iwl-scan.c revision 17f841cd6cb0837ba0599ad18a746c30ddd83e08
1/******************************************************************************
2 *
3 * GPL LICENSE SUMMARY
4 *
5 * Copyright(c) 2008 - 2009 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 LICENSE.GPL.
23 *
24 * Contact Information:
25 *  Intel Linux Wireless <ilw@linux.intel.com>
26 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
27 *****************************************************************************/
28#include <linux/types.h>
29#include <linux/etherdevice.h>
30#include <net/lib80211.h>
31#include <net/mac80211.h>
32
33#include "iwl-eeprom.h"
34#include "iwl-dev.h"
35#include "iwl-core.h"
36#include "iwl-sta.h"
37#include "iwl-io.h"
38#include "iwl-helpers.h"
39
40/* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
41 * sending probe req.  This should be set long enough to hear probe responses
42 * from more than one AP.  */
43#define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
44#define IWL_ACTIVE_DWELL_TIME_52    (20)
45
46#define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
47#define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
48
49/* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
50 * Must be set longer than active dwell time.
51 * For the most reliable scan, set > AP beacon interval (typically 100msec). */
52#define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
53#define IWL_PASSIVE_DWELL_TIME_52   (10)
54#define IWL_PASSIVE_DWELL_BASE      (100)
55#define IWL_CHANNEL_TUNE_TIME       5
56
57
58
59/**
60 * iwl_scan_cancel - Cancel any currently executing HW scan
61 *
62 * NOTE: priv->mutex is not required before calling this function
63 */
64int iwl_scan_cancel(struct iwl_priv *priv)
65{
66	if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
67		clear_bit(STATUS_SCANNING, &priv->status);
68		return 0;
69	}
70
71	if (test_bit(STATUS_SCANNING, &priv->status)) {
72		if (!test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
73			IWL_DEBUG_SCAN("Queuing scan abort.\n");
74			set_bit(STATUS_SCAN_ABORTING, &priv->status);
75			queue_work(priv->workqueue, &priv->abort_scan);
76
77		} else
78			IWL_DEBUG_SCAN("Scan abort already in progress.\n");
79
80		return test_bit(STATUS_SCANNING, &priv->status);
81	}
82
83	return 0;
84}
85EXPORT_SYMBOL(iwl_scan_cancel);
86/**
87 * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
88 * @ms: amount of time to wait (in milliseconds) for scan to abort
89 *
90 * NOTE: priv->mutex must be held before calling this function
91 */
92int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
93{
94	unsigned long now = jiffies;
95	int ret;
96
97	ret = iwl_scan_cancel(priv);
98	if (ret && ms) {
99		mutex_unlock(&priv->mutex);
100		while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
101				test_bit(STATUS_SCANNING, &priv->status))
102			msleep(1);
103		mutex_lock(&priv->mutex);
104
105		return test_bit(STATUS_SCANNING, &priv->status);
106	}
107
108	return ret;
109}
110EXPORT_SYMBOL(iwl_scan_cancel_timeout);
111
112int iwl_send_scan_abort(struct iwl_priv *priv)
113{
114	int ret = 0;
115	struct iwl_rx_packet *res;
116	struct iwl_host_cmd cmd = {
117		.id = REPLY_SCAN_ABORT_CMD,
118		.meta.flags = CMD_WANT_SKB,
119	};
120
121	/* If there isn't a scan actively going on in the hardware
122	 * then we are in between scan bands and not actually
123	 * actively scanning, so don't send the abort command */
124	if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
125		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
126		return 0;
127	}
128
129	ret = iwl_send_cmd_sync(priv, &cmd);
130	if (ret) {
131		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
132		return ret;
133	}
134
135	res = (struct iwl_rx_packet *)cmd.meta.u.skb->data;
136	if (res->u.status != CAN_ABORT_STATUS) {
137		/* The scan abort will return 1 for success or
138		 * 2 for "failure".  A failure condition can be
139		 * due to simply not being in an active scan which
140		 * can occur if we send the scan abort before we
141		 * the microcode has notified us that a scan is
142		 * completed. */
143		IWL_DEBUG_INFO("SCAN_ABORT returned %d.\n", res->u.status);
144		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
145		clear_bit(STATUS_SCAN_HW, &priv->status);
146	}
147
148	priv->alloc_rxb_skb--;
149	dev_kfree_skb_any(cmd.meta.u.skb);
150
151	return ret;
152}
153EXPORT_SYMBOL(iwl_send_scan_abort);
154
155/* Service response to REPLY_SCAN_CMD (0x80) */
156static void iwl_rx_reply_scan(struct iwl_priv *priv,
157			      struct iwl_rx_mem_buffer *rxb)
158{
159#ifdef CONFIG_IWLWIFI_DEBUG
160	struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
161	struct iwl_scanreq_notification *notif =
162	    (struct iwl_scanreq_notification *)pkt->u.raw;
163
164	IWL_DEBUG_RX("Scan request status = 0x%x\n", notif->status);
165#endif
166}
167
168/* Service SCAN_START_NOTIFICATION (0x82) */
169static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
170				    struct iwl_rx_mem_buffer *rxb)
171{
172	struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
173	struct iwl_scanstart_notification *notif =
174	    (struct iwl_scanstart_notification *)pkt->u.raw;
175	priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
176	IWL_DEBUG_SCAN("Scan start: "
177		       "%d [802.11%s] "
178		       "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
179		       notif->channel,
180		       notif->band ? "bg" : "a",
181		       le32_to_cpu(notif->tsf_high),
182		       le32_to_cpu(notif->tsf_low),
183		       notif->status, notif->beacon_timer);
184}
185
186/* Service SCAN_RESULTS_NOTIFICATION (0x83) */
187static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
188				      struct iwl_rx_mem_buffer *rxb)
189{
190#ifdef CONFIG_IWLWIFI_DEBUG
191	struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
192	struct iwl_scanresults_notification *notif =
193	    (struct iwl_scanresults_notification *)pkt->u.raw;
194
195	IWL_DEBUG_SCAN("Scan ch.res: "
196		       "%d [802.11%s] "
197		       "(TSF: 0x%08X:%08X) - %d "
198		       "elapsed=%lu usec (%dms since last)\n",
199		       notif->channel,
200		       notif->band ? "bg" : "a",
201		       le32_to_cpu(notif->tsf_high),
202		       le32_to_cpu(notif->tsf_low),
203		       le32_to_cpu(notif->statistics[0]),
204		       le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf,
205		       jiffies_to_msecs(elapsed_jiffies
206					(priv->last_scan_jiffies, jiffies)));
207#endif
208
209	priv->last_scan_jiffies = jiffies;
210	priv->next_scan_jiffies = 0;
211}
212
213/* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
214static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
215				       struct iwl_rx_mem_buffer *rxb)
216{
217#ifdef CONFIG_IWLWIFI_DEBUG
218	struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
219	struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
220
221	IWL_DEBUG_SCAN("Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
222		       scan_notif->scanned_channels,
223		       scan_notif->tsf_low,
224		       scan_notif->tsf_high, scan_notif->status);
225#endif
226
227	/* The HW is no longer scanning */
228	clear_bit(STATUS_SCAN_HW, &priv->status);
229
230	/* The scan completion notification came in, so kill that timer... */
231	cancel_delayed_work(&priv->scan_check);
232
233	IWL_DEBUG_INFO("Scan pass on %sGHz took %dms\n",
234		       (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
235						"2.4" : "5.2",
236		       jiffies_to_msecs(elapsed_jiffies
237					(priv->scan_pass_start, jiffies)));
238
239	/* Remove this scanned band from the list of pending
240	 * bands to scan, band G precedes A in order of scanning
241	 * as seen in iwl_bg_request_scan */
242	if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
243		priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
244	else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
245		priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
246
247	/* If a request to abort was given, or the scan did not succeed
248	 * then we reset the scan state machine and terminate,
249	 * re-queuing another scan if one has been requested */
250	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
251		IWL_DEBUG_INFO("Aborted scan completed.\n");
252		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
253	} else {
254		/* If there are more bands on this scan pass reschedule */
255		if (priv->scan_bands)
256			goto reschedule;
257	}
258
259	priv->last_scan_jiffies = jiffies;
260	priv->next_scan_jiffies = 0;
261	IWL_DEBUG_INFO("Setting scan to off\n");
262
263	clear_bit(STATUS_SCANNING, &priv->status);
264
265	IWL_DEBUG_INFO("Scan took %dms\n",
266		jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
267
268	queue_work(priv->workqueue, &priv->scan_completed);
269
270	return;
271
272reschedule:
273	priv->scan_pass_start = jiffies;
274	queue_work(priv->workqueue, &priv->request_scan);
275}
276
277void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
278{
279	/* scan handlers */
280	priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
281	priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
282	priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
283					iwl_rx_scan_results_notif;
284	priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
285					iwl_rx_scan_complete_notif;
286}
287EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
288
289inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
290				     enum ieee80211_band band,
291				     u8 n_probes)
292{
293	if (band == IEEE80211_BAND_5GHZ)
294		return IWL_ACTIVE_DWELL_TIME_52 +
295			IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
296	else
297		return IWL_ACTIVE_DWELL_TIME_24 +
298			IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
299}
300EXPORT_SYMBOL(iwl_get_active_dwell_time);
301
302u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
303			       enum ieee80211_band band)
304{
305	u16 passive = (band == IEEE80211_BAND_2GHZ) ?
306	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
307	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
308
309	if (iwl_is_associated(priv)) {
310		/* If we're associated, we clamp the maximum passive
311		 * dwell time to be 98% of the beacon interval (minus
312		 * 2 * channel tune time) */
313		passive = priv->beacon_int;
314		if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
315			passive = IWL_PASSIVE_DWELL_BASE;
316		passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
317	}
318
319	return passive;
320}
321EXPORT_SYMBOL(iwl_get_passive_dwell_time);
322
323static int iwl_get_channels_for_scan(struct iwl_priv *priv,
324				     enum ieee80211_band band,
325				     u8 is_active, u8 n_probes,
326				     struct iwl_scan_channel *scan_ch)
327{
328	const struct ieee80211_channel *channels = NULL;
329	const struct ieee80211_supported_band *sband;
330	const struct iwl_channel_info *ch_info;
331	u16 passive_dwell = 0;
332	u16 active_dwell = 0;
333	int added, i;
334	u16 channel;
335
336	sband = iwl_get_hw_mode(priv, band);
337	if (!sband)
338		return 0;
339
340	channels = sband->channels;
341
342	active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
343	passive_dwell = iwl_get_passive_dwell_time(priv, band);
344
345	if (passive_dwell <= active_dwell)
346		passive_dwell = active_dwell + 1;
347
348	for (i = 0, added = 0; i < sband->n_channels; i++) {
349		if (channels[i].flags & IEEE80211_CHAN_DISABLED)
350			continue;
351
352		channel =
353			ieee80211_frequency_to_channel(channels[i].center_freq);
354		scan_ch->channel = cpu_to_le16(channel);
355
356		ch_info = iwl_get_channel_info(priv, band, channel);
357		if (!is_channel_valid(ch_info)) {
358			IWL_DEBUG_SCAN("Channel %d is INVALID for this band.\n",
359					channel);
360			continue;
361		}
362
363		if (!is_active || is_channel_passive(ch_info) ||
364		    (channels[i].flags & IEEE80211_CHAN_PASSIVE_SCAN))
365			scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
366		else
367			scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
368
369		if (n_probes)
370			scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
371
372		scan_ch->active_dwell = cpu_to_le16(active_dwell);
373		scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
374
375		/* Set txpower levels to defaults */
376		scan_ch->dsp_atten = 110;
377
378		/* NOTE: if we were doing 6Mb OFDM for scans we'd use
379		 * power level:
380		 * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
381		 */
382		if (band == IEEE80211_BAND_5GHZ)
383			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
384		else
385			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
386
387		IWL_DEBUG_SCAN("Scanning ch=%d prob=0x%X [%s %d]\n",
388			       channel, le32_to_cpu(scan_ch->type),
389			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
390				"ACTIVE" : "PASSIVE",
391			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
392			       active_dwell : passive_dwell);
393
394		scan_ch++;
395		added++;
396	}
397
398	IWL_DEBUG_SCAN("total channels to scan %d \n", added);
399	return added;
400}
401
402void iwl_init_scan_params(struct iwl_priv *priv)
403{
404	u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
405	if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
406		priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
407	if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
408		priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
409}
410
411int iwl_scan_initiate(struct iwl_priv *priv)
412{
413	if (!iwl_is_ready_rf(priv)) {
414		IWL_DEBUG_SCAN("Aborting scan due to not ready.\n");
415		return -EIO;
416	}
417
418	if (test_bit(STATUS_SCANNING, &priv->status)) {
419		IWL_DEBUG_SCAN("Scan already in progress.\n");
420		return -EAGAIN;
421	}
422
423	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
424		IWL_DEBUG_SCAN("Scan request while abort pending\n");
425		return -EAGAIN;
426	}
427
428	IWL_DEBUG_INFO("Starting scan...\n");
429	if (priv->cfg->sku & IWL_SKU_G)
430		priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
431	if (priv->cfg->sku & IWL_SKU_A)
432		priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
433	set_bit(STATUS_SCANNING, &priv->status);
434	priv->scan_start = jiffies;
435	priv->scan_pass_start = priv->scan_start;
436
437	queue_work(priv->workqueue, &priv->request_scan);
438
439	return 0;
440}
441EXPORT_SYMBOL(iwl_scan_initiate);
442
443#define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
444
445void iwl_bg_scan_check(struct work_struct *data)
446{
447	struct iwl_priv *priv =
448	    container_of(data, struct iwl_priv, scan_check.work);
449
450	if (test_bit(STATUS_EXIT_PENDING, &priv->status))
451		return;
452
453	mutex_lock(&priv->mutex);
454	if (test_bit(STATUS_SCANNING, &priv->status) ||
455	    test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
456		IWL_DEBUG(IWL_DL_SCAN, "Scan completion watchdog resetting "
457			"adapter (%dms)\n",
458			jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
459
460		if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
461			iwl_send_scan_abort(priv);
462	}
463	mutex_unlock(&priv->mutex);
464}
465EXPORT_SYMBOL(iwl_bg_scan_check);
466
467/**
468 * iwl_supported_rate_to_ie - fill in the supported rate in IE field
469 *
470 * return : set the bit for each supported rate insert in ie
471 */
472static u16 iwl_supported_rate_to_ie(u8 *ie, u16 supported_rate,
473				    u16 basic_rate, int *left)
474{
475	u16 ret_rates = 0, bit;
476	int i;
477	u8 *cnt = ie;
478	u8 *rates = ie + 1;
479
480	for (bit = 1, i = 0; i < IWL_RATE_COUNT; i++, bit <<= 1) {
481		if (bit & supported_rate) {
482			ret_rates |= bit;
483			rates[*cnt] = iwl_rates[i].ieee |
484				((bit & basic_rate) ? 0x80 : 0x00);
485			(*cnt)++;
486			(*left)--;
487			if ((*left <= 0) ||
488			    (*cnt >= IWL_SUPPORTED_RATES_IE_LEN))
489				break;
490		}
491	}
492
493	return ret_rates;
494}
495
496
497static void iwl_ht_cap_to_ie(const struct ieee80211_supported_band *sband,
498			     u8 *pos, int *left)
499{
500	struct ieee80211_ht_cap *ht_cap;
501
502	if (!sband || !sband->ht_cap.ht_supported)
503		return;
504
505	if (*left < sizeof(struct ieee80211_ht_cap))
506		return;
507
508	*pos++ = sizeof(struct ieee80211_ht_cap);
509	ht_cap = (struct ieee80211_ht_cap *) pos;
510
511	ht_cap->cap_info = cpu_to_le16(sband->ht_cap.cap);
512	memcpy(&ht_cap->mcs, &sband->ht_cap.mcs, 16);
513	ht_cap->ampdu_params_info =
514		(sband->ht_cap.ampdu_factor & IEEE80211_HT_AMPDU_PARM_FACTOR) |
515		((sband->ht_cap.ampdu_density << 2) &
516			IEEE80211_HT_AMPDU_PARM_DENSITY);
517	*left -= sizeof(struct ieee80211_ht_cap);
518}
519
520/**
521 * iwl_fill_probe_req - fill in all required fields and IE for probe request
522 */
523
524u16 iwl_fill_probe_req(struct iwl_priv *priv,
525		       enum ieee80211_band band,
526		       struct ieee80211_mgmt *frame,
527		       int left)
528{
529	int len = 0;
530	u8 *pos = NULL;
531	u16 active_rates, ret_rates, cck_rates, active_rate_basic;
532	const struct ieee80211_supported_band *sband =
533						iwl_get_hw_mode(priv, band);
534
535
536	/* Make sure there is enough space for the probe request,
537	 * two mandatory IEs and the data */
538	left -= 24;
539	if (left < 0)
540		return 0;
541
542	frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
543	memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
544	memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
545	memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
546	frame->seq_ctrl = 0;
547
548	len += 24;
549
550	/* ...next IE... */
551	pos = &frame->u.probe_req.variable[0];
552
553	/* fill in our indirect SSID IE */
554	left -= 2;
555	if (left < 0)
556		return 0;
557	*pos++ = WLAN_EID_SSID;
558	*pos++ = 0;
559
560	len += 2;
561
562	/* fill in supported rate */
563	left -= 2;
564	if (left < 0)
565		return 0;
566
567	*pos++ = WLAN_EID_SUPP_RATES;
568	*pos = 0;
569
570	/* exclude 60M rate */
571	active_rates = priv->rates_mask;
572	active_rates &= ~IWL_RATE_60M_MASK;
573
574	active_rate_basic = active_rates & IWL_BASIC_RATES_MASK;
575
576	cck_rates = IWL_CCK_RATES_MASK & active_rates;
577	ret_rates = iwl_supported_rate_to_ie(pos, cck_rates,
578					     active_rate_basic, &left);
579	active_rates &= ~ret_rates;
580
581	ret_rates = iwl_supported_rate_to_ie(pos, active_rates,
582					     active_rate_basic, &left);
583	active_rates &= ~ret_rates;
584
585	len += 2 + *pos;
586	pos += (*pos) + 1;
587
588	if (active_rates == 0)
589		goto fill_end;
590
591	/* fill in supported extended rate */
592	/* ...next IE... */
593	left -= 2;
594	if (left < 0)
595		return 0;
596	/* ... fill it in... */
597	*pos++ = WLAN_EID_EXT_SUPP_RATES;
598	*pos = 0;
599	iwl_supported_rate_to_ie(pos, active_rates, active_rate_basic, &left);
600	if (*pos > 0) {
601		len += 2 + *pos;
602		pos += (*pos) + 1;
603	} else {
604		pos--;
605	}
606
607 fill_end:
608
609	left -= 2;
610	if (left < 0)
611		return 0;
612
613	*pos++ = WLAN_EID_HT_CAPABILITY;
614	*pos = 0;
615	iwl_ht_cap_to_ie(sband, pos, &left);
616	if (*pos > 0)
617		len += 2 + *pos;
618
619	return (u16)len;
620}
621EXPORT_SYMBOL(iwl_fill_probe_req);
622
623static void iwl_bg_request_scan(struct work_struct *data)
624{
625	struct iwl_priv *priv =
626	    container_of(data, struct iwl_priv, request_scan);
627	struct iwl_host_cmd cmd = {
628		.id = REPLY_SCAN_CMD,
629		.len = sizeof(struct iwl_scan_cmd),
630		.meta.flags = CMD_SIZE_HUGE,
631	};
632	struct iwl_scan_cmd *scan;
633	struct ieee80211_conf *conf = NULL;
634	int ret = 0;
635	u32 rate_flags = 0;
636	u16 cmd_len;
637	enum ieee80211_band band;
638	u8 n_probes = 2;
639	u8 rx_chain = priv->hw_params.valid_rx_ant;
640	u8 rate;
641	DECLARE_SSID_BUF(ssid);
642
643	conf = ieee80211_get_hw_conf(priv->hw);
644
645	mutex_lock(&priv->mutex);
646
647	if (!iwl_is_ready(priv)) {
648		IWL_WARN(priv, "request scan called when driver not ready.\n");
649		goto done;
650	}
651
652	/* Make sure the scan wasn't canceled before this queued work
653	 * was given the chance to run... */
654	if (!test_bit(STATUS_SCANNING, &priv->status))
655		goto done;
656
657	/* This should never be called or scheduled if there is currently
658	 * a scan active in the hardware. */
659	if (test_bit(STATUS_SCAN_HW, &priv->status)) {
660		IWL_DEBUG_INFO("Multiple concurrent scan requests in parallel. "
661			       "Ignoring second request.\n");
662		ret = -EIO;
663		goto done;
664	}
665
666	if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
667		IWL_DEBUG_SCAN("Aborting scan due to device shutdown\n");
668		goto done;
669	}
670
671	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
672		IWL_DEBUG_HC("Scan request while abort pending.  Queuing.\n");
673		goto done;
674	}
675
676	if (iwl_is_rfkill(priv)) {
677		IWL_DEBUG_HC("Aborting scan due to RF Kill activation\n");
678		goto done;
679	}
680
681	if (!test_bit(STATUS_READY, &priv->status)) {
682		IWL_DEBUG_HC("Scan request while uninitialized.  Queuing.\n");
683		goto done;
684	}
685
686	if (!priv->scan_bands) {
687		IWL_DEBUG_HC("Aborting scan due to no requested bands\n");
688		goto done;
689	}
690
691	if (!priv->scan) {
692		priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
693				     IWL_MAX_SCAN_SIZE, GFP_KERNEL);
694		if (!priv->scan) {
695			ret = -ENOMEM;
696			goto done;
697		}
698	}
699	scan = priv->scan;
700	memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
701
702	scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
703	scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
704
705	if (iwl_is_associated(priv)) {
706		u16 interval = 0;
707		u32 extra;
708		u32 suspend_time = 100;
709		u32 scan_suspend_time = 100;
710		unsigned long flags;
711
712		IWL_DEBUG_INFO("Scanning while associated...\n");
713
714		spin_lock_irqsave(&priv->lock, flags);
715		interval = priv->beacon_int;
716		spin_unlock_irqrestore(&priv->lock, flags);
717
718		scan->suspend_time = 0;
719		scan->max_out_time = cpu_to_le32(200 * 1024);
720		if (!interval)
721			interval = suspend_time;
722
723		extra = (suspend_time / interval) << 22;
724		scan_suspend_time = (extra |
725		    ((suspend_time % interval) * 1024));
726		scan->suspend_time = cpu_to_le32(scan_suspend_time);
727		IWL_DEBUG_SCAN("suspend_time 0x%X beacon interval %d\n",
728			       scan_suspend_time, interval);
729	}
730
731	/* We should add the ability for user to lock to PASSIVE ONLY */
732	if (priv->one_direct_scan) {
733		IWL_DEBUG_SCAN("Start direct scan for '%s'\n",
734				print_ssid(ssid, priv->direct_ssid,
735					   priv->direct_ssid_len));
736		scan->direct_scan[0].id = WLAN_EID_SSID;
737		scan->direct_scan[0].len = priv->direct_ssid_len;
738		memcpy(scan->direct_scan[0].ssid,
739		       priv->direct_ssid, priv->direct_ssid_len);
740		n_probes++;
741	} else {
742		IWL_DEBUG_SCAN("Start indirect scan.\n");
743	}
744
745	scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
746	scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
747	scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
748
749
750	if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
751		band = IEEE80211_BAND_2GHZ;
752		scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
753		if (priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_PURE_40_MSK) {
754			rate = IWL_RATE_6M_PLCP;
755		} else {
756			rate = IWL_RATE_1M_PLCP;
757			rate_flags = RATE_MCS_CCK_MSK;
758		}
759		scan->good_CRC_th = 0;
760	} else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
761		band = IEEE80211_BAND_5GHZ;
762		rate = IWL_RATE_6M_PLCP;
763		scan->good_CRC_th = IWL_GOOD_CRC_TH;
764
765		/* Force use of chains B and C (0x6) for scan Rx for 4965
766		 * Avoid A (0x1) because of its off-channel reception on A-band.
767		 */
768		if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
769			rx_chain = 0x6;
770	} else {
771		IWL_WARN(priv, "Invalid scan band count\n");
772		goto done;
773	}
774
775	priv->scan_tx_ant[band] =
776			 iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
777	rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
778	scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
779
780	/* MIMO is not used here, but value is required */
781	scan->rx_chain = RXON_RX_CHAIN_DRIVER_FORCE_MSK |
782				cpu_to_le16((0x7 << RXON_RX_CHAIN_VALID_POS) |
783				(rx_chain << RXON_RX_CHAIN_FORCE_SEL_POS) |
784				(0x7 << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS));
785
786	cmd_len = iwl_fill_probe_req(priv, band,
787				     (struct ieee80211_mgmt *)scan->data,
788				     IWL_MAX_SCAN_SIZE - sizeof(*scan));
789
790	scan->tx_cmd.len = cpu_to_le16(cmd_len);
791
792	if (priv->iw_mode == NL80211_IFTYPE_MONITOR)
793		scan->filter_flags = RXON_FILTER_PROMISC_MSK;
794
795	scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
796			       RXON_FILTER_BCON_AWARE_MSK);
797
798	scan->channel_count =
799		iwl_get_channels_for_scan(priv, band, 1, /* active */
800			n_probes,
801			(void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
802
803	if (scan->channel_count == 0) {
804		IWL_DEBUG_SCAN("channel count %d\n", scan->channel_count);
805		goto done;
806	}
807
808	cmd.len += le16_to_cpu(scan->tx_cmd.len) +
809	    scan->channel_count * sizeof(struct iwl_scan_channel);
810	cmd.data = scan;
811	scan->len = cpu_to_le16(cmd.len);
812
813	set_bit(STATUS_SCAN_HW, &priv->status);
814	ret = iwl_send_cmd_sync(priv, &cmd);
815	if (ret)
816		goto done;
817
818	queue_delayed_work(priv->workqueue, &priv->scan_check,
819			   IWL_SCAN_CHECK_WATCHDOG);
820
821	mutex_unlock(&priv->mutex);
822	return;
823
824 done:
825	/* Cannot perform scan. Make sure we clear scanning
826	* bits from status so next scan request can be performed.
827	* If we don't clear scanning status bit here all next scan
828	* will fail
829	*/
830	clear_bit(STATUS_SCAN_HW, &priv->status);
831	clear_bit(STATUS_SCANNING, &priv->status);
832	/* inform mac80211 scan aborted */
833	queue_work(priv->workqueue, &priv->scan_completed);
834	mutex_unlock(&priv->mutex);
835}
836
837void iwl_bg_abort_scan(struct work_struct *work)
838{
839	struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
840
841	if (!iwl_is_ready(priv))
842		return;
843
844	mutex_lock(&priv->mutex);
845
846	set_bit(STATUS_SCAN_ABORTING, &priv->status);
847	iwl_send_scan_abort(priv);
848
849	mutex_unlock(&priv->mutex);
850}
851EXPORT_SYMBOL(iwl_bg_abort_scan);
852
853void iwl_bg_scan_completed(struct work_struct *work)
854{
855	struct iwl_priv *priv =
856	    container_of(work, struct iwl_priv, scan_completed);
857
858	IWL_DEBUG_SCAN("SCAN complete scan\n");
859
860	if (test_bit(STATUS_EXIT_PENDING, &priv->status))
861		return;
862
863	ieee80211_scan_completed(priv->hw);
864
865	/* Since setting the TXPOWER may have been deferred while
866	 * performing the scan, fire one off */
867	mutex_lock(&priv->mutex);
868	iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
869	mutex_unlock(&priv->mutex);
870}
871EXPORT_SYMBOL(iwl_bg_scan_completed);
872
873void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
874{
875	INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
876	INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
877	INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
878	INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
879}
880EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
881
882