iwl-scan.c revision 951891c7ef844919d30aac7b1fc7396fd8be23ff
1/******************************************************************************
2 *
3 * GPL LICENSE SUMMARY
4 *
5 * Copyright(c) 2008 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 * Tomas Winkler <tomas.winkler@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 faster active scanning, scan will move to the next channel if fewer than
50 * PLCP_QUIET_THRESH packets are heard on this channel within
51 * ACTIVE_QUIET_TIME after sending probe request.  This shortens the dwell
52 * time if it's a quiet channel (nothing responded to our probe, and there's
53 * no other traffic).
54 * Disable "quiet" feature by setting PLCP_QUIET_THRESH to 0. */
55#define IWL_PLCP_QUIET_THRESH       __constant_cpu_to_le16(1)  /* packets */
56#define IWL_ACTIVE_QUIET_TIME       __constant_cpu_to_le16(10)  /* msec */
57
58/* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
59 * Must be set longer than active dwell time.
60 * For the most reliable scan, set > AP beacon interval (typically 100msec). */
61#define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
62#define IWL_PASSIVE_DWELL_TIME_52   (10)
63#define IWL_PASSIVE_DWELL_BASE      (100)
64#define IWL_CHANNEL_TUNE_TIME       5
65
66#define IWL_SCAN_PROBE_MASK(n) 	cpu_to_le32((BIT(n) | (BIT(n) - BIT(1))))
67
68
69/**
70 * iwl_scan_cancel - Cancel any currently executing HW scan
71 *
72 * NOTE: priv->mutex is not required before calling this function
73 */
74int iwl_scan_cancel(struct iwl_priv *priv)
75{
76	if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
77		clear_bit(STATUS_SCANNING, &priv->status);
78		return 0;
79	}
80
81	if (test_bit(STATUS_SCANNING, &priv->status)) {
82		if (!test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
83			IWL_DEBUG_SCAN("Queuing scan abort.\n");
84			set_bit(STATUS_SCAN_ABORTING, &priv->status);
85			queue_work(priv->workqueue, &priv->abort_scan);
86
87		} else
88			IWL_DEBUG_SCAN("Scan abort already in progress.\n");
89
90		return test_bit(STATUS_SCANNING, &priv->status);
91	}
92
93	return 0;
94}
95EXPORT_SYMBOL(iwl_scan_cancel);
96/**
97 * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
98 * @ms: amount of time to wait (in milliseconds) for scan to abort
99 *
100 * NOTE: priv->mutex must be held before calling this function
101 */
102int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
103{
104	unsigned long now = jiffies;
105	int ret;
106
107	ret = iwl_scan_cancel(priv);
108	if (ret && ms) {
109		mutex_unlock(&priv->mutex);
110		while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
111				test_bit(STATUS_SCANNING, &priv->status))
112			msleep(1);
113		mutex_lock(&priv->mutex);
114
115		return test_bit(STATUS_SCANNING, &priv->status);
116	}
117
118	return ret;
119}
120EXPORT_SYMBOL(iwl_scan_cancel_timeout);
121
122static int iwl_send_scan_abort(struct iwl_priv *priv)
123{
124	int ret = 0;
125	struct iwl_rx_packet *res;
126	struct iwl_host_cmd cmd = {
127		.id = REPLY_SCAN_ABORT_CMD,
128		.meta.flags = CMD_WANT_SKB,
129	};
130
131	/* If there isn't a scan actively going on in the hardware
132	 * then we are in between scan bands and not actually
133	 * actively scanning, so don't send the abort command */
134	if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
135		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
136		return 0;
137	}
138
139	ret = iwl_send_cmd_sync(priv, &cmd);
140	if (ret) {
141		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
142		return ret;
143	}
144
145	res = (struct iwl_rx_packet *)cmd.meta.u.skb->data;
146	if (res->u.status != CAN_ABORT_STATUS) {
147		/* The scan abort will return 1 for success or
148		 * 2 for "failure".  A failure condition can be
149		 * due to simply not being in an active scan which
150		 * can occur if we send the scan abort before we
151		 * the microcode has notified us that a scan is
152		 * completed. */
153		IWL_DEBUG_INFO("SCAN_ABORT returned %d.\n", res->u.status);
154		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
155		clear_bit(STATUS_SCAN_HW, &priv->status);
156	}
157
158	priv->alloc_rxb_skb--;
159	dev_kfree_skb_any(cmd.meta.u.skb);
160
161	return ret;
162}
163
164
165/* Service response to REPLY_SCAN_CMD (0x80) */
166static void iwl_rx_reply_scan(struct iwl_priv *priv,
167			      struct iwl_rx_mem_buffer *rxb)
168{
169#ifdef CONFIG_IWLWIFI_DEBUG
170	struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
171	struct iwl_scanreq_notification *notif =
172	    (struct iwl_scanreq_notification *)pkt->u.raw;
173
174	IWL_DEBUG_RX("Scan request status = 0x%x\n", notif->status);
175#endif
176}
177
178/* Service SCAN_START_NOTIFICATION (0x82) */
179static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
180				    struct iwl_rx_mem_buffer *rxb)
181{
182	struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
183	struct iwl_scanstart_notification *notif =
184	    (struct iwl_scanstart_notification *)pkt->u.raw;
185	priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
186	IWL_DEBUG_SCAN("Scan start: "
187		       "%d [802.11%s] "
188		       "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
189		       notif->channel,
190		       notif->band ? "bg" : "a",
191		       le32_to_cpu(notif->tsf_high),
192		       le32_to_cpu(notif->tsf_low),
193		       notif->status, notif->beacon_timer);
194}
195
196/* Service SCAN_RESULTS_NOTIFICATION (0x83) */
197static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
198				      struct iwl_rx_mem_buffer *rxb)
199{
200#ifdef CONFIG_IWLWIFI_DEBUG
201	struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
202	struct iwl_scanresults_notification *notif =
203	    (struct iwl_scanresults_notification *)pkt->u.raw;
204
205	IWL_DEBUG_SCAN("Scan ch.res: "
206		       "%d [802.11%s] "
207		       "(TSF: 0x%08X:%08X) - %d "
208		       "elapsed=%lu usec (%dms since last)\n",
209		       notif->channel,
210		       notif->band ? "bg" : "a",
211		       le32_to_cpu(notif->tsf_high),
212		       le32_to_cpu(notif->tsf_low),
213		       le32_to_cpu(notif->statistics[0]),
214		       le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf,
215		       jiffies_to_msecs(elapsed_jiffies
216					(priv->last_scan_jiffies, jiffies)));
217#endif
218
219	priv->last_scan_jiffies = jiffies;
220	priv->next_scan_jiffies = 0;
221}
222
223/* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
224static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
225				       struct iwl_rx_mem_buffer *rxb)
226{
227#ifdef CONFIG_IWLWIFI_DEBUG
228	struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
229	struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
230
231	IWL_DEBUG_SCAN("Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
232		       scan_notif->scanned_channels,
233		       scan_notif->tsf_low,
234		       scan_notif->tsf_high, scan_notif->status);
235#endif
236
237	/* The HW is no longer scanning */
238	clear_bit(STATUS_SCAN_HW, &priv->status);
239
240	/* The scan completion notification came in, so kill that timer... */
241	cancel_delayed_work(&priv->scan_check);
242
243	IWL_DEBUG_INFO("Scan pass on %sGHz took %dms\n",
244		       (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
245						"2.4" : "5.2",
246		       jiffies_to_msecs(elapsed_jiffies
247					(priv->scan_pass_start, jiffies)));
248
249	/* Remove this scanned band from the list of pending
250	 * bands to scan, band G precedes A in order of scanning
251	 * as seen in iwl_bg_request_scan */
252	if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
253		priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
254	else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
255		priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
256
257	/* If a request to abort was given, or the scan did not succeed
258	 * then we reset the scan state machine and terminate,
259	 * re-queuing another scan if one has been requested */
260	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
261		IWL_DEBUG_INFO("Aborted scan completed.\n");
262		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
263	} else {
264		/* If there are more bands on this scan pass reschedule */
265		if (priv->scan_bands)
266			goto reschedule;
267	}
268
269	priv->last_scan_jiffies = jiffies;
270	priv->next_scan_jiffies = 0;
271	IWL_DEBUG_INFO("Setting scan to off\n");
272
273	clear_bit(STATUS_SCANNING, &priv->status);
274
275	IWL_DEBUG_INFO("Scan took %dms\n",
276		jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
277
278	queue_work(priv->workqueue, &priv->scan_completed);
279
280	return;
281
282reschedule:
283	priv->scan_pass_start = jiffies;
284	queue_work(priv->workqueue, &priv->request_scan);
285}
286
287void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
288{
289	/* scan handlers */
290	priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
291	priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
292	priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
293					iwl_rx_scan_results_notif;
294	priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
295					iwl_rx_scan_complete_notif;
296}
297EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
298
299static inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
300					    enum ieee80211_band band,
301					    u8 n_probes)
302{
303	if (band == IEEE80211_BAND_5GHZ)
304		return IWL_ACTIVE_DWELL_TIME_52 +
305			IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
306	else
307		return IWL_ACTIVE_DWELL_TIME_24 +
308			IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
309}
310
311static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
312				      enum ieee80211_band band)
313{
314	u16 passive = (band == IEEE80211_BAND_2GHZ) ?
315	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
316	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
317
318	if (iwl_is_associated(priv)) {
319		/* If we're associated, we clamp the maximum passive
320		 * dwell time to be 98% of the beacon interval (minus
321		 * 2 * channel tune time) */
322		passive = priv->beacon_int;
323		if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
324			passive = IWL_PASSIVE_DWELL_BASE;
325		passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
326	}
327
328	return passive;
329}
330
331static int iwl_get_channels_for_scan(struct iwl_priv *priv,
332				     enum ieee80211_band band,
333				     u8 is_active, u8 n_probes,
334				     struct iwl_scan_channel *scan_ch)
335{
336	const struct ieee80211_channel *channels = NULL;
337	const struct ieee80211_supported_band *sband;
338	const struct iwl_channel_info *ch_info;
339	u16 passive_dwell = 0;
340	u16 active_dwell = 0;
341	int added, i;
342	u16 channel;
343
344	sband = iwl_get_hw_mode(priv, band);
345	if (!sband)
346		return 0;
347
348	channels = sband->channels;
349
350	active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
351	passive_dwell = iwl_get_passive_dwell_time(priv, band);
352
353	if (passive_dwell <= active_dwell)
354		passive_dwell = active_dwell + 1;
355
356	for (i = 0, added = 0; i < sband->n_channels; i++) {
357		if (channels[i].flags & IEEE80211_CHAN_DISABLED)
358			continue;
359
360		channel =
361			ieee80211_frequency_to_channel(channels[i].center_freq);
362		scan_ch->channel = cpu_to_le16(channel);
363
364		ch_info = iwl_get_channel_info(priv, band, channel);
365		if (!is_channel_valid(ch_info)) {
366			IWL_DEBUG_SCAN("Channel %d is INVALID for this band.\n",
367					channel);
368			continue;
369		}
370
371		if (!is_active || is_channel_passive(ch_info) ||
372		    (channels[i].flags & IEEE80211_CHAN_PASSIVE_SCAN))
373			scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
374		else
375			scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
376
377		if (n_probes)
378			scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
379
380		scan_ch->active_dwell = cpu_to_le16(active_dwell);
381		scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
382
383		/* Set txpower levels to defaults */
384		scan_ch->dsp_atten = 110;
385
386		/* NOTE: if we were doing 6Mb OFDM for scans we'd use
387		 * power level:
388		 * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
389		 */
390		if (band == IEEE80211_BAND_5GHZ)
391			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
392		else
393			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
394
395		IWL_DEBUG_SCAN("Scanning ch=%d prob=0x%X [%s %d]\n",
396			       channel, le32_to_cpu(scan_ch->type),
397			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
398				"ACTIVE" : "PASSIVE",
399			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
400			       active_dwell : passive_dwell);
401
402		scan_ch++;
403		added++;
404	}
405
406	IWL_DEBUG_SCAN("total channels to scan %d \n", added);
407	return added;
408}
409
410void iwl_init_scan_params(struct iwl_priv *priv)
411{
412	u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
413	if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
414		priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
415	if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
416		priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
417}
418
419int iwl_scan_initiate(struct iwl_priv *priv)
420{
421	if (!iwl_is_ready_rf(priv)) {
422		IWL_DEBUG_SCAN("Aborting scan due to not ready.\n");
423		return -EIO;
424	}
425
426	if (test_bit(STATUS_SCANNING, &priv->status)) {
427		IWL_DEBUG_SCAN("Scan already in progress.\n");
428		return -EAGAIN;
429	}
430
431	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
432		IWL_DEBUG_SCAN("Scan request while abort pending\n");
433		return -EAGAIN;
434	}
435
436	IWL_DEBUG_INFO("Starting scan...\n");
437	if (priv->cfg->sku & IWL_SKU_G)
438		priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
439	if (priv->cfg->sku & IWL_SKU_A)
440		priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
441	set_bit(STATUS_SCANNING, &priv->status);
442	priv->scan_start = jiffies;
443	priv->scan_pass_start = priv->scan_start;
444
445	queue_work(priv->workqueue, &priv->request_scan);
446
447	return 0;
448}
449EXPORT_SYMBOL(iwl_scan_initiate);
450
451#define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
452
453static void iwl_bg_scan_check(struct work_struct *data)
454{
455	struct iwl_priv *priv =
456	    container_of(data, struct iwl_priv, scan_check.work);
457
458	if (test_bit(STATUS_EXIT_PENDING, &priv->status))
459		return;
460
461	mutex_lock(&priv->mutex);
462	if (test_bit(STATUS_SCANNING, &priv->status) ||
463	    test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
464		IWL_DEBUG(IWL_DL_SCAN, "Scan completion watchdog resetting "
465			"adapter (%dms)\n",
466			jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
467
468		if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
469			iwl_send_scan_abort(priv);
470	}
471	mutex_unlock(&priv->mutex);
472}
473/**
474 * iwl_supported_rate_to_ie - fill in the supported rate in IE field
475 *
476 * return : set the bit for each supported rate insert in ie
477 */
478static u16 iwl_supported_rate_to_ie(u8 *ie, u16 supported_rate,
479				    u16 basic_rate, int *left)
480{
481	u16 ret_rates = 0, bit;
482	int i;
483	u8 *cnt = ie;
484	u8 *rates = ie + 1;
485
486	for (bit = 1, i = 0; i < IWL_RATE_COUNT; i++, bit <<= 1) {
487		if (bit & supported_rate) {
488			ret_rates |= bit;
489			rates[*cnt] = iwl_rates[i].ieee |
490				((bit & basic_rate) ? 0x80 : 0x00);
491			(*cnt)++;
492			(*left)--;
493			if ((*left <= 0) ||
494			    (*cnt >= IWL_SUPPORTED_RATES_IE_LEN))
495				break;
496		}
497	}
498
499	return ret_rates;
500}
501
502
503static void iwl_ht_cap_to_ie(const struct ieee80211_supported_band *sband,
504			     u8 *pos, int *left)
505{
506	struct ieee80211_ht_cap *ht_cap;
507
508	if (!sband || !sband->ht_cap.ht_supported)
509		return;
510
511	if (*left < sizeof(struct ieee80211_ht_cap))
512		return;
513
514	*pos++ = sizeof(struct ieee80211_ht_cap);
515	ht_cap = (struct ieee80211_ht_cap *) pos;
516
517	ht_cap->cap_info = cpu_to_le16(sband->ht_cap.cap);
518	memcpy(&ht_cap->mcs, &sband->ht_cap.mcs, 16);
519	ht_cap->ampdu_params_info =
520		(sband->ht_cap.ampdu_factor & IEEE80211_HT_AMPDU_PARM_FACTOR) |
521		((sband->ht_cap.ampdu_density << 2) &
522			IEEE80211_HT_AMPDU_PARM_DENSITY);
523	*left -= sizeof(struct ieee80211_ht_cap);
524}
525
526/**
527 * iwl_fill_probe_req - fill in all required fields and IE for probe request
528 */
529
530static u16 iwl_fill_probe_req(struct iwl_priv *priv,
531				  enum ieee80211_band band,
532				  struct ieee80211_mgmt *frame,
533				  int left)
534{
535	int len = 0;
536	u8 *pos = NULL;
537	u16 active_rates, ret_rates, cck_rates, active_rate_basic;
538	const struct ieee80211_supported_band *sband =
539						iwl_get_hw_mode(priv, band);
540
541
542	/* Make sure there is enough space for the probe request,
543	 * two mandatory IEs and the data */
544	left -= 24;
545	if (left < 0)
546		return 0;
547
548	frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
549	memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
550	memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
551	memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
552	frame->seq_ctrl = 0;
553
554	len += 24;
555
556	/* ...next IE... */
557	pos = &frame->u.probe_req.variable[0];
558
559	/* fill in our indirect SSID IE */
560	left -= 2;
561	if (left < 0)
562		return 0;
563	*pos++ = WLAN_EID_SSID;
564	*pos++ = 0;
565
566	len += 2;
567
568	/* fill in supported rate */
569	left -= 2;
570	if (left < 0)
571		return 0;
572
573	*pos++ = WLAN_EID_SUPP_RATES;
574	*pos = 0;
575
576	/* exclude 60M rate */
577	active_rates = priv->rates_mask;
578	active_rates &= ~IWL_RATE_60M_MASK;
579
580	active_rate_basic = active_rates & IWL_BASIC_RATES_MASK;
581
582	cck_rates = IWL_CCK_RATES_MASK & active_rates;
583	ret_rates = iwl_supported_rate_to_ie(pos, cck_rates,
584					     active_rate_basic, &left);
585	active_rates &= ~ret_rates;
586
587	ret_rates = iwl_supported_rate_to_ie(pos, active_rates,
588					     active_rate_basic, &left);
589	active_rates &= ~ret_rates;
590
591	len += 2 + *pos;
592	pos += (*pos) + 1;
593
594	if (active_rates == 0)
595		goto fill_end;
596
597	/* fill in supported extended rate */
598	/* ...next IE... */
599	left -= 2;
600	if (left < 0)
601		return 0;
602	/* ... fill it in... */
603	*pos++ = WLAN_EID_EXT_SUPP_RATES;
604	*pos = 0;
605	iwl_supported_rate_to_ie(pos, active_rates, active_rate_basic, &left);
606	if (*pos > 0) {
607		len += 2 + *pos;
608		pos += (*pos) + 1;
609	} else {
610		pos--;
611	}
612
613 fill_end:
614
615	left -= 2;
616	if (left < 0)
617		return 0;
618
619	*pos++ = WLAN_EID_HT_CAPABILITY;
620	*pos = 0;
621	iwl_ht_cap_to_ie(sband, pos, &left);
622	if (*pos > 0)
623		len += 2 + *pos;
624
625	return (u16)len;
626}
627
628static void iwl_bg_request_scan(struct work_struct *data)
629{
630	struct iwl_priv *priv =
631	    container_of(data, struct iwl_priv, request_scan);
632	struct iwl_host_cmd cmd = {
633		.id = REPLY_SCAN_CMD,
634		.len = sizeof(struct iwl_scan_cmd),
635		.meta.flags = CMD_SIZE_HUGE,
636	};
637	struct iwl_scan_cmd *scan;
638	struct ieee80211_conf *conf = NULL;
639	int ret = 0;
640	u32 rate_flags = 0;
641	u16 cmd_len;
642	enum ieee80211_band band;
643	u8 n_probes = 2;
644	u8 rx_chain = priv->hw_params.valid_rx_ant;
645	u8 rate;
646	DECLARE_SSID_BUF(ssid);
647
648	conf = ieee80211_get_hw_conf(priv->hw);
649
650	mutex_lock(&priv->mutex);
651
652	if (!iwl_is_ready(priv)) {
653		IWL_WARNING("request scan called when driver not ready.\n");
654		goto done;
655	}
656
657	/* Make sure the scan wasn't cancelled before this queued work
658	 * was given the chance to run... */
659	if (!test_bit(STATUS_SCANNING, &priv->status))
660		goto done;
661
662	/* This should never be called or scheduled if there is currently
663	 * a scan active in the hardware. */
664	if (test_bit(STATUS_SCAN_HW, &priv->status)) {
665		IWL_DEBUG_INFO("Multiple concurrent scan requests in parallel. "
666			       "Ignoring second request.\n");
667		ret = -EIO;
668		goto done;
669	}
670
671	if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
672		IWL_DEBUG_SCAN("Aborting scan due to device shutdown\n");
673		goto done;
674	}
675
676	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
677		IWL_DEBUG_HC("Scan request while abort pending.  Queuing.\n");
678		goto done;
679	}
680
681	if (iwl_is_rfkill(priv)) {
682		IWL_DEBUG_HC("Aborting scan due to RF Kill activation\n");
683		goto done;
684	}
685
686	if (!test_bit(STATUS_READY, &priv->status)) {
687		IWL_DEBUG_HC("Scan request while uninitialized.  Queuing.\n");
688		goto done;
689	}
690
691	if (!priv->scan_bands) {
692		IWL_DEBUG_HC("Aborting scan due to no requested bands\n");
693		goto done;
694	}
695
696	if (!priv->scan) {
697		priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
698				     IWL_MAX_SCAN_SIZE, GFP_KERNEL);
699		if (!priv->scan) {
700			ret = -ENOMEM;
701			goto done;
702		}
703	}
704	scan = priv->scan;
705	memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
706
707	scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
708	scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
709
710	if (iwl_is_associated(priv)) {
711		u16 interval = 0;
712		u32 extra;
713		u32 suspend_time = 100;
714		u32 scan_suspend_time = 100;
715		unsigned long flags;
716
717		IWL_DEBUG_INFO("Scanning while associated...\n");
718
719		spin_lock_irqsave(&priv->lock, flags);
720		interval = priv->beacon_int;
721		spin_unlock_irqrestore(&priv->lock, flags);
722
723		scan->suspend_time = 0;
724		scan->max_out_time = cpu_to_le32(200 * 1024);
725		if (!interval)
726			interval = suspend_time;
727
728		extra = (suspend_time / interval) << 22;
729		scan_suspend_time = (extra |
730		    ((suspend_time % interval) * 1024));
731		scan->suspend_time = cpu_to_le32(scan_suspend_time);
732		IWL_DEBUG_SCAN("suspend_time 0x%X beacon interval %d\n",
733			       scan_suspend_time, interval);
734	}
735
736	/* We should add the ability for user to lock to PASSIVE ONLY */
737	if (priv->one_direct_scan) {
738		IWL_DEBUG_SCAN("Start direct scan for '%s'\n",
739				print_ssid(ssid, priv->direct_ssid,
740					   priv->direct_ssid_len));
741		scan->direct_scan[0].id = WLAN_EID_SSID;
742		scan->direct_scan[0].len = priv->direct_ssid_len;
743		memcpy(scan->direct_scan[0].ssid,
744		       priv->direct_ssid, priv->direct_ssid_len);
745		n_probes++;
746	} else if (!iwl_is_associated(priv) && priv->essid_len) {
747		IWL_DEBUG_SCAN("Start direct scan for '%s' (not associated)\n",
748				print_ssid(ssid, priv->essid, priv->essid_len));
749		scan->direct_scan[0].id = WLAN_EID_SSID;
750		scan->direct_scan[0].len = priv->essid_len;
751		memcpy(scan->direct_scan[0].ssid, priv->essid, priv->essid_len);
752		n_probes++;
753	} else {
754		IWL_DEBUG_SCAN("Start indirect scan.\n");
755	}
756
757	scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
758	scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
759	scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
760
761
762	if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
763		band = IEEE80211_BAND_2GHZ;
764		scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
765		if (priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_PURE_40_MSK) {
766			rate = IWL_RATE_6M_PLCP;
767		} else {
768			rate = IWL_RATE_1M_PLCP;
769			rate_flags = RATE_MCS_CCK_MSK;
770		}
771		scan->good_CRC_th = 0;
772	} else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
773		band = IEEE80211_BAND_5GHZ;
774		rate = IWL_RATE_6M_PLCP;
775		scan->good_CRC_th = IWL_GOOD_CRC_TH;
776
777		/* Force use of chains B and C (0x6) for scan Rx for 4965
778		 * Avoid A (0x1) because of its off-channel reception on A-band.
779		 */
780		if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
781			rx_chain = 0x6;
782	} else {
783		IWL_WARNING("Invalid scan band count\n");
784		goto done;
785	}
786
787	priv->scan_tx_ant[band] =
788			 iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
789	rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
790	scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
791
792	/* MIMO is not used here, but value is required */
793	scan->rx_chain = RXON_RX_CHAIN_DRIVER_FORCE_MSK |
794				cpu_to_le16((0x7 << RXON_RX_CHAIN_VALID_POS) |
795				(rx_chain << RXON_RX_CHAIN_FORCE_SEL_POS) |
796				(0x7 << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS));
797
798	cmd_len = iwl_fill_probe_req(priv, band,
799				     (struct ieee80211_mgmt *)scan->data,
800				     IWL_MAX_SCAN_SIZE - sizeof(*scan));
801
802	scan->tx_cmd.len = cpu_to_le16(cmd_len);
803
804	if (priv->iw_mode == NL80211_IFTYPE_MONITOR)
805		scan->filter_flags = RXON_FILTER_PROMISC_MSK;
806
807	scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
808			       RXON_FILTER_BCON_AWARE_MSK);
809
810	scan->channel_count =
811		iwl_get_channels_for_scan(priv, band, 1, /* active */
812			n_probes,
813			(void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
814
815	if (scan->channel_count == 0) {
816		IWL_DEBUG_SCAN("channel count %d\n", scan->channel_count);
817		goto done;
818	}
819
820	cmd.len += le16_to_cpu(scan->tx_cmd.len) +
821	    scan->channel_count * sizeof(struct iwl_scan_channel);
822	cmd.data = scan;
823	scan->len = cpu_to_le16(cmd.len);
824
825	set_bit(STATUS_SCAN_HW, &priv->status);
826	ret = iwl_send_cmd_sync(priv, &cmd);
827	if (ret)
828		goto done;
829
830	queue_delayed_work(priv->workqueue, &priv->scan_check,
831			   IWL_SCAN_CHECK_WATCHDOG);
832
833	mutex_unlock(&priv->mutex);
834	return;
835
836 done:
837	/* Cannot perform scan. Make sure we clear scanning
838	* bits from status so next scan request can be performed.
839	* If we don't clear scanning status bit here all next scan
840	* will fail
841	*/
842	clear_bit(STATUS_SCAN_HW, &priv->status);
843	clear_bit(STATUS_SCANNING, &priv->status);
844	/* inform mac80211 scan aborted */
845	queue_work(priv->workqueue, &priv->scan_completed);
846	mutex_unlock(&priv->mutex);
847}
848
849static void iwl_bg_abort_scan(struct work_struct *work)
850{
851	struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
852
853	if (!iwl_is_ready(priv))
854		return;
855
856	mutex_lock(&priv->mutex);
857
858	set_bit(STATUS_SCAN_ABORTING, &priv->status);
859	iwl_send_scan_abort(priv);
860
861	mutex_unlock(&priv->mutex);
862}
863
864static void iwl_bg_scan_completed(struct work_struct *work)
865{
866	struct iwl_priv *priv =
867	    container_of(work, struct iwl_priv, scan_completed);
868
869	IWL_DEBUG_SCAN("SCAN complete scan\n");
870
871	if (test_bit(STATUS_EXIT_PENDING, &priv->status))
872		return;
873
874	ieee80211_scan_completed(priv->hw);
875
876	/* Since setting the TXPOWER may have been deferred while
877	 * performing the scan, fire one off */
878	mutex_lock(&priv->mutex);
879	iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
880	mutex_unlock(&priv->mutex);
881}
882
883
884void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
885{
886	INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
887	INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
888	INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
889	INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
890}
891EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
892
893