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 <ilw@linux.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
57static 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
95static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
96{
97	/* check if scan was requested from mac80211 */
98	if (priv->scan_request) {
99		IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
100		ieee80211_scan_completed(priv->hw, aborted);
101	}
102
103	priv->scan_type = IWL_SCAN_NORMAL;
104	priv->scan_vif = NULL;
105	priv->scan_request = NULL;
106}
107
108static void iwl_process_scan_complete(struct iwl_priv *priv)
109{
110	bool aborted;
111
112	lockdep_assert_held(&priv->mutex);
113
114	if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->status))
115		return;
116
117	IWL_DEBUG_SCAN(priv, "Completed scan.\n");
118
119	cancel_delayed_work(&priv->scan_check);
120
121	aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
122	if (aborted)
123		IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
124
125	if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
126		IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
127		goto out_settings;
128	}
129
130	if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
131		int err;
132
133		/* Check if mac80211 requested scan during our internal scan */
134		if (priv->scan_request == NULL)
135			goto out_complete;
136
137		/* If so request a new scan */
138		err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
139					priv->scan_request->channels[0]->band);
140		if (err) {
141			IWL_DEBUG_SCAN(priv,
142				"failed to initiate pending scan: %d\n", err);
143			aborted = true;
144			goto out_complete;
145		}
146
147		return;
148	}
149
150out_complete:
151	iwl_complete_scan(priv, aborted);
152
153out_settings:
154	/* Can we still talk to firmware ? */
155	if (!iwl_is_ready_rf(priv))
156		return;
157
158	iwlagn_post_scan(priv);
159}
160
161void iwl_force_scan_end(struct iwl_priv *priv)
162{
163	lockdep_assert_held(&priv->mutex);
164
165	if (!test_bit(STATUS_SCANNING, &priv->status)) {
166		IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
167		return;
168	}
169
170	IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
171	clear_bit(STATUS_SCANNING, &priv->status);
172	clear_bit(STATUS_SCAN_HW, &priv->status);
173	clear_bit(STATUS_SCAN_ABORTING, &priv->status);
174	clear_bit(STATUS_SCAN_COMPLETE, &priv->status);
175	iwl_complete_scan(priv, true);
176}
177
178static void iwl_do_scan_abort(struct iwl_priv *priv)
179{
180	int ret;
181
182	lockdep_assert_held(&priv->mutex);
183
184	if (!test_bit(STATUS_SCANNING, &priv->status)) {
185		IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
186		return;
187	}
188
189	if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
190		IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
191		return;
192	}
193
194	ret = iwl_send_scan_abort(priv);
195	if (ret) {
196		IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
197		iwl_force_scan_end(priv);
198	} else
199		IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
200}
201
202/**
203 * iwl_scan_cancel - Cancel any currently executing HW scan
204 */
205int iwl_scan_cancel(struct iwl_priv *priv)
206{
207	IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
208	queue_work(priv->workqueue, &priv->abort_scan);
209	return 0;
210}
211
212/**
213 * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
214 * @ms: amount of time to wait (in milliseconds) for scan to abort
215 *
216 */
217void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
218{
219	unsigned long timeout = jiffies + msecs_to_jiffies(ms);
220
221	lockdep_assert_held(&priv->mutex);
222
223	IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
224
225	iwl_do_scan_abort(priv);
226
227	while (time_before_eq(jiffies, timeout)) {
228		if (!test_bit(STATUS_SCAN_HW, &priv->status))
229			goto finished;
230		msleep(20);
231	}
232
233	return;
234
235 finished:
236	/*
237	 * Now STATUS_SCAN_HW is clear. This means that the
238	 * device finished, but the background work is going
239	 * to execute at best as soon as we release the mutex.
240	 * Since we need to be able to issue a new scan right
241	 * after this function returns, run the complete here.
242	 * The STATUS_SCAN_COMPLETE bit will then be cleared
243	 * and prevent the background work from "completing"
244	 * a possible new scan.
245	 */
246	iwl_process_scan_complete(priv);
247}
248
249/* Service response to REPLY_SCAN_CMD (0x80) */
250static void iwl_rx_reply_scan(struct iwl_priv *priv,
251			      struct iwl_rx_cmd_buffer *rxb)
252{
253#ifdef CONFIG_IWLWIFI_DEBUG
254	struct iwl_rx_packet *pkt = rxb_addr(rxb);
255	struct iwl_scanreq_notification *notif = (void *)pkt->data;
256
257	IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
258#endif
259}
260
261/* Service SCAN_START_NOTIFICATION (0x82) */
262static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
263				    struct iwl_rx_cmd_buffer *rxb)
264{
265	struct iwl_rx_packet *pkt = rxb_addr(rxb);
266	struct iwl_scanstart_notification *notif = (void *)pkt->data;
267
268	priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
269	IWL_DEBUG_SCAN(priv, "Scan start: "
270		       "%d [802.11%s] "
271		       "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
272		       notif->channel,
273		       notif->band ? "bg" : "a",
274		       le32_to_cpu(notif->tsf_high),
275		       le32_to_cpu(notif->tsf_low),
276		       notif->status, notif->beacon_timer);
277}
278
279/* Service SCAN_RESULTS_NOTIFICATION (0x83) */
280static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
281				      struct iwl_rx_cmd_buffer *rxb)
282{
283#ifdef CONFIG_IWLWIFI_DEBUG
284	struct iwl_rx_packet *pkt = rxb_addr(rxb);
285	struct iwl_scanresults_notification *notif = (void *)pkt->data;
286
287	IWL_DEBUG_SCAN(priv, "Scan ch.res: "
288		       "%d [802.11%s] "
289		       "probe status: %u:%u "
290		       "(TSF: 0x%08X:%08X) - %d "
291		       "elapsed=%lu usec\n",
292		       notif->channel,
293		       notif->band ? "bg" : "a",
294		       notif->probe_status, notif->num_probe_not_sent,
295		       le32_to_cpu(notif->tsf_high),
296		       le32_to_cpu(notif->tsf_low),
297		       le32_to_cpu(notif->statistics[0]),
298		       le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
299#endif
300}
301
302/* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
303static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
304				       struct iwl_rx_cmd_buffer *rxb)
305{
306	struct iwl_rx_packet *pkt = rxb_addr(rxb);
307	struct iwl_scancomplete_notification *scan_notif = (void *)pkt->data;
308
309	IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
310		       scan_notif->scanned_channels,
311		       scan_notif->tsf_low,
312		       scan_notif->tsf_high, scan_notif->status);
313
314	IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
315		       (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
316		       jiffies_to_msecs(jiffies - priv->scan_start));
317
318	/*
319	 * When aborting, we run the scan completed background work inline
320	 * and the background work must then do nothing. The SCAN_COMPLETE
321	 * bit helps implement that logic and thus needs to be set before
322	 * queueing the work. Also, since the scan abort waits for SCAN_HW
323	 * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
324	 * to avoid a race there.
325	 */
326	set_bit(STATUS_SCAN_COMPLETE, &priv->status);
327	clear_bit(STATUS_SCAN_HW, &priv->status);
328	queue_work(priv->workqueue, &priv->scan_completed);
329
330	if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
331	    iwl_advanced_bt_coexist(priv) &&
332	    priv->bt_status != scan_notif->bt_status) {
333		if (scan_notif->bt_status) {
334			/* BT on */
335			if (!priv->bt_ch_announce)
336				priv->bt_traffic_load =
337					IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
338			/*
339			 * otherwise, no traffic load information provided
340			 * no changes made
341			 */
342		} else {
343			/* BT off */
344			priv->bt_traffic_load =
345				IWL_BT_COEX_TRAFFIC_LOAD_NONE;
346		}
347		priv->bt_status = scan_notif->bt_status;
348		queue_work(priv->workqueue,
349			   &priv->bt_traffic_change_work);
350	}
351}
352
353void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
354{
355	/* scan handlers */
356	priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
357	priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
358	priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
359					iwl_rx_scan_results_notif;
360	priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
361					iwl_rx_scan_complete_notif;
362}
363
364static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
365				     enum ieee80211_band band, u8 n_probes)
366{
367	if (band == IEEE80211_BAND_5GHZ)
368		return IWL_ACTIVE_DWELL_TIME_52 +
369			IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
370	else
371		return IWL_ACTIVE_DWELL_TIME_24 +
372			IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
373}
374
375static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
376{
377	struct iwl_rxon_context *ctx;
378	int limits[NUM_IWL_RXON_CTX] = {};
379	int n_active = 0;
380	u16 limit;
381
382	BUILD_BUG_ON(NUM_IWL_RXON_CTX != 2);
383
384	/*
385	 * If we're associated, we clamp the dwell time 98%
386	 * of the beacon interval (minus 2 * channel tune time)
387	 * If both contexts are active, we have to restrict to
388	 * 1/2 of the minimum of them, because they might be in
389	 * lock-step with the time inbetween only half of what
390	 * time we'd have in each of them.
391	 */
392	for_each_context(priv, ctx) {
393		switch (ctx->staging.dev_type) {
394		case RXON_DEV_TYPE_P2P:
395			/* no timing constraints */
396			continue;
397		case RXON_DEV_TYPE_ESS:
398		default:
399			/* timing constraints if associated */
400			if (!iwl_is_associated_ctx(ctx))
401				continue;
402			break;
403		case RXON_DEV_TYPE_CP:
404		case RXON_DEV_TYPE_2STA:
405			/*
406			 * These seem to always have timers for TBTT
407			 * active in uCode even when not associated yet.
408			 */
409			break;
410		}
411
412		limits[n_active++] = ctx->beacon_int ?: IWL_PASSIVE_DWELL_BASE;
413	}
414
415	switch (n_active) {
416	case 0:
417		return dwell_time;
418	case 2:
419		limit = (limits[1] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
420		limit /= 2;
421		dwell_time = min(limit, dwell_time);
422		/* fall through to limit further */
423	case 1:
424		limit = (limits[0] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
425		limit /= n_active;
426		return min(limit, dwell_time);
427	default:
428		WARN_ON_ONCE(1);
429		return dwell_time;
430	}
431}
432
433static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
434				      enum ieee80211_band band)
435{
436	u16 passive = (band == IEEE80211_BAND_2GHZ) ?
437	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
438	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
439
440	return iwl_limit_dwell(priv, passive);
441}
442
443/* Return valid, unused, channel for a passive scan to reset the RF */
444static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
445					enum ieee80211_band band)
446{
447	struct ieee80211_supported_band *sband = priv->hw->wiphy->bands[band];
448	struct iwl_rxon_context *ctx;
449	int i;
450
451	for (i = 0; i < sband->n_channels; i++) {
452		bool busy = false;
453
454		for_each_context(priv, ctx) {
455			busy = sband->channels[i].hw_value ==
456				le16_to_cpu(ctx->staging.channel);
457			if (busy)
458				break;
459		}
460
461		if (busy)
462			continue;
463
464		if (!(sband->channels[i].flags & IEEE80211_CHAN_DISABLED))
465			return sband->channels[i].hw_value;
466	}
467
468	return 0;
469}
470
471static int iwl_get_channel_for_reset_scan(struct iwl_priv *priv,
472					  struct ieee80211_vif *vif,
473					  enum ieee80211_band band,
474					  struct iwl_scan_channel *scan_ch)
475{
476	const struct ieee80211_supported_band *sband;
477	u16 channel;
478
479	sband = iwl_get_hw_mode(priv, band);
480	if (!sband) {
481		IWL_ERR(priv, "invalid band\n");
482		return 0;
483	}
484
485	channel = iwl_get_single_channel_number(priv, band);
486	if (channel) {
487		scan_ch->channel = cpu_to_le16(channel);
488		scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
489		scan_ch->active_dwell =
490			cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
491		scan_ch->passive_dwell =
492			cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
493		/* Set txpower levels to defaults */
494		scan_ch->dsp_atten = 110;
495		if (band == IEEE80211_BAND_5GHZ)
496			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
497		else
498			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
499		return 1;
500	}
501
502	IWL_ERR(priv, "no valid channel found\n");
503	return 0;
504}
505
506static int iwl_get_channels_for_scan(struct iwl_priv *priv,
507				     struct ieee80211_vif *vif,
508				     enum ieee80211_band band,
509				     u8 is_active, u8 n_probes,
510				     struct iwl_scan_channel *scan_ch)
511{
512	struct ieee80211_channel *chan;
513	const struct ieee80211_supported_band *sband;
514	u16 passive_dwell = 0;
515	u16 active_dwell = 0;
516	int added, i;
517	u16 channel;
518
519	sband = iwl_get_hw_mode(priv, band);
520	if (!sband)
521		return 0;
522
523	active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
524	passive_dwell = iwl_get_passive_dwell_time(priv, band);
525
526	if (passive_dwell <= active_dwell)
527		passive_dwell = active_dwell + 1;
528
529	for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
530		chan = priv->scan_request->channels[i];
531
532		if (chan->band != band)
533			continue;
534
535		channel = chan->hw_value;
536		scan_ch->channel = cpu_to_le16(channel);
537
538		if (!is_active || (chan->flags & IEEE80211_CHAN_NO_IR))
539			scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
540		else
541			scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
542
543		if (n_probes)
544			scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
545
546		scan_ch->active_dwell = cpu_to_le16(active_dwell);
547		scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
548
549		/* Set txpower levels to defaults */
550		scan_ch->dsp_atten = 110;
551
552		/* NOTE: if we were doing 6Mb OFDM for scans we'd use
553		 * power level:
554		 * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
555		 */
556		if (band == IEEE80211_BAND_5GHZ)
557			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
558		else
559			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
560
561		IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
562			       channel, le32_to_cpu(scan_ch->type),
563			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
564				"ACTIVE" : "PASSIVE",
565			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
566			       active_dwell : passive_dwell);
567
568		scan_ch++;
569		added++;
570	}
571
572	IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
573	return added;
574}
575
576/**
577 * iwl_fill_probe_req - fill in all required fields and IE for probe request
578 */
579
580static u16 iwl_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
581			      const u8 *ies, int ie_len, const u8 *ssid,
582			      u8 ssid_len, int left)
583{
584	int len = 0;
585	u8 *pos = NULL;
586
587	/* Make sure there is enough space for the probe request,
588	 * two mandatory IEs and the data */
589	left -= 24;
590	if (left < 0)
591		return 0;
592
593	frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
594	eth_broadcast_addr(frame->da);
595	memcpy(frame->sa, ta, ETH_ALEN);
596	eth_broadcast_addr(frame->bssid);
597	frame->seq_ctrl = 0;
598
599	len += 24;
600
601	/* ...next IE... */
602	pos = &frame->u.probe_req.variable[0];
603
604	/* fill in our SSID IE */
605	left -= ssid_len + 2;
606	if (left < 0)
607		return 0;
608	*pos++ = WLAN_EID_SSID;
609	*pos++ = ssid_len;
610	if (ssid && ssid_len) {
611		memcpy(pos, ssid, ssid_len);
612		pos += ssid_len;
613	}
614
615	len += ssid_len + 2;
616
617	if (WARN_ON(left < ie_len))
618		return len;
619
620	if (ies && ie_len) {
621		memcpy(pos, ies, ie_len);
622		len += ie_len;
623	}
624
625	return (u16)len;
626}
627
628static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
629{
630	struct iwl_host_cmd cmd = {
631		.id = REPLY_SCAN_CMD,
632		.len = { sizeof(struct iwl_scan_cmd), },
633	};
634	struct iwl_scan_cmd *scan;
635	struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
636	u32 rate_flags = 0;
637	u16 cmd_len = 0;
638	u16 rx_chain = 0;
639	enum ieee80211_band band;
640	u8 n_probes = 0;
641	u8 rx_ant = priv->nvm_data->valid_rx_ant;
642	u8 rate;
643	bool is_active = false;
644	int  chan_mod;
645	u8 active_chains;
646	u8 scan_tx_antennas = priv->nvm_data->valid_tx_ant;
647	int ret;
648	int scan_cmd_size = sizeof(struct iwl_scan_cmd) +
649			    MAX_SCAN_CHANNEL * sizeof(struct iwl_scan_channel) +
650			    priv->fw->ucode_capa.max_probe_length;
651	const u8 *ssid = NULL;
652	u8 ssid_len = 0;
653
654	if (WARN_ON(priv->scan_type == IWL_SCAN_NORMAL &&
655		    (!priv->scan_request ||
656		     priv->scan_request->n_channels > MAX_SCAN_CHANNEL)))
657		return -EINVAL;
658
659	lockdep_assert_held(&priv->mutex);
660
661	if (vif)
662		ctx = iwl_rxon_ctx_from_vif(vif);
663
664	if (!priv->scan_cmd) {
665		priv->scan_cmd = kmalloc(scan_cmd_size, GFP_KERNEL);
666		if (!priv->scan_cmd) {
667			IWL_DEBUG_SCAN(priv,
668				       "fail to allocate memory for scan\n");
669			return -ENOMEM;
670		}
671	}
672	scan = priv->scan_cmd;
673	memset(scan, 0, scan_cmd_size);
674
675	scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
676	scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
677
678	if (iwl_is_any_associated(priv)) {
679		u16 interval = 0;
680		u32 extra;
681		u32 suspend_time = 100;
682		u32 scan_suspend_time = 100;
683
684		IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
685		switch (priv->scan_type) {
686		case IWL_SCAN_RADIO_RESET:
687			interval = 0;
688			break;
689		case IWL_SCAN_NORMAL:
690			interval = vif->bss_conf.beacon_int;
691			break;
692		}
693
694		scan->suspend_time = 0;
695		scan->max_out_time = cpu_to_le32(200 * 1024);
696		if (!interval)
697			interval = suspend_time;
698
699		extra = (suspend_time / interval) << 22;
700		scan_suspend_time = (extra |
701		    ((suspend_time % interval) * 1024));
702		scan->suspend_time = cpu_to_le32(scan_suspend_time);
703		IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
704			       scan_suspend_time, interval);
705	}
706
707	switch (priv->scan_type) {
708	case IWL_SCAN_RADIO_RESET:
709		IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
710		/*
711		 * Override quiet time as firmware checks that active
712		 * dwell is >= quiet; since we use passive scan it'll
713		 * not actually be used.
714		 */
715		scan->quiet_time = cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
716		break;
717	case IWL_SCAN_NORMAL:
718		if (priv->scan_request->n_ssids) {
719			int i, p = 0;
720			IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
721			/*
722			 * The highest priority SSID is inserted to the
723			 * probe request template.
724			 */
725			ssid_len = priv->scan_request->ssids[0].ssid_len;
726			ssid = priv->scan_request->ssids[0].ssid;
727
728			/*
729			 * Invert the order of ssids, the firmware will invert
730			 * it back.
731			 */
732			for (i = priv->scan_request->n_ssids - 1; i >= 1; i--) {
733				scan->direct_scan[p].id = WLAN_EID_SSID;
734				scan->direct_scan[p].len =
735					priv->scan_request->ssids[i].ssid_len;
736				memcpy(scan->direct_scan[p].ssid,
737				       priv->scan_request->ssids[i].ssid,
738				       priv->scan_request->ssids[i].ssid_len);
739				n_probes++;
740				p++;
741			}
742			is_active = true;
743		} else
744			IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
745		break;
746	}
747
748	scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
749	scan->tx_cmd.sta_id = ctx->bcast_sta_id;
750	scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
751
752	switch (priv->scan_band) {
753	case IEEE80211_BAND_2GHZ:
754		scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
755		chan_mod = le32_to_cpu(
756			priv->contexts[IWL_RXON_CTX_BSS].active.flags &
757						RXON_FLG_CHANNEL_MODE_MSK)
758				       >> RXON_FLG_CHANNEL_MODE_POS;
759		if ((priv->scan_request && priv->scan_request->no_cck) ||
760		    chan_mod == CHANNEL_MODE_PURE_40) {
761			rate = IWL_RATE_6M_PLCP;
762		} else {
763			rate = IWL_RATE_1M_PLCP;
764			rate_flags = RATE_MCS_CCK_MSK;
765		}
766		/*
767		 * Internal scans are passive, so we can indiscriminately set
768		 * the BT ignore flag on 2.4 GHz since it applies to TX only.
769		 */
770		if (priv->lib->bt_params &&
771		    priv->lib->bt_params->advanced_bt_coexist)
772			scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
773		break;
774	case IEEE80211_BAND_5GHZ:
775		rate = IWL_RATE_6M_PLCP;
776		break;
777	default:
778		IWL_WARN(priv, "Invalid scan band\n");
779		return -EIO;
780	}
781
782	/*
783	 * If active scanning is requested but a certain channel is
784	 * marked passive, we can do active scanning if we detect
785	 * transmissions.
786	 *
787	 * There is an issue with some firmware versions that triggers
788	 * a sysassert on a "good CRC threshold" of zero (== disabled),
789	 * on a radar channel even though this means that we should NOT
790	 * send probes.
791	 *
792	 * The "good CRC threshold" is the number of frames that we
793	 * need to receive during our dwell time on a channel before
794	 * sending out probes -- setting this to a huge value will
795	 * mean we never reach it, but at the same time work around
796	 * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
797	 * here instead of IWL_GOOD_CRC_TH_DISABLED.
798	 *
799	 * This was fixed in later versions along with some other
800	 * scan changes, and the threshold behaves as a flag in those
801	 * versions.
802	 */
803	if (priv->new_scan_threshold_behaviour)
804		scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
805						IWL_GOOD_CRC_TH_DISABLED;
806	else
807		scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
808						IWL_GOOD_CRC_TH_NEVER;
809
810	band = priv->scan_band;
811
812	if (band == IEEE80211_BAND_2GHZ &&
813	    priv->lib->bt_params &&
814	    priv->lib->bt_params->advanced_bt_coexist) {
815		/* transmit 2.4 GHz probes only on first antenna */
816		scan_tx_antennas = first_antenna(scan_tx_antennas);
817	}
818
819	priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
820						    priv->scan_tx_ant[band],
821						    scan_tx_antennas);
822	rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
823	scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
824
825	/*
826	 * In power save mode while associated use one chain,
827	 * otherwise use all chains
828	 */
829	if (test_bit(STATUS_POWER_PMI, &priv->status) &&
830	    !(priv->hw->conf.flags & IEEE80211_CONF_IDLE)) {
831		/* rx_ant has been set to all valid chains previously */
832		active_chains = rx_ant &
833				((u8)(priv->chain_noise_data.active_chains));
834		if (!active_chains)
835			active_chains = rx_ant;
836
837		IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
838				priv->chain_noise_data.active_chains);
839
840		rx_ant = first_antenna(active_chains);
841	}
842	if (priv->lib->bt_params &&
843	    priv->lib->bt_params->advanced_bt_coexist &&
844	    priv->bt_full_concurrent) {
845		/* operated as 1x1 in full concurrency mode */
846		rx_ant = first_antenna(rx_ant);
847	}
848
849	/* MIMO is not used here, but value is required */
850	rx_chain |=
851		priv->nvm_data->valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
852	rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
853	rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
854	rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
855	scan->rx_chain = cpu_to_le16(rx_chain);
856	switch (priv->scan_type) {
857	case IWL_SCAN_NORMAL:
858		cmd_len = iwl_fill_probe_req(
859					(struct ieee80211_mgmt *)scan->data,
860					vif->addr,
861					priv->scan_request->ie,
862					priv->scan_request->ie_len,
863					ssid, ssid_len,
864					scan_cmd_size - sizeof(*scan));
865		break;
866	case IWL_SCAN_RADIO_RESET:
867		/* use bcast addr, will not be transmitted but must be valid */
868		cmd_len = iwl_fill_probe_req(
869					(struct ieee80211_mgmt *)scan->data,
870					iwl_bcast_addr, NULL, 0,
871					NULL, 0,
872					scan_cmd_size - sizeof(*scan));
873		break;
874	default:
875		BUG();
876	}
877	scan->tx_cmd.len = cpu_to_le16(cmd_len);
878
879	scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
880			       RXON_FILTER_BCON_AWARE_MSK);
881
882	switch (priv->scan_type) {
883	case IWL_SCAN_RADIO_RESET:
884		scan->channel_count =
885			iwl_get_channel_for_reset_scan(priv, vif, band,
886				(void *)&scan->data[cmd_len]);
887		break;
888	case IWL_SCAN_NORMAL:
889		scan->channel_count =
890			iwl_get_channels_for_scan(priv, vif, band,
891				is_active, n_probes,
892				(void *)&scan->data[cmd_len]);
893		break;
894	}
895
896	if (scan->channel_count == 0) {
897		IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
898		return -EIO;
899	}
900
901	cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
902	    scan->channel_count * sizeof(struct iwl_scan_channel);
903	cmd.data[0] = scan;
904	cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
905	scan->len = cpu_to_le16(cmd.len[0]);
906
907	/* set scan bit here for PAN params */
908	set_bit(STATUS_SCAN_HW, &priv->status);
909
910	ret = iwlagn_set_pan_params(priv);
911	if (ret) {
912		clear_bit(STATUS_SCAN_HW, &priv->status);
913		return ret;
914	}
915
916	ret = iwl_dvm_send_cmd(priv, &cmd);
917	if (ret) {
918		clear_bit(STATUS_SCAN_HW, &priv->status);
919		iwlagn_set_pan_params(priv);
920	}
921
922	return ret;
923}
924
925void iwl_init_scan_params(struct iwl_priv *priv)
926{
927	u8 ant_idx = fls(priv->nvm_data->valid_tx_ant) - 1;
928	if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
929		priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
930	if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
931		priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
932}
933
934int __must_check iwl_scan_initiate(struct iwl_priv *priv,
935				   struct ieee80211_vif *vif,
936				   enum iwl_scan_type scan_type,
937				   enum ieee80211_band band)
938{
939	int ret;
940
941	lockdep_assert_held(&priv->mutex);
942
943	cancel_delayed_work(&priv->scan_check);
944
945	if (!iwl_is_ready_rf(priv)) {
946		IWL_WARN(priv, "Request scan called when driver not ready.\n");
947		return -EIO;
948	}
949
950	if (test_bit(STATUS_SCAN_HW, &priv->status)) {
951		IWL_DEBUG_SCAN(priv,
952			"Multiple concurrent scan requests in parallel.\n");
953		return -EBUSY;
954	}
955
956	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
957		IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
958		return -EBUSY;
959	}
960
961	IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
962			scan_type == IWL_SCAN_NORMAL ? "" :
963			"internal short ");
964
965	set_bit(STATUS_SCANNING, &priv->status);
966	priv->scan_type = scan_type;
967	priv->scan_start = jiffies;
968	priv->scan_band = band;
969
970	ret = iwlagn_request_scan(priv, vif);
971	if (ret) {
972		clear_bit(STATUS_SCANNING, &priv->status);
973		priv->scan_type = IWL_SCAN_NORMAL;
974		return ret;
975	}
976
977	queue_delayed_work(priv->workqueue, &priv->scan_check,
978			   IWL_SCAN_CHECK_WATCHDOG);
979
980	return 0;
981}
982
983
984/*
985 * internal short scan, this function should only been called while associated.
986 * It will reset and tune the radio to prevent possible RF related problem
987 */
988void iwl_internal_short_hw_scan(struct iwl_priv *priv)
989{
990	queue_work(priv->workqueue, &priv->start_internal_scan);
991}
992
993static void iwl_bg_start_internal_scan(struct work_struct *work)
994{
995	struct iwl_priv *priv =
996		container_of(work, struct iwl_priv, start_internal_scan);
997
998	IWL_DEBUG_SCAN(priv, "Start internal scan\n");
999
1000	mutex_lock(&priv->mutex);
1001
1002	if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
1003		IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
1004		goto unlock;
1005	}
1006
1007	if (test_bit(STATUS_SCANNING, &priv->status)) {
1008		IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
1009		goto unlock;
1010	}
1011
1012	if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
1013		IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
1014 unlock:
1015	mutex_unlock(&priv->mutex);
1016}
1017
1018static void iwl_bg_scan_check(struct work_struct *data)
1019{
1020	struct iwl_priv *priv =
1021	    container_of(data, struct iwl_priv, scan_check.work);
1022
1023	IWL_DEBUG_SCAN(priv, "Scan check work\n");
1024
1025	/* Since we are here firmware does not finish scan and
1026	 * most likely is in bad shape, so we don't bother to
1027	 * send abort command, just force scan complete to mac80211 */
1028	mutex_lock(&priv->mutex);
1029	iwl_force_scan_end(priv);
1030	mutex_unlock(&priv->mutex);
1031}
1032
1033static void iwl_bg_abort_scan(struct work_struct *work)
1034{
1035	struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
1036
1037	IWL_DEBUG_SCAN(priv, "Abort scan work\n");
1038
1039	/* We keep scan_check work queued in case when firmware will not
1040	 * report back scan completed notification */
1041	mutex_lock(&priv->mutex);
1042	iwl_scan_cancel_timeout(priv, 200);
1043	mutex_unlock(&priv->mutex);
1044}
1045
1046static void iwl_bg_scan_completed(struct work_struct *work)
1047{
1048	struct iwl_priv *priv =
1049		container_of(work, struct iwl_priv, scan_completed);
1050
1051	mutex_lock(&priv->mutex);
1052	iwl_process_scan_complete(priv);
1053	mutex_unlock(&priv->mutex);
1054}
1055
1056void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
1057{
1058	INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
1059	INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
1060	INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
1061	INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
1062}
1063
1064void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
1065{
1066	cancel_work_sync(&priv->start_internal_scan);
1067	cancel_work_sync(&priv->abort_scan);
1068	cancel_work_sync(&priv->scan_completed);
1069
1070	if (cancel_delayed_work_sync(&priv->scan_check)) {
1071		mutex_lock(&priv->mutex);
1072		iwl_force_scan_end(priv);
1073		mutex_unlock(&priv->mutex);
1074	}
1075}
1076