483 	sband = iwl_get_hw_mode(priv, band);
484 	if (!sband) {
485 		IWL_ERR(priv, "invalid band\n");
486 		return 0;
487 	}
488 
489 	channel = iwl_get_single_channel_number(priv, band);
490 	if (channel) {
491 		scan_ch->channel = cpu_to_le16(channel);
492 		scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
493 		scan_ch->active_dwell =
494 			cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
495 		scan_ch->passive_dwell =
496 			cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
497 		/* Set txpower levels to defaults */
498 		scan_ch->dsp_atten = 110;
499 		if (band == NL80211_BAND_5GHZ)
500 			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
501 		else
502 			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
503 		return 1;
504 	}
505 
506 	IWL_ERR(priv, "no valid channel found\n");
507 	return 0;
508 }
509 
510 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
511 				     struct ieee80211_vif *vif,
512 				     enum nl80211_band band,
513 				     u8 is_active, u8 n_probes,
514 				     struct iwl_scan_channel *scan_ch)
515 {
516 	struct ieee80211_channel *chan;
517 	const struct ieee80211_supported_band *sband;
518 	u16 passive_dwell = 0;
519 	u16 active_dwell = 0;
520 	int added, i;
521 	u16 channel;
522 
523 	sband = iwl_get_hw_mode(priv, band);
524 	if (!sband)
525 		return 0;
526 
527 	active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
528 	passive_dwell = iwl_get_passive_dwell_time(priv, band);
529 
530 	if (passive_dwell <= active_dwell)
531 		passive_dwell = active_dwell + 1;
532 
533 	for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
534 		chan = priv->scan_request->channels[i];
535 
536 		if (chan->band != band)
537 			continue;
538 
539 		channel = chan->hw_value;
540 		scan_ch->channel = cpu_to_le16(channel);
541 
542 		if (!is_active || (chan->flags & IEEE80211_CHAN_NO_IR))
543 			scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
544 		else
545 			scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
546 
547 		if (n_probes)
548 			scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
549 
550 		scan_ch->active_dwell = cpu_to_le16(active_dwell);
551 		scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
552 
553 		/* Set txpower levels to defaults */
554 		scan_ch->dsp_atten = 110;
555 
556 		/* NOTE: if we were doing 6Mb OFDM for scans we'd use
557 		 * power level:
558 		 * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
559 		 */
560 		if (band == NL80211_BAND_5GHZ)
561 			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
562 		else
563 			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
564 
565 		IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
566 			       channel, le32_to_cpu(scan_ch->type),
567 			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
568 				"ACTIVE" : "PASSIVE",
569 			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
570 			       active_dwell : passive_dwell);
571 
572 		scan_ch++;
573 		added++;
574 	}
575 
576 	IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
577 	return added;
578 }
579 
580 /**
581  * iwl_fill_probe_req - fill in all required fields and IE for probe request
582  */
583 
584 static u16 iwl_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
585 			      const u8 *ies, int ie_len, const u8 *ssid,
586 			      u8 ssid_len, int left)
587 {
588 	int len = 0;
589 	u8 *pos = NULL;
590 
591 	/* Make sure there is enough space for the probe request,
592 	 * two mandatory IEs and the data */
593 	left -= 24;
594 	if (left < 0)
595 		return 0;
596 
597 	frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
598 	eth_broadcast_addr(frame->da);
599 	memcpy(frame->sa, ta, ETH_ALEN);
600 	eth_broadcast_addr(frame->bssid);
601 	frame->seq_ctrl = 0;
602 
603 	len += 24;
604 
605 	/* ...next IE... */
606 	pos = &frame->u.probe_req.variable[0];
607 
608 	/* fill in our SSID IE */
609 	left -= ssid_len + 2;
610 	if (left < 0)
611 		return 0;
612 	*pos++ = WLAN_EID_SSID;
613 	*pos++ = ssid_len;
614 	if (ssid && ssid_len) {
615 		memcpy(pos, ssid, ssid_len);
616 		pos += ssid_len;
617 	}
618 
619 	len += ssid_len + 2;
620 
621 	if (WARN_ON(left < ie_len))
622 		return len;
623 
624 	if (ies && ie_len) {
625 		memcpy(pos, ies, ie_len);
626 		len += ie_len;
627 	}
628 
629 	return (u16)len;
630 }
631 
632 static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
633 {
634 	struct iwl_host_cmd cmd = {
635 		.id = REPLY_SCAN_CMD,
636 		.len = { sizeof(struct iwl_scan_cmd), },
637 	};
638 	struct iwl_scan_cmd *scan;
639 	struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
640 	u32 rate_flags = 0;
641 	u16 cmd_len = 0;
642 	u16 rx_chain = 0;
643 	enum nl80211_band band;
644 	u8 n_probes = 0;
645 	u8 rx_ant = priv->nvm_data->valid_rx_ant;
646 	u8 rate;
647 	bool is_active = false;
648 	int  chan_mod;
649 	u8 active_chains;
650 	u8 scan_tx_antennas = priv->nvm_data->valid_tx_ant;
651 	int ret;
652 	int scan_cmd_size = sizeof(struct iwl_scan_cmd) +
653 			    MAX_SCAN_CHANNEL * sizeof(struct iwl_scan_channel) +
654 			    priv->fw->ucode_capa.max_probe_length;
655 	const u8 *ssid = NULL;
656 	u8 ssid_len = 0;
657 
658 	if (WARN_ON(priv->scan_type == IWL_SCAN_NORMAL &&
659 		    (!priv->scan_request ||
660 		     priv->scan_request->n_channels > MAX_SCAN_CHANNEL)))
661 		return -EINVAL;
662 
663 	lockdep_assert_held(&priv->mutex);
664 
665 	if (vif)
666 		ctx = iwl_rxon_ctx_from_vif(vif);
667 
668 	if (!priv->scan_cmd) {
669 		priv->scan_cmd = kmalloc(scan_cmd_size, GFP_KERNEL);
670 		if (!priv->scan_cmd) {
671 			IWL_DEBUG_SCAN(priv,
672 				       "fail to allocate memory for scan\n");
673 			return -ENOMEM;
674 		}
675 	}
676 	scan = priv->scan_cmd;
677 	memset(scan, 0, scan_cmd_size);
678 
679 	scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
680 	scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
681 
682 	if (iwl_is_any_associated(priv)) {
683 		u16 interval = 0;
684 		u32 extra;
685 		u32 suspend_time = 100;
686 		u32 scan_suspend_time = 100;
687 
688 		IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
689 		switch (priv->scan_type) {
690 		case IWL_SCAN_RADIO_RESET:
691 			interval = 0;
692 			break;
693 		case IWL_SCAN_NORMAL:
694 			interval = vif->bss_conf.beacon_int;
695 			break;
696 		}
697 
698 		scan->suspend_time = 0;
699 		scan->max_out_time = cpu_to_le32(200 * 1024);
700 		if (!interval)
701 			interval = suspend_time;
702 
703 		extra = (suspend_time / interval) << 22;
704 		scan_suspend_time = (extra |
705 		    ((suspend_time % interval) * 1024));
706 		scan->suspend_time = cpu_to_le32(scan_suspend_time);
707 		IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
708 			       scan_suspend_time, interval);
709 	}
710 
711 	switch (priv->scan_type) {
712 	case IWL_SCAN_RADIO_RESET:
713 		IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
714 		/*
715 		 * Override quiet time as firmware checks that active
716 		 * dwell is >= quiet; since we use passive scan it'll
717 		 * not actually be used.
718 		 */
719 		scan->quiet_time = cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
720 		break;
721 	case IWL_SCAN_NORMAL:
722 		if (priv->scan_request->n_ssids) {
723 			int i, p = 0;
724 			IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
725 			/*
726 			 * The highest priority SSID is inserted to the
727 			 * probe request template.
728 			 */
729 			ssid_len = priv->scan_request->ssids[0].ssid_len;
730 			ssid = priv->scan_request->ssids[0].ssid;
731 
732 			/*
733 			 * Invert the order of ssids, the firmware will invert
734 			 * it back.
735 			 */
736 			for (i = priv->scan_request->n_ssids - 1; i >= 1; i--) {
737 				scan->direct_scan[p].id = WLAN_EID_SSID;
738 				scan->direct_scan[p].len =
739 					priv->scan_request->ssids[i].ssid_len;
740 				memcpy(scan->direct_scan[p].ssid,
741 				       priv->scan_request->ssids[i].ssid,
742 				       priv->scan_request->ssids[i].ssid_len);
743 				n_probes++;
744 				p++;
745 			}
746 			is_active = true;
747 		} else
748 			IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
749 		break;
750 	}
751 
752 	scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
753 	scan->tx_cmd.sta_id = ctx->bcast_sta_id;
754 	scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
755 
756 	switch (priv->scan_band) {
757 	case NL80211_BAND_2GHZ:
758 		scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
759 		chan_mod = le32_to_cpu(
760 			priv->contexts[IWL_RXON_CTX_BSS].active.flags &
761 						RXON_FLG_CHANNEL_MODE_MSK)
762 				       >> RXON_FLG_CHANNEL_MODE_POS;
763 		if ((priv->scan_request && priv->scan_request->no_cck) ||
764 		    chan_mod == CHANNEL_MODE_PURE_40) {
765 			rate = IWL_RATE_6M_PLCP;
766 		} else {
767 			rate = IWL_RATE_1M_PLCP;
768 			rate_flags = RATE_MCS_CCK_MSK;
769 		}
770 		/*
771 		 * Internal scans are passive, so we can indiscriminately set
772 		 * the BT ignore flag on 2.4 GHz since it applies to TX only.
773 		 */
774 		if (priv->lib->bt_params &&
775 		    priv->lib->bt_params->advanced_bt_coexist)
776 			scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
777 		break;
778 	case NL80211_BAND_5GHZ:
779 		rate = IWL_RATE_6M_PLCP;
780 		break;
781 	default:
782 		IWL_WARN(priv, "Invalid scan band\n");
783 		return -EIO;
784 	}
785 
786 	/*
787 	 * If active scanning is requested but a certain channel is
788 	 * marked passive, we can do active scanning if we detect
789 	 * transmissions.
790 	 *
791 	 * There is an issue with some firmware versions that triggers
792 	 * a sysassert on a "good CRC threshold" of zero (== disabled),
793 	 * on a radar channel even though this means that we should NOT
794 	 * send probes.
795 	 *
796 	 * The "good CRC threshold" is the number of frames that we
797 	 * need to receive during our dwell time on a channel before
798 	 * sending out probes -- setting this to a huge value will
799 	 * mean we never reach it, but at the same time work around
800 	 * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
801 	 * here instead of IWL_GOOD_CRC_TH_DISABLED.
802 	 *
803 	 * This was fixed in later versions along with some other
804 	 * scan changes, and the threshold behaves as a flag in those
805 	 * versions.
806 	 */
807 	if (priv->new_scan_threshold_behaviour)
808 		scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
809 						IWL_GOOD_CRC_TH_DISABLED;
810 	else
811 		scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
812 						IWL_GOOD_CRC_TH_NEVER;
813 
814 	band = priv->scan_band;
815 
816 	if (band == NL80211_BAND_2GHZ &&
817 	    priv->lib->bt_params &&
818 	    priv->lib->bt_params->advanced_bt_coexist) {
819 		/* transmit 2.4 GHz probes only on first antenna */
820 		scan_tx_antennas = first_antenna(scan_tx_antennas);
821 	}
822 
823 	priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
824 						    priv->scan_tx_ant[band],
825 						    scan_tx_antennas);
826 	rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
827 	scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
828 
829 	/*
830 	 * In power save mode while associated use one chain,
831 	 * otherwise use all chains
832 	 */
833 	if (test_bit(STATUS_POWER_PMI, &priv->status) &&
834 	    !(priv->hw->conf.flags & IEEE80211_CONF_IDLE)) {
835 		/* rx_ant has been set to all valid chains previously */
836 		active_chains = rx_ant &
837 				((u8)(priv->chain_noise_data.active_chains));
838 		if (!active_chains)
839 			active_chains = rx_ant;
840 
841 		IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
842 				priv->chain_noise_data.active_chains);
843 
844 		rx_ant = first_antenna(active_chains);
845 	}
846 	if (priv->lib->bt_params &&
847 	    priv->lib->bt_params->advanced_bt_coexist &&
848 	    priv->bt_full_concurrent) {
849 		/* operated as 1x1 in full concurrency mode */
850 		rx_ant = first_antenna(rx_ant);
851 	}
852 
853 	/* MIMO is not used here, but value is required */
854 	rx_chain |=
855 		priv->nvm_data->valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
856 	rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
857 	rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
858 	rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
859 	scan->rx_chain = cpu_to_le16(rx_chain);
860 	switch (priv->scan_type) {
861 	case IWL_SCAN_NORMAL:
862 		cmd_len = iwl_fill_probe_req(
863 					(struct ieee80211_mgmt *)scan->data,
864 					vif->addr,
865 					priv->scan_request->ie,
866 					priv->scan_request->ie_len,
867 					ssid, ssid_len,
868 					scan_cmd_size - sizeof(*scan));
869 		break;
870 	case IWL_SCAN_RADIO_RESET:
871 		/* use bcast addr, will not be transmitted but must be valid */
872 		cmd_len = iwl_fill_probe_req(
873 					(struct ieee80211_mgmt *)scan->data,
874 					iwl_bcast_addr, NULL, 0,
875 					NULL, 0,
876 					scan_cmd_size - sizeof(*scan));
877 		break;
878 	default:
879 		BUG();
880 	}
881 	scan->tx_cmd.len = cpu_to_le16(cmd_len);
882 
883 	scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
884 			       RXON_FILTER_BCON_AWARE_MSK);
885 
886 	switch (priv->scan_type) {
887 	case IWL_SCAN_RADIO_RESET:
888 		scan->channel_count =
889 			iwl_get_channel_for_reset_scan(priv, vif, band,
890 				(void *)&scan->data[cmd_len]);
891 		break;
892 	case IWL_SCAN_NORMAL:
893 		scan->channel_count =
894 			iwl_get_channels_for_scan(priv, vif, band,
895 				is_active, n_probes,
896 				(void *)&scan->data[cmd_len]);
897 		break;
898 	}
899 
900 	if (scan->channel_count == 0) {
901 		IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
902 		return -EIO;
903 	}
904 
905 	cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
906 	    scan->channel_count * sizeof(struct iwl_scan_channel);
907 	cmd.data[0] = scan;
908 	cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
909 	scan->len = cpu_to_le16(cmd.len[0]);
910 
911 	/* set scan bit here for PAN params */
912 	set_bit(STATUS_SCAN_HW, &priv->status);
913 
914 	ret = iwlagn_set_pan_params(priv);
915 	if (ret) {
916 		clear_bit(STATUS_SCAN_HW, &priv->status);
917 		return ret;
918 	}
919 
920 	ret = iwl_dvm_send_cmd(priv, &cmd);
921 	if (ret) {
922 		clear_bit(STATUS_SCAN_HW, &priv->status);
923 		iwlagn_set_pan_params(priv);
924 	}
925 
926 	return ret;
927 }
928 
929 void iwl_init_scan_params(struct iwl_priv *priv)
930 {
931 	u8 ant_idx = fls(priv->nvm_data->valid_tx_ant) - 1;
932 	if (!priv->scan_tx_ant[NL80211_BAND_5GHZ])
933 		priv->scan_tx_ant[NL80211_BAND_5GHZ] = ant_idx;
934 	if (!priv->scan_tx_ant[NL80211_BAND_2GHZ])
935 		priv->scan_tx_ant[NL80211_BAND_2GHZ] = ant_idx;
936 }
937 
938 int __must_check iwl_scan_initiate(struct iwl_priv *priv,
939 				   struct ieee80211_vif *vif,
940 				   enum iwl_scan_type scan_type,
941 				   enum nl80211_band band)
942 {
943 	int ret;
944 
945 	lockdep_assert_held(&priv->mutex);
946 
947 	cancel_delayed_work(&priv->scan_check);
948 
949 	if (!iwl_is_ready_rf(priv)) {
950 		IWL_WARN(priv, "Request scan called when driver not ready.\n");
951 		return -EIO;
952 	}
953 
954 	if (test_bit(STATUS_SCAN_HW, &priv->status)) {
955 		IWL_DEBUG_SCAN(priv,
956 			"Multiple concurrent scan requests in parallel.\n");
957 		return -EBUSY;
958 	}
959 
960 	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
961 		IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
962 		return -EBUSY;
963 	}
964 
965 	IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
966 			scan_type == IWL_SCAN_NORMAL ? "" :
967 			"internal short ");
968 
969 	set_bit(STATUS_SCANNING, &priv->status);
970 	priv->scan_type = scan_type;
971 	priv->scan_start = jiffies;
972 	priv->scan_band = band;
973 
974 	ret = iwlagn_request_scan(priv, vif);
975 	if (ret) {
976 		clear_bit(STATUS_SCANNING, &priv->status);
977 		priv->scan_type = IWL_SCAN_NORMAL;
978 		return ret;
979 	}
980 
981 	queue_delayed_work(priv->workqueue, &priv->scan_check,
982 			   IWL_SCAN_CHECK_WATCHDOG);
983 
984 	return 0;
985 }
986 
987 
988 /*
989  * internal short scan, this function should only been called while associated.
990  * It will reset and tune the radio to prevent possible RF related problem
991  */
992 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
993 {
994 	queue_work(priv->workqueue, &priv->start_internal_scan);
995 }
996 
997 static void iwl_bg_start_internal_scan(struct work_struct *work)
998 {
999 	struct iwl_priv *priv =
1000 		container_of(work, struct iwl_priv, start_internal_scan);
1001 
1002 	IWL_DEBUG_SCAN(priv, "Start internal scan\n");
1003 
1004 	mutex_lock(&priv->mutex);
1005 
1006 	if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
1007 		IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
1008 		goto unlock;
1009 	}
1010 
1011 	if (test_bit(STATUS_SCANNING, &priv->status)) {
1012 		IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
1013 		goto unlock;
1014 	}
1015 
1016 	if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
1017 		IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
1018  unlock:
1019 	mutex_unlock(&priv->mutex);
1020 }
1021 
1022 static void iwl_bg_scan_check(struct work_struct *data)
1023 {
1024 	struct iwl_priv *priv =
1025 	    container_of(data, struct iwl_priv, scan_check.work);
1026 
1027 	IWL_DEBUG_SCAN(priv, "Scan check work\n");
1028 
1029 	/* Since we are here firmware does not finish scan and
1030 	 * most likely is in bad shape, so we don't bother to
1031 	 * send abort command, just force scan complete to mac80211 */
1032 	mutex_lock(&priv->mutex);
1033 	iwl_force_scan_end(priv);
1034 	mutex_unlock(&priv->mutex);
1035 }
1036 
1037 static void iwl_bg_abort_scan(struct work_struct *work)
1038 {
1039 	struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
1040 
1041 	IWL_DEBUG_SCAN(priv, "Abort scan work\n");
1042 
1043 	/* We keep scan_check work queued in case when firmware will not
1044 	 * report back scan completed notification */
1045 	mutex_lock(&priv->mutex);
1046 	iwl_scan_cancel_timeout(priv, 200);
1047 	mutex_unlock(&priv->mutex);
1048 }
1049 
1050 static void iwl_bg_scan_completed(struct work_struct *work)
1051 {
1052 	struct iwl_priv *priv =
1053 		container_of(work, struct iwl_priv, scan_completed);
1054 
1055 	mutex_lock(&priv->mutex);
1056 	iwl_process_scan_complete(priv);
1057 	mutex_unlock(&priv->mutex);
1058 }
1059 
1060 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
1061 {
1062 	INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
1063 	INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
1064 	INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
1065 	INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
1066 }
1067 
1068 void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
1069 {
1070 	cancel_work_sync(&priv->start_internal_scan);
1071 	cancel_work_sync(&priv->abort_scan);
1072 	cancel_work_sync(&priv->scan_completed);
1073 
1074 	if (cancel_delayed_work_sync(&priv->scan_check)) {
1075 		mutex_lock(&priv->mutex);
1076 		iwl_force_scan_end(priv);
1077 		mutex_unlock(&priv->mutex);
1078 	}
1079 }
1080