iwlwifi: mvm: implement remote wake

[mirror_ubuntu-eoan-kernel.git] / drivers / net / wireless / iwlwifi / mvm / sta.c

/******************************************************************************
 *
 * 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 <net/mac80211.h>

#include "mvm.h"
#include "sta.h"

static int iwl_mvm_find_free_sta_id(struct iwl_mvm *mvm)
{
	int sta_id;

	WARN_ON_ONCE(test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status));

	lockdep_assert_held(&mvm->mutex);

	/* Don't take rcu_read_lock() since we are protected by mvm->mutex */
	for (sta_id = 0; sta_id < IWL_MVM_STATION_COUNT; sta_id++)
		if (!rcu_dereference_protected(mvm->fw_id_to_mac_id[sta_id],
					       lockdep_is_held(&mvm->mutex)))
			return sta_id;
	return IWL_MVM_STATION_COUNT;
}

/* send station add/update command to firmware */
int iwl_mvm_sta_send_to_fw(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
			   bool update)
{
	struct iwl_mvm_sta *mvm_sta = (void *)sta->drv_priv;
	struct iwl_mvm_add_sta_cmd add_sta_cmd;
	int ret;
	u32 status;
	u32 agg_size = 0, mpdu_dens = 0;

	memset(&add_sta_cmd, 0, sizeof(add_sta_cmd));

	add_sta_cmd.sta_id = mvm_sta->sta_id;
	add_sta_cmd.mac_id_n_color = cpu_to_le32(mvm_sta->mac_id_n_color);
	if (!update) {
		add_sta_cmd.tfd_queue_msk = cpu_to_le32(mvm_sta->tfd_queue_msk);
		memcpy(&add_sta_cmd.addr, sta->addr, ETH_ALEN);
	}
	add_sta_cmd.add_modify = update ? 1 : 0;

	/* STA_FLG_FAT_EN_MSK ? */
	/* STA_FLG_MIMO_EN_MSK ? */

	if (sta->ht_cap.ht_supported) {
		add_sta_cmd.station_flags_msk |=
			cpu_to_le32(STA_FLG_MAX_AGG_SIZE_MSK |
				    STA_FLG_AGG_MPDU_DENS_MSK);

		mpdu_dens = sta->ht_cap.ampdu_density;
	}

	if (sta->vht_cap.vht_supported) {
		agg_size = sta->vht_cap.cap &
			IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
		agg_size >>=
			IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_SHIFT;
	} else if (sta->ht_cap.ht_supported) {
		agg_size = sta->ht_cap.ampdu_factor;
	}

	add_sta_cmd.station_flags |=
		cpu_to_le32(agg_size << STA_FLG_MAX_AGG_SIZE_SHIFT);
	add_sta_cmd.station_flags |=
		cpu_to_le32(mpdu_dens << STA_FLG_AGG_MPDU_DENS_SHIFT);

	status = ADD_STA_SUCCESS;
	ret = iwl_mvm_send_cmd_pdu_status(mvm, ADD_STA, sizeof(add_sta_cmd),
					  &add_sta_cmd, &status);
	if (ret)
		return ret;

	switch (status) {
	case ADD_STA_SUCCESS:
		IWL_DEBUG_ASSOC(mvm, "ADD_STA PASSED\n");
		break;
	default:
		ret = -EIO;
		IWL_ERR(mvm, "ADD_STA failed\n");
		break;
	}

	return ret;
}

int iwl_mvm_add_sta(struct iwl_mvm *mvm,
		    struct ieee80211_vif *vif,
		    struct ieee80211_sta *sta)
{
	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
	struct iwl_mvm_sta *mvm_sta = (void *)sta->drv_priv;
	int i, ret, sta_id;

	lockdep_assert_held(&mvm->mutex);

	if (!test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status))
		sta_id = iwl_mvm_find_free_sta_id(mvm);
	else
		sta_id = mvm_sta->sta_id;

	if (WARN_ON_ONCE(sta_id == IWL_MVM_STATION_COUNT))
		return -ENOSPC;

	spin_lock_init(&mvm_sta->lock);

	mvm_sta->sta_id = sta_id;
	mvm_sta->mac_id_n_color = FW_CMD_ID_AND_COLOR(mvmvif->id,
						      mvmvif->color);
	mvm_sta->vif = vif;
	mvm_sta->max_agg_bufsize = LINK_QUAL_AGG_FRAME_LIMIT_DEF;

	/* HW restart, don't assume the memory has been zeroed */
	atomic_set(&mvm_sta->pending_frames, 0);
	mvm_sta->tid_disable_agg = 0;
	mvm_sta->tfd_queue_msk = 0;
	for (i = 0; i < IEEE80211_NUM_ACS; i++)
		if (vif->hw_queue[i] != IEEE80211_INVAL_HW_QUEUE)
			mvm_sta->tfd_queue_msk |= BIT(vif->hw_queue[i]);

	if (vif->cab_queue != IEEE80211_INVAL_HW_QUEUE)
		mvm_sta->tfd_queue_msk |= BIT(vif->cab_queue);

	/* for HW restart - need to reset the seq_number etc... */
	memset(mvm_sta->tid_data, 0, sizeof(mvm_sta->tid_data));

	ret = iwl_mvm_sta_send_to_fw(mvm, sta, false);
	if (ret)
		return ret;

	/* The first station added is the AP, the others are TDLS STAs */
	if (vif->type == NL80211_IFTYPE_STATION &&
	    mvmvif->ap_sta_id == IWL_MVM_STATION_COUNT)
		mvmvif->ap_sta_id = sta_id;

	rcu_assign_pointer(mvm->fw_id_to_mac_id[sta_id], sta);

	return 0;
}

int iwl_mvm_update_sta(struct iwl_mvm *mvm,
		       struct ieee80211_vif *vif,
		       struct ieee80211_sta *sta)
{
	return iwl_mvm_sta_send_to_fw(mvm, sta, true);
}

int iwl_mvm_drain_sta(struct iwl_mvm *mvm, struct iwl_mvm_sta *mvmsta,
		      bool drain)
{
	struct iwl_mvm_add_sta_cmd cmd = {};
	int ret;
	u32 status;

	lockdep_assert_held(&mvm->mutex);

	cmd.mac_id_n_color = cpu_to_le32(mvmsta->mac_id_n_color);
	cmd.sta_id = mvmsta->sta_id;
	cmd.add_modify = STA_MODE_MODIFY;
	cmd.station_flags = drain ? cpu_to_le32(STA_FLG_DRAIN_FLOW) : 0;
	cmd.station_flags_msk = cpu_to_le32(STA_FLG_DRAIN_FLOW);

	status = ADD_STA_SUCCESS;
	ret = iwl_mvm_send_cmd_pdu_status(mvm, ADD_STA, sizeof(cmd),
					  &cmd, &status);
	if (ret)
		return ret;

	switch (status) {
	case ADD_STA_SUCCESS:
		IWL_DEBUG_INFO(mvm, "Frames for staid %d will drained in fw\n",
			       mvmsta->sta_id);
		break;
	default:
		ret = -EIO;
		IWL_ERR(mvm, "Couldn't drain frames for staid %d\n",
			mvmsta->sta_id);
		break;
	}

	return ret;
}

/*
 * Remove a station from the FW table. Before sending the command to remove
 * the station validate that the station is indeed known to the driver (sanity
 * only).
 */
static int iwl_mvm_rm_sta_common(struct iwl_mvm *mvm, u8 sta_id)
{
	struct ieee80211_sta *sta;
	struct iwl_mvm_rm_sta_cmd rm_sta_cmd = {
		.sta_id = sta_id,
	};
	int ret;

	sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[sta_id],
					lockdep_is_held(&mvm->mutex));

	/* Note: internal stations are marked as error values */
	if (!sta) {
		IWL_ERR(mvm, "Invalid station id\n");
		return -EINVAL;
	}

	ret = iwl_mvm_send_cmd_pdu(mvm, REMOVE_STA, CMD_SYNC,
				   sizeof(rm_sta_cmd), &rm_sta_cmd);
	if (ret) {
		IWL_ERR(mvm, "Failed to remove station. Id=%d\n", sta_id);
		return ret;
	}

	return 0;
}

void iwl_mvm_sta_drained_wk(struct work_struct *wk)
{
	struct iwl_mvm *mvm = container_of(wk, struct iwl_mvm, sta_drained_wk);
	u8 sta_id;

	/*
	 * The mutex is needed because of the SYNC cmd, but not only: if the
	 * work would run concurrently with iwl_mvm_rm_sta, it would run before
	 * iwl_mvm_rm_sta sets the station as busy, and exit. Then
	 * iwl_mvm_rm_sta would set the station as busy, and nobody will clean
	 * that later.
	 */
	mutex_lock(&mvm->mutex);

	for_each_set_bit(sta_id, mvm->sta_drained, IWL_MVM_STATION_COUNT) {
		int ret;
		struct ieee80211_sta *sta =
			rcu_dereference_protected(mvm->fw_id_to_mac_id[sta_id],
						  lockdep_is_held(&mvm->mutex));

		/* This station is in use */
		if (!IS_ERR(sta))
			continue;

		if (PTR_ERR(sta) == -EINVAL) {
			IWL_ERR(mvm, "Drained sta %d, but it is internal?\n",
				sta_id);
			continue;
		}

		if (!sta) {
			IWL_ERR(mvm, "Drained sta %d, but it was NULL?\n",
				sta_id);
			continue;
		}

		WARN_ON(PTR_ERR(sta) != -EBUSY);
		/* This station was removed and we waited until it got drained,
		 * we can now proceed and remove it.
		 */
		ret = iwl_mvm_rm_sta_common(mvm, sta_id);
		if (ret) {
			IWL_ERR(mvm,
				"Couldn't remove sta %d after it was drained\n",
				sta_id);
			continue;
		}
		rcu_assign_pointer(mvm->fw_id_to_mac_id[sta_id], NULL);
		clear_bit(sta_id, mvm->sta_drained);
	}

	mutex_unlock(&mvm->mutex);
}

int iwl_mvm_rm_sta(struct iwl_mvm *mvm,
		   struct ieee80211_vif *vif,
		   struct ieee80211_sta *sta)
{
	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
	struct iwl_mvm_sta *mvm_sta = (void *)sta->drv_priv;
	int ret;

	lockdep_assert_held(&mvm->mutex);

	if (vif->type == NL80211_IFTYPE_STATION &&
	    mvmvif->ap_sta_id == mvm_sta->sta_id) {
		/* flush its queues here since we are freeing mvm_sta */
		ret = iwl_mvm_flush_tx_path(mvm, mvm_sta->tfd_queue_msk, true);

		/*
		 * Put a non-NULL since the fw station isn't removed.
		 * It will be removed after the MAC will be set as
		 * unassoc.
		 */
		rcu_assign_pointer(mvm->fw_id_to_mac_id[mvm_sta->sta_id],
				   ERR_PTR(-EINVAL));

		/* if we are associated - we can't remove the AP STA now */
		if (vif->bss_conf.assoc)
			return ret;

		/* unassoc - go ahead - remove the AP STA now */
		mvmvif->ap_sta_id = IWL_MVM_STATION_COUNT;
	}

	/*
	 * There are frames pending on the AC queues for this station.
	 * We need to wait until all the frames are drained...
	 */
	if (atomic_read(&mvm_sta->pending_frames)) {
		ret = iwl_mvm_drain_sta(mvm, mvm_sta, true);
		rcu_assign_pointer(mvm->fw_id_to_mac_id[mvm_sta->sta_id],
				   ERR_PTR(-EBUSY));
	} else {
		ret = iwl_mvm_rm_sta_common(mvm, mvm_sta->sta_id);
		rcu_assign_pointer(mvm->fw_id_to_mac_id[mvm_sta->sta_id], NULL);
	}

	return ret;
}

int iwl_mvm_rm_sta_id(struct iwl_mvm *mvm,
		      struct ieee80211_vif *vif,
		      u8 sta_id)
{
	int ret = iwl_mvm_rm_sta_common(mvm, sta_id);

	lockdep_assert_held(&mvm->mutex);

	rcu_assign_pointer(mvm->fw_id_to_mac_id[sta_id], NULL);
	return ret;
}

int iwl_mvm_allocate_int_sta(struct iwl_mvm *mvm, struct iwl_mvm_int_sta *sta,
			     u32 qmask)
{
	if (!test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status)) {
		sta->sta_id = iwl_mvm_find_free_sta_id(mvm);
		if (WARN_ON_ONCE(sta->sta_id == IWL_MVM_STATION_COUNT))
			return -ENOSPC;
	}

	sta->tfd_queue_msk = qmask;

	/* put a non-NULL value so iterating over the stations won't stop */
	rcu_assign_pointer(mvm->fw_id_to_mac_id[sta->sta_id], ERR_PTR(-EINVAL));
	return 0;
}

void iwl_mvm_dealloc_int_sta(struct iwl_mvm *mvm, struct iwl_mvm_int_sta *sta)
{
	rcu_assign_pointer(mvm->fw_id_to_mac_id[sta->sta_id], NULL);
	memset(sta, 0, sizeof(struct iwl_mvm_int_sta));
	sta->sta_id = IWL_MVM_STATION_COUNT;
}

static int iwl_mvm_add_int_sta_common(struct iwl_mvm *mvm,
				      struct iwl_mvm_int_sta *sta,
				      const u8 *addr,
				      u16 mac_id, u16 color)
{
	struct iwl_mvm_add_sta_cmd cmd;
	int ret;
	u32 status;

	lockdep_assert_held(&mvm->mutex);

	memset(&cmd, 0, sizeof(struct iwl_mvm_add_sta_cmd));
	cmd.sta_id = sta->sta_id;
	cmd.mac_id_n_color = cpu_to_le32(FW_CMD_ID_AND_COLOR(mac_id,
							     color));

	cmd.tfd_queue_msk = cpu_to_le32(sta->tfd_queue_msk);

	if (addr)
		memcpy(cmd.addr, addr, ETH_ALEN);

	ret = iwl_mvm_send_cmd_pdu_status(mvm, ADD_STA, sizeof(cmd),
					  &cmd, &status);
	if (ret)
		return ret;

	switch (status) {
	case ADD_STA_SUCCESS:
		IWL_DEBUG_INFO(mvm, "Internal station added.\n");
		return 0;
	default:
		ret = -EIO;
		IWL_ERR(mvm, "Add internal station failed, status=0x%x\n",
			status);
		break;
	}
	return ret;
}

int iwl_mvm_add_aux_sta(struct iwl_mvm *mvm)
{
	int ret;

	lockdep_assert_held(&mvm->mutex);

	/* Add the aux station, but without any queues */
	ret = iwl_mvm_allocate_int_sta(mvm, &mvm->aux_sta, 0);
	if (ret)
		return ret;

	ret = iwl_mvm_add_int_sta_common(mvm, &mvm->aux_sta, NULL,
					 MAC_INDEX_AUX, 0);

	if (ret)
		iwl_mvm_dealloc_int_sta(mvm, &mvm->aux_sta);
	return ret;
}

/*
 * Send the add station command for the vif's broadcast station.
 * Assumes that the station was already allocated.
 *
 * @mvm: the mvm component
 * @vif: the interface to which the broadcast station is added
 * @bsta: the broadcast station to add.
 */
int iwl_mvm_send_bcast_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
			   struct iwl_mvm_int_sta *bsta)
{
	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
	static const u8 baddr[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};

	lockdep_assert_held(&mvm->mutex);

	if (WARN_ON_ONCE(bsta->sta_id == IWL_MVM_STATION_COUNT))
		return -ENOSPC;

	return iwl_mvm_add_int_sta_common(mvm, bsta, baddr,
					  mvmvif->id, mvmvif->color);
}

/* Send the FW a request to remove the station from it's internal data
 * structures, but DO NOT remove the entry from the local data structures. */
int iwl_mvm_send_rm_bcast_sta(struct iwl_mvm *mvm,
			      struct iwl_mvm_int_sta *bsta)
{
	int ret;

	lockdep_assert_held(&mvm->mutex);

	ret = iwl_mvm_rm_sta_common(mvm, bsta->sta_id);
	if (ret)
		IWL_WARN(mvm, "Failed sending remove station\n");
	return ret;
}

/* Allocate a new station entry for the broadcast station to the given vif,
 * and send it to the FW.
 * Note that each P2P mac should have its own broadcast station.
 *
 * @mvm: the mvm component
 * @vif: the interface to which the broadcast station is added
 * @bsta: the broadcast station to add. */
int iwl_mvm_add_bcast_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
			  struct iwl_mvm_int_sta *bsta)
{
	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
	static const u8 baddr[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
	u32 qmask;
	int ret;

	lockdep_assert_held(&mvm->mutex);

	qmask = iwl_mvm_mac_get_queues_mask(mvm, vif);
	ret = iwl_mvm_allocate_int_sta(mvm, bsta, qmask);
	if (ret)
		return ret;

	ret = iwl_mvm_add_int_sta_common(mvm, bsta, baddr,
					 mvmvif->id, mvmvif->color);

	if (ret)
		iwl_mvm_dealloc_int_sta(mvm, bsta);
	return ret;
}

/*
 * Send the FW a request to remove the station from it's internal data
 * structures, and in addition remove it from the local data structure.
 */
int iwl_mvm_rm_bcast_sta(struct iwl_mvm *mvm, struct iwl_mvm_int_sta *bsta)
{
	int ret;

	lockdep_assert_held(&mvm->mutex);

	ret = iwl_mvm_rm_sta_common(mvm, bsta->sta_id);
	if (ret)
		return ret;

	iwl_mvm_dealloc_int_sta(mvm, bsta);
	return ret;
}

int iwl_mvm_sta_rx_agg(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
		       int tid, u16 ssn, bool start)
{
	struct iwl_mvm_sta *mvm_sta = (void *)sta->drv_priv;
	struct iwl_mvm_add_sta_cmd cmd = {};
	int ret;
	u32 status;

	lockdep_assert_held(&mvm->mutex);

	cmd.mac_id_n_color = cpu_to_le32(mvm_sta->mac_id_n_color);
	cmd.sta_id = mvm_sta->sta_id;
	cmd.add_modify = STA_MODE_MODIFY;
	cmd.add_immediate_ba_tid = (u8) tid;
	cmd.add_immediate_ba_ssn = cpu_to_le16(ssn);
	cmd.modify_mask = start ? STA_MODIFY_ADD_BA_TID :
				  STA_MODIFY_REMOVE_BA_TID;

	status = ADD_STA_SUCCESS;
	ret = iwl_mvm_send_cmd_pdu_status(mvm, ADD_STA, sizeof(cmd),
					  &cmd, &status);
	if (ret)
		return ret;

	switch (status) {
	case ADD_STA_SUCCESS:
		IWL_DEBUG_INFO(mvm, "RX BA Session %sed in fw\n",
			       start ? "start" : "stopp");
		break;
	case ADD_STA_IMMEDIATE_BA_FAILURE:
		IWL_WARN(mvm, "RX BA Session refused by fw\n");
		ret = -ENOSPC;
		break;
	default:
		ret = -EIO;
		IWL_ERR(mvm, "RX BA Session failed %sing, status 0x%x\n",
			start ? "start" : "stopp", status);
		break;
	}

	return ret;
}

static int iwl_mvm_sta_tx_agg(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
			      int tid, u8 queue, bool start)
{
	struct iwl_mvm_sta *mvm_sta = (void *)sta->drv_priv;
	struct iwl_mvm_add_sta_cmd cmd = {};
	int ret;
	u32 status;

	lockdep_assert_held(&mvm->mutex);

	if (start) {
		mvm_sta->tfd_queue_msk |= BIT(queue);
		mvm_sta->tid_disable_agg &= ~BIT(tid);
	} else {
		mvm_sta->tfd_queue_msk &= ~BIT(queue);
		mvm_sta->tid_disable_agg |= BIT(tid);
	}

	cmd.mac_id_n_color = cpu_to_le32(mvm_sta->mac_id_n_color);
	cmd.sta_id = mvm_sta->sta_id;
	cmd.add_modify = STA_MODE_MODIFY;
	cmd.modify_mask = STA_MODIFY_QUEUES | STA_MODIFY_TID_DISABLE_TX;
	cmd.tfd_queue_msk = cpu_to_le32(mvm_sta->tfd_queue_msk);
	cmd.tid_disable_tx = cpu_to_le16(mvm_sta->tid_disable_agg);

	status = ADD_STA_SUCCESS;
	ret = iwl_mvm_send_cmd_pdu_status(mvm, ADD_STA, sizeof(cmd),
					  &cmd, &status);
	if (ret)
		return ret;

	switch (status) {
	case ADD_STA_SUCCESS:
		break;
	default:
		ret = -EIO;
		IWL_ERR(mvm, "TX BA Session failed %sing, status 0x%x\n",
			start ? "start" : "stopp", status);
		break;
	}

	return ret;
}

static const u8 tid_to_ac[] = {
	IEEE80211_AC_BE,
	IEEE80211_AC_BK,
	IEEE80211_AC_BK,
	IEEE80211_AC_BE,
	IEEE80211_AC_VI,
	IEEE80211_AC_VI,
	IEEE80211_AC_VO,
	IEEE80211_AC_VO,
};

int iwl_mvm_sta_tx_agg_start(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
			     struct ieee80211_sta *sta, u16 tid, u16 *ssn)
{
	struct iwl_mvm_sta *mvmsta = (void *)sta->drv_priv;
	struct iwl_mvm_tid_data *tid_data;
	int txq_id;

	if (WARN_ON_ONCE(tid >= IWL_MAX_TID_COUNT))
		return -EINVAL;

	if (mvmsta->tid_data[tid].state != IWL_AGG_OFF) {
		IWL_ERR(mvm, "Start AGG when state is not IWL_AGG_OFF %d!\n",
			mvmsta->tid_data[tid].state);
		return -ENXIO;
	}

	lockdep_assert_held(&mvm->mutex);

	for (txq_id = IWL_MVM_FIRST_AGG_QUEUE;
	     txq_id <= IWL_MVM_LAST_AGG_QUEUE; txq_id++)
		if (mvm->queue_to_mac80211[txq_id] ==
		    IWL_INVALID_MAC80211_QUEUE)
			break;

	if (txq_id > IWL_MVM_LAST_AGG_QUEUE) {
		IWL_ERR(mvm, "Failed to allocate agg queue\n");
		return -EIO;
	}

	/* the new tx queue is still connected to the same mac80211 queue */
	mvm->queue_to_mac80211[txq_id] = vif->hw_queue[tid_to_ac[tid]];

	spin_lock_bh(&mvmsta->lock);
	tid_data = &mvmsta->tid_data[tid];
	tid_data->ssn = SEQ_TO_SN(tid_data->seq_number);
	tid_data->txq_id = txq_id;
	*ssn = tid_data->ssn;

	IWL_DEBUG_TX_QUEUES(mvm,
			    "Start AGG: sta %d tid %d queue %d - ssn = %d, next_recl = %d\n",
			    mvmsta->sta_id, tid, txq_id, tid_data->ssn,
			    tid_data->next_reclaimed);

	if (tid_data->ssn == tid_data->next_reclaimed) {
		tid_data->state = IWL_AGG_STARTING;
		ieee80211_start_tx_ba_cb_irqsafe(vif, sta->addr, tid);
	} else {
		tid_data->state = IWL_EMPTYING_HW_QUEUE_ADDBA;
	}

	spin_unlock_bh(&mvmsta->lock);

	return 0;
}

int iwl_mvm_sta_tx_agg_oper(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
			    struct ieee80211_sta *sta, u16 tid, u8 buf_size)
{
	struct iwl_mvm_sta *mvmsta = (void *)sta->drv_priv;
	struct iwl_mvm_tid_data *tid_data = &mvmsta->tid_data[tid];
	int queue, fifo, ret;
	u16 ssn;

	buf_size = min_t(int, buf_size, LINK_QUAL_AGG_FRAME_LIMIT_DEF);

	spin_lock_bh(&mvmsta->lock);
	ssn = tid_data->ssn;
	queue = tid_data->txq_id;
	tid_data->state = IWL_AGG_ON;
	tid_data->ssn = 0xffff;
	spin_unlock_bh(&mvmsta->lock);

	fifo = iwl_mvm_ac_to_tx_fifo[tid_to_ac[tid]];

	ret = iwl_mvm_sta_tx_agg(mvm, sta, tid, queue, true);
	if (ret)
		return -EIO;

	iwl_trans_txq_enable(mvm->trans, queue, fifo, mvmsta->sta_id, tid,
			     buf_size, ssn);

	/*
	 * Even though in theory the peer could have different
	 * aggregation reorder buffer sizes for different sessions,
	 * our ucode doesn't allow for that and has a global limit
	 * for each station. Therefore, use the minimum of all the
	 * aggregation sessions and our default value.
	 */
	mvmsta->max_agg_bufsize =
		min(mvmsta->max_agg_bufsize, buf_size);
	mvmsta->lq_sta.lq.agg_frame_cnt_limit = mvmsta->max_agg_bufsize;

	if (mvm->cfg->ht_params->use_rts_for_aggregation) {
		/*
		 * switch to RTS/CTS if it is the prefer protection
		 * method for HT traffic
		 */
		mvmsta->lq_sta.lq.flags |= LQ_FLAG_SET_STA_TLC_RTS_MSK;
		/*
		 * TODO: remove the TLC_RTS flag when we tear down the last
		 * AGG session (agg_tids_count in DVM)
		 */
	}

	IWL_DEBUG_HT(mvm, "Tx aggregation enabled on ra = %pM tid = %d\n",
		     sta->addr, tid);

	return iwl_mvm_send_lq_cmd(mvm, &mvmsta->lq_sta.lq, CMD_ASYNC, false);
}

int iwl_mvm_sta_tx_agg_stop(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
			    struct ieee80211_sta *sta, u16 tid)
{
	struct iwl_mvm_sta *mvmsta = (void *)sta->drv_priv;
	struct iwl_mvm_tid_data *tid_data = &mvmsta->tid_data[tid];
	u16 txq_id;
	int err;


	/*
	 * If mac80211 is cleaning its state, then say that we finished since
	 * our state has been cleared anyway.
	 */
	if (test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status)) {
		ieee80211_stop_tx_ba_cb_irqsafe(vif, sta->addr, tid);
		return 0;
	}

	spin_lock_bh(&mvmsta->lock);

	txq_id = tid_data->txq_id;

	IWL_DEBUG_TX_QUEUES(mvm, "Stop AGG: sta %d tid %d q %d state %d\n",
			    mvmsta->sta_id, tid, txq_id, tid_data->state);

	switch (tid_data->state) {
	case IWL_AGG_ON:
		tid_data->ssn = SEQ_TO_SN(tid_data->seq_number);

		IWL_DEBUG_TX_QUEUES(mvm,
				    "ssn = %d, next_recl = %d\n",
				    tid_data->ssn, tid_data->next_reclaimed);

		/* There are still packets for this RA / TID in the HW */
		if (tid_data->ssn != tid_data->next_reclaimed) {
			tid_data->state = IWL_EMPTYING_HW_QUEUE_DELBA;
			err = 0;
			break;
		}

		tid_data->ssn = 0xffff;
		iwl_trans_txq_disable(mvm->trans, txq_id);
		/* fall through */
	case IWL_AGG_STARTING:
	case IWL_EMPTYING_HW_QUEUE_ADDBA:
		/*
		 * The agg session has been stopped before it was set up. This
		 * can happen when the AddBA timer times out for example.
		 */

		/* No barriers since we are under mutex */
		lockdep_assert_held(&mvm->mutex);
		mvm->queue_to_mac80211[txq_id] = IWL_INVALID_MAC80211_QUEUE;

		ieee80211_stop_tx_ba_cb_irqsafe(vif, sta->addr, tid);
		tid_data->state = IWL_AGG_OFF;
		err = 0;
		break;
	default:
		IWL_ERR(mvm,
			"Stopping AGG while state not ON or starting for %d on %d (%d)\n",
			mvmsta->sta_id, tid, tid_data->state);
		IWL_ERR(mvm,
			"\ttid_data->txq_id = %d\n", tid_data->txq_id);
		err = -EINVAL;
	}

	spin_unlock_bh(&mvmsta->lock);

	return err;
}

int iwl_mvm_sta_tx_agg_flush(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
			    struct ieee80211_sta *sta, u16 tid)
{
	struct iwl_mvm_sta *mvmsta = (void *)sta->drv_priv;
	struct iwl_mvm_tid_data *tid_data = &mvmsta->tid_data[tid];
	u16 txq_id;

	/*
	 * First set the agg state to OFF to avoid calling
	 * ieee80211_stop_tx_ba_cb in iwl_mvm_check_ratid_empty.
	 */
	spin_lock_bh(&mvmsta->lock);
	txq_id = tid_data->txq_id;
	IWL_DEBUG_TX_QUEUES(mvm, "Flush AGG: sta %d tid %d q %d state %d\n",
			    mvmsta->sta_id, tid, txq_id, tid_data->state);
	tid_data->state = IWL_AGG_OFF;
	spin_unlock_bh(&mvmsta->lock);

	if (iwl_mvm_flush_tx_path(mvm, BIT(txq_id), true))
		IWL_ERR(mvm, "Couldn't flush the AGG queue\n");

	iwl_trans_txq_disable(mvm->trans, tid_data->txq_id);
	mvm->queue_to_mac80211[tid_data->txq_id] =
				IWL_INVALID_MAC80211_QUEUE;

	return 0;
}

static int iwl_mvm_set_fw_key_idx(struct iwl_mvm *mvm)
{
	int i;

	lockdep_assert_held(&mvm->mutex);

	i = find_first_zero_bit(mvm->fw_key_table, STA_KEY_MAX_NUM);

	if (i == STA_KEY_MAX_NUM)
		return STA_KEY_IDX_INVALID;

	__set_bit(i, mvm->fw_key_table);

	return i;
}

static u8 iwl_mvm_get_key_sta_id(struct ieee80211_vif *vif,
				 struct ieee80211_sta *sta)
{
	struct iwl_mvm_vif *mvmvif = (void *)vif->drv_priv;

	if (sta) {
		struct iwl_mvm_sta *mvm_sta = (void *)sta->drv_priv;

		return mvm_sta->sta_id;
	}

	/*
	 * The device expects GTKs for station interfaces to be
	 * installed as GTKs for the AP station. If we have no
	 * station ID, then use AP's station ID.
	 */
	if (vif->type == NL80211_IFTYPE_STATION &&
	    mvmvif->ap_sta_id != IWL_MVM_STATION_COUNT)
		return mvmvif->ap_sta_id;

	return IWL_INVALID_STATION;
}

static int iwl_mvm_send_sta_key(struct iwl_mvm *mvm,
				struct iwl_mvm_sta *mvm_sta,
				struct ieee80211_key_conf *keyconf,
				u8 sta_id, u32 tkip_iv32, u16 *tkip_p1k,
				u32 cmd_flags)
{
	__le16 key_flags;
	struct iwl_mvm_add_sta_cmd cmd = {};
	int ret, status;
	u16 keyidx;
	int i;

	keyidx = (keyconf->keyidx << STA_KEY_FLG_KEYID_POS) &
		 STA_KEY_FLG_KEYID_MSK;
	key_flags = cpu_to_le16(keyidx);
	key_flags |= cpu_to_le16(STA_KEY_FLG_WEP_KEY_MAP);

	switch (keyconf->cipher) {
	case WLAN_CIPHER_SUITE_TKIP:
		key_flags |= cpu_to_le16(STA_KEY_FLG_TKIP);
		cmd.key.tkip_rx_tsc_byte2 = tkip_iv32;
		for (i = 0; i < 5; i++)
			cmd.key.tkip_rx_ttak[i] = cpu_to_le16(tkip_p1k[i]);
		memcpy(cmd.key.key, keyconf->key, keyconf->keylen);
		break;
	case WLAN_CIPHER_SUITE_CCMP:
		key_flags |= cpu_to_le16(STA_KEY_FLG_CCM);
		memcpy(cmd.key.key, keyconf->key, keyconf->keylen);
		break;
	default:
		WARN_ON(1);
		return -EINVAL;
	}

	if (!(keyconf->flags & IEEE80211_KEY_FLAG_PAIRWISE))
		key_flags |= cpu_to_le16(STA_KEY_MULTICAST);

	cmd.mac_id_n_color = cpu_to_le32(mvm_sta->mac_id_n_color);
	cmd.key.key_offset = keyconf->hw_key_idx;
	cmd.key.key_flags = key_flags;
	cmd.add_modify = STA_MODE_MODIFY;
	cmd.modify_mask = STA_MODIFY_KEY;
	cmd.sta_id = sta_id;

	status = ADD_STA_SUCCESS;
	if (cmd_flags == CMD_SYNC)
		ret = iwl_mvm_send_cmd_pdu_status(mvm, ADD_STA, sizeof(cmd),
						  &cmd, &status);
	else
		ret = iwl_mvm_send_cmd_pdu(mvm, ADD_STA, CMD_ASYNC,
					   sizeof(cmd), &cmd);

	switch (status) {
	case ADD_STA_SUCCESS:
		IWL_DEBUG_WEP(mvm, "MODIFY_STA: set dynamic key passed\n");
		break;
	default:
		ret = -EIO;
		IWL_ERR(mvm, "MODIFY_STA: set dynamic key failed\n");
		break;
	}

	return ret;
}

static int iwl_mvm_send_sta_igtk(struct iwl_mvm *mvm,
				 struct ieee80211_key_conf *keyconf,
				 u8 sta_id, bool remove_key)
{
	struct iwl_mvm_mgmt_mcast_key_cmd igtk_cmd = {};

	/* verify the key details match the required command's expectations */
	if (WARN_ON((keyconf->cipher != WLAN_CIPHER_SUITE_AES_CMAC) ||
		    (keyconf->flags & IEEE80211_KEY_FLAG_PAIRWISE) ||
		    (keyconf->keyidx != 4 && keyconf->keyidx != 5)))
		return -EINVAL;

	igtk_cmd.key_id = cpu_to_le32(keyconf->keyidx);
	igtk_cmd.sta_id = cpu_to_le32(sta_id);

	if (remove_key) {
		igtk_cmd.ctrl_flags |= cpu_to_le32(STA_KEY_NOT_VALID);
	} else {
		struct ieee80211_key_seq seq;
		const u8 *pn;

		memcpy(igtk_cmd.IGTK, keyconf->key, keyconf->keylen);
		ieee80211_aes_cmac_calculate_k1_k2(keyconf,
						   igtk_cmd.K1, igtk_cmd.K2);
		ieee80211_get_key_rx_seq(keyconf, 0, &seq);
		pn = seq.aes_cmac.pn;
		igtk_cmd.receive_seq_cnt = cpu_to_le64(((u64) pn[5] << 0) |
						       ((u64) pn[4] << 8) |
						       ((u64) pn[3] << 16) |
						       ((u64) pn[2] << 24) |
						       ((u64) pn[1] << 32) |
						       ((u64) pn[0] << 40));
	}

	IWL_DEBUG_INFO(mvm, "%s igtk for sta %u\n",
		       remove_key ? "removing" : "installing",
		       igtk_cmd.sta_id);

	return iwl_mvm_send_cmd_pdu(mvm, MGMT_MCAST_KEY, CMD_SYNC,
				    sizeof(igtk_cmd), &igtk_cmd);
}


static inline u8 *iwl_mvm_get_mac_addr(struct iwl_mvm *mvm,
				       struct ieee80211_vif *vif,
				       struct ieee80211_sta *sta)
{
	struct iwl_mvm_vif *mvmvif = (void *)vif->drv_priv;

	if (sta)
		return sta->addr;

	if (vif->type == NL80211_IFTYPE_STATION &&
	    mvmvif->ap_sta_id != IWL_MVM_STATION_COUNT) {
		u8 sta_id = mvmvif->ap_sta_id;
		sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[sta_id],
						lockdep_is_held(&mvm->mutex));
		return sta->addr;
	}


	return NULL;
}

int iwl_mvm_set_sta_key(struct iwl_mvm *mvm,
			struct ieee80211_vif *vif,
			struct ieee80211_sta *sta,
			struct ieee80211_key_conf *keyconf,
			bool have_key_offset)
{
	struct iwl_mvm_sta *mvm_sta;
	int ret;
	u8 *addr, sta_id;
	struct ieee80211_key_seq seq;
	u16 p1k[5];

	lockdep_assert_held(&mvm->mutex);

	/* Get the station id from the mvm local station table */
	sta_id = iwl_mvm_get_key_sta_id(vif, sta);
	if (sta_id == IWL_INVALID_STATION) {
		IWL_ERR(mvm, "Failed to find station id\n");
		return -EINVAL;
	}

	if (keyconf->cipher == WLAN_CIPHER_SUITE_AES_CMAC) {
		ret = iwl_mvm_send_sta_igtk(mvm, keyconf, sta_id, false);
		goto end;
	}

	/*
	 * It is possible that the 'sta' parameter is NULL, and thus
	 * there is a need to retrieve  the sta from the local station table.
	 */
	if (!sta) {
		sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[sta_id],
						lockdep_is_held(&mvm->mutex));
		if (IS_ERR_OR_NULL(sta)) {
			IWL_ERR(mvm, "Invalid station id\n");
			return -EINVAL;
		}
	}

	mvm_sta = (struct iwl_mvm_sta *)sta->drv_priv;
	if (WARN_ON_ONCE(mvm_sta->vif != vif))
		return -EINVAL;

	if (!have_key_offset) {
		/*
		 * The D3 firmware hardcodes the PTK offset to 0, so we have to
		 * configure it there. As a result, this workaround exists to
		 * let the caller set the key offset (hw_key_idx), see d3.c.
		 */
		keyconf->hw_key_idx = iwl_mvm_set_fw_key_idx(mvm);
		if (keyconf->hw_key_idx == STA_KEY_IDX_INVALID)
			return -ENOSPC;
	}

	switch (keyconf->cipher) {
	case WLAN_CIPHER_SUITE_TKIP:
		addr = iwl_mvm_get_mac_addr(mvm, vif, sta);
		/* get phase 1 key from mac80211 */
		ieee80211_get_key_rx_seq(keyconf, 0, &seq);
		ieee80211_get_tkip_rx_p1k(keyconf, addr, seq.tkip.iv32, p1k);
		ret = iwl_mvm_send_sta_key(mvm, mvm_sta, keyconf, sta_id,
					   seq.tkip.iv32, p1k, CMD_SYNC);
		break;
	case WLAN_CIPHER_SUITE_CCMP:
		ret = iwl_mvm_send_sta_key(mvm, mvm_sta, keyconf, sta_id,
					   0, NULL, CMD_SYNC);
		break;
	default:
		IWL_ERR(mvm, "Unknown cipher %x\n", keyconf->cipher);
		ret = -EINVAL;
	}

	if (ret)
		__clear_bit(keyconf->hw_key_idx, mvm->fw_key_table);

end:
	IWL_DEBUG_WEP(mvm, "key: cipher=%x len=%d idx=%d sta=%pM ret=%d\n",
		      keyconf->cipher, keyconf->keylen, keyconf->keyidx,
		      sta->addr, ret);
	return ret;
}

int iwl_mvm_remove_sta_key(struct iwl_mvm *mvm,
			   struct ieee80211_vif *vif,
			   struct ieee80211_sta *sta,
			   struct ieee80211_key_conf *keyconf)
{
	struct iwl_mvm_sta *mvm_sta;
	struct iwl_mvm_add_sta_cmd cmd = {};
	__le16 key_flags;
	int ret, status;
	u8 sta_id;

	lockdep_assert_held(&mvm->mutex);

	/* Get the station id from the mvm local station table */
	sta_id = iwl_mvm_get_key_sta_id(vif, sta);

	IWL_DEBUG_WEP(mvm, "mvm remove dynamic key: idx=%d sta=%d\n",
		      keyconf->keyidx, sta_id);

	if (keyconf->cipher == WLAN_CIPHER_SUITE_AES_CMAC)
		return iwl_mvm_send_sta_igtk(mvm, keyconf, sta_id, true);

	ret = __test_and_clear_bit(keyconf->hw_key_idx, mvm->fw_key_table);
	if (!ret) {
		IWL_ERR(mvm, "offset %d not used in fw key table.\n",
			keyconf->hw_key_idx);
		return -ENOENT;
	}

	if (sta_id == IWL_INVALID_STATION) {
		IWL_DEBUG_WEP(mvm, "station non-existent, early return.\n");
		return 0;
	}

	/*
	 * It is possible that the 'sta' parameter is NULL, and thus
	 * there is a need to retrieve the sta from the local station table,
	 * for example when a GTK is removed (where the sta_id will then be
	 * the AP ID, and no station was passed by mac80211.)
	 */
	if (!sta) {
		sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[sta_id],
						lockdep_is_held(&mvm->mutex));
		if (!sta) {
			IWL_ERR(mvm, "Invalid station id\n");
			return -EINVAL;
		}
	}

	mvm_sta = (struct iwl_mvm_sta *)sta->drv_priv;
	if (WARN_ON_ONCE(mvm_sta->vif != vif))
		return -EINVAL;

	key_flags = cpu_to_le16((keyconf->keyidx << STA_KEY_FLG_KEYID_POS) &
				 STA_KEY_FLG_KEYID_MSK);
	key_flags |= cpu_to_le16(STA_KEY_FLG_NO_ENC | STA_KEY_FLG_WEP_KEY_MAP);
	key_flags |= cpu_to_le16(STA_KEY_NOT_VALID);

	if (!(keyconf->flags & IEEE80211_KEY_FLAG_PAIRWISE))
		key_flags |= cpu_to_le16(STA_KEY_MULTICAST);

	cmd.mac_id_n_color = cpu_to_le32(mvm_sta->mac_id_n_color);
	cmd.key.key_flags = key_flags;
	cmd.key.key_offset = keyconf->hw_key_idx;
	cmd.sta_id = sta_id;

	cmd.modify_mask = STA_MODIFY_KEY;
	cmd.add_modify = STA_MODE_MODIFY;

	status = ADD_STA_SUCCESS;
	ret = iwl_mvm_send_cmd_pdu_status(mvm, ADD_STA, sizeof(cmd),
					  &cmd, &status);

	switch (status) {
	case ADD_STA_SUCCESS:
		IWL_DEBUG_WEP(mvm, "MODIFY_STA: remove sta key passed\n");
		break;
	default:
		ret = -EIO;
		IWL_ERR(mvm, "MODIFY_STA: remove sta key failed\n");
		break;
	}

	return ret;
}

void iwl_mvm_update_tkip_key(struct iwl_mvm *mvm,
			     struct ieee80211_vif *vif,
			     struct ieee80211_key_conf *keyconf,
			     struct ieee80211_sta *sta, u32 iv32,
			     u16 *phase1key)
{
	struct iwl_mvm_sta *mvm_sta;
	u8 sta_id = iwl_mvm_get_key_sta_id(vif, sta);

	if (WARN_ON_ONCE(sta_id == IWL_INVALID_STATION))
		return;

	rcu_read_lock();

	if (!sta) {
		sta = rcu_dereference(mvm->fw_id_to_mac_id[sta_id]);
		if (WARN_ON(IS_ERR_OR_NULL(sta))) {
			rcu_read_unlock();
			return;
		}
	}

	mvm_sta = (void *)sta->drv_priv;
	iwl_mvm_send_sta_key(mvm, mvm_sta, keyconf, sta_id,
			     iv32, phase1key, CMD_ASYNC);
	rcu_read_unlock();
}

void iwl_mvm_sta_modify_ps_wake(struct iwl_mvm *mvm,
				struct ieee80211_sta *sta)
{
	struct iwl_mvm_sta *mvmsta = (void *)sta->drv_priv;
	struct iwl_mvm_add_sta_cmd cmd = {
		.add_modify = STA_MODE_MODIFY,
		.sta_id = mvmsta->sta_id,
		.modify_mask = STA_MODIFY_SLEEPING_STA_TX_COUNT,
		.sleep_state_flags = cpu_to_le16(STA_SLEEP_STATE_AWAKE),
		.mac_id_n_color = cpu_to_le32(mvmsta->mac_id_n_color),
	};
	int ret;

	/*
	 * Same modify mask for sleep_tx_count and sleep_state_flags but this
	 * should be fine since if we set the STA as "awake", then
	 * sleep_tx_count is not relevant.
	 */
	ret = iwl_mvm_send_cmd_pdu(mvm, ADD_STA, CMD_ASYNC, sizeof(cmd), &cmd);
	if (ret)
		IWL_ERR(mvm, "Failed to send ADD_STA command (%d)\n", ret);
}

void iwl_mvm_sta_modify_sleep_tx_count(struct iwl_mvm *mvm,
				       struct ieee80211_sta *sta,
				       enum ieee80211_frame_release_type reason,
				       u16 cnt)
{
	u16 sleep_state_flags =
		(reason == IEEE80211_FRAME_RELEASE_UAPSD) ?
			STA_SLEEP_STATE_UAPSD : STA_SLEEP_STATE_PS_POLL;
	struct iwl_mvm_sta *mvmsta = (void *)sta->drv_priv;
	struct iwl_mvm_add_sta_cmd cmd = {
		.add_modify = STA_MODE_MODIFY,
		.sta_id = mvmsta->sta_id,
		.modify_mask = STA_MODIFY_SLEEPING_STA_TX_COUNT,
		.sleep_tx_count = cpu_to_le16(cnt),
		.mac_id_n_color = cpu_to_le32(mvmsta->mac_id_n_color),
		/*
		 * Same modify mask for sleep_tx_count and sleep_state_flags so
		 * we must set the sleep_state_flags too.
		 */
		.sleep_state_flags = cpu_to_le16(sleep_state_flags),
	};
	int ret;

	/* TODO: somehow the fw doesn't seem to take PS_POLL into account */
	ret = iwl_mvm_send_cmd_pdu(mvm, ADD_STA, CMD_ASYNC, sizeof(cmd), &cmd);
	if (ret)
		IWL_ERR(mvm, "Failed to send ADD_STA command (%d)\n", ret);
}