summaryrefslogtreecommitdiff
path: root/drivers/net/wireless/intel/iwlwifi/mvm/tdls.c
blob: 9df21a8d1fc1f48cd513236bcbe5789c285dca33 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
/******************************************************************************
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2014 Intel Mobile Communications GmbH
 * Copyright(c) 2017 Intel Deutschland GmbH
 * Copyright(C) 2018 - 2019 Intel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * The full GNU General Public License is included in this distribution
 * in the file called COPYING.
 *
 * Contact Information:
 *  Intel Linux Wireless <linuxwifi@intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 * BSD LICENSE
 *
 * Copyright(c) 2014 Intel Mobile Communications GmbH
 * Copyright(c) 2017 Intel Deutschland GmbH
 * Copyright(C) 2018 - 2019 Intel Corporation
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  * Neither the name Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *****************************************************************************/

#include <linux/etherdevice.h>
#include "mvm.h"
#include "time-event.h"
#include "iwl-io.h"
#include "iwl-prph.h"

#define TU_TO_US(x) (x * 1024)
#define TU_TO_MS(x) (TU_TO_US(x) / 1000)

void iwl_mvm_teardown_tdls_peers(struct iwl_mvm *mvm)
{
	struct ieee80211_sta *sta;
	struct iwl_mvm_sta *mvmsta;
	int i;

	lockdep_assert_held(&mvm->mutex);

	for (i = 0; i < ARRAY_SIZE(mvm->fw_id_to_mac_id); i++) {
		sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[i],
						lockdep_is_held(&mvm->mutex));
		if (!sta || IS_ERR(sta) || !sta->tdls)
			continue;

		mvmsta = iwl_mvm_sta_from_mac80211(sta);
		ieee80211_tdls_oper_request(mvmsta->vif, sta->addr,
				NL80211_TDLS_TEARDOWN,
				WLAN_REASON_TDLS_TEARDOWN_UNSPECIFIED,
				GFP_KERNEL);
	}
}

int iwl_mvm_tdls_sta_count(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
{
	struct ieee80211_sta *sta;
	struct iwl_mvm_sta *mvmsta;
	int count = 0;
	int i;

	lockdep_assert_held(&mvm->mutex);

	for (i = 0; i < ARRAY_SIZE(mvm->fw_id_to_mac_id); i++) {
		sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[i],
						lockdep_is_held(&mvm->mutex));
		if (!sta || IS_ERR(sta) || !sta->tdls)
			continue;

		if (vif) {
			mvmsta = iwl_mvm_sta_from_mac80211(sta);
			if (mvmsta->vif != vif)
				continue;
		}

		count++;
	}

	return count;
}

static void iwl_mvm_tdls_config(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
{
	struct iwl_rx_packet *pkt;
	struct iwl_tdls_config_res *resp;
	struct iwl_tdls_config_cmd tdls_cfg_cmd = {};
	struct iwl_host_cmd cmd = {
		.id = TDLS_CONFIG_CMD,
		.flags = CMD_WANT_SKB,
		.data = { &tdls_cfg_cmd, },
		.len = { sizeof(struct iwl_tdls_config_cmd), },
	};
	struct ieee80211_sta *sta;
	int ret, i, cnt;
	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);

	lockdep_assert_held(&mvm->mutex);

	tdls_cfg_cmd.id_and_color =
		cpu_to_le32(FW_CMD_ID_AND_COLOR(mvmvif->id, mvmvif->color));
	tdls_cfg_cmd.tx_to_ap_tid = IWL_MVM_TDLS_FW_TID;
	tdls_cfg_cmd.tx_to_ap_ssn = cpu_to_le16(0); /* not used for now */

	/* for now the Tx cmd is empty and unused */

	/* populate TDLS peer data */
	cnt = 0;
	for (i = 0; i < ARRAY_SIZE(mvm->fw_id_to_mac_id); i++) {
		sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[i],
						lockdep_is_held(&mvm->mutex));
		if (IS_ERR_OR_NULL(sta) || !sta->tdls)
			continue;

		tdls_cfg_cmd.sta_info[cnt].sta_id = i;
		tdls_cfg_cmd.sta_info[cnt].tx_to_peer_tid =
							IWL_MVM_TDLS_FW_TID;
		tdls_cfg_cmd.sta_info[cnt].tx_to_peer_ssn = cpu_to_le16(0);
		tdls_cfg_cmd.sta_info[cnt].is_initiator =
				cpu_to_le32(sta->tdls_initiator ? 1 : 0);

		cnt++;
	}

	tdls_cfg_cmd.tdls_peer_count = cnt;
	IWL_DEBUG_TDLS(mvm, "send TDLS config to FW for %d peers\n", cnt);

	ret = iwl_mvm_send_cmd(mvm, &cmd);
	if (WARN_ON_ONCE(ret))
		return;

	pkt = cmd.resp_pkt;

	WARN_ON_ONCE(iwl_rx_packet_payload_len(pkt) != sizeof(*resp));

	/* we don't really care about the response at this point */

	iwl_free_resp(&cmd);
}

void iwl_mvm_recalc_tdls_state(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
			       bool sta_added)
{
	int tdls_sta_cnt = iwl_mvm_tdls_sta_count(mvm, vif);

	/* when the first peer joins, send a power update first */
	if (tdls_sta_cnt == 1 && sta_added)
		iwl_mvm_power_update_mac(mvm);

	/* Configure the FW with TDLS peer info only if TDLS channel switch
	 * capability is set.
	 * TDLS config data is used currently only in TDLS channel switch code.
	 * Supposed to serve also TDLS buffer station which is not implemneted
	 * yet in FW*/
	if (fw_has_capa(&mvm->fw->ucode_capa,
			IWL_UCODE_TLV_CAPA_TDLS_CHANNEL_SWITCH))
		iwl_mvm_tdls_config(mvm, vif);

	/* when the last peer leaves, send a power update last */
	if (tdls_sta_cnt == 0 && !sta_added)
		iwl_mvm_power_update_mac(mvm);
}

void iwl_mvm_mac_mgd_protect_tdls_discover(struct ieee80211_hw *hw,
					   struct ieee80211_vif *vif)
{
	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
	u32 duration = 2 * vif->bss_conf.dtim_period * vif->bss_conf.beacon_int;

	/*
	 * iwl_mvm_protect_session() reads directly from the device
	 * (the system time), so make sure it is available.
	 */
	if (iwl_mvm_ref_sync(mvm, IWL_MVM_REF_PROTECT_TDLS))
		return;

	mutex_lock(&mvm->mutex);
	/* Protect the session to hear the TDLS setup response on the channel */
	iwl_mvm_protect_session(mvm, vif, duration, duration, 100, true);
	mutex_unlock(&mvm->mutex);

	iwl_mvm_unref(mvm, IWL_MVM_REF_PROTECT_TDLS);
}

static const char *
iwl_mvm_tdls_cs_state_str(enum iwl_mvm_tdls_cs_state state)
{
	switch (state) {
	case IWL_MVM_TDLS_SW_IDLE:
		return "IDLE";
	case IWL_MVM_TDLS_SW_REQ_SENT:
		return "REQ SENT";
	case IWL_MVM_TDLS_SW_RESP_RCVD:
		return "RESP RECEIVED";
	case IWL_MVM_TDLS_SW_REQ_RCVD:
		return "REQ RECEIVED";
	case IWL_MVM_TDLS_SW_ACTIVE:
		return "ACTIVE";
	}

	return NULL;
}

static void iwl_mvm_tdls_update_cs_state(struct iwl_mvm *mvm,
					 enum iwl_mvm_tdls_cs_state state)
{
	if (mvm->tdls_cs.state == state)
		return;

	IWL_DEBUG_TDLS(mvm, "TDLS channel switch state: %s -> %s\n",
		       iwl_mvm_tdls_cs_state_str(mvm->tdls_cs.state),
		       iwl_mvm_tdls_cs_state_str(state));
	mvm->tdls_cs.state = state;

	/* we only send requests to our switching peer - update sent time */
	if (state == IWL_MVM_TDLS_SW_REQ_SENT)
		mvm->tdls_cs.peer.sent_timestamp = iwl_mvm_get_systime(mvm);

	if (state == IWL_MVM_TDLS_SW_IDLE)
		mvm->tdls_cs.cur_sta_id = IWL_MVM_INVALID_STA;
}

void iwl_mvm_rx_tdls_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb)
{
	struct iwl_rx_packet *pkt = rxb_addr(rxb);
	struct iwl_tdls_channel_switch_notif *notif = (void *)pkt->data;
	struct ieee80211_sta *sta;
	unsigned int delay;
	struct iwl_mvm_sta *mvmsta;
	struct ieee80211_vif *vif;
	u32 sta_id = le32_to_cpu(notif->sta_id);

	lockdep_assert_held(&mvm->mutex);

	/* can fail sometimes */
	if (!le32_to_cpu(notif->status)) {
		iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_IDLE);
		return;
	}

	if (WARN_ON(sta_id >= IWL_MVM_STATION_COUNT))
		return;

	sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[sta_id],
					lockdep_is_held(&mvm->mutex));
	/* the station may not be here, but if it is, it must be a TDLS peer */
	if (IS_ERR_OR_NULL(sta) || WARN_ON(!sta->tdls))
		return;

	mvmsta = iwl_mvm_sta_from_mac80211(sta);
	vif = mvmsta->vif;

	/*
	 * Update state and possibly switch again after this is over (DTIM).
	 * Also convert TU to msec.
	 */
	delay = TU_TO_MS(vif->bss_conf.dtim_period * vif->bss_conf.beacon_int);
	mod_delayed_work(system_wq, &mvm->tdls_cs.dwork,
			 msecs_to_jiffies(delay));

	iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_ACTIVE);
}

static int
iwl_mvm_tdls_check_action(struct iwl_mvm *mvm,
			  enum iwl_tdls_channel_switch_type type,
			  const u8 *peer, bool peer_initiator, u32 timestamp)
{
	bool same_peer = false;
	int ret = 0;

	/* get the existing peer if it's there */
	if (mvm->tdls_cs.state != IWL_MVM_TDLS_SW_IDLE &&
	    mvm->tdls_cs.cur_sta_id != IWL_MVM_INVALID_STA) {
		struct ieee80211_sta *sta = rcu_dereference_protected(
				mvm->fw_id_to_mac_id[mvm->tdls_cs.cur_sta_id],
				lockdep_is_held(&mvm->mutex));
		if (!IS_ERR_OR_NULL(sta))
			same_peer = ether_addr_equal(peer, sta->addr);
	}

	switch (mvm->tdls_cs.state) {
	case IWL_MVM_TDLS_SW_IDLE:
		/*
		 * might be spurious packet from the peer after the switch is
		 * already done
		 */
		if (type == TDLS_MOVE_CH)
			ret = -EINVAL;
		break;
	case IWL_MVM_TDLS_SW_REQ_SENT:
		/* only allow requests from the same peer */
		if (!same_peer)
			ret = -EBUSY;
		else if (type == TDLS_SEND_CHAN_SW_RESP_AND_MOVE_CH &&
			 !peer_initiator)
			/*
			 * We received a ch-switch request while an outgoing
			 * one is pending. Allow it if the peer is the link
			 * initiator.
			 */
			ret = -EBUSY;
		else if (type == TDLS_SEND_CHAN_SW_REQ)
			/* wait for idle before sending another request */
			ret = -EBUSY;
		else if (timestamp <= mvm->tdls_cs.peer.sent_timestamp)
			/* we got a stale response - ignore it */
			ret = -EINVAL;
		break;
	case IWL_MVM_TDLS_SW_RESP_RCVD:
		/*
		 * we are waiting for the FW to give an "active" notification,
		 * so ignore requests in the meantime
		 */
		ret = -EBUSY;
		break;
	case IWL_MVM_TDLS_SW_REQ_RCVD:
		/* as above, allow the link initiator to proceed */
		if (type == TDLS_SEND_CHAN_SW_REQ) {
			if (!same_peer)
				ret = -EBUSY;
			else if (peer_initiator) /* they are the initiator */
				ret = -EBUSY;
		} else if (type == TDLS_MOVE_CH) {
			ret = -EINVAL;
		}
		break;
	case IWL_MVM_TDLS_SW_ACTIVE:
		/*
		 * the only valid request when active is a request to return
		 * to the base channel by the current off-channel peer
		 */
		if (type != TDLS_MOVE_CH || !same_peer)
			ret = -EBUSY;
		break;
	}

	if (ret)
		IWL_DEBUG_TDLS(mvm,
			       "Invalid TDLS action %d state %d peer %pM same_peer %d initiator %d\n",
			       type, mvm->tdls_cs.state, peer, same_peer,
			       peer_initiator);

	return ret;
}

static int
iwl_mvm_tdls_config_channel_switch(struct iwl_mvm *mvm,
				   struct ieee80211_vif *vif,
				   enum iwl_tdls_channel_switch_type type,
				   const u8 *peer, bool peer_initiator,
				   u8 oper_class,
				   struct cfg80211_chan_def *chandef,
				   u32 timestamp, u16 switch_time,
				   u16 switch_timeout, struct sk_buff *skb,
				   u32 ch_sw_tm_ie)
{
	struct ieee80211_sta *sta;
	struct iwl_mvm_sta *mvmsta;
	struct ieee80211_tx_info *info;
	struct ieee80211_hdr *hdr;
	struct iwl_tdls_channel_switch_cmd cmd = {0};
	struct iwl_tdls_channel_switch_cmd_tail *tail =
		iwl_mvm_chan_info_cmd_tail(mvm, &cmd.ci);
	u16 len = sizeof(cmd) - iwl_mvm_chan_info_padding(mvm);
	int ret;

	lockdep_assert_held(&mvm->mutex);

	ret = iwl_mvm_tdls_check_action(mvm, type, peer, peer_initiator,
					timestamp);
	if (ret)
		return ret;

	if (!skb || WARN_ON(skb->len > IWL_TDLS_CH_SW_FRAME_MAX_SIZE)) {
		ret = -EINVAL;
		goto out;
	}

	cmd.switch_type = type;
	tail->timing.frame_timestamp = cpu_to_le32(timestamp);
	tail->timing.switch_time = cpu_to_le32(switch_time);
	tail->timing.switch_timeout = cpu_to_le32(switch_timeout);

	rcu_read_lock();
	sta = ieee80211_find_sta(vif, peer);
	if (!sta) {
		rcu_read_unlock();
		ret = -ENOENT;
		goto out;
	}
	mvmsta = iwl_mvm_sta_from_mac80211(sta);
	cmd.peer_sta_id = cpu_to_le32(mvmsta->sta_id);

	if (!chandef) {
		if (mvm->tdls_cs.state == IWL_MVM_TDLS_SW_REQ_SENT &&
		    mvm->tdls_cs.peer.chandef.chan) {
			/* actually moving to the channel */
			chandef = &mvm->tdls_cs.peer.chandef;
		} else if (mvm->tdls_cs.state == IWL_MVM_TDLS_SW_ACTIVE &&
			   type == TDLS_MOVE_CH) {
			/* we need to return to base channel */
			struct ieee80211_chanctx_conf *chanctx =
					rcu_dereference(vif->chanctx_conf);

			if (WARN_ON_ONCE(!chanctx)) {
				rcu_read_unlock();
				goto out;
			}

			chandef = &chanctx->def;
		}
	}

	if (chandef)
		iwl_mvm_set_chan_info_chandef(mvm, &cmd.ci, chandef);

	/* keep quota calculation simple for now - 50% of DTIM for TDLS */
	tail->timing.max_offchan_duration =
			cpu_to_le32(TU_TO_US(vif->bss_conf.dtim_period *
					     vif->bss_conf.beacon_int) / 2);

	/* Switch time is the first element in the switch-timing IE. */
	tail->frame.switch_time_offset = cpu_to_le32(ch_sw_tm_ie + 2);

	info = IEEE80211_SKB_CB(skb);
	hdr = (void *)skb->data;
	if (info->control.hw_key) {
		if (info->control.hw_key->cipher != WLAN_CIPHER_SUITE_CCMP) {
			rcu_read_unlock();
			ret = -EINVAL;
			goto out;
		}
		iwl_mvm_set_tx_cmd_ccmp(info, &tail->frame.tx_cmd);
	}

	iwl_mvm_set_tx_cmd(mvm, skb, &tail->frame.tx_cmd, info,
			   mvmsta->sta_id);

	iwl_mvm_set_tx_cmd_rate(mvm, &tail->frame.tx_cmd, info, sta,
				hdr->frame_control);
	rcu_read_unlock();

	memcpy(tail->frame.data, skb->data, skb->len);

	ret = iwl_mvm_send_cmd_pdu(mvm, TDLS_CHANNEL_SWITCH_CMD, 0, len, &cmd);
	if (ret) {
		IWL_ERR(mvm, "Failed to send TDLS_CHANNEL_SWITCH cmd: %d\n",
			ret);
		goto out;
	}

	/* channel switch has started, update state */
	if (type != TDLS_MOVE_CH) {
		mvm->tdls_cs.cur_sta_id = mvmsta->sta_id;
		iwl_mvm_tdls_update_cs_state(mvm,
					     type == TDLS_SEND_CHAN_SW_REQ ?
					     IWL_MVM_TDLS_SW_REQ_SENT :
					     IWL_MVM_TDLS_SW_REQ_RCVD);
	} else {
		iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_RESP_RCVD);
	}

out:

	/* channel switch failed - we are idle */
	if (ret)
		iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_IDLE);

	return ret;
}

void iwl_mvm_tdls_ch_switch_work(struct work_struct *work)
{
	struct iwl_mvm *mvm;
	struct ieee80211_sta *sta;
	struct iwl_mvm_sta *mvmsta;
	struct ieee80211_vif *vif;
	unsigned int delay;
	int ret;

	mvm = container_of(work, struct iwl_mvm, tdls_cs.dwork.work);
	mutex_lock(&mvm->mutex);

	/* called after an active channel switch has finished or timed-out */
	iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_IDLE);

	/* station might be gone, in that case do nothing */
	if (mvm->tdls_cs.peer.sta_id == IWL_MVM_INVALID_STA)
		goto out;

	sta = rcu_dereference_protected(
				mvm->fw_id_to_mac_id[mvm->tdls_cs.peer.sta_id],
				lockdep_is_held(&mvm->mutex));
	/* the station may not be here, but if it is, it must be a TDLS peer */
	if (!sta || IS_ERR(sta) || WARN_ON(!sta->tdls))
		goto out;

	mvmsta = iwl_mvm_sta_from_mac80211(sta);
	vif = mvmsta->vif;
	ret = iwl_mvm_tdls_config_channel_switch(mvm, vif,
						 TDLS_SEND_CHAN_SW_REQ,
						 sta->addr,
						 mvm->tdls_cs.peer.initiator,
						 mvm->tdls_cs.peer.op_class,
						 &mvm->tdls_cs.peer.chandef,
						 0, 0, 0,
						 mvm->tdls_cs.peer.skb,
						 mvm->tdls_cs.peer.ch_sw_tm_ie);
	if (ret)
		IWL_ERR(mvm, "Not sending TDLS channel switch: %d\n", ret);

	/* retry after a DTIM if we failed sending now */
	delay = TU_TO_MS(vif->bss_conf.dtim_period * vif->bss_conf.beacon_int);
	schedule_delayed_work(&mvm->tdls_cs.dwork, msecs_to_jiffies(delay));
out:
	mutex_unlock(&mvm->mutex);
}

int
iwl_mvm_tdls_channel_switch(struct ieee80211_hw *hw,
			    struct ieee80211_vif *vif,
			    struct ieee80211_sta *sta, u8 oper_class,
			    struct cfg80211_chan_def *chandef,
			    struct sk_buff *tmpl_skb, u32 ch_sw_tm_ie)
{
	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
	struct iwl_mvm_sta *mvmsta;
	unsigned int delay;
	int ret;

	mutex_lock(&mvm->mutex);

	IWL_DEBUG_TDLS(mvm, "TDLS channel switch with %pM ch %d width %d\n",
		       sta->addr, chandef->chan->center_freq, chandef->width);

	/* we only support a single peer for channel switching */
	if (mvm->tdls_cs.peer.sta_id != IWL_MVM_INVALID_STA) {
		IWL_DEBUG_TDLS(mvm,
			       "Existing peer. Can't start switch with %pM\n",
			       sta->addr);
		ret = -EBUSY;
		goto out;
	}

	ret = iwl_mvm_tdls_config_channel_switch(mvm, vif,
						 TDLS_SEND_CHAN_SW_REQ,
						 sta->addr, sta->tdls_initiator,
						 oper_class, chandef, 0, 0, 0,
						 tmpl_skb, ch_sw_tm_ie);
	if (ret)
		goto out;

	/*
	 * Mark the peer as "in tdls switch" for this vif. We only allow a
	 * single such peer per vif.
	 */
	mvm->tdls_cs.peer.skb = skb_copy(tmpl_skb, GFP_KERNEL);
	if (!mvm->tdls_cs.peer.skb) {
		ret = -ENOMEM;
		goto out;
	}

	mvmsta = iwl_mvm_sta_from_mac80211(sta);
	mvm->tdls_cs.peer.sta_id = mvmsta->sta_id;
	mvm->tdls_cs.peer.chandef = *chandef;
	mvm->tdls_cs.peer.initiator = sta->tdls_initiator;
	mvm->tdls_cs.peer.op_class = oper_class;
	mvm->tdls_cs.peer.ch_sw_tm_ie = ch_sw_tm_ie;

	/*
	 * Wait for 2 DTIM periods before attempting the next switch. The next
	 * switch will be made sooner if the current one completes before that.
	 */
	delay = 2 * TU_TO_MS(vif->bss_conf.dtim_period *
			     vif->bss_conf.beacon_int);
	mod_delayed_work(system_wq, &mvm->tdls_cs.dwork,
			 msecs_to_jiffies(delay));

out:
	mutex_unlock(&mvm->mutex);
	return ret;
}

void iwl_mvm_tdls_cancel_channel_switch(struct ieee80211_hw *hw,
					struct ieee80211_vif *vif,
					struct ieee80211_sta *sta)
{
	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
	struct ieee80211_sta *cur_sta;
	bool wait_for_phy = false;

	mutex_lock(&mvm->mutex);

	IWL_DEBUG_TDLS(mvm, "TDLS cancel channel switch with %pM\n", sta->addr);

	/* we only support a single peer for channel switching */
	if (mvm->tdls_cs.peer.sta_id == IWL_MVM_INVALID_STA) {
		IWL_DEBUG_TDLS(mvm, "No ch switch peer - %pM\n", sta->addr);
		goto out;
	}

	cur_sta = rcu_dereference_protected(
				mvm->fw_id_to_mac_id[mvm->tdls_cs.peer.sta_id],
				lockdep_is_held(&mvm->mutex));
	/* make sure it's the same peer */
	if (cur_sta != sta)
		goto out;

	/*
	 * If we're currently in a switch because of the now canceled peer,
	 * wait a DTIM here to make sure the phy is back on the base channel.
	 * We can't otherwise force it.
	 */
	if (mvm->tdls_cs.cur_sta_id == mvm->tdls_cs.peer.sta_id &&
	    mvm->tdls_cs.state != IWL_MVM_TDLS_SW_IDLE)
		wait_for_phy = true;

	mvm->tdls_cs.peer.sta_id = IWL_MVM_INVALID_STA;
	dev_kfree_skb(mvm->tdls_cs.peer.skb);
	mvm->tdls_cs.peer.skb = NULL;

out:
	mutex_unlock(&mvm->mutex);

	/* make sure the phy is on the base channel */
	if (wait_for_phy)
		msleep(TU_TO_MS(vif->bss_conf.dtim_period *
				vif->bss_conf.beacon_int));

	/* flush the channel switch state */
	flush_delayed_work(&mvm->tdls_cs.dwork);

	IWL_DEBUG_TDLS(mvm, "TDLS ending channel switch with %pM\n", sta->addr);
}

void
iwl_mvm_tdls_recv_channel_switch(struct ieee80211_hw *hw,
				 struct ieee80211_vif *vif,
				 struct ieee80211_tdls_ch_sw_params *params)
{
	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
	enum iwl_tdls_channel_switch_type type;
	unsigned int delay;
	const char *action_str =
		params->action_code == WLAN_TDLS_CHANNEL_SWITCH_REQUEST ?
		"REQ" : "RESP";

	mutex_lock(&mvm->mutex);

	IWL_DEBUG_TDLS(mvm,
		       "Received TDLS ch switch action %s from %pM status %d\n",
		       action_str, params->sta->addr, params->status);

	/*
	 * we got a non-zero status from a peer we were switching to - move to
	 * the idle state and retry again later
	 */
	if (params->action_code == WLAN_TDLS_CHANNEL_SWITCH_RESPONSE &&
	    params->status != 0 &&
	    mvm->tdls_cs.state == IWL_MVM_TDLS_SW_REQ_SENT &&
	    mvm->tdls_cs.cur_sta_id != IWL_MVM_INVALID_STA) {
		struct ieee80211_sta *cur_sta;

		/* make sure it's the same peer */
		cur_sta = rcu_dereference_protected(
				mvm->fw_id_to_mac_id[mvm->tdls_cs.cur_sta_id],
				lockdep_is_held(&mvm->mutex));
		if (cur_sta == params->sta) {
			iwl_mvm_tdls_update_cs_state(mvm,
						     IWL_MVM_TDLS_SW_IDLE);
			goto retry;
		}
	}

	type = (params->action_code == WLAN_TDLS_CHANNEL_SWITCH_REQUEST) ?
	       TDLS_SEND_CHAN_SW_RESP_AND_MOVE_CH : TDLS_MOVE_CH;

	iwl_mvm_tdls_config_channel_switch(mvm, vif, type, params->sta->addr,
					   params->sta->tdls_initiator, 0,
					   params->chandef, params->timestamp,
					   params->switch_time,
					   params->switch_timeout,
					   params->tmpl_skb,
					   params->ch_sw_tm_ie);

retry:
	/* register a timeout in case we don't succeed in switching */
	delay = vif->bss_conf.dtim_period * vif->bss_conf.beacon_int *
		1024 / 1000;
	mod_delayed_work(system_wq, &mvm->tdls_cs.dwork,
			 msecs_to_jiffies(delay));
	mutex_unlock(&mvm->mutex);
}