1// SPDX-License-Identifier: GPL-2.0-only
2/******************************************************************************
3 *
4 * Copyright(c) 2008 - 2014 Intel Corporation. All rights reserved.
5 * Copyright(c) 2018        Intel Corporation
6 *****************************************************************************/
7#include <linux/slab.h>
8#include <linux/types.h>
9#include <linux/etherdevice.h>
10#include <net/mac80211.h>
11
12#include "dev.h"
13#include "agn.h"
14
15/* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
16 * sending probe req.  This should be set long enough to hear probe responses
17 * from more than one AP.  */
18#define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
19#define IWL_ACTIVE_DWELL_TIME_52    (20)
20
21#define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
22#define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
23
24/* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
25 * Must be set longer than active dwell time.
26 * For the most reliable scan, set > AP beacon interval (typically 100msec). */
27#define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
28#define IWL_PASSIVE_DWELL_TIME_52   (10)
29#define IWL_PASSIVE_DWELL_BASE      (100)
30#define IWL_CHANNEL_TUNE_TIME       5
31#define MAX_SCAN_CHANNEL	    50
32
33/* For reset radio, need minimal dwell time only */
34#define IWL_RADIO_RESET_DWELL_TIME	5
35
36static int iwl_send_scan_abort(struct iwl_priv *priv)
37{
38	int ret;
39	struct iwl_host_cmd cmd = {
40		.id = REPLY_SCAN_ABORT_CMD,
41		.flags = CMD_WANT_SKB,
42	};
43	__le32 *status;
44
45	/* Exit instantly with error when device is not ready
46	 * to receive scan abort command or it does not perform
47	 * hardware scan currently */
48	if (!test_bit(STATUS_READY, &priv->status) ||
49	    !test_bit(STATUS_SCAN_HW, &priv->status) ||
50	    test_bit(STATUS_FW_ERROR, &priv->status))
51		return -EIO;
52
53	ret = iwl_dvm_send_cmd(priv, &cmd);
54	if (ret)
55		return ret;
56
57	status = (void *)cmd.resp_pkt->data;
58	if (*status != CAN_ABORT_STATUS) {
59		/* The scan abort will return 1 for success or
60		 * 2 for "failure".  A failure condition can be
61		 * due to simply not being in an active scan which
62		 * can occur if we send the scan abort before we
63		 * the microcode has notified us that a scan is
64		 * completed. */
65		IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n",
66			       le32_to_cpu(*status));
67		ret = -EIO;
68	}
69
70	iwl_free_resp(&cmd);
71	return ret;
72}
73
74static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
75{
76	struct cfg80211_scan_info info = {
77		.aborted = aborted,
78	};
79
80	/* check if scan was requested from mac80211 */
81	if (priv->scan_request) {
82		IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
83		ieee80211_scan_completed(priv->hw, &info);
84	}
85
86	priv->scan_type = IWL_SCAN_NORMAL;
87	priv->scan_vif = NULL;
88	priv->scan_request = NULL;
89}
90
91static void iwl_process_scan_complete(struct iwl_priv *priv)
92{
93	bool aborted;
94
95	lockdep_assert_held(&priv->mutex);
96
97	if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->status))
98		return;
99
100	IWL_DEBUG_SCAN(priv, "Completed scan.\n");
101
102	cancel_delayed_work(&priv->scan_check);
103
104	aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
105	if (aborted)
106		IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
107
108	if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
109		IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
110		goto out_settings;
111	}
112
113	if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
114		int err;
115
116		/* Check if mac80211 requested scan during our internal scan */
117		if (priv->scan_request == NULL)
118			goto out_complete;
119
120		/* If so request a new scan */
121		err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
122					priv->scan_request->channels[0]->band);
123		if (err) {
124			IWL_DEBUG_SCAN(priv,
125				"failed to initiate pending scan: %d\n", err);
126			aborted = true;
127			goto out_complete;
128		}
129
130		return;
131	}
132
133out_complete:
134	iwl_complete_scan(priv, aborted);
135
136out_settings:
137	/* Can we still talk to firmware ? */
138	if (!iwl_is_ready_rf(priv))
139		return;
140
141	iwlagn_post_scan(priv);
142}
143
144void iwl_force_scan_end(struct iwl_priv *priv)
145{
146	lockdep_assert_held(&priv->mutex);
147
148	if (!test_bit(STATUS_SCANNING, &priv->status)) {
149		IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
150		return;
151	}
152
153	IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
154	clear_bit(STATUS_SCANNING, &priv->status);
155	clear_bit(STATUS_SCAN_HW, &priv->status);
156	clear_bit(STATUS_SCAN_ABORTING, &priv->status);
157	clear_bit(STATUS_SCAN_COMPLETE, &priv->status);
158	iwl_complete_scan(priv, true);
159}
160
161static void iwl_do_scan_abort(struct iwl_priv *priv)
162{
163	int ret;
164
165	lockdep_assert_held(&priv->mutex);
166
167	if (!test_bit(STATUS_SCANNING, &priv->status)) {
168		IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
169		return;
170	}
171
172	if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
173		IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
174		return;
175	}
176
177	ret = iwl_send_scan_abort(priv);
178	if (ret) {
179		IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
180		iwl_force_scan_end(priv);
181	} else
182		IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
183}
184
185/*
186 * iwl_scan_cancel - Cancel any currently executing HW scan
187 */
188int iwl_scan_cancel(struct iwl_priv *priv)
189{
190	IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
191	queue_work(priv->workqueue, &priv->abort_scan);
192	return 0;
193}
194
195/*
196 * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
197 * @ms: amount of time to wait (in milliseconds) for scan to abort
198 */
199void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
200{
201	unsigned long timeout = jiffies + msecs_to_jiffies(ms);
202
203	lockdep_assert_held(&priv->mutex);
204
205	IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
206
207	iwl_do_scan_abort(priv);
208
209	while (time_before_eq(jiffies, timeout)) {
210		if (!test_bit(STATUS_SCAN_HW, &priv->status))
211			goto finished;
212		msleep(20);
213	}
214
215	return;
216
217 finished:
218	/*
219	 * Now STATUS_SCAN_HW is clear. This means that the
220	 * device finished, but the background work is going
221	 * to execute at best as soon as we release the mutex.
222	 * Since we need to be able to issue a new scan right
223	 * after this function returns, run the complete here.
224	 * The STATUS_SCAN_COMPLETE bit will then be cleared
225	 * and prevent the background work from "completing"
226	 * a possible new scan.
227	 */
228	iwl_process_scan_complete(priv);
229}
230
231/* Service response to REPLY_SCAN_CMD (0x80) */
232static void iwl_rx_reply_scan(struct iwl_priv *priv,
233			      struct iwl_rx_cmd_buffer *rxb)
234{
235#ifdef CONFIG_IWLWIFI_DEBUG
236	struct iwl_rx_packet *pkt = rxb_addr(rxb);
237	struct iwl_scanreq_notification *notif = (void *)pkt->data;
238
239	IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
240#endif
241}
242
243/* Service SCAN_START_NOTIFICATION (0x82) */
244static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
245				    struct iwl_rx_cmd_buffer *rxb)
246{
247	struct iwl_rx_packet *pkt = rxb_addr(rxb);
248	struct iwl_scanstart_notification *notif = (void *)pkt->data;
249
250	priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
251	IWL_DEBUG_SCAN(priv, "Scan start: "
252		       "%d [802.11%s] "
253		       "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
254		       notif->channel,
255		       notif->band ? "bg" : "a",
256		       le32_to_cpu(notif->tsf_high),
257		       le32_to_cpu(notif->tsf_low),
258		       notif->status, notif->beacon_timer);
259}
260
261/* Service SCAN_RESULTS_NOTIFICATION (0x83) */
262static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
263				      struct iwl_rx_cmd_buffer *rxb)
264{
265#ifdef CONFIG_IWLWIFI_DEBUG
266	struct iwl_rx_packet *pkt = rxb_addr(rxb);
267	struct iwl_scanresults_notification *notif = (void *)pkt->data;
268
269	IWL_DEBUG_SCAN(priv, "Scan ch.res: "
270		       "%d [802.11%s] "
271		       "probe status: %u:%u "
272		       "(TSF: 0x%08X:%08X) - %d "
273		       "elapsed=%lu usec\n",
274		       notif->channel,
275		       notif->band ? "bg" : "a",
276		       notif->probe_status, notif->num_probe_not_sent,
277		       le32_to_cpu(notif->tsf_high),
278		       le32_to_cpu(notif->tsf_low),
279		       le32_to_cpu(notif->statistics[0]),
280		       le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
281#endif
282}
283
284/* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
285static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
286				       struct iwl_rx_cmd_buffer *rxb)
287{
288	struct iwl_rx_packet *pkt = rxb_addr(rxb);
289	struct iwl_scancomplete_notification *scan_notif = (void *)pkt->data;
290
291	IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
292		       scan_notif->scanned_channels,
293		       scan_notif->tsf_low,
294		       scan_notif->tsf_high, scan_notif->status);
295
296	IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
297		       (priv->scan_band == NL80211_BAND_2GHZ) ? "2.4" : "5.2",
298		       jiffies_to_msecs(jiffies - priv->scan_start));
299
300	/*
301	 * When aborting, we run the scan completed background work inline
302	 * and the background work must then do nothing. The SCAN_COMPLETE
303	 * bit helps implement that logic and thus needs to be set before
304	 * queueing the work. Also, since the scan abort waits for SCAN_HW
305	 * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
306	 * to avoid a race there.
307	 */
308	set_bit(STATUS_SCAN_COMPLETE, &priv->status);
309	clear_bit(STATUS_SCAN_HW, &priv->status);
310	queue_work(priv->workqueue, &priv->scan_completed);
311
312	if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
313	    iwl_advanced_bt_coexist(priv) &&
314	    priv->bt_status != scan_notif->bt_status) {
315		if (scan_notif->bt_status) {
316			/* BT on */
317			if (!priv->bt_ch_announce)
318				priv->bt_traffic_load =
319					IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
320			/*
321			 * otherwise, no traffic load information provided
322			 * no changes made
323			 */
324		} else {
325			/* BT off */
326			priv->bt_traffic_load =
327				IWL_BT_COEX_TRAFFIC_LOAD_NONE;
328		}
329		priv->bt_status = scan_notif->bt_status;
330		queue_work(priv->workqueue,
331			   &priv->bt_traffic_change_work);
332	}
333}
334
335void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
336{
337	/* scan handlers */
338	priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
339	priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
340	priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
341					iwl_rx_scan_results_notif;
342	priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
343					iwl_rx_scan_complete_notif;
344}
345
346static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
347				     enum nl80211_band band, u8 n_probes)
348{
349	if (band == NL80211_BAND_5GHZ)
350		return IWL_ACTIVE_DWELL_TIME_52 +
351			IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
352	else
353		return IWL_ACTIVE_DWELL_TIME_24 +
354			IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
355}
356
357static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
358{
359	struct iwl_rxon_context *ctx;
360	int limits[NUM_IWL_RXON_CTX] = {};
361	int n_active = 0;
362	u16 limit;
363
364	BUILD_BUG_ON(NUM_IWL_RXON_CTX != 2);
365
366	/*
367	 * If we're associated, we clamp the dwell time 98%
368	 * of the beacon interval (minus 2 * channel tune time)
369	 * If both contexts are active, we have to restrict to
370	 * 1/2 of the minimum of them, because they might be in
371	 * lock-step with the time inbetween only half of what
372	 * time we'd have in each of them.
373	 */
374	for_each_context(priv, ctx) {
375		switch (ctx->staging.dev_type) {
376		case RXON_DEV_TYPE_P2P:
377			/* no timing constraints */
378			continue;
379		case RXON_DEV_TYPE_ESS:
380		default:
381			/* timing constraints if associated */
382			if (!iwl_is_associated_ctx(ctx))
383				continue;
384			break;
385		case RXON_DEV_TYPE_CP:
386		case RXON_DEV_TYPE_2STA:
387			/*
388			 * These seem to always have timers for TBTT
389			 * active in uCode even when not associated yet.
390			 */
391			break;
392		}
393
394		limits[n_active++] = ctx->beacon_int ?: IWL_PASSIVE_DWELL_BASE;
395	}
396
397	switch (n_active) {
398	case 0:
399		return dwell_time;
400	case 2:
401		limit = (limits[1] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
402		limit /= 2;
403		dwell_time = min(limit, dwell_time);
404		fallthrough;
405	case 1:
406		limit = (limits[0] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
407		limit /= n_active;
408		return min(limit, dwell_time);
409	default:
410		WARN_ON_ONCE(1);
411		return dwell_time;
412	}
413}
414
415static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
416				      enum nl80211_band band)
417{
418	u16 passive = (band == NL80211_BAND_2GHZ) ?
419	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
420	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
421
422	return iwl_limit_dwell(priv, passive);
423}
424
425/* Return valid, unused, channel for a passive scan to reset the RF */
426static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
427					enum nl80211_band band)
428{
429	struct ieee80211_supported_band *sband = priv->hw->wiphy->bands[band];
430	struct iwl_rxon_context *ctx;
431	int i;
432
433	for (i = 0; i < sband->n_channels; i++) {
434		bool busy = false;
435
436		for_each_context(priv, ctx) {
437			busy = sband->channels[i].hw_value ==
438				le16_to_cpu(ctx->staging.channel);
439			if (busy)
440				break;
441		}
442
443		if (busy)
444			continue;
445
446		if (!(sband->channels[i].flags & IEEE80211_CHAN_DISABLED))
447			return sband->channels[i].hw_value;
448	}
449
450	return 0;
451}
452
453static int iwl_get_channel_for_reset_scan(struct iwl_priv *priv,
454					  struct ieee80211_vif *vif,
455					  enum nl80211_band band,
456					  struct iwl_scan_channel *scan_ch)
457{
458	const struct ieee80211_supported_band *sband;
459	u16 channel;
460
461	sband = iwl_get_hw_mode(priv, band);
462	if (!sband) {
463		IWL_ERR(priv, "invalid band\n");
464		return 0;
465	}
466
467	channel = iwl_get_single_channel_number(priv, band);
468	if (channel) {
469		scan_ch->channel = cpu_to_le16(channel);
470		scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
471		scan_ch->active_dwell =
472			cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
473		scan_ch->passive_dwell =
474			cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
475		/* Set txpower levels to defaults */
476		scan_ch->dsp_atten = 110;
477		if (band == NL80211_BAND_5GHZ)
478			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
479		else
480			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
481		return 1;
482	}
483
484	IWL_ERR(priv, "no valid channel found\n");
485	return 0;
486}
487
488static int iwl_get_channels_for_scan(struct iwl_priv *priv,
489				     struct ieee80211_vif *vif,
490				     enum nl80211_band band,
491				     u8 is_active, u8 n_probes,
492				     struct iwl_scan_channel *scan_ch)
493{
494	struct ieee80211_channel *chan;
495	const struct ieee80211_supported_band *sband;
496	u16 passive_dwell = 0;
497	u16 active_dwell = 0;
498	int added, i;
499	u16 channel;
500
501	sband = iwl_get_hw_mode(priv, band);
502	if (!sband)
503		return 0;
504
505	active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
506	passive_dwell = iwl_get_passive_dwell_time(priv, band);
507
508	if (passive_dwell <= active_dwell)
509		passive_dwell = active_dwell + 1;
510
511	for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
512		chan = priv->scan_request->channels[i];
513
514		if (chan->band != band)
515			continue;
516
517		channel = chan->hw_value;
518		scan_ch->channel = cpu_to_le16(channel);
519
520		if (!is_active || (chan->flags & IEEE80211_CHAN_NO_IR))
521			scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
522		else
523			scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
524
525		if (n_probes)
526			scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
527
528		scan_ch->active_dwell = cpu_to_le16(active_dwell);
529		scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
530
531		/* Set txpower levels to defaults */
532		scan_ch->dsp_atten = 110;
533
534		/* NOTE: if we were doing 6Mb OFDM for scans we'd use
535		 * power level:
536		 * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
537		 */
538		if (band == NL80211_BAND_5GHZ)
539			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
540		else
541			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
542
543		IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
544			       channel, le32_to_cpu(scan_ch->type),
545			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
546				"ACTIVE" : "PASSIVE",
547			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
548			       active_dwell : passive_dwell);
549
550		scan_ch++;
551		added++;
552	}
553
554	IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
555	return added;
556}
557
558/*
559 * iwl_fill_probe_req - fill in all required fields and IE for probe request
560 */
561static u16 iwl_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
562			      const u8 *ies, int ie_len, const u8 *ssid,
563			      u8 ssid_len, int left)
564{
565	int len = 0;
566	u8 *pos = NULL;
567
568	/* Make sure there is enough space for the probe request,
569	 * two mandatory IEs and the data */
570	left -= 24;
571	if (left < 0)
572		return 0;
573
574	frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
575	eth_broadcast_addr(frame->da);
576	memcpy(frame->sa, ta, ETH_ALEN);
577	eth_broadcast_addr(frame->bssid);
578	frame->seq_ctrl = 0;
579
580	len += 24;
581
582	/* ...next IE... */
583	pos = &frame->u.probe_req.variable[0];
584
585	/* fill in our SSID IE */
586	left -= ssid_len + 2;
587	if (left < 0)
588		return 0;
589	*pos++ = WLAN_EID_SSID;
590	*pos++ = ssid_len;
591	if (ssid && ssid_len) {
592		memcpy(pos, ssid, ssid_len);
593		pos += ssid_len;
594	}
595
596	len += ssid_len + 2;
597
598	if (WARN_ON(left < ie_len))
599		return len;
600
601	if (ies && ie_len) {
602		memcpy(pos, ies, ie_len);
603		len += ie_len;
604	}
605
606	return (u16)len;
607}
608
609static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
610{
611	struct iwl_host_cmd cmd = {
612		.id = REPLY_SCAN_CMD,
613		.len = { sizeof(struct iwl_scan_cmd), },
614	};
615	struct iwl_scan_cmd *scan;
616	struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
617	u32 rate_flags = 0;
618	u16 cmd_len = 0;
619	u16 rx_chain = 0;
620	enum nl80211_band band;
621	u8 n_probes = 0;
622	u8 rx_ant = priv->nvm_data->valid_rx_ant;
623	u8 rate;
624	bool is_active = false;
625	int  chan_mod;
626	u8 active_chains;
627	u8 scan_tx_antennas = priv->nvm_data->valid_tx_ant;
628	int ret;
629	size_t scan_cmd_size = sizeof(struct iwl_scan_cmd) +
630			    MAX_SCAN_CHANNEL * sizeof(struct iwl_scan_channel) +
631			    priv->fw->ucode_capa.max_probe_length;
632	const u8 *ssid = NULL;
633	u8 ssid_len = 0;
634
635	if (WARN_ON(priv->scan_type == IWL_SCAN_NORMAL &&
636		    (!priv->scan_request ||
637		     priv->scan_request->n_channels > MAX_SCAN_CHANNEL)))
638		return -EINVAL;
639
640	lockdep_assert_held(&priv->mutex);
641
642	if (vif)
643		ctx = iwl_rxon_ctx_from_vif(vif);
644
645	if (!priv->scan_cmd) {
646		priv->scan_cmd = kmalloc(scan_cmd_size, GFP_KERNEL);
647		if (!priv->scan_cmd) {
648			IWL_DEBUG_SCAN(priv,
649				       "fail to allocate memory for scan\n");
650			return -ENOMEM;
651		}
652		priv->scan_cmd_size = scan_cmd_size;
653	}
654	if (priv->scan_cmd_size < scan_cmd_size) {
655		IWL_DEBUG_SCAN(priv,
656			       "memory needed for scan grew unexpectedly\n");
657		return -ENOMEM;
658	}
659	scan = priv->scan_cmd;
660	memset(scan, 0, priv->scan_cmd_size);
661
662	scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
663	scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
664
665	if (iwl_is_any_associated(priv)) {
666		u16 interval = 0;
667		u32 extra;
668		u32 suspend_time = 100;
669		u32 scan_suspend_time = 100;
670
671		IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
672		switch (priv->scan_type) {
673		case IWL_SCAN_RADIO_RESET:
674			interval = 0;
675			break;
676		case IWL_SCAN_NORMAL:
677			interval = vif->bss_conf.beacon_int;
678			break;
679		}
680
681		scan->suspend_time = 0;
682		scan->max_out_time = cpu_to_le32(200 * 1024);
683		if (!interval)
684			interval = suspend_time;
685
686		extra = (suspend_time / interval) << 22;
687		scan_suspend_time = (extra |
688		    ((suspend_time % interval) * 1024));
689		scan->suspend_time = cpu_to_le32(scan_suspend_time);
690		IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
691			       scan_suspend_time, interval);
692	}
693
694	switch (priv->scan_type) {
695	case IWL_SCAN_RADIO_RESET:
696		IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
697		/*
698		 * Override quiet time as firmware checks that active
699		 * dwell is >= quiet; since we use passive scan it'll
700		 * not actually be used.
701		 */
702		scan->quiet_time = cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
703		break;
704	case IWL_SCAN_NORMAL:
705		if (priv->scan_request->n_ssids) {
706			int i, p = 0;
707			IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
708			/*
709			 * The highest priority SSID is inserted to the
710			 * probe request template.
711			 */
712			ssid_len = priv->scan_request->ssids[0].ssid_len;
713			ssid = priv->scan_request->ssids[0].ssid;
714
715			/*
716			 * Invert the order of ssids, the firmware will invert
717			 * it back.
718			 */
719			for (i = priv->scan_request->n_ssids - 1; i >= 1; i--) {
720				scan->direct_scan[p].id = WLAN_EID_SSID;
721				scan->direct_scan[p].len =
722					priv->scan_request->ssids[i].ssid_len;
723				memcpy(scan->direct_scan[p].ssid,
724				       priv->scan_request->ssids[i].ssid,
725				       priv->scan_request->ssids[i].ssid_len);
726				n_probes++;
727				p++;
728			}
729			is_active = true;
730		} else
731			IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
732		break;
733	}
734
735	scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
736	scan->tx_cmd.sta_id = ctx->bcast_sta_id;
737	scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
738
739	switch (priv->scan_band) {
740	case NL80211_BAND_2GHZ:
741		scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
742		chan_mod = le32_to_cpu(
743			priv->contexts[IWL_RXON_CTX_BSS].active.flags &
744						RXON_FLG_CHANNEL_MODE_MSK)
745				       >> RXON_FLG_CHANNEL_MODE_POS;
746		if ((priv->scan_request && priv->scan_request->no_cck) ||
747		    chan_mod == CHANNEL_MODE_PURE_40) {
748			rate = IWL_RATE_6M_PLCP;
749		} else {
750			rate = IWL_RATE_1M_PLCP;
751			rate_flags = RATE_MCS_CCK_MSK;
752		}
753		/*
754		 * Internal scans are passive, so we can indiscriminately set
755		 * the BT ignore flag on 2.4 GHz since it applies to TX only.
756		 */
757		if (priv->lib->bt_params &&
758		    priv->lib->bt_params->advanced_bt_coexist)
759			scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
760		break;
761	case NL80211_BAND_5GHZ:
762		rate = IWL_RATE_6M_PLCP;
763		break;
764	default:
765		IWL_WARN(priv, "Invalid scan band\n");
766		return -EIO;
767	}
768
769	/*
770	 * If active scanning is requested but a certain channel is
771	 * marked passive, we can do active scanning if we detect
772	 * transmissions.
773	 *
774	 * There is an issue with some firmware versions that triggers
775	 * a sysassert on a "good CRC threshold" of zero (== disabled),
776	 * on a radar channel even though this means that we should NOT
777	 * send probes.
778	 *
779	 * The "good CRC threshold" is the number of frames that we
780	 * need to receive during our dwell time on a channel before
781	 * sending out probes -- setting this to a huge value will
782	 * mean we never reach it, but at the same time work around
783	 * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
784	 * here instead of IWL_GOOD_CRC_TH_DISABLED.
785	 *
786	 * This was fixed in later versions along with some other
787	 * scan changes, and the threshold behaves as a flag in those
788	 * versions.
789	 */
790	if (priv->new_scan_threshold_behaviour)
791		scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
792						IWL_GOOD_CRC_TH_DISABLED;
793	else
794		scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
795						IWL_GOOD_CRC_TH_NEVER;
796
797	band = priv->scan_band;
798
799	if (band == NL80211_BAND_2GHZ &&
800	    priv->lib->bt_params &&
801	    priv->lib->bt_params->advanced_bt_coexist) {
802		/* transmit 2.4 GHz probes only on first antenna */
803		scan_tx_antennas = first_antenna(scan_tx_antennas);
804	}
805
806	priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
807						    priv->scan_tx_ant[band],
808						    scan_tx_antennas);
809	rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
810	scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
811
812	/*
813	 * In power save mode while associated use one chain,
814	 * otherwise use all chains
815	 */
816	if (test_bit(STATUS_POWER_PMI, &priv->status) &&
817	    !(priv->hw->conf.flags & IEEE80211_CONF_IDLE)) {
818		/* rx_ant has been set to all valid chains previously */
819		active_chains = rx_ant &
820				((u8)(priv->chain_noise_data.active_chains));
821		if (!active_chains)
822			active_chains = rx_ant;
823
824		IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
825				priv->chain_noise_data.active_chains);
826
827		rx_ant = first_antenna(active_chains);
828	}
829	if (priv->lib->bt_params &&
830	    priv->lib->bt_params->advanced_bt_coexist &&
831	    priv->bt_full_concurrent) {
832		/* operated as 1x1 in full concurrency mode */
833		rx_ant = first_antenna(rx_ant);
834	}
835
836	/* MIMO is not used here, but value is required */
837	rx_chain |=
838		priv->nvm_data->valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
839	rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
840	rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
841	rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
842	scan->rx_chain = cpu_to_le16(rx_chain);
843	switch (priv->scan_type) {
844	case IWL_SCAN_NORMAL:
845		cmd_len = iwl_fill_probe_req(
846					(struct ieee80211_mgmt *)scan->data,
847					vif->addr,
848					priv->scan_request->ie,
849					priv->scan_request->ie_len,
850					ssid, ssid_len,
851					scan_cmd_size - sizeof(*scan));
852		break;
853	case IWL_SCAN_RADIO_RESET:
854		/* use bcast addr, will not be transmitted but must be valid */
855		cmd_len = iwl_fill_probe_req(
856					(struct ieee80211_mgmt *)scan->data,
857					iwl_bcast_addr, NULL, 0,
858					NULL, 0,
859					scan_cmd_size - sizeof(*scan));
860		break;
861	default:
862		BUG();
863	}
864	scan->tx_cmd.len = cpu_to_le16(cmd_len);
865
866	scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
867			       RXON_FILTER_BCON_AWARE_MSK);
868
869	switch (priv->scan_type) {
870	case IWL_SCAN_RADIO_RESET:
871		scan->channel_count =
872			iwl_get_channel_for_reset_scan(priv, vif, band,
873				(void *)&scan->data[cmd_len]);
874		break;
875	case IWL_SCAN_NORMAL:
876		scan->channel_count =
877			iwl_get_channels_for_scan(priv, vif, band,
878				is_active, n_probes,
879				(void *)&scan->data[cmd_len]);
880		break;
881	}
882
883	if (scan->channel_count == 0) {
884		IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
885		return -EIO;
886	}
887
888	cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
889	    scan->channel_count * sizeof(struct iwl_scan_channel);
890	cmd.data[0] = scan;
891	cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
892	scan->len = cpu_to_le16(cmd.len[0]);
893
894	/* set scan bit here for PAN params */
895	set_bit(STATUS_SCAN_HW, &priv->status);
896
897	ret = iwlagn_set_pan_params(priv);
898	if (ret) {
899		clear_bit(STATUS_SCAN_HW, &priv->status);
900		return ret;
901	}
902
903	ret = iwl_dvm_send_cmd(priv, &cmd);
904	if (ret) {
905		clear_bit(STATUS_SCAN_HW, &priv->status);
906		iwlagn_set_pan_params(priv);
907	}
908
909	return ret;
910}
911
912void iwl_init_scan_params(struct iwl_priv *priv)
913{
914	u8 ant_idx = fls(priv->nvm_data->valid_tx_ant) - 1;
915	if (!priv->scan_tx_ant[NL80211_BAND_5GHZ])
916		priv->scan_tx_ant[NL80211_BAND_5GHZ] = ant_idx;
917	if (!priv->scan_tx_ant[NL80211_BAND_2GHZ])
918		priv->scan_tx_ant[NL80211_BAND_2GHZ] = ant_idx;
919}
920
921int __must_check iwl_scan_initiate(struct iwl_priv *priv,
922				   struct ieee80211_vif *vif,
923				   enum iwl_scan_type scan_type,
924				   enum nl80211_band band)
925{
926	int ret;
927
928	lockdep_assert_held(&priv->mutex);
929
930	cancel_delayed_work(&priv->scan_check);
931
932	if (!iwl_is_ready_rf(priv)) {
933		IWL_WARN(priv, "Request scan called when driver not ready.\n");
934		return -EIO;
935	}
936
937	if (test_bit(STATUS_SCAN_HW, &priv->status)) {
938		IWL_DEBUG_SCAN(priv,
939			"Multiple concurrent scan requests in parallel.\n");
940		return -EBUSY;
941	}
942
943	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
944		IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
945		return -EBUSY;
946	}
947
948	IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
949			scan_type == IWL_SCAN_NORMAL ? "" :
950			"internal short ");
951
952	set_bit(STATUS_SCANNING, &priv->status);
953	priv->scan_type = scan_type;
954	priv->scan_start = jiffies;
955	priv->scan_band = band;
956
957	ret = iwlagn_request_scan(priv, vif);
958	if (ret) {
959		clear_bit(STATUS_SCANNING, &priv->status);
960		priv->scan_type = IWL_SCAN_NORMAL;
961		return ret;
962	}
963
964	queue_delayed_work(priv->workqueue, &priv->scan_check,
965			   IWL_SCAN_CHECK_WATCHDOG);
966
967	return 0;
968}
969
970
971/*
972 * internal short scan, this function should only been called while associated.
973 * It will reset and tune the radio to prevent possible RF related problem
974 */
975void iwl_internal_short_hw_scan(struct iwl_priv *priv)
976{
977	queue_work(priv->workqueue, &priv->start_internal_scan);
978}
979
980static void iwl_bg_start_internal_scan(struct work_struct *work)
981{
982	struct iwl_priv *priv =
983		container_of(work, struct iwl_priv, start_internal_scan);
984
985	IWL_DEBUG_SCAN(priv, "Start internal scan\n");
986
987	mutex_lock(&priv->mutex);
988
989	if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
990		IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
991		goto unlock;
992	}
993
994	if (test_bit(STATUS_SCANNING, &priv->status)) {
995		IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
996		goto unlock;
997	}
998
999	if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
1000		IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
1001 unlock:
1002	mutex_unlock(&priv->mutex);
1003}
1004
1005static void iwl_bg_scan_check(struct work_struct *data)
1006{
1007	struct iwl_priv *priv =
1008	    container_of(data, struct iwl_priv, scan_check.work);
1009
1010	IWL_DEBUG_SCAN(priv, "Scan check work\n");
1011
1012	/* Since we are here firmware does not finish scan and
1013	 * most likely is in bad shape, so we don't bother to
1014	 * send abort command, just force scan complete to mac80211 */
1015	mutex_lock(&priv->mutex);
1016	iwl_force_scan_end(priv);
1017	mutex_unlock(&priv->mutex);
1018}
1019
1020static void iwl_bg_abort_scan(struct work_struct *work)
1021{
1022	struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
1023
1024	IWL_DEBUG_SCAN(priv, "Abort scan work\n");
1025
1026	/* We keep scan_check work queued in case when firmware will not
1027	 * report back scan completed notification */
1028	mutex_lock(&priv->mutex);
1029	iwl_scan_cancel_timeout(priv, 200);
1030	mutex_unlock(&priv->mutex);
1031}
1032
1033static void iwl_bg_scan_completed(struct work_struct *work)
1034{
1035	struct iwl_priv *priv =
1036		container_of(work, struct iwl_priv, scan_completed);
1037
1038	mutex_lock(&priv->mutex);
1039	iwl_process_scan_complete(priv);
1040	mutex_unlock(&priv->mutex);
1041}
1042
1043void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
1044{
1045	INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
1046	INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
1047	INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
1048	INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
1049}
1050
1051void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
1052{
1053	cancel_work_sync(&priv->start_internal_scan);
1054	cancel_work_sync(&priv->abort_scan);
1055	cancel_work_sync(&priv->scan_completed);
1056
1057	if (cancel_delayed_work_sync(&priv->scan_check)) {
1058		mutex_lock(&priv->mutex);
1059		iwl_force_scan_end(priv);
1060		mutex_unlock(&priv->mutex);
1061	}
1062}
1063