drivers/net/wireless/iwlwifi/mvm/time-event.c - kernel/msm-4.9 - Gitiles

 /******************************************************************************
  *
  * 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 - 2013 Intel Corporation. All rights reserved.
  *
  * 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.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
  * USA
  *
  * The full GNU General Public License is included in this distribution
  * in the file called COPYING.
  *
  * Contact Information:
  *  Intel Linux Wireless <ilw@linux.intel.com>
  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  *
  * BSD LICENSE
  *
  * Copyright(c) 2012 - 2013 Intel Corporation. All rights reserved.
  * All rights reserved.
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  *  * Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
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  *    notice, this list of conditions and the following disclaimer in
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  *    from this software without specific prior written permission.
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  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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  *****************************************************************************/

 #include <linux/jiffies.h>
 #include <net/mac80211.h>

 #include "iwl-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"

 /* A TimeUnit is 1024 microsecond */
 #define TU_TO_JIFFIES(_tu)	(usecs_to_jiffies((_tu) * 1024))
 #define MSEC_TO_TU(_msec)	(_msec*1000/1024)

 /*
  * 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->id == TE_MAX)
 		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);

 	synchronize_net();

 	/*
 	 * Flush the offchannel queue -- this is called when the time
 	 * event finishes or is cancelled, 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_tx_path(mvm, BIT(IWL_MVM_OFFCHANNEL_QUEUE), false);
 }

 static void iwl_mvm_roc_finished(struct iwl_mvm *mvm)
 {
 	/*
 	 * First, clear the ROC_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).
 	 */
 	clear_bit(IWL_MVM_STATUS_ROC_RUNNING, &mvm->status);

 	/*
 	 * 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);
 }

 /*
  * 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));

 	/*
 	 * 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).
 	 */
 	WARN_ONCE(!le32_to_cpu(notif->status),
 		  "Failed to schedule time event\n");

 	if (le32_to_cpu(notif->action) & TE_NOTIF_HOST_EVENT_END) {
 		IWL_DEBUG_TE(mvm,
 			     "TE ended - current time %lu, estimated end %lu\n",
 			     jiffies, te_data->end_jiffies);

 		if (te_data->vif->type == NL80211_IFTYPE_P2P_DEVICE) {
 			ieee80211_remain_on_channel_expired(mvm->hw);
 			iwl_mvm_roc_finished(mvm);
 		}

 		/*
 		 * By now, we should have finished association
 		 * and know the dtim period.
 		 */
 		if (te_data->vif->type == NL80211_IFTYPE_STATION &&
 		    (!te_data->vif->bss_conf.assoc ||
 		     !te_data->vif->bss_conf.dtim_period)) {
 			IWL_ERR(mvm,
 				"No assocation and the time event is over already...\n");
 			ieee80211_connection_loss(te_data->vif);
 		}

 		iwl_mvm_te_clear_data(mvm, te_data);
 	} else if (le32_to_cpu(notif->action) & TE_NOTIF_HOST_EVENT_START) {
 		te_data->running = true;
 		te_data->end_jiffies = jiffies +
 			TU_TO_JIFFIES(te_data->duration);

 		if (te_data->vif->type == NL80211_IFTYPE_P2P_DEVICE) {
 			set_bit(IWL_MVM_STATUS_ROC_RUNNING, &mvm->status);
 			ieee80211_ready_on_channel(mvm->hw);
 		}
 	} else {
 		IWL_WARN(mvm, "Got TE with unknown action\n");
 	}
 }

 /*
  * The Rx handler for time event notifications
  */
 int iwl_mvm_rx_time_event_notif(struct iwl_mvm *mvm,
 				struct iwl_rx_cmd_buffer *rxb,
 				struct iwl_device_cmd *cmd)
 {
 	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);
 	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);
 	}
 	spin_unlock_bh(&mvm->time_event_lock);

 	return 0;
 }

 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 = le32_to_cpu(pkt->len_n_flags) & FH_RSCSR_FRAME_SIZE_MSK;

 	if (WARN_ON(pkt->hdr.cmd != TIME_EVENT_CMD))
 		return true;

 	if (WARN_ON_ONCE(resp_len != sizeof(pkt->hdr) + 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 u8 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, CMD_SYNC,
 				   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)
 {
 	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 &&
 	    time_after(te_data->end_jiffies,
 		       jiffies + TU_TO_JIFFIES(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(iwl_read_prph(mvm->trans, DEVICE_SYSTEM_TIME_REG));

 	time_cmd.dep_policy = TE_INDEPENDENT;
 	time_cmd.is_present = cpu_to_le32(1);
 	time_cmd.max_frags = cpu_to_le32(TE_FRAG_NONE);
 	time_cmd.max_delay = cpu_to_le32(500);
 	/* TODO: why do we need to interval = bi if it is not periodic? */
 	time_cmd.interval = cpu_to_le32(1);
 	time_cmd.interval_reciprocal = cpu_to_le32(iwl_mvm_reciprocal(1));
 	time_cmd.duration = cpu_to_le32(duration);
 	time_cmd.repeat = cpu_to_le32(1);
 	time_cmd.notify = cpu_to_le32(TE_NOTIF_HOST_EVENT_START |
 				      TE_NOTIF_HOST_EVENT_END);

 	iwl_mvm_time_event_send_add(mvm, vif, te_data, &time_cmd);
 }

 /*
  * 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 id, uid;
 	int ret;

 	/*
 	 * 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;
 	}

 	/* 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, CMD_SYNC,
 				   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;

 	lockdep_assert_held(&mvm->mutex);
 	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;
 	}

 	/*
 	 * Flush the done work, just in case it's still pending, so that
 	 * the work it does can complete and we can accept new frames.
 	 */
 	flush_work(&mvm->roc_done_wk);

 	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.dep_policy = cpu_to_le32(TE_INDEPENDENT);
 	time_cmd.is_present = cpu_to_le32(1);
 	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 = cpu_to_le32(MSEC_TO_TU(duration)/20);
 	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 = cpu_to_le32(1);
 	time_cmd.notify = cpu_to_le32(TE_NOTIF_HOST_EVENT_START |
 				      TE_NOTIF_HOST_EVENT_END);

 	return iwl_mvm_time_event_send_add(mvm, vif, te_data, &time_cmd);
 }

 void iwl_mvm_stop_p2p_roc(struct iwl_mvm *mvm)
 {
 	struct iwl_mvm_vif *mvmvif;
 	struct iwl_mvm_time_event_data *te_data;

 	lockdep_assert_held(&mvm->mutex);

 	/*
 	 * 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
 	 */
 	mvmvif = NULL;
 	spin_lock_bh(&mvm->time_event_lock);
 	list_for_each_entry(te_data, &mvm->time_event_list, list) {
 		if (te_data->vif->type == NL80211_IFTYPE_P2P_DEVICE) {
 			mvmvif = iwl_mvm_vif_from_mac80211(te_data->vif);
 			break;
 		}
 	}
 	spin_unlock_bh(&mvm->time_event_lock);

 	if (!mvmvif) {
 		IWL_WARN(mvm, "P2P_DEVICE no remain on channel event\n");
 		return;
 	}

 	iwl_mvm_remove_time_event(mvm, mvmvif, te_data);

 	iwl_mvm_roc_finished(mvm);
 }
	/******************************************************************************
	*
	* 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 - 2013 Intel Corporation. All rights reserved.
	*
	* 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.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
	* USA
	*
	* The full GNU General Public License is included in this distribution
	* in the file called COPYING.
	*
	* Contact Information:
	* Intel Linux Wireless <ilw@linux.intel.com>
	* Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
	*
	* BSD LICENSE
	*
	* Copyright(c) 2012 - 2013 Intel Corporation. All rights reserved.
	* 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 "iwl-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"

	/* A TimeUnit is 1024 microsecond */
	#define TU_TO_JIFFIES(_tu) (usecs_to_jiffies((_tu) * 1024))
	#define MSEC_TO_TU(_msec) (_msec*1000/1024)

	/*
	* 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->id == TE_MAX)
	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);

	synchronize_net();

	/*
	* Flush the offchannel queue -- this is called when the time
	* event finishes or is cancelled, 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_tx_path(mvm, BIT(IWL_MVM_OFFCHANNEL_QUEUE), false);
	}

	static void iwl_mvm_roc_finished(struct iwl_mvm *mvm)
	{
	/*
	* First, clear the ROC_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).
	*/
	clear_bit(IWL_MVM_STATUS_ROC_RUNNING, &mvm->status);

	/*
	* 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);
	}

	/*
	* 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));

	/*
	* 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).
	*/
	WARN_ONCE(!le32_to_cpu(notif->status),
	"Failed to schedule time event\n");

	if (le32_to_cpu(notif->action) & TE_NOTIF_HOST_EVENT_END) {
	IWL_DEBUG_TE(mvm,
	"TE ended - current time %lu, estimated end %lu\n",
	jiffies, te_data->end_jiffies);

	if (te_data->vif->type == NL80211_IFTYPE_P2P_DEVICE) {
	ieee80211_remain_on_channel_expired(mvm->hw);
	iwl_mvm_roc_finished(mvm);
	}

	/*
	* By now, we should have finished association
	* and know the dtim period.
	*/
	if (te_data->vif->type == NL80211_IFTYPE_STATION &&
	(!te_data->vif->bss_conf.assoc \|\|
	!te_data->vif->bss_conf.dtim_period)) {
	IWL_ERR(mvm,
	"No assocation and the time event is over already...\n");
	ieee80211_connection_loss(te_data->vif);
	}

	iwl_mvm_te_clear_data(mvm, te_data);
	} else if (le32_to_cpu(notif->action) & TE_NOTIF_HOST_EVENT_START) {
	te_data->running = true;
	te_data->end_jiffies = jiffies +
	TU_TO_JIFFIES(te_data->duration);

	if (te_data->vif->type == NL80211_IFTYPE_P2P_DEVICE) {
	set_bit(IWL_MVM_STATUS_ROC_RUNNING, &mvm->status);
	ieee80211_ready_on_channel(mvm->hw);
	}
	} else {
	IWL_WARN(mvm, "Got TE with unknown action\n");
	}
	}

	/*
	* The Rx handler for time event notifications
	*/
	int iwl_mvm_rx_time_event_notif(struct iwl_mvm *mvm,
	struct iwl_rx_cmd_buffer *rxb,
	struct iwl_device_cmd *cmd)
	{
	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);
	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);
	}
	spin_unlock_bh(&mvm->time_event_lock);

	return 0;
	}

	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 = le32_to_cpu(pkt->len_n_flags) & FH_RSCSR_FRAME_SIZE_MSK;

	if (WARN_ON(pkt->hdr.cmd != TIME_EVENT_CMD))
	return true;

	if (WARN_ON_ONCE(resp_len != sizeof(pkt->hdr) + 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 u8 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, CMD_SYNC,
	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)
	{
	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 &&
	time_after(te_data->end_jiffies,
	jiffies + TU_TO_JIFFIES(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(iwl_read_prph(mvm->trans, DEVICE_SYSTEM_TIME_REG));

	time_cmd.dep_policy = TE_INDEPENDENT;
	time_cmd.is_present = cpu_to_le32(1);
	time_cmd.max_frags = cpu_to_le32(TE_FRAG_NONE);
	time_cmd.max_delay = cpu_to_le32(500);
	/* TODO: why do we need to interval = bi if it is not periodic? */
	time_cmd.interval = cpu_to_le32(1);
	time_cmd.interval_reciprocal = cpu_to_le32(iwl_mvm_reciprocal(1));
	time_cmd.duration = cpu_to_le32(duration);
	time_cmd.repeat = cpu_to_le32(1);
	time_cmd.notify = cpu_to_le32(TE_NOTIF_HOST_EVENT_START \|
	TE_NOTIF_HOST_EVENT_END);

	iwl_mvm_time_event_send_add(mvm, vif, te_data, &time_cmd);
	}

	/*
	* 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 id, uid;
	int ret;

	/*
	* 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;
	}

	/* 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, CMD_SYNC,
	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;

	lockdep_assert_held(&mvm->mutex);
	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;
	}

	/*
	* Flush the done work, just in case it's still pending, so that
	* the work it does can complete and we can accept new frames.
	*/
	flush_work(&mvm->roc_done_wk);

	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.dep_policy = cpu_to_le32(TE_INDEPENDENT);
	time_cmd.is_present = cpu_to_le32(1);
	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 = cpu_to_le32(MSEC_TO_TU(duration)/20);
	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 = cpu_to_le32(1);
	time_cmd.notify = cpu_to_le32(TE_NOTIF_HOST_EVENT_START \|
	TE_NOTIF_HOST_EVENT_END);

	return iwl_mvm_time_event_send_add(mvm, vif, te_data, &time_cmd);
	}

	void iwl_mvm_stop_p2p_roc(struct iwl_mvm *mvm)
	{
	struct iwl_mvm_vif *mvmvif;
	struct iwl_mvm_time_event_data *te_data;

	lockdep_assert_held(&mvm->mutex);

	/*
	* 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
	*/
	mvmvif = NULL;
	spin_lock_bh(&mvm->time_event_lock);
	list_for_each_entry(te_data, &mvm->time_event_list, list) {
	if (te_data->vif->type == NL80211_IFTYPE_P2P_DEVICE) {
	mvmvif = iwl_mvm_vif_from_mac80211(te_data->vif);
	break;
	}
	}
	spin_unlock_bh(&mvm->time_event_lock);

	if (!mvmvif) {
	IWL_WARN(mvm, "P2P_DEVICE no remain on channel event\n");
	return;
	}

	iwl_mvm_remove_time_event(mvm, mvmvif, te_data);

	iwl_mvm_roc_finished(mvm);
	}