1 /******************************************************************************
2  *
3  * This file is provided under a dual BSD/GPLv2 license.  When using or
4  * redistributing this file, you may do so under either license.
5  *
6  * GPL LICENSE SUMMARY
7  *
8  * Copyright(c) 2014 Intel Mobile Communications GmbH
9  * Copyright(c) 2017 Intel Deutschland GmbH
10  * Copyright(C) 2018 - 2019 Intel Corporation
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of version 2 of the GNU General Public License as
14  * published by the Free Software Foundation.
15  *
16  * This program is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  * General Public License for more details.
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 <linuxwifi@intel.com>
26  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
27  *
28  * BSD LICENSE
29  *
30  * Copyright(c) 2014 Intel Mobile Communications GmbH
31  * Copyright(c) 2017 Intel Deutschland GmbH
32  * Copyright(C) 2018 - 2019 Intel Corporation
33  * All rights reserved.
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36  * modification, are permitted provided that the following conditions
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40  *    notice, this list of conditions and the following disclaimer.
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47  *    from this software without specific prior written permission.
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49  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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51  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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58  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
59  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
60  *
61  *****************************************************************************/
62 
63 #include <linux/etherdevice.h>
64 #include "mvm.h"
65 #include "time-event.h"
66 #include "iwl-io.h"
67 #include "iwl-prph.h"
68 
69 #define TU_TO_US(x) (x * 1024)
70 #define TU_TO_MS(x) (TU_TO_US(x) / 1000)
71 
72 void iwl_mvm_teardown_tdls_peers(struct iwl_mvm *mvm)
73 {
74 	struct ieee80211_sta *sta;
75 	struct iwl_mvm_sta *mvmsta;
76 	int i;
77 
78 	lockdep_assert_held(&mvm->mutex);
79 
80 	for (i = 0; i < ARRAY_SIZE(mvm->fw_id_to_mac_id); i++) {
81 		sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[i],
82 						lockdep_is_held(&mvm->mutex));
83 		if (!sta || IS_ERR(sta) || !sta->tdls)
84 			continue;
85 
86 		mvmsta = iwl_mvm_sta_from_mac80211(sta);
87 		ieee80211_tdls_oper_request(mvmsta->vif, sta->addr,
88 				NL80211_TDLS_TEARDOWN,
89 				WLAN_REASON_TDLS_TEARDOWN_UNSPECIFIED,
90 				GFP_KERNEL);
91 	}
92 }
93 
94 int iwl_mvm_tdls_sta_count(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
95 {
96 	struct ieee80211_sta *sta;
97 	struct iwl_mvm_sta *mvmsta;
98 	int count = 0;
99 	int i;
100 
101 	lockdep_assert_held(&mvm->mutex);
102 
103 	for (i = 0; i < ARRAY_SIZE(mvm->fw_id_to_mac_id); i++) {
104 		sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[i],
105 						lockdep_is_held(&mvm->mutex));
106 		if (!sta || IS_ERR(sta) || !sta->tdls)
107 			continue;
108 
109 		if (vif) {
110 			mvmsta = iwl_mvm_sta_from_mac80211(sta);
111 			if (mvmsta->vif != vif)
112 				continue;
113 		}
114 
115 		count++;
116 	}
117 
118 	return count;
119 }
120 
121 static void iwl_mvm_tdls_config(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
122 {
123 	struct iwl_rx_packet *pkt;
124 	struct iwl_tdls_config_res *resp;
125 	struct iwl_tdls_config_cmd tdls_cfg_cmd = {};
126 	struct iwl_host_cmd cmd = {
127 		.id = TDLS_CONFIG_CMD,
128 		.flags = CMD_WANT_SKB,
129 		.data = { &tdls_cfg_cmd, },
130 		.len = { sizeof(struct iwl_tdls_config_cmd), },
131 	};
132 	struct ieee80211_sta *sta;
133 	int ret, i, cnt;
134 	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
135 
136 	lockdep_assert_held(&mvm->mutex);
137 
138 	tdls_cfg_cmd.id_and_color =
139 		cpu_to_le32(FW_CMD_ID_AND_COLOR(mvmvif->id, mvmvif->color));
140 	tdls_cfg_cmd.tx_to_ap_tid = IWL_MVM_TDLS_FW_TID;
141 	tdls_cfg_cmd.tx_to_ap_ssn = cpu_to_le16(0); /* not used for now */
142 
143 	/* for now the Tx cmd is empty and unused */
144 
145 	/* populate TDLS peer data */
146 	cnt = 0;
147 	for (i = 0; i < ARRAY_SIZE(mvm->fw_id_to_mac_id); i++) {
148 		sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[i],
149 						lockdep_is_held(&mvm->mutex));
150 		if (IS_ERR_OR_NULL(sta) || !sta->tdls)
151 			continue;
152 
153 		tdls_cfg_cmd.sta_info[cnt].sta_id = i;
154 		tdls_cfg_cmd.sta_info[cnt].tx_to_peer_tid =
155 							IWL_MVM_TDLS_FW_TID;
156 		tdls_cfg_cmd.sta_info[cnt].tx_to_peer_ssn = cpu_to_le16(0);
157 		tdls_cfg_cmd.sta_info[cnt].is_initiator =
158 				cpu_to_le32(sta->tdls_initiator ? 1 : 0);
159 
160 		cnt++;
161 	}
162 
163 	tdls_cfg_cmd.tdls_peer_count = cnt;
164 	IWL_DEBUG_TDLS(mvm, "send TDLS config to FW for %d peers\n", cnt);
165 
166 	ret = iwl_mvm_send_cmd(mvm, &cmd);
167 	if (WARN_ON_ONCE(ret))
168 		return;
169 
170 	pkt = cmd.resp_pkt;
171 
172 	WARN_ON_ONCE(iwl_rx_packet_payload_len(pkt) != sizeof(*resp));
173 
174 	/* we don't really care about the response at this point */
175 
176 	iwl_free_resp(&cmd);
177 }
178 
179 void iwl_mvm_recalc_tdls_state(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
180 			       bool sta_added)
181 {
182 	int tdls_sta_cnt = iwl_mvm_tdls_sta_count(mvm, vif);
183 
184 	/* when the first peer joins, send a power update first */
185 	if (tdls_sta_cnt == 1 && sta_added)
186 		iwl_mvm_power_update_mac(mvm);
187 
188 	/* Configure the FW with TDLS peer info only if TDLS channel switch
189 	 * capability is set.
190 	 * TDLS config data is used currently only in TDLS channel switch code.
191 	 * Supposed to serve also TDLS buffer station which is not implemneted
192 	 * yet in FW*/
193 	if (fw_has_capa(&mvm->fw->ucode_capa,
194 			IWL_UCODE_TLV_CAPA_TDLS_CHANNEL_SWITCH))
195 		iwl_mvm_tdls_config(mvm, vif);
196 
197 	/* when the last peer leaves, send a power update last */
198 	if (tdls_sta_cnt == 0 && !sta_added)
199 		iwl_mvm_power_update_mac(mvm);
200 }
201 
202 void iwl_mvm_mac_mgd_protect_tdls_discover(struct ieee80211_hw *hw,
203 					   struct ieee80211_vif *vif)
204 {
205 	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
206 	u32 duration = 2 * vif->bss_conf.dtim_period * vif->bss_conf.beacon_int;
207 
208 	mutex_lock(&mvm->mutex);
209 	/* Protect the session to hear the TDLS setup response on the channel */
210 	iwl_mvm_protect_session(mvm, vif, duration, duration, 100, true);
211 	mutex_unlock(&mvm->mutex);
212 }
213 
214 static const char *
215 iwl_mvm_tdls_cs_state_str(enum iwl_mvm_tdls_cs_state state)
216 {
217 	switch (state) {
218 	case IWL_MVM_TDLS_SW_IDLE:
219 		return "IDLE";
220 	case IWL_MVM_TDLS_SW_REQ_SENT:
221 		return "REQ SENT";
222 	case IWL_MVM_TDLS_SW_RESP_RCVD:
223 		return "RESP RECEIVED";
224 	case IWL_MVM_TDLS_SW_REQ_RCVD:
225 		return "REQ RECEIVED";
226 	case IWL_MVM_TDLS_SW_ACTIVE:
227 		return "ACTIVE";
228 	}
229 
230 	return NULL;
231 }
232 
233 static void iwl_mvm_tdls_update_cs_state(struct iwl_mvm *mvm,
234 					 enum iwl_mvm_tdls_cs_state state)
235 {
236 	if (mvm->tdls_cs.state == state)
237 		return;
238 
239 	IWL_DEBUG_TDLS(mvm, "TDLS channel switch state: %s -> %s\n",
240 		       iwl_mvm_tdls_cs_state_str(mvm->tdls_cs.state),
241 		       iwl_mvm_tdls_cs_state_str(state));
242 	mvm->tdls_cs.state = state;
243 
244 	/* we only send requests to our switching peer - update sent time */
245 	if (state == IWL_MVM_TDLS_SW_REQ_SENT)
246 		mvm->tdls_cs.peer.sent_timestamp = iwl_mvm_get_systime(mvm);
247 
248 	if (state == IWL_MVM_TDLS_SW_IDLE)
249 		mvm->tdls_cs.cur_sta_id = IWL_MVM_INVALID_STA;
250 }
251 
252 void iwl_mvm_rx_tdls_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb)
253 {
254 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
255 	struct iwl_tdls_channel_switch_notif *notif = (void *)pkt->data;
256 	struct ieee80211_sta *sta;
257 	unsigned int delay;
258 	struct iwl_mvm_sta *mvmsta;
259 	struct ieee80211_vif *vif;
260 	u32 sta_id = le32_to_cpu(notif->sta_id);
261 
262 	lockdep_assert_held(&mvm->mutex);
263 
264 	/* can fail sometimes */
265 	if (!le32_to_cpu(notif->status)) {
266 		iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_IDLE);
267 		return;
268 	}
269 
270 	if (WARN_ON(sta_id >= IWL_MVM_STATION_COUNT))
271 		return;
272 
273 	sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[sta_id],
274 					lockdep_is_held(&mvm->mutex));
275 	/* the station may not be here, but if it is, it must be a TDLS peer */
276 	if (IS_ERR_OR_NULL(sta) || WARN_ON(!sta->tdls))
277 		return;
278 
279 	mvmsta = iwl_mvm_sta_from_mac80211(sta);
280 	vif = mvmsta->vif;
281 
282 	/*
283 	 * Update state and possibly switch again after this is over (DTIM).
284 	 * Also convert TU to msec.
285 	 */
286 	delay = TU_TO_MS(vif->bss_conf.dtim_period * vif->bss_conf.beacon_int);
287 	mod_delayed_work(system_wq, &mvm->tdls_cs.dwork,
288 			 msecs_to_jiffies(delay));
289 
290 	iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_ACTIVE);
291 }
292 
293 static int
294 iwl_mvm_tdls_check_action(struct iwl_mvm *mvm,
295 			  enum iwl_tdls_channel_switch_type type,
296 			  const u8 *peer, bool peer_initiator, u32 timestamp)
297 {
298 	bool same_peer = false;
299 	int ret = 0;
300 
301 	/* get the existing peer if it's there */
302 	if (mvm->tdls_cs.state != IWL_MVM_TDLS_SW_IDLE &&
303 	    mvm->tdls_cs.cur_sta_id != IWL_MVM_INVALID_STA) {
304 		struct ieee80211_sta *sta = rcu_dereference_protected(
305 				mvm->fw_id_to_mac_id[mvm->tdls_cs.cur_sta_id],
306 				lockdep_is_held(&mvm->mutex));
307 		if (!IS_ERR_OR_NULL(sta))
308 			same_peer = ether_addr_equal(peer, sta->addr);
309 	}
310 
311 	switch (mvm->tdls_cs.state) {
312 	case IWL_MVM_TDLS_SW_IDLE:
313 		/*
314 		 * might be spurious packet from the peer after the switch is
315 		 * already done
316 		 */
317 		if (type == TDLS_MOVE_CH)
318 			ret = -EINVAL;
319 		break;
320 	case IWL_MVM_TDLS_SW_REQ_SENT:
321 		/* only allow requests from the same peer */
322 		if (!same_peer)
323 			ret = -EBUSY;
324 		else if (type == TDLS_SEND_CHAN_SW_RESP_AND_MOVE_CH &&
325 			 !peer_initiator)
326 			/*
327 			 * We received a ch-switch request while an outgoing
328 			 * one is pending. Allow it if the peer is the link
329 			 * initiator.
330 			 */
331 			ret = -EBUSY;
332 		else if (type == TDLS_SEND_CHAN_SW_REQ)
333 			/* wait for idle before sending another request */
334 			ret = -EBUSY;
335 		else if (timestamp <= mvm->tdls_cs.peer.sent_timestamp)
336 			/* we got a stale response - ignore it */
337 			ret = -EINVAL;
338 		break;
339 	case IWL_MVM_TDLS_SW_RESP_RCVD:
340 		/*
341 		 * we are waiting for the FW to give an "active" notification,
342 		 * so ignore requests in the meantime
343 		 */
344 		ret = -EBUSY;
345 		break;
346 	case IWL_MVM_TDLS_SW_REQ_RCVD:
347 		/* as above, allow the link initiator to proceed */
348 		if (type == TDLS_SEND_CHAN_SW_REQ) {
349 			if (!same_peer)
350 				ret = -EBUSY;
351 			else if (peer_initiator) /* they are the initiator */
352 				ret = -EBUSY;
353 		} else if (type == TDLS_MOVE_CH) {
354 			ret = -EINVAL;
355 		}
356 		break;
357 	case IWL_MVM_TDLS_SW_ACTIVE:
358 		/*
359 		 * the only valid request when active is a request to return
360 		 * to the base channel by the current off-channel peer
361 		 */
362 		if (type != TDLS_MOVE_CH || !same_peer)
363 			ret = -EBUSY;
364 		break;
365 	}
366 
367 	if (ret)
368 		IWL_DEBUG_TDLS(mvm,
369 			       "Invalid TDLS action %d state %d peer %pM same_peer %d initiator %d\n",
370 			       type, mvm->tdls_cs.state, peer, same_peer,
371 			       peer_initiator);
372 
373 	return ret;
374 }
375 
376 static int
377 iwl_mvm_tdls_config_channel_switch(struct iwl_mvm *mvm,
378 				   struct ieee80211_vif *vif,
379 				   enum iwl_tdls_channel_switch_type type,
380 				   const u8 *peer, bool peer_initiator,
381 				   u8 oper_class,
382 				   struct cfg80211_chan_def *chandef,
383 				   u32 timestamp, u16 switch_time,
384 				   u16 switch_timeout, struct sk_buff *skb,
385 				   u32 ch_sw_tm_ie)
386 {
387 	struct ieee80211_sta *sta;
388 	struct iwl_mvm_sta *mvmsta;
389 	struct ieee80211_tx_info *info;
390 	struct ieee80211_hdr *hdr;
391 	struct iwl_tdls_channel_switch_cmd cmd = {0};
392 	struct iwl_tdls_channel_switch_cmd_tail *tail =
393 		iwl_mvm_chan_info_cmd_tail(mvm, &cmd.ci);
394 	u16 len = sizeof(cmd) - iwl_mvm_chan_info_padding(mvm);
395 	int ret;
396 
397 	lockdep_assert_held(&mvm->mutex);
398 
399 	ret = iwl_mvm_tdls_check_action(mvm, type, peer, peer_initiator,
400 					timestamp);
401 	if (ret)
402 		return ret;
403 
404 	if (!skb || WARN_ON(skb->len > IWL_TDLS_CH_SW_FRAME_MAX_SIZE)) {
405 		ret = -EINVAL;
406 		goto out;
407 	}
408 
409 	cmd.switch_type = type;
410 	tail->timing.frame_timestamp = cpu_to_le32(timestamp);
411 	tail->timing.switch_time = cpu_to_le32(switch_time);
412 	tail->timing.switch_timeout = cpu_to_le32(switch_timeout);
413 
414 	rcu_read_lock();
415 	sta = ieee80211_find_sta(vif, peer);
416 	if (!sta) {
417 		rcu_read_unlock();
418 		ret = -ENOENT;
419 		goto out;
420 	}
421 	mvmsta = iwl_mvm_sta_from_mac80211(sta);
422 	cmd.peer_sta_id = cpu_to_le32(mvmsta->sta_id);
423 
424 	if (!chandef) {
425 		if (mvm->tdls_cs.state == IWL_MVM_TDLS_SW_REQ_SENT &&
426 		    mvm->tdls_cs.peer.chandef.chan) {
427 			/* actually moving to the channel */
428 			chandef = &mvm->tdls_cs.peer.chandef;
429 		} else if (mvm->tdls_cs.state == IWL_MVM_TDLS_SW_ACTIVE &&
430 			   type == TDLS_MOVE_CH) {
431 			/* we need to return to base channel */
432 			struct ieee80211_chanctx_conf *chanctx =
433 					rcu_dereference(vif->chanctx_conf);
434 
435 			if (WARN_ON_ONCE(!chanctx)) {
436 				rcu_read_unlock();
437 				goto out;
438 			}
439 
440 			chandef = &chanctx->def;
441 		}
442 	}
443 
444 	if (chandef)
445 		iwl_mvm_set_chan_info_chandef(mvm, &cmd.ci, chandef);
446 
447 	/* keep quota calculation simple for now - 50% of DTIM for TDLS */
448 	tail->timing.max_offchan_duration =
449 			cpu_to_le32(TU_TO_US(vif->bss_conf.dtim_period *
450 					     vif->bss_conf.beacon_int) / 2);
451 
452 	/* Switch time is the first element in the switch-timing IE. */
453 	tail->frame.switch_time_offset = cpu_to_le32(ch_sw_tm_ie + 2);
454 
455 	info = IEEE80211_SKB_CB(skb);
456 	hdr = (void *)skb->data;
457 	if (info->control.hw_key) {
458 		if (info->control.hw_key->cipher != WLAN_CIPHER_SUITE_CCMP) {
459 			rcu_read_unlock();
460 			ret = -EINVAL;
461 			goto out;
462 		}
463 		iwl_mvm_set_tx_cmd_ccmp(info, &tail->frame.tx_cmd);
464 	}
465 
466 	iwl_mvm_set_tx_cmd(mvm, skb, &tail->frame.tx_cmd, info,
467 			   mvmsta->sta_id);
468 
469 	iwl_mvm_set_tx_cmd_rate(mvm, &tail->frame.tx_cmd, info, sta,
470 				hdr->frame_control);
471 	rcu_read_unlock();
472 
473 	memcpy(tail->frame.data, skb->data, skb->len);
474 
475 	ret = iwl_mvm_send_cmd_pdu(mvm, TDLS_CHANNEL_SWITCH_CMD, 0, len, &cmd);
476 	if (ret) {
477 		IWL_ERR(mvm, "Failed to send TDLS_CHANNEL_SWITCH cmd: %d\n",
478 			ret);
479 		goto out;
480 	}
481 
482 	/* channel switch has started, update state */
483 	if (type != TDLS_MOVE_CH) {
484 		mvm->tdls_cs.cur_sta_id = mvmsta->sta_id;
485 		iwl_mvm_tdls_update_cs_state(mvm,
486 					     type == TDLS_SEND_CHAN_SW_REQ ?
487 					     IWL_MVM_TDLS_SW_REQ_SENT :
488 					     IWL_MVM_TDLS_SW_REQ_RCVD);
489 	} else {
490 		iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_RESP_RCVD);
491 	}
492 
493 out:
494 
495 	/* channel switch failed - we are idle */
496 	if (ret)
497 		iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_IDLE);
498 
499 	return ret;
500 }
501 
502 void iwl_mvm_tdls_ch_switch_work(struct work_struct *work)
503 {
504 	struct iwl_mvm *mvm;
505 	struct ieee80211_sta *sta;
506 	struct iwl_mvm_sta *mvmsta;
507 	struct ieee80211_vif *vif;
508 	unsigned int delay;
509 	int ret;
510 
511 	mvm = container_of(work, struct iwl_mvm, tdls_cs.dwork.work);
512 	mutex_lock(&mvm->mutex);
513 
514 	/* called after an active channel switch has finished or timed-out */
515 	iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_IDLE);
516 
517 	/* station might be gone, in that case do nothing */
518 	if (mvm->tdls_cs.peer.sta_id == IWL_MVM_INVALID_STA)
519 		goto out;
520 
521 	sta = rcu_dereference_protected(
522 				mvm->fw_id_to_mac_id[mvm->tdls_cs.peer.sta_id],
523 				lockdep_is_held(&mvm->mutex));
524 	/* the station may not be here, but if it is, it must be a TDLS peer */
525 	if (!sta || IS_ERR(sta) || WARN_ON(!sta->tdls))
526 		goto out;
527 
528 	mvmsta = iwl_mvm_sta_from_mac80211(sta);
529 	vif = mvmsta->vif;
530 	ret = iwl_mvm_tdls_config_channel_switch(mvm, vif,
531 						 TDLS_SEND_CHAN_SW_REQ,
532 						 sta->addr,
533 						 mvm->tdls_cs.peer.initiator,
534 						 mvm->tdls_cs.peer.op_class,
535 						 &mvm->tdls_cs.peer.chandef,
536 						 0, 0, 0,
537 						 mvm->tdls_cs.peer.skb,
538 						 mvm->tdls_cs.peer.ch_sw_tm_ie);
539 	if (ret)
540 		IWL_ERR(mvm, "Not sending TDLS channel switch: %d\n", ret);
541 
542 	/* retry after a DTIM if we failed sending now */
543 	delay = TU_TO_MS(vif->bss_conf.dtim_period * vif->bss_conf.beacon_int);
544 	schedule_delayed_work(&mvm->tdls_cs.dwork, msecs_to_jiffies(delay));
545 out:
546 	mutex_unlock(&mvm->mutex);
547 }
548 
549 int
550 iwl_mvm_tdls_channel_switch(struct ieee80211_hw *hw,
551 			    struct ieee80211_vif *vif,
552 			    struct ieee80211_sta *sta, u8 oper_class,
553 			    struct cfg80211_chan_def *chandef,
554 			    struct sk_buff *tmpl_skb, u32 ch_sw_tm_ie)
555 {
556 	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
557 	struct iwl_mvm_sta *mvmsta;
558 	unsigned int delay;
559 	int ret;
560 
561 	mutex_lock(&mvm->mutex);
562 
563 	IWL_DEBUG_TDLS(mvm, "TDLS channel switch with %pM ch %d width %d\n",
564 		       sta->addr, chandef->chan->center_freq, chandef->width);
565 
566 	/* we only support a single peer for channel switching */
567 	if (mvm->tdls_cs.peer.sta_id != IWL_MVM_INVALID_STA) {
568 		IWL_DEBUG_TDLS(mvm,
569 			       "Existing peer. Can't start switch with %pM\n",
570 			       sta->addr);
571 		ret = -EBUSY;
572 		goto out;
573 	}
574 
575 	ret = iwl_mvm_tdls_config_channel_switch(mvm, vif,
576 						 TDLS_SEND_CHAN_SW_REQ,
577 						 sta->addr, sta->tdls_initiator,
578 						 oper_class, chandef, 0, 0, 0,
579 						 tmpl_skb, ch_sw_tm_ie);
580 	if (ret)
581 		goto out;
582 
583 	/*
584 	 * Mark the peer as "in tdls switch" for this vif. We only allow a
585 	 * single such peer per vif.
586 	 */
587 	mvm->tdls_cs.peer.skb = skb_copy(tmpl_skb, GFP_KERNEL);
588 	if (!mvm->tdls_cs.peer.skb) {
589 		ret = -ENOMEM;
590 		goto out;
591 	}
592 
593 	mvmsta = iwl_mvm_sta_from_mac80211(sta);
594 	mvm->tdls_cs.peer.sta_id = mvmsta->sta_id;
595 	mvm->tdls_cs.peer.chandef = *chandef;
596 	mvm->tdls_cs.peer.initiator = sta->tdls_initiator;
597 	mvm->tdls_cs.peer.op_class = oper_class;
598 	mvm->tdls_cs.peer.ch_sw_tm_ie = ch_sw_tm_ie;
599 
600 	/*
601 	 * Wait for 2 DTIM periods before attempting the next switch. The next
602 	 * switch will be made sooner if the current one completes before that.
603 	 */
604 	delay = 2 * TU_TO_MS(vif->bss_conf.dtim_period *
605 			     vif->bss_conf.beacon_int);
606 	mod_delayed_work(system_wq, &mvm->tdls_cs.dwork,
607 			 msecs_to_jiffies(delay));
608 
609 out:
610 	mutex_unlock(&mvm->mutex);
611 	return ret;
612 }
613 
614 void iwl_mvm_tdls_cancel_channel_switch(struct ieee80211_hw *hw,
615 					struct ieee80211_vif *vif,
616 					struct ieee80211_sta *sta)
617 {
618 	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
619 	struct ieee80211_sta *cur_sta;
620 	bool wait_for_phy = false;
621 
622 	mutex_lock(&mvm->mutex);
623 
624 	IWL_DEBUG_TDLS(mvm, "TDLS cancel channel switch with %pM\n", sta->addr);
625 
626 	/* we only support a single peer for channel switching */
627 	if (mvm->tdls_cs.peer.sta_id == IWL_MVM_INVALID_STA) {
628 		IWL_DEBUG_TDLS(mvm, "No ch switch peer - %pM\n", sta->addr);
629 		goto out;
630 	}
631 
632 	cur_sta = rcu_dereference_protected(
633 				mvm->fw_id_to_mac_id[mvm->tdls_cs.peer.sta_id],
634 				lockdep_is_held(&mvm->mutex));
635 	/* make sure it's the same peer */
636 	if (cur_sta != sta)
637 		goto out;
638 
639 	/*
640 	 * If we're currently in a switch because of the now canceled peer,
641 	 * wait a DTIM here to make sure the phy is back on the base channel.
642 	 * We can't otherwise force it.
643 	 */
644 	if (mvm->tdls_cs.cur_sta_id == mvm->tdls_cs.peer.sta_id &&
645 	    mvm->tdls_cs.state != IWL_MVM_TDLS_SW_IDLE)
646 		wait_for_phy = true;
647 
648 	mvm->tdls_cs.peer.sta_id = IWL_MVM_INVALID_STA;
649 	dev_kfree_skb(mvm->tdls_cs.peer.skb);
650 	mvm->tdls_cs.peer.skb = NULL;
651 
652 out:
653 	mutex_unlock(&mvm->mutex);
654 
655 	/* make sure the phy is on the base channel */
656 	if (wait_for_phy)
657 		msleep(TU_TO_MS(vif->bss_conf.dtim_period *
658 				vif->bss_conf.beacon_int));
659 
660 	/* flush the channel switch state */
661 	flush_delayed_work(&mvm->tdls_cs.dwork);
662 
663 	IWL_DEBUG_TDLS(mvm, "TDLS ending channel switch with %pM\n", sta->addr);
664 }
665 
666 void
667 iwl_mvm_tdls_recv_channel_switch(struct ieee80211_hw *hw,
668 				 struct ieee80211_vif *vif,
669 				 struct ieee80211_tdls_ch_sw_params *params)
670 {
671 	struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
672 	enum iwl_tdls_channel_switch_type type;
673 	unsigned int delay;
674 	const char *action_str =
675 		params->action_code == WLAN_TDLS_CHANNEL_SWITCH_REQUEST ?
676 		"REQ" : "RESP";
677 
678 	mutex_lock(&mvm->mutex);
679 
680 	IWL_DEBUG_TDLS(mvm,
681 		       "Received TDLS ch switch action %s from %pM status %d\n",
682 		       action_str, params->sta->addr, params->status);
683 
684 	/*
685 	 * we got a non-zero status from a peer we were switching to - move to
686 	 * the idle state and retry again later
687 	 */
688 	if (params->action_code == WLAN_TDLS_CHANNEL_SWITCH_RESPONSE &&
689 	    params->status != 0 &&
690 	    mvm->tdls_cs.state == IWL_MVM_TDLS_SW_REQ_SENT &&
691 	    mvm->tdls_cs.cur_sta_id != IWL_MVM_INVALID_STA) {
692 		struct ieee80211_sta *cur_sta;
693 
694 		/* make sure it's the same peer */
695 		cur_sta = rcu_dereference_protected(
696 				mvm->fw_id_to_mac_id[mvm->tdls_cs.cur_sta_id],
697 				lockdep_is_held(&mvm->mutex));
698 		if (cur_sta == params->sta) {
699 			iwl_mvm_tdls_update_cs_state(mvm,
700 						     IWL_MVM_TDLS_SW_IDLE);
701 			goto retry;
702 		}
703 	}
704 
705 	type = (params->action_code == WLAN_TDLS_CHANNEL_SWITCH_REQUEST) ?
706 	       TDLS_SEND_CHAN_SW_RESP_AND_MOVE_CH : TDLS_MOVE_CH;
707 
708 	iwl_mvm_tdls_config_channel_switch(mvm, vif, type, params->sta->addr,
709 					   params->sta->tdls_initiator, 0,
710 					   params->chandef, params->timestamp,
711 					   params->switch_time,
712 					   params->switch_timeout,
713 					   params->tmpl_skb,
714 					   params->ch_sw_tm_ie);
715 
716 retry:
717 	/* register a timeout in case we don't succeed in switching */
718 	delay = vif->bss_conf.dtim_period * vif->bss_conf.beacon_int *
719 		1024 / 1000;
720 	mod_delayed_work(system_wq, &mvm->tdls_cs.dwork,
721 			 msecs_to_jiffies(delay));
722 	mutex_unlock(&mvm->mutex);
723 }
724