text: /******************************************************************************
   *
   * 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) 2012 - 2014 Intel Corporation. All rights reserved.
   * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
   * Copyright(c) 2017 Intel Deutschland GmbH
   * Copyright(c) 2018 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) 2012 - 2014 Intel Corporation. All rights reserved.
   * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
   * Copyright(c) 2017 Intel Deutschland GmbH
   * Copyright(c) 2018 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/jiffies.h>
  #include <net/mac80211.h>
  
  #include "fw/notif-wait.h"
  #include "iwl-trans.h"
  #include "fw-api.h"
  #include "time-event.h"
  #include "mvm.h"
  #include "iwl-io.h"
  #include "iwl-prph.h"
  
  /*
   * For the high priority TE use a time event type that has similar priority to
   * the FW's action scan priority.
   */
  #define IWL_MVM_ROC_TE_TYPE_NORMAL TE_P2P_DEVICE_DISCOVERABLE
  #define IWL_MVM_ROC_TE_TYPE_MGMT_TX TE_P2P_CLIENT_ASSOC
  
  void iwl_mvm_te_clear_data(struct iwl_mvm *mvm,
  			   struct iwl_mvm_time_event_data *te_data)
  {
  	lockdep_assert_held(&mvm->time_event_lock);
  
  	if (!te_data->vif)
  		return;
  
  	list_del(&te_data->list);
  	te_data->running = false;
  	te_data->uid = 0;
  	te_data->id = TE_MAX;
  	te_data->vif = NULL;
  }
  
  void iwl_mvm_roc_done_wk(struct work_struct *wk)
  {
  	struct iwl_mvm *mvm = container_of(wk, struct iwl_mvm, roc_done_wk);
  
  	/*
  	 * Clear the ROC_RUNNING /ROC_AUX_RUNNING status bit.
  	 * This will cause the TX path to drop offchannel transmissions.
  	 * That would also be done by mac80211, but it is racy, in particular
  	 * in the case that the time event actually completed in the firmware
  	 * (which is handled in iwl_mvm_te_handle_notif).
  	 */
  	if (test_and_clear_bit(IWL_MVM_STATUS_ROC_RUNNING, &mvm->status))
  		iwl_mvm_unref(mvm, IWL_MVM_REF_ROC);
  	if (test_and_clear_bit(IWL_MVM_STATUS_ROC_AUX_RUNNING, &mvm->status))
  		iwl_mvm_unref(mvm, IWL_MVM_REF_ROC_AUX);
  
  	synchronize_net();
  
  	/*
  	 * Flush the offchannel queue -- this is called when the time
  	 * event finishes or is canceled, so that frames queued for it
  	 * won't get stuck on the queue and be transmitted in the next
  	 * time event.
  	 * We have to send the command asynchronously since this cannot
  	 * be under the mutex for locking reasons, but that's not an
  	 * issue as it will have to complete before the next command is
  	 * executed, and a new time event means a new command.
  	 */
  	iwl_mvm_flush_sta(mvm, &mvm->aux_sta, true, CMD_ASYNC);
  
  	/* Do the same for the P2P device queue (STA) */
  	if (test_and_clear_bit(IWL_MVM_STATUS_NEED_FLUSH_P2P, &mvm->status)) {
  		struct iwl_mvm_vif *mvmvif;
  
  		/*
  		 * NB: access to this pointer would be racy, but the flush bit
  		 * can only be set when we had a P2P-Device VIF, and we have a
  		 * flush of this work in iwl_mvm_prepare_mac_removal() so it's
  		 * not really racy.
  		 */
  
  		if (!WARN_ON(!mvm->p2p_device_vif)) {
  			mvmvif = iwl_mvm_vif_from_mac80211(mvm->p2p_device_vif);
  			iwl_mvm_flush_sta(mvm, &mvmvif->bcast_sta, true,
  					  CMD_ASYNC);
  		}
  	}
  }
  
  static void iwl_mvm_roc_finished(struct iwl_mvm *mvm)
  {
  	/*
  	 * Of course, our status bit is just as racy as mac80211, so in
  	 * addition, fire off the work struct which will drop all frames
  	 * from the hardware queues that made it through the race. First
  	 * it will of course synchronize the TX path to make sure that
  	 * any *new* TX will be rejected.
  	 */
  	schedule_work(&mvm->roc_done_wk);
  }
  
  static void iwl_mvm_csa_noa_start(struct iwl_mvm *mvm)
  {
  	struct ieee80211_vif *csa_vif;
  
  	rcu_read_lock();
  
  	csa_vif = rcu_dereference(mvm->csa_vif);
  	if (!csa_vif || !csa_vif->csa_active)
  		goto out_unlock;
  
  	IWL_DEBUG_TE(mvm, "CSA NOA started\n");
  
  	/*
  	 * CSA NoA is started but we still have beacons to
  	 * transmit on the current channel.
  	 * So we just do nothing here and the switch
  	 * will be performed on the last TBTT.
  	 */
  	if (!ieee80211_csa_is_complete(csa_vif)) {
  		IWL_WARN(mvm, "CSA NOA started too early\n");
  		goto out_unlock;
  	}
  
  	ieee80211_csa_finish(csa_vif);
  
  	rcu_read_unlock();
  
  	RCU_INIT_POINTER(mvm->csa_vif, NULL);
  
  	return;
  
  out_unlock:
  	rcu_read_unlock();
  }
  
  static bool iwl_mvm_te_check_disconnect(struct iwl_mvm *mvm,
  					struct ieee80211_vif *vif,
  					const char *errmsg)
  {
  	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
  
  	if (vif->type != NL80211_IFTYPE_STATION)
  		return false;
  
  	if (!mvmvif->csa_bcn_pending && vif->bss_conf.assoc &&
  	    vif->bss_conf.dtim_period)
  		return false;
  	if (errmsg)
  		IWL_ERR(mvm, "%s\n", errmsg);
  
  	iwl_mvm_connection_loss(mvm, vif, errmsg);
  	return true;
  }
  
  static void
  iwl_mvm_te_handle_notify_csa(struct iwl_mvm *mvm,
  			     struct iwl_mvm_time_event_data *te_data,
  			     struct iwl_time_event_notif *notif)
  {
  	struct ieee80211_vif *vif = te_data->vif;
  	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
  
  	if (!notif->status)
  		IWL_DEBUG_TE(mvm, "CSA time event failed to start\n");
  
  	switch (te_data->vif->type) {
  	case NL80211_IFTYPE_AP:
  		if (!notif->status)
  			mvmvif->csa_failed = true;
  		iwl_mvm_csa_noa_start(mvm);
  		break;
  	case NL80211_IFTYPE_STATION:
  		if (!notif->status) {
  			iwl_mvm_connection_loss(mvm, vif,
  						"CSA TE failed to start");
  			break;
  		}
  		iwl_mvm_csa_client_absent(mvm, te_data->vif);
  		ieee80211_chswitch_done(te_data->vif, true);
  		break;
  	default:
  		/* should never happen */
  		WARN_ON_ONCE(1);
  		break;
  	}
  
  	/* we don't need it anymore */
  	iwl_mvm_te_clear_data(mvm, te_data);
  }
  
  static void iwl_mvm_te_check_trigger(struct iwl_mvm *mvm,
  				     struct iwl_time_event_notif *notif,
  				     struct iwl_mvm_time_event_data *te_data)
  {
  	struct iwl_fw_dbg_trigger_tlv *trig;
  	struct iwl_fw_dbg_trigger_time_event *te_trig;
  	int i;
  
  	if (!iwl_fw_dbg_trigger_enabled(mvm->fw, FW_DBG_TRIGGER_TIME_EVENT))
  		return;
  
  	trig = iwl_fw_dbg_get_trigger(mvm->fw, FW_DBG_TRIGGER_TIME_EVENT);
  	te_trig = (void *)trig->data;
  
  	if (!iwl_fw_dbg_trigger_check_stop(&mvm->fwrt,
  					   ieee80211_vif_to_wdev(te_data->vif),
  					   trig))
  		return;
  
  	for (i = 0; i < ARRAY_SIZE(te_trig->time_events); i++) {
  		u32 trig_te_id = le32_to_cpu(te_trig->time_events[i].id);
  		u32 trig_action_bitmap =
  			le32_to_cpu(te_trig->time_events[i].action_bitmap);
  		u32 trig_status_bitmap =
  			le32_to_cpu(te_trig->time_events[i].status_bitmap);
  
  		if (trig_te_id != te_data->id ||
  		    !(trig_action_bitmap & le32_to_cpu(notif->action)) ||
  		    !(trig_status_bitmap & BIT(le32_to_cpu(notif->status))))
  			continue;
  
  		iwl_fw_dbg_collect_trig(&mvm->fwrt, trig,
  					"Time event %d Action 0x%x received status: %d",
  					te_data->id,
  					le32_to_cpu(notif->action),
  					le32_to_cpu(notif->status));
  		break;
  	}
  }
  
  /*
   * Handles a FW notification for an event that is known to the driver.
   *
   * @mvm: the mvm component
   * @te_data: the time event data
   * @notif: the notification data corresponding the time event data.
   */
  static void iwl_mvm_te_handle_notif(struct iwl_mvm *mvm,
  				    struct iwl_mvm_time_event_data *te_data,
  				    struct iwl_time_event_notif *notif)
  {
  	lockdep_assert_held(&mvm->time_event_lock);
  
  	IWL_DEBUG_TE(mvm, "Handle time event notif - UID = 0x%x action %d\n",
  		     le32_to_cpu(notif->unique_id),
  		     le32_to_cpu(notif->action));
  
  	iwl_mvm_te_check_trigger(mvm, notif, te_data);
  
  	/*
  	 * The FW sends the start/end time event notifications even for events
  	 * that it fails to schedule. This is indicated in the status field of
  	 * the notification. This happens in cases that the scheduler cannot
  	 * find a schedule that can handle the event (for example requesting a
  	 * P2P Device discoveribility, while there are other higher priority
  	 * events in the system).
  	 */
  	if (!le32_to_cpu(notif->status)) {
  		const char *msg;
  
  		if (notif->action & cpu_to_le32(TE_V2_NOTIF_HOST_EVENT_START))
  			msg = "Time Event start notification failure";
  		else
  			msg = "Time Event end notification failure";
  
  		IWL_DEBUG_TE(mvm, "%s\n", msg);
  
  		if (iwl_mvm_te_check_disconnect(mvm, te_data->vif, msg)) {
  			iwl_mvm_te_clear_data(mvm, te_data);
  			return;
  		}
  	}
  
  	if (le32_to_cpu(notif->action) & TE_V2_NOTIF_HOST_EVENT_END) {
  		IWL_DEBUG_TE(mvm,
  			     "TE ended - current time %lu, estimated end %lu\n",
  			     jiffies, te_data->end_jiffies);
  
  		switch (te_data->vif->type) {
  		case NL80211_IFTYPE_P2P_DEVICE:
  			ieee80211_remain_on_channel_expired(mvm->hw);
  			iwl_mvm_roc_finished(mvm);
  			break;
  		case NL80211_IFTYPE_STATION:
  			/*
  			 * By now, we should have finished association
  			 * and know the dtim period.
  			 */
  			iwl_mvm_te_check_disconnect(mvm, te_data->vif,
  				"No beacon heard and the time event is over already...");
  			break;
  		default:
  			break;
  		}
  
  		iwl_mvm_te_clear_data(mvm, te_data);
  	} else if (le32_to_cpu(notif->action) & TE_V2_NOTIF_HOST_EVENT_START) {
  		te_data->running = true;
  		te_data->end_jiffies = TU_TO_EXP_TIME(te_data->duration);
  
  		if (te_data->vif->type == NL80211_IFTYPE_P2P_DEVICE) {
  			set_bit(IWL_MVM_STATUS_ROC_RUNNING, &mvm->status);
  			iwl_mvm_ref(mvm, IWL_MVM_REF_ROC);
  			ieee80211_ready_on_channel(mvm->hw);
  		} else if (te_data->id == TE_CHANNEL_SWITCH_PERIOD) {
  			iwl_mvm_te_handle_notify_csa(mvm, te_data, notif);
  		}
  	} else {
  		IWL_WARN(mvm, "Got TE with unknown action\n");
  	}
  }
  
  /*
   * Handle A Aux ROC time event
   */
  static int iwl_mvm_aux_roc_te_handle_notif(struct iwl_mvm *mvm,
  					   struct iwl_time_event_notif *notif)
  {
  	struct iwl_mvm_time_event_data *te_data, *tmp;
  	bool aux_roc_te = false;
  
  	list_for_each_entry_safe(te_data, tmp, &mvm->aux_roc_te_list, list) {
  		if (le32_to_cpu(notif->unique_id) == te_data->uid) {
  			aux_roc_te = true;
  			break;
  		}
  	}
  	if (!aux_roc_te) /* Not a Aux ROC time event */
  		return -EINVAL;
  
  	iwl_mvm_te_check_trigger(mvm, notif, te_data);
  
  	IWL_DEBUG_TE(mvm,
  		     "Aux ROC time event notification  - UID = 0x%x action %d (error = %d)\n",
  		     le32_to_cpu(notif->unique_id),
  		     le32_to_cpu(notif->action), le32_to_cpu(notif->status));
  
  	if (!le32_to_cpu(notif->status) ||
  	    le32_to_cpu(notif->action) == TE_V2_NOTIF_HOST_EVENT_END) {
  		/* End TE, notify mac80211 */
  		ieee80211_remain_on_channel_expired(mvm->hw);
  		iwl_mvm_roc_finished(mvm); /* flush aux queue */
  		list_del(&te_data->list); /* remove from list */
  		te_data->running = false;
  		te_data->vif = NULL;
  		te_data->uid = 0;
  		te_data->id = TE_MAX;
  	} else if (le32_to_cpu(notif->action) == TE_V2_NOTIF_HOST_EVENT_START) {
  		set_bit(IWL_MVM_STATUS_ROC_AUX_RUNNING, &mvm->status);
  		te_data->running = true;
  		iwl_mvm_ref(mvm, IWL_MVM_REF_ROC_AUX);
  		ieee80211_ready_on_channel(mvm->hw); /* Start TE */
  	} else {
  		IWL_DEBUG_TE(mvm,
  			     "ERROR: Unknown Aux ROC Time Event (action = %d)\n",
  			     le32_to_cpu(notif->action));
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  /*
   * The Rx handler for time event notifications
   */
  void iwl_mvm_rx_time_event_notif(struct iwl_mvm *mvm,
  				 struct iwl_rx_cmd_buffer *rxb)
  {
  	struct iwl_rx_packet *pkt = rxb_addr(rxb);
  	struct iwl_time_event_notif *notif = (void *)pkt->data;
  	struct iwl_mvm_time_event_data *te_data, *tmp;
  
  	IWL_DEBUG_TE(mvm, "Time event notification - UID = 0x%x action %d\n",
  		     le32_to_cpu(notif->unique_id),
  		     le32_to_cpu(notif->action));
  
  	spin_lock_bh(&mvm->time_event_lock);
  	/* This time event is triggered for Aux ROC request */
  	if (!iwl_mvm_aux_roc_te_handle_notif(mvm, notif))
  		goto unlock;
  
  	list_for_each_entry_safe(te_data, tmp, &mvm->time_event_list, list) {
  		if (le32_to_cpu(notif->unique_id) == te_data->uid)
  			iwl_mvm_te_handle_notif(mvm, te_data, notif);
  	}
  unlock:
  	spin_unlock_bh(&mvm->time_event_lock);
  }
  
  static bool iwl_mvm_te_notif(struct iwl_notif_wait_data *notif_wait,
  			     struct iwl_rx_packet *pkt, void *data)
  {
  	struct iwl_mvm *mvm =
  		container_of(notif_wait, struct iwl_mvm, notif_wait);
  	struct iwl_mvm_time_event_data *te_data = data;
  	struct iwl_time_event_notif *resp;
  	int resp_len = iwl_rx_packet_payload_len(pkt);
  
  	if (WARN_ON(pkt->hdr.cmd != TIME_EVENT_NOTIFICATION))
  		return true;
  
  	if (WARN_ON_ONCE(resp_len != sizeof(*resp))) {
  		IWL_ERR(mvm, "Invalid TIME_EVENT_NOTIFICATION response\n");
  		return true;
  	}
  
  	resp = (void *)pkt->data;
  
  	/* te_data->uid is already set in the TIME_EVENT_CMD response */
  	if (le32_to_cpu(resp->unique_id) != te_data->uid)
  		return false;
  
  	IWL_DEBUG_TE(mvm, "TIME_EVENT_NOTIFICATION response - UID = 0x%x\n",
  		     te_data->uid);
  	if (!resp->status)
  		IWL_ERR(mvm,
  			"TIME_EVENT_NOTIFICATION received but not executed\n");
  
  	return true;
  }
  
  static bool iwl_mvm_time_event_response(struct iwl_notif_wait_data *notif_wait,
  					struct iwl_rx_packet *pkt, void *data)
  {
  	struct iwl_mvm *mvm =
  		container_of(notif_wait, struct iwl_mvm, notif_wait);
  	struct iwl_mvm_time_event_data *te_data = data;
  	struct iwl_time_event_resp *resp;
  	int resp_len = iwl_rx_packet_payload_len(pkt);
  
  	if (WARN_ON(pkt->hdr.cmd != TIME_EVENT_CMD))
  		return true;
  
  	if (WARN_ON_ONCE(resp_len != sizeof(*resp))) {
  		IWL_ERR(mvm, "Invalid TIME_EVENT_CMD response\n");
  		return true;
  	}
  
  	resp = (void *)pkt->data;
  
  	/* we should never get a response to another TIME_EVENT_CMD here */
  	if (WARN_ON_ONCE(le32_to_cpu(resp->id) != te_data->id))
  		return false;
  
  	te_data->uid = le32_to_cpu(resp->unique_id);
  	IWL_DEBUG_TE(mvm, "TIME_EVENT_CMD response - UID = 0x%x\n",
  		     te_data->uid);
  	return true;
  }
  
  static int iwl_mvm_time_event_send_add(struct iwl_mvm *mvm,
  				       struct ieee80211_vif *vif,
  				       struct iwl_mvm_time_event_data *te_data,
  				       struct iwl_time_event_cmd *te_cmd)
  {
  	static const u16 time_event_response[] = { TIME_EVENT_CMD };
  	struct iwl_notification_wait wait_time_event;
  	int ret;
  
  	lockdep_assert_held(&mvm->mutex);
  
  	IWL_DEBUG_TE(mvm, "Add new TE, duration %d TU\n",
  		     le32_to_cpu(te_cmd->duration));
  
  	spin_lock_bh(&mvm->time_event_lock);
  	if (WARN_ON(te_data->id != TE_MAX)) {
  		spin_unlock_bh(&mvm->time_event_lock);
  		return -EIO;
  	}
  	te_data->vif = vif;
  	te_data->duration = le32_to_cpu(te_cmd->duration);
  	te_data->id = le32_to_cpu(te_cmd->id);
  	list_add_tail(&te_data->list, &mvm->time_event_list);
  	spin_unlock_bh(&mvm->time_event_lock);
  
  	/*
  	 * Use a notification wait, which really just processes the
  	 * command response and doesn't wait for anything, in order
  	 * to be able to process the response and get the UID inside
  	 * the RX path. Using CMD_WANT_SKB doesn't work because it
  	 * stores the buffer and then wakes up this thread, by which
  	 * time another notification (that the time event started)
  	 * might already be processed unsuccessfully.
  	 */
  	iwl_init_notification_wait(&mvm->notif_wait, &wait_time_event,
  				   time_event_response,
  				   ARRAY_SIZE(time_event_response),
  				   iwl_mvm_time_event_response, te_data);
  
  	ret = iwl_mvm_send_cmd_pdu(mvm, TIME_EVENT_CMD, 0,
  					    sizeof(*te_cmd), te_cmd);
  	if (ret) {
  		IWL_ERR(mvm, "Couldn't send TIME_EVENT_CMD: %d\n", ret);
  		iwl_remove_notification(&mvm->notif_wait, &wait_time_event);
  		goto out_clear_te;
  	}
  
  	/* No need to wait for anything, so just pass 1 (0 isn't valid) */
  	ret = iwl_wait_notification(&mvm->notif_wait, &wait_time_event, 1);
  	/* should never fail */
  	WARN_ON_ONCE(ret);
  
  	if (ret) {
   out_clear_te:
  		spin_lock_bh(&mvm->time_event_lock);
  		iwl_mvm_te_clear_data(mvm, te_data);
  		spin_unlock_bh(&mvm->time_event_lock);
  	}
  	return ret;
  }
  
  void iwl_mvm_protect_session(struct iwl_mvm *mvm,
  			     struct ieee80211_vif *vif,
  			     u32 duration, u32 min_duration,
  			     u32 max_delay, bool wait_for_notif)
  {
  	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
  	struct iwl_mvm_time_event_data *te_data = &mvmvif->time_event_data;
  	const u16 te_notif_response[] = { TIME_EVENT_NOTIFICATION };
  	struct iwl_notification_wait wait_te_notif;
  	struct iwl_time_event_cmd time_cmd = {};
  
  	lockdep_assert_held(&mvm->mutex);
  
  	if (te_data->running &&
  	    time_after(te_data->end_jiffies, TU_TO_EXP_TIME(min_duration))) {
  		IWL_DEBUG_TE(mvm, "We have enough time in the current TE: %u\n",
  			     jiffies_to_msecs(te_data->end_jiffies - jiffies));
  		return;
  	}
  
  	if (te_data->running) {
  		IWL_DEBUG_TE(mvm, "extend 0x%x: only %u ms left\n",
  			     te_data->uid,
  			     jiffies_to_msecs(te_data->end_jiffies - jiffies));
  		/*
  		 * we don't have enough time
  		 * cancel the current TE and issue a new one
  		 * Of course it would be better to remove the old one only
  		 * when the new one is added, but we don't care if we are off
  		 * channel for a bit. All we need to do, is not to return
  		 * before we actually begin to be on the channel.
  		 */
  		iwl_mvm_stop_session_protection(mvm, vif);
  	}
  
  	time_cmd.action = cpu_to_le32(FW_CTXT_ACTION_ADD);
  	time_cmd.id_and_color =
  		cpu_to_le32(FW_CMD_ID_AND_COLOR(mvmvif->id, mvmvif->color));
  	time_cmd.id = cpu_to_le32(TE_BSS_STA_AGGRESSIVE_ASSOC);
  
  	time_cmd.apply_time = cpu_to_le32(0);
  
  	time_cmd.max_frags = TE_V2_FRAG_NONE;
  	time_cmd.max_delay = cpu_to_le32(max_delay);
  	/* TODO: why do we need to interval = bi if it is not periodic? */
  	time_cmd.interval = cpu_to_le32(1);
  	time_cmd.duration = cpu_to_le32(duration);
  	time_cmd.repeat = 1;
  	time_cmd.policy = cpu_to_le16(TE_V2_NOTIF_HOST_EVENT_START |
  				      TE_V2_NOTIF_HOST_EVENT_END |
  				      TE_V2_START_IMMEDIATELY);
  
  	if (!wait_for_notif) {
  		iwl_mvm_time_event_send_add(mvm, vif, te_data, &time_cmd);
  		return;
  	}
  
  	/*
  	 * Create notification_wait for the TIME_EVENT_NOTIFICATION to use
  	 * right after we send the time event
  	 */
  	iwl_init_notification_wait(&mvm->notif_wait, &wait_te_notif,
  				   te_notif_response,
  				   ARRAY_SIZE(te_notif_response),
  				   iwl_mvm_te_notif, te_data);
  
  	/* If TE was sent OK - wait for the notification that started */
  	if (iwl_mvm_time_event_send_add(mvm, vif, te_data, &time_cmd)) {
  		IWL_ERR(mvm, "Failed to add TE to protect session\n");
  		iwl_remove_notification(&mvm->notif_wait, &wait_te_notif);
  	} else if (iwl_wait_notification(&mvm->notif_wait, &wait_te_notif,
  					 TU_TO_JIFFIES(max_delay))) {
  		IWL_ERR(mvm, "Failed to protect session until TE\n");
  	}
  }
  
  static bool __iwl_mvm_remove_time_event(struct iwl_mvm *mvm,
  					struct iwl_mvm_time_event_data *te_data,
  					u32 *uid)
  {
  	u32 id;
  
  	/*
  	 * It is possible that by the time we got to this point the time
  	 * event was already removed.
  	 */
  	spin_lock_bh(&mvm->time_event_lock);
  
  	/* Save time event uid before clearing its data */
  	*uid = te_data->uid;
  	id = te_data->id;
  
  	/*
  	 * The clear_data function handles time events that were already removed
  	 */
  	iwl_mvm_te_clear_data(mvm, te_data);
  	spin_unlock_bh(&mvm->time_event_lock);
  
  	/*
  	 * It is possible that by the time we try to remove it, the time event
  	 * has already ended and removed. In such a case there is no need to
  	 * send a removal command.
  	 */
  	if (id == TE_MAX) {
  		IWL_DEBUG_TE(mvm, "TE 0x%x has already ended\n", *uid);
  		return false;
  	}
  
  	return true;
  }
  
  /*
   * Explicit request to remove a aux roc time event. The removal of a time
   * event needs to be synchronized with the flow of a time event's end
   * notification, which also removes the time event from the op mode
   * data structures.
   */
  static void iwl_mvm_remove_aux_roc_te(struct iwl_mvm *mvm,
  				      struct iwl_mvm_vif *mvmvif,
  				      struct iwl_mvm_time_event_data *te_data)
  {
  	struct iwl_hs20_roc_req aux_cmd = {};
  	u32 uid;
  	int ret;
  
  	if (!__iwl_mvm_remove_time_event(mvm, te_data, &uid))
  		return;
  
  	aux_cmd.event_unique_id = cpu_to_le32(uid);
  	aux_cmd.action = cpu_to_le32(FW_CTXT_ACTION_REMOVE);
  	aux_cmd.id_and_color =
  		cpu_to_le32(FW_CMD_ID_AND_COLOR(mvmvif->id, mvmvif->color));
  	IWL_DEBUG_TE(mvm, "Removing BSS AUX ROC TE 0x%x\n",
  		     le32_to_cpu(aux_cmd.event_unique_id));
  	ret = iwl_mvm_send_cmd_pdu(mvm, HOT_SPOT_CMD, 0,
  				   sizeof(aux_cmd), &aux_cmd);
  
  	if (WARN_ON(ret))
  		return;
  }
  
  /*
   * Explicit request to remove a time event. The removal of a time event needs to
   * be synchronized with the flow of a time event's end notification, which also
   * removes the time event from the op mode data structures.
   */
  void iwl_mvm_remove_time_event(struct iwl_mvm *mvm,
  			       struct iwl_mvm_vif *mvmvif,
  			       struct iwl_mvm_time_event_data *te_data)
  {
  	struct iwl_time_event_cmd time_cmd = {};
  	u32 uid;
  	int ret;
  
  	if (!__iwl_mvm_remove_time_event(mvm, te_data, &uid))
  		return;
  
  	/* When we remove a TE, the UID is to be set in the id field */
  	time_cmd.id = cpu_to_le32(uid);
  	time_cmd.action = cpu_to_le32(FW_CTXT_ACTION_REMOVE);
  	time_cmd.id_and_color =
  		cpu_to_le32(FW_CMD_ID_AND_COLOR(mvmvif->id, mvmvif->color));
  
  	IWL_DEBUG_TE(mvm, "Removing TE 0x%x\n", le32_to_cpu(time_cmd.id));
  	ret = iwl_mvm_send_cmd_pdu(mvm, TIME_EVENT_CMD, 0,
  				   sizeof(time_cmd), &time_cmd);
  	if (WARN_ON(ret))
  		return;
  }
  
  void iwl_mvm_stop_session_protection(struct iwl_mvm *mvm,
  				     struct ieee80211_vif *vif)
  {
  	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
  	struct iwl_mvm_time_event_data *te_data = &mvmvif->time_event_data;
  	u32 id;
  
  	lockdep_assert_held(&mvm->mutex);
  
  	spin_lock_bh(&mvm->time_event_lock);
  	id = te_data->id;
  	spin_unlock_bh(&mvm->time_event_lock);
  
  	if (id != TE_BSS_STA_AGGRESSIVE_ASSOC) {
  		IWL_DEBUG_TE(mvm,
  			     "don't remove TE with id=%u (not session protection)\n",
  			     id);
  		return;
  	}
  
  	iwl_mvm_remove_time_event(mvm, mvmvif, te_data);
  }
  
  int iwl_mvm_start_p2p_roc(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
  			  int duration, enum ieee80211_roc_type type)
  {
  	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
  	struct iwl_mvm_time_event_data *te_data = &mvmvif->time_event_data;
  	struct iwl_time_event_cmd time_cmd = {};
  
  	lockdep_assert_held(&mvm->mutex);
  	if (te_data->running) {
  		IWL_WARN(mvm, "P2P_DEVICE remain on channel already running\n");
  		return -EBUSY;
  	}
  
  	time_cmd.action = cpu_to_le32(FW_CTXT_ACTION_ADD);
  	time_cmd.id_and_color =
  		cpu_to_le32(FW_CMD_ID_AND_COLOR(mvmvif->id, mvmvif->color));
  
  	switch (type) {
  	case IEEE80211_ROC_TYPE_NORMAL:
  		time_cmd.id = cpu_to_le32(IWL_MVM_ROC_TE_TYPE_NORMAL);
  		break;
  	case IEEE80211_ROC_TYPE_MGMT_TX:
  		time_cmd.id = cpu_to_le32(IWL_MVM_ROC_TE_TYPE_MGMT_TX);
  		break;
  	default:
  		WARN_ONCE(1, "Got an invalid ROC type\n");
  		return -EINVAL;
  	}
  
  	time_cmd.apply_time = cpu_to_le32(0);
  	time_cmd.interval = cpu_to_le32(1);
  
  	/*
  	 * The P2P Device TEs can have lower priority than other events
  	 * that are being scheduled by the driver/fw, and thus it might not be
  	 * scheduled. To improve the chances of it being scheduled, allow them
  	 * to be fragmented, and in addition allow them to be delayed.
  	 */
  	time_cmd.max_frags = min(MSEC_TO_TU(duration)/50, TE_V2_FRAG_ENDLESS);
  	time_cmd.max_delay = cpu_to_le32(MSEC_TO_TU(duration/2));
  	time_cmd.duration = cpu_to_le32(MSEC_TO_TU(duration));
  	time_cmd.repeat = 1;
  	time_cmd.policy = cpu_to_le16(TE_V2_NOTIF_HOST_EVENT_START |
  				      TE_V2_NOTIF_HOST_EVENT_END |
  				      TE_V2_START_IMMEDIATELY);
  
  	return iwl_mvm_time_event_send_add(mvm, vif, te_data, &time_cmd);
  }
  
  static struct iwl_mvm_time_event_data *iwl_mvm_get_roc_te(struct iwl_mvm *mvm)
  {
  	struct iwl_mvm_time_event_data *te_data;
  
  	lockdep_assert_held(&mvm->mutex);
  
  	spin_lock_bh(&mvm->time_event_lock);
  
  	/*
  	 * Iterate over the list of time events and find the time event that is
  	 * associated with a P2P_DEVICE interface.
  	 * This assumes that a P2P_DEVICE interface can have only a single time
  	 * event at any given time and this time event coresponds to a ROC
  	 * request
  	 */
  	list_for_each_entry(te_data, &mvm->time_event_list, list) {
  		if (te_data->vif->type == NL80211_IFTYPE_P2P_DEVICE)
  			goto out;
  	}
  
  	/* There can only be at most one AUX ROC time event, we just use the
  	 * list to simplify/unify code. Remove it if it exists.
  	 */
  	te_data = list_first_entry_or_null(&mvm->aux_roc_te_list,
  					   struct iwl_mvm_time_event_data,
  					   list);
  out:
  	spin_unlock_bh(&mvm->time_event_lock);
  	return te_data;
  }
  
  void iwl_mvm_cleanup_roc_te(struct iwl_mvm *mvm)
  {
  	struct iwl_mvm_time_event_data *te_data;
  	u32 uid;
  
  	te_data = iwl_mvm_get_roc_te(mvm);
  	if (te_data)
  		__iwl_mvm_remove_time_event(mvm, te_data, &uid);
  }
  
  void iwl_mvm_stop_roc(struct iwl_mvm *mvm)
  {
  	struct iwl_mvm_vif *mvmvif;
  	struct iwl_mvm_time_event_data *te_data;
  
  	te_data = iwl_mvm_get_roc_te(mvm);
  	if (!te_data) {
  		IWL_WARN(mvm, "No remain on channel event\n");
  		return;
  	}
  
  	mvmvif = iwl_mvm_vif_from_mac80211(te_data->vif);
  
  	if (te_data->vif->type == NL80211_IFTYPE_P2P_DEVICE) {
  		iwl_mvm_remove_time_event(mvm, mvmvif, te_data);
  		set_bit(IWL_MVM_STATUS_NEED_FLUSH_P2P, &mvm->status);
  	} else {
  		iwl_mvm_remove_aux_roc_te(mvm, mvmvif, te_data);
  	}
  
  	iwl_mvm_roc_finished(mvm);
  }
  
  int iwl_mvm_schedule_csa_period(struct iwl_mvm *mvm,
  				struct ieee80211_vif *vif,
  				u32 duration, u32 apply_time)
  {
  	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
  	struct iwl_mvm_time_event_data *te_data = &mvmvif->time_event_data;
  	struct iwl_time_event_cmd time_cmd = {};
  
  	lockdep_assert_held(&mvm->mutex);
  
  	if (te_data->running) {
  		u32 id;
  
  		spin_lock_bh(&mvm->time_event_lock);
  		id = te_data->id;
  		spin_unlock_bh(&mvm->time_event_lock);
  
  		if (id == TE_CHANNEL_SWITCH_PERIOD) {
  			IWL_DEBUG_TE(mvm, "CS period is already scheduled\n");
  			return -EBUSY;
  		}
  
  		/*
  		 * Remove the session protection time event to allow the
  		 * channel switch. If we got here, we just heard a beacon so
  		 * the session protection is not needed anymore anyway.
  		 */
  		iwl_mvm_remove_time_event(mvm, mvmvif, te_data);
  	}
  
  	time_cmd.action = cpu_to_le32(FW_CTXT_ACTION_ADD);
  	time_cmd.id_and_color =
  		cpu_to_le32(FW_CMD_ID_AND_COLOR(mvmvif->id, mvmvif->color));
  	time_cmd.id = cpu_to_le32(TE_CHANNEL_SWITCH_PERIOD);
  	time_cmd.apply_time = cpu_to_le32(apply_time);
  	time_cmd.max_frags = TE_V2_FRAG_NONE;
  	time_cmd.duration = cpu_to_le32(duration);
  	time_cmd.repeat = 1;
  	time_cmd.interval = cpu_to_le32(1);
  	time_cmd.policy = cpu_to_le16(TE_V2_NOTIF_HOST_EVENT_START |
  				      TE_V2_ABSENCE);
  	if (!apply_time)
  		time_cmd.policy |= cpu_to_le16(TE_V2_START_IMMEDIATELY);
  
  	return iwl_mvm_time_event_send_add(mvm, vif, te_data, &time_cmd);
  }
  