/******************************************************************************
 *
 * 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 - 2015 Intel Corporation. All rights reserved.
 * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
 * Copyright(c) 2016 - 2017 Intel Deutschland GmbH
 * Copyright(c) 2018 - 2019 Intel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * The full GNU General Public License is included in this distribution
 * in the file called COPYING.
 *
 * Contact Information:
 *  Intel Linux Wireless <linuxwifi@intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 * BSD LICENSE
 *
 * Copyright(c) 2012 - 2015 Intel Corporation. All rights reserved.
 * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
 * Copyright(c) 2016 - 2017 Intel Deutschland GmbH
 * Copyright(c) 2018 - 2019 Intel Corporation
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  * Neither the name Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *****************************************************************************/
#include <net/mac80211.h>

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

static int iwl_mvm_set_fw_key_idx(struct iwl_mvm *mvm);

static int iwl_mvm_send_sta_key(struct iwl_mvm *mvm,
                                u32 sta_id,
                                struct ieee80211_key_conf *key, bool mcast,
                                u32 tkip_iv32, u16 *tkip_p1k, u32 cmd_flags,
                                u8 key_offset, bool mfp);

/*
 * New version of ADD_STA_sta command added new fields at the end of the
 * structure, so sending the size of the relevant API's structure is enough to
 * support both API versions.
 */
static inline int iwl_mvm_add_sta_cmd_size(struct iwl_mvm *mvm)
{
        if (iwl_mvm_has_new_rx_api(mvm) ||
            fw_has_api(&mvm->fw->ucode_capa, IWL_UCODE_TLV_API_STA_TYPE))
                return sizeof(struct iwl_mvm_add_sta_cmd);
        else
                return sizeof(struct iwl_mvm_add_sta_cmd_v7);
}

static int iwl_mvm_find_free_sta_id(struct iwl_mvm *mvm,
                                    enum nl80211_iftype iftype)
{
        int sta_id;
        u32 reserved_ids = 0;

        BUILD_BUG_ON(IWL_MVM_STATION_COUNT > 32);
        WARN_ON_ONCE(test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status));

        lockdep_assert_held(&mvm->mutex);

        /* d0i3/d3 assumes the AP's sta_id (of sta vif) is 0. reserve it. */
        if (iftype != NL80211_IFTYPE_STATION)
                reserved_ids = BIT(0);

        /* Don't take rcu_read_lock() since we are protected by mvm->mutex */
        for (sta_id = 0; sta_id < ARRAY_SIZE(mvm->fw_id_to_mac_id); sta_id++) {
                if (BIT(sta_id) & reserved_ids)
                        continue;

                if (!rcu_dereference_protected(mvm->fw_id_to_mac_id[sta_id],
                                               lockdep_is_held(&mvm->mutex)))
                        return sta_id;
        }
        return IWL_MVM_INVALID_STA;
}

/* send station add/update command to firmware */
int iwl_mvm_sta_send_to_fw(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
                           bool update, unsigned int flags)
{
        struct iwl_mvm_sta *mvm_sta = iwl_mvm_sta_from_mac80211(sta);
        struct iwl_mvm_add_sta_cmd add_sta_cmd = {
                .sta_id = mvm_sta->sta_id,
                .mac_id_n_color = cpu_to_le32(mvm_sta->mac_id_n_color),
                .add_modify = update ? 1 : 0,
                .station_flags_msk = cpu_to_le32(STA_FLG_FAT_EN_MSK |
                                                 STA_FLG_MIMO_EN_MSK |
                                                 STA_FLG_RTS_MIMO_PROT),
                .tid_disable_tx = cpu_to_le16(mvm_sta->tid_disable_agg),
        };
        int ret;
        u32 status;
        u32 agg_size = 0, mpdu_dens = 0;

        if (fw_has_api(&mvm->fw->ucode_capa, IWL_UCODE_TLV_API_STA_TYPE))
                add_sta_cmd.station_type = mvm_sta->sta_type;

        if (!update || (flags & STA_MODIFY_QUEUES)) {
                memcpy(&add_sta_cmd.addr, sta->addr, ETH_ALEN);

                if (!iwl_mvm_has_new_tx_api(mvm)) {
                        add_sta_cmd.tfd_queue_msk =
                                cpu_to_le32(mvm_sta->tfd_queue_msk);

                        if (flags & STA_MODIFY_QUEUES)
                                add_sta_cmd.modify_mask |= STA_MODIFY_QUEUES;
                } else {
                        WARN_ON(flags & STA_MODIFY_QUEUES);
                }
        }

        switch (sta->bandwidth) {
        case IEEE80211_STA_RX_BW_160:
                add_sta_cmd.station_flags |= cpu_to_le32(STA_FLG_FAT_EN_160MHZ);
                /* fall through */
        case IEEE80211_STA_RX_BW_80:
                add_sta_cmd.station_flags |= cpu_to_le32(STA_FLG_FAT_EN_80MHZ);
                /* fall through */
        case IEEE80211_STA_RX_BW_40:
                add_sta_cmd.station_flags |= cpu_to_le32(STA_FLG_FAT_EN_40MHZ);
                /* fall through */
        case IEEE80211_STA_RX_BW_20:
                if (sta->ht_cap.ht_supported)
                        add_sta_cmd.station_flags |=
                                cpu_to_le32(STA_FLG_FAT_EN_20MHZ);
                break;
        }

        switch (sta->rx_nss) {
        case 1:
                add_sta_cmd.station_flags |= cpu_to_le32(STA_FLG_MIMO_EN_SISO);
                break;
        case 2:
                add_sta_cmd.station_flags |= cpu_to_le32(STA_FLG_MIMO_EN_MIMO2);
                break;
        case 3 ... 8:
                add_sta_cmd.station_flags |= cpu_to_le32(STA_FLG_MIMO_EN_MIMO3);
                break;
        }

        switch (sta->smps_mode) {
        case IEEE80211_SMPS_AUTOMATIC:
        case IEEE80211_SMPS_NUM_MODES:
                WARN_ON(1);
                break;
        case IEEE80211_SMPS_STATIC:
                /* override NSS */
                add_sta_cmd.station_flags &= ~cpu_to_le32(STA_FLG_MIMO_EN_MSK);
                add_sta_cmd.station_flags |= cpu_to_le32(STA_FLG_MIMO_EN_SISO);
                break;
        case IEEE80211_SMPS_DYNAMIC:
                add_sta_cmd.station_flags |= cpu_to_le32(STA_FLG_RTS_MIMO_PROT);
                break;
        case IEEE80211_SMPS_OFF:
                /* nothing */
                break;
        }

        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);
        if (mvm_sta->sta_state >= IEEE80211_STA_ASSOC)
                add_sta_cmd.assoc_id = cpu_to_le16(sta->aid);

        if (sta->wme) {
                add_sta_cmd.modify_mask |= STA_MODIFY_UAPSD_ACS;

                if (sta->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_BK)
                        add_sta_cmd.uapsd_acs |= BIT(AC_BK);
                if (sta->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_BE)
                        add_sta_cmd.uapsd_acs |= BIT(AC_BE);
                if (sta->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VI)
                        add_sta_cmd.uapsd_acs |= BIT(AC_VI);
                if (sta->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VO)
                        add_sta_cmd.uapsd_acs |= BIT(AC_VO);
                add_sta_cmd.uapsd_acs |= add_sta_cmd.uapsd_acs << 4;
                add_sta_cmd.sp_length = sta->max_sp ? sta->max_sp * 2 : 128;
        }

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

        switch (status & IWL_ADD_STA_STATUS_MASK) {
        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;
}

static void iwl_mvm_rx_agg_session_expired(struct timer_list *t)
{
        struct iwl_mvm_baid_data *data =
                from_timer(data, t, session_timer);
        struct iwl_mvm_baid_data __rcu **rcu_ptr = data->rcu_ptr;
        struct iwl_mvm_baid_data *ba_data;
        struct ieee80211_sta *sta;
        struct iwl_mvm_sta *mvm_sta;
        unsigned long timeout;

        rcu_read_lock();

        ba_data = rcu_dereference(*rcu_ptr);

        if (WARN_ON(!ba_data))
                goto unlock;

        if (!ba_data->timeout)
                goto unlock;

        timeout = ba_data->last_rx + TU_TO_JIFFIES(ba_data->timeout * 2);
        if (time_is_after_jiffies(timeout)) {
                mod_timer(&ba_data->session_timer, timeout);
                goto unlock;
        }

        /* Timer expired */
        sta = rcu_dereference(ba_data->mvm->fw_id_to_mac_id[ba_data->sta_id]);

        /*
         * sta should be valid unless the following happens:
         * The firmware asserts which triggers a reconfig flow, but
         * the reconfig fails before we set the pointer to sta into
         * the fw_id_to_mac_id pointer table. Mac80211 can't stop
         * A-MDPU and hence the timer continues to run. Then, the
         * timer expires and sta is NULL.
         */
        if (!sta)
                goto unlock;

        mvm_sta = iwl_mvm_sta_from_mac80211(sta);
        ieee80211_rx_ba_timer_expired(mvm_sta->vif,
                                      sta->addr, ba_data->tid);
unlock:
        rcu_read_unlock();
}

/* Disable aggregations for a bitmap of TIDs for a given station */
static int iwl_mvm_invalidate_sta_queue(struct iwl_mvm *mvm, int queue,
                                        unsigned long disable_agg_tids,
                                        bool remove_queue)
{
        struct iwl_mvm_add_sta_cmd cmd = {};
        struct ieee80211_sta *sta;
        struct iwl_mvm_sta *mvmsta;
        u32 status;
        u8 sta_id;

        if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
                return -EINVAL;

        sta_id = mvm->queue_info[queue].ra_sta_id;

        rcu_read_lock();

        sta = rcu_dereference(mvm->fw_id_to_mac_id[sta_id]);

        if (WARN_ON_ONCE(IS_ERR_OR_NULL(sta))) {
                rcu_read_unlock();
                return -EINVAL;
        }

        mvmsta = iwl_mvm_sta_from_mac80211(sta);

        mvmsta->tid_disable_agg |= disable_agg_tids;

        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.modify_mask = STA_MODIFY_QUEUES;
        if (disable_agg_tids)
                cmd.modify_mask |= STA_MODIFY_TID_DISABLE_TX;
        if (remove_queue)
                cmd.modify_mask |= STA_MODIFY_QUEUE_REMOVAL;
        cmd.tfd_queue_msk = cpu_to_le32(mvmsta->tfd_queue_msk);
        cmd.tid_disable_tx = cpu_to_le16(mvmsta->tid_disable_agg);

        rcu_read_unlock();

        /* Notify FW of queue removal from the STA queues */
        status = ADD_STA_SUCCESS;
        return iwl_mvm_send_cmd_pdu_status(mvm, ADD_STA,
                                           iwl_mvm_add_sta_cmd_size(mvm),
                                           &cmd, &status);
}

static int iwl_mvm_disable_txq(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
                               int queue, u8 tid, u8 flags)
{
        struct iwl_scd_txq_cfg_cmd cmd = {
                .scd_queue = queue,
                .action = SCD_CFG_DISABLE_QUEUE,
        };
        int ret;

        if (iwl_mvm_has_new_tx_api(mvm)) {
                iwl_trans_txq_free(mvm->trans, queue);

                return 0;
        }

        if (WARN_ON(mvm->queue_info[queue].tid_bitmap == 0))
                return 0;

        mvm->queue_info[queue].tid_bitmap &= ~BIT(tid);

        cmd.action = mvm->queue_info[queue].tid_bitmap ?
                SCD_CFG_ENABLE_QUEUE : SCD_CFG_DISABLE_QUEUE;
        if (cmd.action == SCD_CFG_DISABLE_QUEUE)
                mvm->queue_info[queue].status = IWL_MVM_QUEUE_FREE;

        IWL_DEBUG_TX_QUEUES(mvm,
                            "Disabling TXQ #%d tids=0x%x\n",
                            queue,
                            mvm->queue_info[queue].tid_bitmap);

        /* If the queue is still enabled - nothing left to do in this func */
        if (cmd.action == SCD_CFG_ENABLE_QUEUE)
                return 0;

        cmd.sta_id = mvm->queue_info[queue].ra_sta_id;
        cmd.tid = mvm->queue_info[queue].txq_tid;

        /* Make sure queue info is correct even though we overwrite it */
        WARN(mvm->queue_info[queue].tid_bitmap,
             "TXQ #%d info out-of-sync - tids=0x%x\n",
             queue, mvm->queue_info[queue].tid_bitmap);

        /* If we are here - the queue is freed and we can zero out these vals */
        mvm->queue_info[queue].tid_bitmap = 0;

        if (sta) {
                struct iwl_mvm_txq *mvmtxq =
                        iwl_mvm_txq_from_tid(sta, tid);

                mvmtxq->txq_id = IWL_MVM_INVALID_QUEUE;
        }

        /* Regardless if this is a reserved TXQ for a STA - mark it as false */
        mvm->queue_info[queue].reserved = false;

        iwl_trans_txq_disable(mvm->trans, queue, false);
        ret = iwl_mvm_send_cmd_pdu(mvm, SCD_QUEUE_CFG, flags,
                                   sizeof(struct iwl_scd_txq_cfg_cmd), &cmd);

        if (ret)
                IWL_ERR(mvm, "Failed to disable queue %d (ret=%d)\n",
                        queue, ret);
        return ret;
}

static int iwl_mvm_get_queue_agg_tids(struct iwl_mvm *mvm, int queue)
{
        struct ieee80211_sta *sta;
        struct iwl_mvm_sta *mvmsta;
        unsigned long tid_bitmap;
        unsigned long agg_tids = 0;
        u8 sta_id;
        int tid;

        lockdep_assert_held(&mvm->mutex);

        if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
                return -EINVAL;

        sta_id = mvm->queue_info[queue].ra_sta_id;
        tid_bitmap = mvm->queue_info[queue].tid_bitmap;

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

        if (WARN_ON_ONCE(IS_ERR_OR_NULL(sta)))
                return -EINVAL;

        mvmsta = iwl_mvm_sta_from_mac80211(sta);

        spin_lock_bh(&mvmsta->lock);
        for_each_set_bit(tid, &tid_bitmap, IWL_MAX_TID_COUNT + 1) {
                if (mvmsta->tid_data[tid].state == IWL_AGG_ON)
                        agg_tids |= BIT(tid);
        }
        spin_unlock_bh(&mvmsta->lock);

        return agg_tids;
}

/*
 * Remove a queue from a station's resources.
 * Note that this only marks as free. It DOESN'T delete a BA agreement, and
 * doesn't disable the queue
 */
static int iwl_mvm_remove_sta_queue_marking(struct iwl_mvm *mvm, int queue)
{
        struct ieee80211_sta *sta;
        struct iwl_mvm_sta *mvmsta;
        unsigned long tid_bitmap;
        unsigned long disable_agg_tids = 0;
        u8 sta_id;
        int tid;

        lockdep_assert_held(&mvm->mutex);

        if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
                return -EINVAL;

        sta_id = mvm->queue_info[queue].ra_sta_id;
        tid_bitmap = mvm->queue_info[queue].tid_bitmap;

        rcu_read_lock();

        sta = rcu_dereference(mvm->fw_id_to_mac_id[sta_id]);

        if (WARN_ON_ONCE(IS_ERR_OR_NULL(sta))) {
                rcu_read_unlock();
                return 0;
        }

        mvmsta = iwl_mvm_sta_from_mac80211(sta);

        spin_lock_bh(&mvmsta->lock);
        /* Unmap MAC queues and TIDs from this queue */
        for_each_set_bit(tid, &tid_bitmap, IWL_MAX_TID_COUNT + 1) {
                struct iwl_mvm_txq *mvmtxq =
                        iwl_mvm_txq_from_tid(sta, tid);

                if (mvmsta->tid_data[tid].state == IWL_AGG_ON)
                        disable_agg_tids |= BIT(tid);
                mvmsta->tid_data[tid].txq_id = IWL_MVM_INVALID_QUEUE;

                mvmtxq->txq_id = IWL_MVM_INVALID_QUEUE;
        }

        mvmsta->tfd_queue_msk &= ~BIT(queue); /* Don't use this queue anymore */
        spin_unlock_bh(&mvmsta->lock);

        rcu_read_unlock();

        /*
         * The TX path may have been using this TXQ_ID from the tid_data,
         * so make sure it's no longer running so that we can safely reuse
         * this TXQ later. We've set all the TIDs to IWL_MVM_INVALID_QUEUE
         * above, but nothing guarantees we've stopped using them. Thus,
         * without this, we could get to iwl_mvm_disable_txq() and remove
         * the queue while still sending frames to it.
         */
        synchronize_net();

        return disable_agg_tids;
}

static int iwl_mvm_free_inactive_queue(struct iwl_mvm *mvm, int queue,
                                       struct ieee80211_sta *old_sta,
                                       u8 new_sta_id)
{
        struct iwl_mvm_sta *mvmsta;
        u8 sta_id, tid;
        unsigned long disable_agg_tids = 0;
        bool same_sta;
        int ret;

        lockdep_assert_held(&mvm->mutex);

        if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
                return -EINVAL;

        sta_id = mvm->queue_info[queue].ra_sta_id;
        tid = mvm->queue_info[queue].txq_tid;

        same_sta = sta_id == new_sta_id;

        mvmsta = iwl_mvm_sta_from_staid_protected(mvm, sta_id);
        if (WARN_ON(!mvmsta))
                return -EINVAL;

        disable_agg_tids = iwl_mvm_remove_sta_queue_marking(mvm, queue);
        /* Disable the queue */
        if (disable_agg_tids)
                iwl_mvm_invalidate_sta_queue(mvm, queue,
                                             disable_agg_tids, false);

        ret = iwl_mvm_disable_txq(mvm, old_sta, queue, tid, 0);
        if (ret) {
                IWL_ERR(mvm,
                        "Failed to free inactive queue %d (ret=%d)\n",
                        queue, ret);

                return ret;
        }

        /* If TXQ is allocated to another STA, update removal in FW */
        if (!same_sta)
                iwl_mvm_invalidate_sta_queue(mvm, queue, 0, true);

        return 0;
}

static int iwl_mvm_get_shared_queue(struct iwl_mvm *mvm,
                                    unsigned long tfd_queue_mask, u8 ac)
{
        int queue = 0;
        u8 ac_to_queue[IEEE80211_NUM_ACS];
        int i;

        /*
         * This protects us against grabbing a queue that's being reconfigured
         * by the inactivity checker.
         */
        lockdep_assert_held(&mvm->mutex);

        if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
                return -EINVAL;

        memset(&ac_to_queue, IEEE80211_INVAL_HW_QUEUE, sizeof(ac_to_queue));

        /* See what ACs the existing queues for this STA have */
        for_each_set_bit(i, &tfd_queue_mask, IWL_MVM_DQA_MAX_DATA_QUEUE) {
                /* Only DATA queues can be shared */
                if (i < IWL_MVM_DQA_MIN_DATA_QUEUE &&
                    i != IWL_MVM_DQA_BSS_CLIENT_QUEUE)
                        continue;

                ac_to_queue[mvm->queue_info[i].mac80211_ac] = i;
        }

        /*
         * The queue to share is chosen only from DATA queues as follows (in
         * descending priority):
         * 1. An AC_BE queue
         * 2. Same AC queue
         * 3. Highest AC queue that is lower than new AC
         * 4. Any existing AC (there always is at least 1 DATA queue)
         */

        /* Priority 1: An AC_BE queue */
        if (ac_to_queue[IEEE80211_AC_BE] != IEEE80211_INVAL_HW_QUEUE)
                queue = ac_to_queue[IEEE80211_AC_BE];
        /* Priority 2: Same AC queue */
        else if (ac_to_queue[ac] != IEEE80211_INVAL_HW_QUEUE)
                queue = ac_to_queue[ac];
        /* Priority 3a: If new AC is VO and VI exists - use VI */
        else if (ac == IEEE80211_AC_VO &&
                 ac_to_queue[IEEE80211_AC_VI] != IEEE80211_INVAL_HW_QUEUE)
                queue = ac_to_queue[IEEE80211_AC_VI];
        /* Priority 3b: No BE so only AC less than the new one is BK */
        else if (ac_to_queue[IEEE80211_AC_BK] != IEEE80211_INVAL_HW_QUEUE)
                queue = ac_to_queue[IEEE80211_AC_BK];
        /* Priority 4a: No BE nor BK - use VI if exists */
        else if (ac_to_queue[IEEE80211_AC_VI] != IEEE80211_INVAL_HW_QUEUE)
                queue = ac_to_queue[IEEE80211_AC_VI];
        /* Priority 4b: No BE, BK nor VI - use VO if exists */
        else if (ac_to_queue[IEEE80211_AC_VO] != IEEE80211_INVAL_HW_QUEUE)
                queue = ac_to_queue[IEEE80211_AC_VO];

        /* Make sure queue found (or not) is legal */
        if (!iwl_mvm_is_dqa_data_queue(mvm, queue) &&
            !iwl_mvm_is_dqa_mgmt_queue(mvm, queue) &&
            (queue != IWL_MVM_DQA_BSS_CLIENT_QUEUE)) {
                IWL_ERR(mvm, "No DATA queues available to share\n");
                return -ENOSPC;
        }

        return queue;
}

/*
 * If a given queue has a higher AC than the TID stream that is being compared
 * to, the queue needs to be redirected to the lower AC. This function does that
 * in such a case, otherwise - if no redirection required - it does nothing,
 * unless the %force param is true.
 */
static int iwl_mvm_redirect_queue(struct iwl_mvm *mvm, int queue, int tid,
                                  int ac, int ssn, unsigned int wdg_timeout,
                                  bool force, struct iwl_mvm_txq *txq)
{
        struct iwl_scd_txq_cfg_cmd cmd = {
                .scd_queue = queue,
                .action = SCD_CFG_DISABLE_QUEUE,
        };
        bool shared_queue;
        int ret;

        if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
                return -EINVAL;

        /*
         * If the AC is lower than current one - FIFO needs to be redirected to
         * the lowest one of the streams in the queue. Check if this is needed
         * here.
         * Notice that the enum ieee80211_ac_numbers is "flipped", so BK is with
         * value 3 and VO with value 0, so to check if ac X is lower than ac Y
         * we need to check if the numerical value of X is LARGER than of Y.
         */
        if (ac <= mvm->queue_info[queue].mac80211_ac && !force) {
                IWL_DEBUG_TX_QUEUES(mvm,
                                    "No redirection needed on TXQ #%d\n",
                                    queue);
                return 0;
        }

        cmd.sta_id = mvm->queue_info[queue].ra_sta_id;
        cmd.tx_fifo = iwl_mvm_ac_to_tx_fifo[mvm->queue_info[queue].mac80211_ac];
        cmd.tid = mvm->queue_info[queue].txq_tid;
        shared_queue = hweight16(mvm->queue_info[queue].tid_bitmap) > 1;

        IWL_DEBUG_TX_QUEUES(mvm, "Redirecting TXQ #%d to FIFO #%d\n",
                            queue, iwl_mvm_ac_to_tx_fifo[ac]);

        /* Stop the queue and wait for it to empty */
        txq->stopped = true;

        ret = iwl_trans_wait_tx_queues_empty(mvm->trans, BIT(queue));
        if (ret) {
                IWL_ERR(mvm, "Error draining queue %d before reconfig\n",
                        queue);
                ret = -EIO;
                goto out;
        }

        /* Before redirecting the queue we need to de-activate it */
        iwl_trans_txq_disable(mvm->trans, queue, false);
        ret = iwl_mvm_send_cmd_pdu(mvm, SCD_QUEUE_CFG, 0, sizeof(cmd), &cmd);
        if (ret)
                IWL_ERR(mvm, "Failed SCD disable TXQ %d (ret=%d)\n", queue,
                        ret);

        /* Make sure the SCD wrptr is correctly set before reconfiguring */
        iwl_trans_txq_enable_cfg(mvm->trans, queue, ssn, NULL, wdg_timeout);

        /* Update the TID "owner" of the queue */
        mvm->queue_info[queue].txq_tid = tid;

        /* TODO: Work-around SCD bug when moving back by multiples of 0x40 */

        /* Redirect to lower AC */
        iwl_mvm_reconfig_scd(mvm, queue, iwl_mvm_ac_to_tx_fifo[ac],
                             cmd.sta_id, tid, IWL_FRAME_LIMIT, ssn);

        /* Update AC marking of the queue */
        mvm->queue_info[queue].mac80211_ac = ac;

        /*
         * Mark queue as shared in transport if shared
         * Note this has to be done after queue enablement because enablement
         * can also set this value, and there is no indication there to shared
         * queues
         */
        if (shared_queue)
                iwl_trans_txq_set_shared_mode(mvm->trans, queue, true);

out:
        /* Continue using the queue */
        txq->stopped = false;

        return ret;
}

static int iwl_mvm_find_free_queue(struct iwl_mvm *mvm, u8 sta_id,
                                   u8 minq, u8 maxq)
{
        int i;

        lockdep_assert_held(&mvm->mutex);

        /* This should not be hit with new TX path */
        if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
                return -ENOSPC;

        /* Start by looking for a free queue */
        for (i = minq; i <= maxq; i++)
                if (mvm->queue_info[i].tid_bitmap == 0 &&
                    mvm->queue_info[i].status == IWL_MVM_QUEUE_FREE)
                        return i;

        return -ENOSPC;
}

static int iwl_mvm_tvqm_enable_txq(struct iwl_mvm *mvm,
                                   u8 sta_id, u8 tid, unsigned int timeout)
{
        int queue, size = max_t(u32, IWL_DEFAULT_QUEUE_SIZE,
                                mvm->trans->cfg->min_256_ba_txq_size);

        if (tid == IWL_MAX_TID_COUNT) {
                tid = IWL_MGMT_TID;
                size = max_t(u32, IWL_MGMT_QUEUE_SIZE,
                             mvm->trans->cfg->min_txq_size);
        }
        queue = iwl_trans_txq_alloc(mvm->trans,
                                    cpu_to_le16(TX_QUEUE_CFG_ENABLE_QUEUE),
                                    sta_id, tid, SCD_QUEUE_CFG, size, timeout);

        if (queue < 0) {
                IWL_DEBUG_TX_QUEUES(mvm,
                                    "Failed allocating TXQ for sta %d tid %d, ret: %d\n",
                                    sta_id, tid, queue);
                return queue;
        }

        IWL_DEBUG_TX_QUEUES(mvm, "Enabling TXQ #%d for sta %d tid %d\n",
                            queue, sta_id, tid);

        IWL_DEBUG_TX_QUEUES(mvm, "Enabling TXQ #%d\n", queue);

        return queue;
}

static int iwl_mvm_sta_alloc_queue_tvqm(struct iwl_mvm *mvm,
                                        struct ieee80211_sta *sta, u8 ac,
                                        int tid)
{
        struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
        struct iwl_mvm_txq *mvmtxq =
                iwl_mvm_txq_from_tid(sta, tid);
        unsigned int wdg_timeout =
                iwl_mvm_get_wd_timeout(mvm, mvmsta->vif, false, false);
        int queue = -1;

        lockdep_assert_held(&mvm->mutex);

        IWL_DEBUG_TX_QUEUES(mvm,
                            "Allocating queue for sta %d on tid %d\n",
                            mvmsta->sta_id, tid);
        queue = iwl_mvm_tvqm_enable_txq(mvm, mvmsta->sta_id, tid, wdg_timeout);
        if (queue < 0)
                return queue;

        mvmtxq->txq_id = queue;
        mvm->tvqm_info[queue].txq_tid = tid;
        mvm->tvqm_info[queue].sta_id = mvmsta->sta_id;

        IWL_DEBUG_TX_QUEUES(mvm, "Allocated queue is %d\n", queue);

        spin_lock_bh(&mvmsta->lock);
        mvmsta->tid_data[tid].txq_id = queue;
        spin_unlock_bh(&mvmsta->lock);

        return 0;
}

static bool iwl_mvm_update_txq_mapping(struct iwl_mvm *mvm,
                                       struct ieee80211_sta *sta,
                                       int queue, u8 sta_id, u8 tid)
{
        bool enable_queue = true;

        /* Make sure this TID isn't already enabled */
        if (mvm->queue_info[queue].tid_bitmap & BIT(tid)) {
                IWL_ERR(mvm, "Trying to enable TXQ %d with existing TID %d\n",
                        queue, tid);
                return false;
        }

        /* Update mappings and refcounts */
        if (mvm->queue_info[queue].tid_bitmap)
                enable_queue = false;

        mvm->queue_info[queue].tid_bitmap |= BIT(tid);
        mvm->queue_info[queue].ra_sta_id = sta_id;

        if (enable_queue) {
                if (tid != IWL_MAX_TID_COUNT)
                        mvm->queue_info[queue].mac80211_ac =
                                tid_to_mac80211_ac[tid];
                else
                        mvm->queue_info[queue].mac80211_ac = IEEE80211_AC_VO;

                mvm->queue_info[queue].txq_tid = tid;
        }

        if (sta) {
                struct iwl_mvm_txq *mvmtxq =
                        iwl_mvm_txq_from_tid(sta, tid);

                mvmtxq->txq_id = queue;
        }

        IWL_DEBUG_TX_QUEUES(mvm,
                            "Enabling TXQ #%d tids=0x%x\n",
                            queue, mvm->queue_info[queue].tid_bitmap);

        return enable_queue;
}

static bool iwl_mvm_enable_txq(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
                               int queue, u16 ssn,
                               const struct iwl_trans_txq_scd_cfg *cfg,
                               unsigned int wdg_timeout)
{
        struct iwl_scd_txq_cfg_cmd cmd = {
                .scd_queue = queue,
                .action = SCD_CFG_ENABLE_QUEUE,
                .window = cfg->frame_limit,
                .sta_id = cfg->sta_id,
                .ssn = cpu_to_le16(ssn),
                .tx_fifo = cfg->fifo,
                .aggregate = cfg->aggregate,
                .tid = cfg->tid,
        };
        bool inc_ssn;

        if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
                return false;

        /* Send the enabling command if we need to */
        if (!iwl_mvm_update_txq_mapping(mvm, sta, queue, cfg->sta_id, cfg->tid))
                return false;

        inc_ssn = iwl_trans_txq_enable_cfg(mvm->trans, queue, ssn,
                                           NULL, wdg_timeout);
        if (inc_ssn)
                le16_add_cpu(&cmd.ssn, 1);

        WARN(iwl_mvm_send_cmd_pdu(mvm, SCD_QUEUE_CFG, 0, sizeof(cmd), &cmd),
             "Failed to configure queue %d on FIFO %d\n", queue, cfg->fifo);

        return inc_ssn;
}

static void iwl_mvm_change_queue_tid(struct iwl_mvm *mvm, int queue)
{
        struct iwl_scd_txq_cfg_cmd cmd = {
                .scd_queue = queue,
                .action = SCD_CFG_UPDATE_QUEUE_TID,
        };
        int tid;
        unsigned long tid_bitmap;
        int ret;

        lockdep_assert_held(&mvm->mutex);

        if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
                return;

        tid_bitmap = mvm->queue_info[queue].tid_bitmap;

        if (WARN(!tid_bitmap, "TXQ %d has no tids assigned to it\n", queue))
                return;

        /* Find any TID for queue */
        tid = find_first_bit(&tid_bitmap, IWL_MAX_TID_COUNT + 1);
        cmd.tid = tid;
        cmd.tx_fifo = iwl_mvm_ac_to_tx_fifo[tid_to_mac80211_ac[tid]];

        ret = iwl_mvm_send_cmd_pdu(mvm, SCD_QUEUE_CFG, 0, sizeof(cmd), &cmd);
        if (ret) {
                IWL_ERR(mvm, "Failed to update owner of TXQ %d (ret=%d)\n",
                        queue, ret);
                return;
        }

        mvm->queue_info[queue].txq_tid = tid;
        IWL_DEBUG_TX_QUEUES(mvm, "Changed TXQ %d ownership to tid %d\n",
                            queue, tid);
}

static void iwl_mvm_unshare_queue(struct iwl_mvm *mvm, int queue)
{
        struct ieee80211_sta *sta;
        struct iwl_mvm_sta *mvmsta;
        u8 sta_id;
        int tid = -1;
        unsigned long tid_bitmap;
        unsigned int wdg_timeout;
        int ssn;
        int ret = true;

        /* queue sharing is disabled on new TX path */
        if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
                return;

        lockdep_assert_held(&mvm->mutex);

        sta_id = mvm->queue_info[queue].ra_sta_id;
        tid_bitmap = mvm->queue_info[queue].tid_bitmap;

        /* Find TID for queue, and make sure it is the only one on the queue */
        tid = find_first_bit(&tid_bitmap, IWL_MAX_TID_COUNT + 1);
        if (tid_bitmap != BIT(tid)) {
                IWL_ERR(mvm, "Failed to unshare q %d, active tids=0x%lx\n",
                        queue, tid_bitmap);
                return;
        }

        IWL_DEBUG_TX_QUEUES(mvm, "Unsharing TXQ %d, keeping tid %d\n", queue,
                            tid);

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

        if (WARN_ON_ONCE(IS_ERR_OR_NULL(sta)))
                return;

        mvmsta = iwl_mvm_sta_from_mac80211(sta);
        wdg_timeout = iwl_mvm_get_wd_timeout(mvm, mvmsta->vif, false, false);

        ssn = IEEE80211_SEQ_TO_SN(mvmsta->tid_data[tid].seq_number);

        ret = iwl_mvm_redirect_queue(mvm, queue, tid,
                                     tid_to_mac80211_ac[tid], ssn,
                                     wdg_timeout, true,
                                     iwl_mvm_txq_from_tid(sta, tid));
        if (ret) {
                IWL_ERR(mvm, "Failed to redirect TXQ %d\n", queue);
                return;
        }

        /* If aggs should be turned back on - do it */
        if (mvmsta->tid_data[tid].state == IWL_AGG_ON) {
                struct iwl_mvm_add_sta_cmd cmd = {0};

                mvmsta->tid_disable_agg &= ~BIT(tid);

                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.modify_mask = STA_MODIFY_TID_DISABLE_TX;
                cmd.tfd_queue_msk = cpu_to_le32(mvmsta->tfd_queue_msk);
                cmd.tid_disable_tx = cpu_to_le16(mvmsta->tid_disable_agg);

                ret = iwl_mvm_send_cmd_pdu(mvm, ADD_STA, CMD_ASYNC,
                                           iwl_mvm_add_sta_cmd_size(mvm), &cmd);
                if (!ret) {
                        IWL_DEBUG_TX_QUEUES(mvm,
                                            "TXQ #%d is now aggregated again\n",
                                            queue);

                        /* Mark queue intenally as aggregating again */
                        iwl_trans_txq_set_shared_mode(mvm->trans, queue, false);
                }
        }

        mvm->queue_info[queue].status = IWL_MVM_QUEUE_READY;
}

/*
 * Remove inactive TIDs of a given queue.
 * If all queue TIDs are inactive - mark the queue as inactive
 * If only some the queue TIDs are inactive - unmap them from the queue
 *
 * Returns %true if all TIDs were removed and the queue could be reused.
 */
static bool iwl_mvm_remove_inactive_tids(struct iwl_mvm *mvm,
                                         struct iwl_mvm_sta *mvmsta, int queue,
                                         unsigned long tid_bitmap,
                                         unsigned long *unshare_queues,
                                         unsigned long *changetid_queues)
{
        int tid;

        lockdep_assert_held(&mvmsta->lock);
        lockdep_assert_held(&mvm->mutex);

        if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
                return false;

        /* Go over all non-active TIDs, incl. IWL_MAX_TID_COUNT (for mgmt) */
        for_each_set_bit(tid, &tid_bitmap, IWL_MAX_TID_COUNT + 1) {
                /* If some TFDs are still queued - don't mark TID as inactive */
                if (iwl_mvm_tid_queued(mvm, &mvmsta->tid_data[tid]))
                        tid_bitmap &= ~BIT(tid);

                /* Don't mark as inactive any TID that has an active BA */
                if (mvmsta->tid_data[tid].state != IWL_AGG_OFF)
                        tid_bitmap &= ~BIT(tid);
        }

        /* If all TIDs in the queue are inactive - return it can be reused */
        if (tid_bitmap == mvm->queue_info[queue].tid_bitmap) {
                IWL_DEBUG_TX_QUEUES(mvm, "Queue %d is inactive\n", queue);
                return true;
        }

        /*
         * If we are here, this is a shared queue and not all TIDs timed-out.
         * Remove the ones that did.
         */
        for_each_set_bit(tid, &tid_bitmap, IWL_MAX_TID_COUNT + 1) {
                u16 tid_bitmap;

                mvmsta->tid_data[tid].txq_id = IWL_MVM_INVALID_QUEUE;
                mvm->queue_info[queue].tid_bitmap &= ~BIT(tid);

                tid_bitmap = mvm->queue_info[queue].tid_bitmap;

                /*
                 * We need to take into account a situation in which a TXQ was
                 * allocated to TID x, and then turned shared by adding TIDs y
                 * and z. If TID x becomes inactive and is removed from the TXQ,
                 * ownership must be given to one of the remaining TIDs.
                 * This is mainly because if TID x continues - a new queue can't
                 * be allocated for it as long as it is an owner of another TXQ.
                 *
                 * Mark this queue in the right bitmap, we'll send the command
                 * to the firmware later.
                 */
                if (!(tid_bitmap & BIT(mvm->queue_info[queue].txq_tid)))
                        set_bit(queue, changetid_queues);

                IWL_DEBUG_TX_QUEUES(mvm,
                                    "Removing inactive TID %d from shared Q:%d\n",
                                    tid, queue);
        }

        IWL_DEBUG_TX_QUEUES(mvm,
                            "TXQ #%d left with tid bitmap 0x%x\n", queue,
                            mvm->queue_info[queue].tid_bitmap);

        /*
         * There may be different TIDs with the same mac queues, so make
         * sure all TIDs have existing corresponding mac queues enabled
         */
        tid_bitmap = mvm->queue_info[queue].tid_bitmap;

        /* If the queue is marked as shared - "unshare" it */
        if (hweight16(mvm->queue_info[queue].tid_bitmap) == 1 &&
            mvm->queue_info[queue].status == IWL_MVM_QUEUE_SHARED) {
                IWL_DEBUG_TX_QUEUES(mvm, "Marking Q:%d for reconfig\n",
                                    queue);
                set_bit(queue, unshare_queues);
        }

        return false;
}

/*
 * Check for inactivity - this includes checking if any queue
 * can be unshared and finding one (and only one) that can be
 * reused.
 * This function is also invoked as a sort of clean-up task,
 * in which case @alloc_for_sta is IWL_MVM_INVALID_STA.
 *
 * Returns the queue number, or -ENOSPC.
 */
static int iwl_mvm_inactivity_check(struct iwl_mvm *mvm, u8 alloc_for_sta)
{
        unsigned long now = jiffies;
        unsigned long unshare_queues = 0;
        unsigned long changetid_queues = 0;
        int i, ret, free_queue = -ENOSPC;
        struct ieee80211_sta *queue_owner  = NULL;

        lockdep_assert_held(&mvm->mutex);

        if (iwl_mvm_has_new_tx_api(mvm))
                return -ENOSPC;

        rcu_read_lock();

        /* we skip the CMD queue below by starting at 1 */
        BUILD_BUG_ON(IWL_MVM_DQA_CMD_QUEUE != 0);

        for (i = 1; i < IWL_MAX_HW_QUEUES; i++) {
                struct ieee80211_sta *sta;
                struct iwl_mvm_sta *mvmsta;
                u8 sta_id;
                int tid;
                unsigned long inactive_tid_bitmap = 0;
                unsigned long queue_tid_bitmap;

                queue_tid_bitmap = mvm->queue_info[i].tid_bitmap;
                if (!queue_tid_bitmap)
                        continue;

                /* If TXQ isn't in active use anyway - nothing to do here... */
                if (mvm->queue_info[i].status != IWL_MVM_QUEUE_READY &&
                    mvm->queue_info[i].status != IWL_MVM_QUEUE_SHARED)
                        continue;

                /* Check to see if there are inactive TIDs on this queue */
                for_each_set_bit(tid, &queue_tid_bitmap,
                                 IWL_MAX_TID_COUNT + 1) {
                        if (time_after(mvm->queue_info[i].last_frame_time[tid] +
                                       IWL_MVM_DQA_QUEUE_TIMEOUT, now))
                                continue;

                        inactive_tid_bitmap |= BIT(tid);
                }

                /* If all TIDs are active - finish check on this queue */
                if (!inactive_tid_bitmap)
                        continue;

                /*
                 * If we are here - the queue hadn't been served recently and is
                 * in use
                 */

                sta_id = mvm->queue_info[i].ra_sta_id;
                sta = rcu_dereference(mvm->fw_id_to_mac_id[sta_id]);

                /*
                 * If the STA doesn't exist anymore, it isn't an error. It could
                 * be that it was removed since getting the queues, and in this
                 * case it should've inactivated its queues anyway.
                 */
                if (IS_ERR_OR_NULL(sta))
                        continue;

                mvmsta = iwl_mvm_sta_from_mac80211(sta);

                spin_lock_bh(&mvmsta->lock);
                ret = iwl_mvm_remove_inactive_tids(mvm, mvmsta, i,
                                                   inactive_tid_bitmap,
                                                   &unshare_queues,
                                                   &changetid_queues);
                if (ret >= 0 && free_queue < 0) {
                        queue_owner = sta;
                        free_queue = ret;
                }
                /* only unlock sta lock - we still need the queue info lock */
                spin_unlock_bh(&mvmsta->lock);
        }


        /* Reconfigure queues requiring reconfiguation */
        for_each_set_bit(i, &unshare_queues, IWL_MAX_HW_QUEUES)
                iwl_mvm_unshare_queue(mvm, i);
        for_each_set_bit(i, &changetid_queues, IWL_MAX_HW_QUEUES)
                iwl_mvm_change_queue_tid(mvm, i);

        if (free_queue >= 0 && alloc_for_sta != IWL_MVM_INVALID_STA) {
                ret = iwl_mvm_free_inactive_queue(mvm, free_queue, queue_owner,
                                                  alloc_for_sta);
                if (ret) {
                        rcu_read_unlock();
                        return ret;
                }
        }

        rcu_read_unlock();

        return free_queue;
}

static int iwl_mvm_sta_alloc_queue(struct iwl_mvm *mvm,
                                   struct ieee80211_sta *sta, u8 ac, int tid)
{
        struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
        struct iwl_trans_txq_scd_cfg cfg = {
                .fifo = iwl_mvm_mac_ac_to_tx_fifo(mvm, ac),
                .sta_id = mvmsta->sta_id,
                .tid = tid,
                .frame_limit = IWL_FRAME_LIMIT,
        };
        unsigned int wdg_timeout =
                iwl_mvm_get_wd_timeout(mvm, mvmsta->vif, false, false);
        int queue = -1;
        unsigned long disable_agg_tids = 0;
        enum iwl_mvm_agg_state queue_state;
        bool shared_queue = false, inc_ssn;
        int ssn;
        unsigned long tfd_queue_mask;
        int ret;

        lockdep_assert_held(&mvm->mutex);

        if (iwl_mvm_has_new_tx_api(mvm))
                return iwl_mvm_sta_alloc_queue_tvqm(mvm, sta, ac, tid);

        spin_lock_bh(&mvmsta->lock);
        tfd_queue_mask = mvmsta->tfd_queue_msk;
        ssn = IEEE80211_SEQ_TO_SN(mvmsta->tid_data[tid].seq_number);
        spin_unlock_bh(&mvmsta->lock);

        if (tid == IWL_MAX_TID_COUNT) {
                queue = iwl_mvm_find_free_queue(mvm, mvmsta->sta_id,
                                                IWL_MVM_DQA_MIN_MGMT_QUEUE,
                                                IWL_MVM_DQA_MAX_MGMT_QUEUE);
                if (queue >= IWL_MVM_DQA_MIN_MGMT_QUEUE)
                        IWL_DEBUG_TX_QUEUES(mvm, "Found free MGMT queue #%d\n",
                                            queue);

                /* If no such queue is found, we'll use a DATA queue instead */
        }

        if ((queue < 0 && mvmsta->reserved_queue != IEEE80211_INVAL_HW_QUEUE) &&
            (mvm->queue_info[mvmsta->reserved_queue].status ==
                        IWL_MVM_QUEUE_RESERVED)) {
                queue = mvmsta->reserved_queue;
                mvm->queue_info[queue].reserved = true;
                IWL_DEBUG_TX_QUEUES(mvm, "Using reserved queue #%d\n", queue);
        }

        if (queue < 0)
                queue = iwl_mvm_find_free_queue(mvm, mvmsta->sta_id,
                                                IWL_MVM_DQA_MIN_DATA_QUEUE,
                                                IWL_MVM_DQA_MAX_DATA_QUEUE);
        if (queue < 0) {
                /* try harder - perhaps kill an inactive queue */
                queue = iwl_mvm_inactivity_check(mvm, mvmsta->sta_id);
        }

        /* No free queue - we'll have to share */
        if (queue <= 0) {
                queue = iwl_mvm_get_shared_queue(mvm, tfd_queue_mask, ac);
                if (queue > 0) {
                        shared_queue = true;
                        mvm->queue_info[queue].status = IWL_MVM_QUEUE_SHARED;
                }
        }

        /*
         * Mark TXQ as ready, even though it hasn't been fully configured yet,
         * to make sure no one else takes it.
         * This will allow avoiding re-acquiring the lock at the end of the
         * configuration. On error we'll mark it back as free.
         */
        if (queue > 0 && !shared_queue)
                mvm->queue_info[queue].status = IWL_MVM_QUEUE_READY;

        /* This shouldn't happen - out of queues */
        if (WARN_ON(queue <= 0)) {
                IWL_ERR(mvm, "No available queues for tid %d on sta_id %d\n",
                        tid, cfg.sta_id);
                return queue;
        }

        /*
         * Actual en/disablement of aggregations is through the ADD_STA HCMD,
         * but for configuring the SCD to send A-MPDUs we need to mark the queue
         * as aggregatable.
         * Mark all DATA queues as allowing to be aggregated at some point
         */
        cfg.aggregate = (queue >= IWL_MVM_DQA_MIN_DATA_QUEUE ||
                         queue == IWL_MVM_DQA_BSS_CLIENT_QUEUE);

        IWL_DEBUG_TX_QUEUES(mvm,
                            "Allocating %squeue #%d to sta %d on tid %d\n",
                            shared_queue ? "shared " : "", queue,
                            mvmsta->sta_id, tid);

        if (shared_queue) {
                /* Disable any open aggs on this queue */
                disable_agg_tids = iwl_mvm_get_queue_agg_tids(mvm, queue);

                if (disable_agg_tids) {
                        IWL_DEBUG_TX_QUEUES(mvm, "Disabling aggs on queue %d\n",
                                            queue);
                        iwl_mvm_invalidate_sta_queue(mvm, queue,
                                                     disable_agg_tids, false);
                }
        }

        inc_ssn = iwl_mvm_enable_txq(mvm, sta, queue, ssn, &cfg, wdg_timeout);

        /*
         * Mark queue as shared in transport if shared
         * Note this has to be done after queue enablement because enablement
         * can also set this value, and there is no indication there to shared
         * queues
         */
        if (shared_queue)
                iwl_trans_txq_set_shared_mode(mvm->trans, queue, true);

        spin_lock_bh(&mvmsta->lock);
        /*
         * This looks racy, but it is not. We have only one packet for
         * this ra/tid in our Tx path since we stop the Qdisc when we
         * need to allocate a new TFD queue.
         */
        if (inc_ssn) {
                mvmsta->tid_data[tid].seq_number += 0x10;
                ssn = (ssn + 1) & IEEE80211_SCTL_SEQ;
        }
        mvmsta->tid_data[tid].txq_id = queue;
        mvmsta->tfd_queue_msk |= BIT(queue);
        queue_state = mvmsta->tid_data[tid].state;

        if (mvmsta->reserved_queue == queue)
                mvmsta->reserved_queue = IEEE80211_INVAL_HW_QUEUE;
        spin_unlock_bh(&mvmsta->lock);

        if (!shared_queue) {
                ret = iwl_mvm_sta_send_to_fw(mvm, sta, true, STA_MODIFY_QUEUES);
                if (ret)
                        goto out_err;

                /* If we need to re-enable aggregations... */
                if (queue_state == IWL_AGG_ON) {
                        ret = iwl_mvm_sta_tx_agg(mvm, sta, tid, queue, true);
                        if (ret)
                                goto out_err;
                }
        } else {
                /* Redirect queue, if needed */
                ret = iwl_mvm_redirect_queue(mvm, queue, tid, ac, ssn,
                                             wdg_timeout, false,
                                             iwl_mvm_txq_from_tid(sta, tid));
                if (ret)
                        goto out_err;
        }

        return 0;

out_err:
        iwl_mvm_disable_txq(mvm, sta, queue, tid, 0);

        return ret;
}

static inline u8 iwl_mvm_tid_to_ac_queue(int tid)
{
        if (tid == IWL_MAX_TID_COUNT)
                return IEEE80211_AC_VO; /* MGMT */

        return tid_to_mac80211_ac[tid];
}

void iwl_mvm_add_new_dqa_stream_wk(struct work_struct *wk)
{
        struct iwl_mvm *mvm = container_of(wk, struct iwl_mvm,
                                           add_stream_wk);

        mutex_lock(&mvm->mutex);

        iwl_mvm_inactivity_check(mvm, IWL_MVM_INVALID_STA);

        while (!list_empty(&mvm->add_stream_txqs)) {
                struct iwl_mvm_txq *mvmtxq;
                struct ieee80211_txq *txq;
                u8 tid;

                mvmtxq = list_first_entry(&mvm->add_stream_txqs,
                                          struct iwl_mvm_txq, list);

                txq = container_of((void *)mvmtxq, struct ieee80211_txq,
                                   drv_priv);
                tid = txq->tid;
                if (tid == IEEE80211_NUM_TIDS)
                        tid = IWL_MAX_TID_COUNT;

                iwl_mvm_sta_alloc_queue(mvm, txq->sta, txq->ac, tid);
                list_del_init(&mvmtxq->list);
                local_bh_disable();
                iwl_mvm_mac_itxq_xmit(mvm->hw, txq);
                local_bh_enable();
        }

        mutex_unlock(&mvm->mutex);
}

static int iwl_mvm_reserve_sta_stream(struct iwl_mvm *mvm,
                                      struct ieee80211_sta *sta,
                                      enum nl80211_iftype vif_type)
{
        struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
        int queue;

        /* queue reserving is disabled on new TX path */
        if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
                return 0;

        /* run the general cleanup/unsharing of queues */
        iwl_mvm_inactivity_check(mvm, IWL_MVM_INVALID_STA);

        /* Make sure we have free resources for this STA */
        if (vif_type == NL80211_IFTYPE_STATION && !sta->tdls &&
            !mvm->queue_info[IWL_MVM_DQA_BSS_CLIENT_QUEUE].tid_bitmap &&
            (mvm->queue_info[IWL_MVM_DQA_BSS_CLIENT_QUEUE].status ==
             IWL_MVM_QUEUE_FREE))
                queue = IWL_MVM_DQA_BSS_CLIENT_QUEUE;
        else
                queue = iwl_mvm_find_free_queue(mvm, mvmsta->sta_id,
                                                IWL_MVM_DQA_MIN_DATA_QUEUE,
                                                IWL_MVM_DQA_MAX_DATA_QUEUE);
        if (queue < 0) {
                /* try again - this time kick out a queue if needed */
                queue = iwl_mvm_inactivity_check(mvm, mvmsta->sta_id);
                if (queue < 0) {
                        IWL_ERR(mvm, "No available queues for new station\n");
                        return -ENOSPC;
                }
        }
        mvm->queue_info[queue].status = IWL_MVM_QUEUE_RESERVED;

        mvmsta->reserved_queue = queue;

        IWL_DEBUG_TX_QUEUES(mvm, "Reserving data queue #%d for sta_id %d\n",
                            queue, mvmsta->sta_id);

        return 0;
}

/*
 * In DQA mode, after a HW restart the queues should be allocated as before, in
 * order to avoid race conditions when there are shared queues. This function
 * does the re-mapping and queue allocation.
 *
 * Note that re-enabling aggregations isn't done in this function.
 */
static void iwl_mvm_realloc_queues_after_restart(struct iwl_mvm *mvm,
                                                 struct ieee80211_sta *sta)
{
        struct iwl_mvm_sta *mvm_sta = iwl_mvm_sta_from_mac80211(sta);
        unsigned int wdg =
                iwl_mvm_get_wd_timeout(mvm, mvm_sta->vif, false, false);
        int i;
        struct iwl_trans_txq_scd_cfg cfg = {
                .sta_id = mvm_sta->sta_id,
                .frame_limit = IWL_FRAME_LIMIT,
        };

        /* Make sure reserved queue is still marked as such (if allocated) */
        if (mvm_sta->reserved_queue != IEEE80211_INVAL_HW_QUEUE)
                mvm->queue_info[mvm_sta->reserved_queue].status =
                        IWL_MVM_QUEUE_RESERVED;

        for (i = 0; i <= IWL_MAX_TID_COUNT; i++) {
                struct iwl_mvm_tid_data *tid_data = &mvm_sta->tid_data[i];
                int txq_id = tid_data->txq_id;
                int ac;

                if (txq_id == IWL_MVM_INVALID_QUEUE)
                        continue;

                ac = tid_to_mac80211_ac[i];

                if (iwl_mvm_has_new_tx_api(mvm)) {
                        IWL_DEBUG_TX_QUEUES(mvm,
                                            "Re-mapping sta %d tid %d\n",
                                            mvm_sta->sta_id, i);
                        txq_id = iwl_mvm_tvqm_enable_txq(mvm, mvm_sta->sta_id,
                                                         i, wdg);
                        tid_data->txq_id = txq_id;

                        /*
                         * Since we don't set the seq number after reset, and HW
                         * sets it now, FW reset will cause the seq num to start
                         * at 0 again, so driver will need to update it
                         * internally as well, so it keeps in sync with real val
                         */
                        tid_data->seq_number = 0;
                } else {
                        u16 seq = IEEE80211_SEQ_TO_SN(tid_data->seq_number);

                        cfg.tid = i;
                        cfg.fifo = iwl_mvm_mac_ac_to_tx_fifo(mvm, ac);
                        cfg.aggregate = (txq_id >= IWL_MVM_DQA_MIN_DATA_QUEUE ||
                                         txq_id ==
                                         IWL_MVM_DQA_BSS_CLIENT_QUEUE);

                        IWL_DEBUG_TX_QUEUES(mvm,
                                            "Re-mapping sta %d tid %d to queue %d\n",
                                            mvm_sta->sta_id, i, txq_id);

                        iwl_mvm_enable_txq(mvm, sta, txq_id, seq, &cfg, wdg);
                        mvm->queue_info[txq_id].status = IWL_MVM_QUEUE_READY;
                }
        }
}

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 = ADD_STA_SUCCESS;

        lockdep_assert_held(&mvm->mutex);

        memset(&cmd, 0, sizeof(cmd));
        cmd.sta_id = sta->sta_id;
        cmd.mac_id_n_color = cpu_to_le32(FW_CMD_ID_AND_COLOR(mac_id,
                                                             color));
        if (fw_has_api(&mvm->fw->ucode_capa, IWL_UCODE_TLV_API_STA_TYPE))
                cmd.station_type = sta->type;

        if (!iwl_mvm_has_new_tx_api(mvm))
                cmd.tfd_queue_msk = cpu_to_le32(sta->tfd_queue_msk);
        cmd.tid_disable_tx = cpu_to_le16(0xffff);

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

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

        switch (status & IWL_ADD_STA_STATUS_MASK) {
        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_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 = iwl_mvm_sta_from_mac80211(sta);
        struct iwl_mvm_rxq_dup_data *dup_data;
        int i, ret, sta_id;
        bool sta_update = false;
        unsigned int sta_flags = 0;

        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,
                                                  ieee80211_vif_type_p2p(vif));
        else
                sta_id = mvm_sta->sta_id;

        if (sta_id == IWL_MVM_INVALID_STA)
                return -ENOSPC;

        spin_lock_init(&mvm_sta->lock);

        /* if this is a HW restart re-alloc existing queues */
        if (test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status)) {
                struct iwl_mvm_int_sta tmp_sta = {
                        .sta_id = sta_id,
                        .type = mvm_sta->sta_type,
                };

                /*
                 * First add an empty station since allocating
                 * a queue requires a valid station
                 */
                ret = iwl_mvm_add_int_sta_common(mvm, &tmp_sta, sta->addr,
                                                 mvmvif->id, mvmvif->color);
                if (ret)
                        goto err;

                iwl_mvm_realloc_queues_after_restart(mvm, sta);
                sta_update = true;
                sta_flags = iwl_mvm_has_new_tx_api(mvm) ? 0 : STA_MODIFY_QUEUES;
                goto update_fw;
        }

        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;
        if (!mvm->trans->cfg->gen2)
                mvm_sta->max_agg_bufsize = LINK_QUAL_AGG_FRAME_LIMIT_DEF;
        else
                mvm_sta->max_agg_bufsize = LINK_QUAL_AGG_FRAME_LIMIT_GEN2_DEF;
        mvm_sta->tx_protection = 0;
        mvm_sta->tt_tx_protection = false;
        mvm_sta->sta_type = sta->tdls ? IWL_STA_TDLS_LINK : IWL_STA_LINK;

        /* HW restart, don't assume the memory has been zeroed */
        mvm_sta->tid_disable_agg = 0xffff; /* No aggs at first */
        mvm_sta->tfd_queue_msk = 0;

        /* for HW restart - reset everything but the sequence number */
        for (i = 0; i <= IWL_MAX_TID_COUNT; i++) {
                u16 seq = mvm_sta->tid_data[i].seq_number;
                memset(&mvm_sta->tid_data[i], 0, sizeof(mvm_sta->tid_data[i]));
                mvm_sta->tid_data[i].seq_number = seq;

                /*
                 * Mark all queues for this STA as unallocated and defer TX
                 * frames until the queue is allocated
                 */
                mvm_sta->tid_data[i].txq_id = IWL_MVM_INVALID_QUEUE;
        }

        for (i = 0; i < ARRAY_SIZE(sta->txq); i++) {
                struct iwl_mvm_txq *mvmtxq =
                        iwl_mvm_txq_from_mac80211(sta->txq[i]);

                mvmtxq->txq_id = IWL_MVM_INVALID_QUEUE;
                INIT_LIST_HEAD(&mvmtxq->list);
                atomic_set(&mvmtxq->tx_request, 0);
        }

        mvm_sta->agg_tids = 0;

        if (iwl_mvm_has_new_rx_api(mvm) &&
            !test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status)) {
                int q;

                dup_data = kcalloc(mvm->trans->num_rx_queues,
                                   sizeof(*dup_data), GFP_KERNEL);
                if (!dup_data)
                        return -ENOMEM;
                /*
                 * Initialize all the last_seq values to 0xffff which can never
                 * compare equal to the frame's seq_ctrl in the check in
                 * iwl_mvm_is_dup() since the lower 4 bits are the fragment
                 * number and fragmented packets don't reach that function.
                 *
                 * This thus allows receiving a packet with seqno 0 and the
                 * retry bit set as the very first packet on a new TID.
                 */
                for (q = 0; q < mvm->trans->num_rx_queues; q++)
                        memset(dup_data[q].last_seq, 0xff,
                               sizeof(dup_data[q].last_seq));
                mvm_sta->dup_data = dup_data;
        }

        if (!iwl_mvm_has_new_tx_api(mvm)) {
                ret = iwl_mvm_reserve_sta_stream(mvm, sta,
                                                 ieee80211_vif_type_p2p(vif));
                if (ret)
                        goto err;
        }

        /*
         * if rs is registered with mac80211, then "add station" will be handled
         * via the corresponding ops, otherwise need to notify rate scaling here
         */
        if (iwl_mvm_has_tlc_offload(mvm))
                iwl_mvm_rs_add_sta(mvm, mvm_sta);
        else
                spin_lock_init(&mvm_sta->lq_sta.rs_drv.pers.lock);

        iwl_mvm_toggle_tx_ant(mvm, &mvm_sta->tx_ant);

update_fw:
        ret = iwl_mvm_sta_send_to_fw(mvm, sta, sta_update, sta_flags);
        if (ret)
                goto err;

        if (vif->type == NL80211_IFTYPE_STATION) {
                if (!sta->tdls) {
                        WARN_ON(mvmvif->ap_sta_id != IWL_MVM_INVALID_STA);
                        mvmvif->ap_sta_id = sta_id;
                } else {
                        WARN_ON(mvmvif->ap_sta_id == IWL_MVM_INVALID_STA);
                }
        }

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

        return 0;

err:
        return ret;
}

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,
                                          iwl_mvm_add_sta_cmd_size(mvm),
                                          &cmd, &status);
        if (ret)
                return ret;

        switch (status & IWL_ADD_STA_STATUS_MASK) {
        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, 0,
                                   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;
}

static void iwl_mvm_disable_sta_queues(struct iwl_mvm *mvm,
                                       struct ieee80211_vif *vif,
                                       struct ieee80211_sta *sta)
{
        struct iwl_mvm_sta *mvm_sta = iwl_mvm_sta_from_mac80211(sta);
        int i;

        lockdep_assert_held(&mvm->mutex);

        for (i = 0; i < ARRAY_SIZE(mvm_sta->tid_data); i++) {
                if (mvm_sta->tid_data[i].txq_id == IWL_MVM_INVALID_QUEUE)
                        continue;

                iwl_mvm_disable_txq(mvm, sta, mvm_sta->tid_data[i].txq_id, i,
                                    0);
                mvm_sta->tid_data[i].txq_id = IWL_MVM_INVALID_QUEUE;
        }

        for (i = 0; i < ARRAY_SIZE(sta->txq); i++) {
                struct iwl_mvm_txq *mvmtxq =
                        iwl_mvm_txq_from_mac80211(sta->txq[i]);

                mvmtxq->txq_id = IWL_MVM_INVALID_QUEUE;
        }
}

int iwl_mvm_wait_sta_queues_empty(struct iwl_mvm *mvm,
                                  struct iwl_mvm_sta *mvm_sta)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(mvm_sta->tid_data); i++) {
                u16 txq_id;
                int ret;

                spin_lock_bh(&mvm_sta->lock);
                txq_id = mvm_sta->tid_data[i].txq_id;
                spin_unlock_bh(&mvm_sta->lock);

                if (txq_id == IWL_MVM_INVALID_QUEUE)
                        continue;

                ret = iwl_trans_wait_txq_empty(mvm->trans, txq_id);
                if (ret)
                        return ret;
        }

        return 0;
}

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 = iwl_mvm_sta_from_mac80211(sta);
        u8 sta_id = mvm_sta->sta_id;
        int ret;

        lockdep_assert_held(&mvm->mutex);

        if (iwl_mvm_has_new_rx_api(mvm))
                kfree(mvm_sta->dup_data);

        ret = iwl_mvm_drain_sta(mvm, mvm_sta, true);
        if (ret)
                return ret;

        /* flush its queues here since we are freeing mvm_sta */
        ret = iwl_mvm_flush_sta(mvm, mvm_sta, false, 0);
        if (ret)
                return ret;
        if (iwl_mvm_has_new_tx_api(mvm)) {
                ret = iwl_mvm_wait_sta_queues_empty(mvm, mvm_sta);
        } else {
                u32 q_mask = mvm_sta->tfd_queue_msk;

                ret = iwl_trans_wait_tx_queues_empty(mvm->trans,
                                                     q_mask);
        }
        if (ret)
                return ret;

        ret = iwl_mvm_drain_sta(mvm, mvm_sta, false);

        iwl_mvm_disable_sta_queues(mvm, vif, sta);

        /* If there is a TXQ still marked as reserved - free it */
        if (mvm_sta->reserved_queue != IEEE80211_INVAL_HW_QUEUE) {
                u8 reserved_txq = mvm_sta->reserved_queue;
                enum iwl_mvm_queue_status *status;

                /*
                 * If no traffic has gone through the reserved TXQ - it
                 * is still marked as IWL_MVM_QUEUE_RESERVED, and
                 * should be manually marked as free again
                 */
                status = &mvm->queue_info[reserved_txq].status;
                if (WARN((*status != IWL_MVM_QUEUE_RESERVED) &&
                         (*status != IWL_MVM_QUEUE_FREE),
                         "sta_id %d reserved txq %d status %d",
                         sta_id, reserved_txq, *status))
                        return -EINVAL;

                *status = IWL_MVM_QUEUE_FREE;
        }

        if (vif->type == NL80211_IFTYPE_STATION &&
            mvmvif->ap_sta_id == sta_id) {
                /* if 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_INVALID_STA;

                /* clear d0i3_ap_sta_id if no longer relevant */
                if (mvm->d0i3_ap_sta_id == sta_id)
                        mvm->d0i3_ap_sta_id = IWL_MVM_INVALID_STA;
        }

        /*
         * This shouldn't happen - the TDLS channel switch should be canceled
         * before the STA is removed.
         */
        if (WARN_ON_ONCE(mvm->tdls_cs.peer.sta_id == sta_id)) {
                mvm->tdls_cs.peer.sta_id = IWL_MVM_INVALID_STA;
                cancel_delayed_work(&mvm->tdls_cs.dwork);
        }

        /*
         * Make sure that the tx response code sees the station as -EBUSY and
         * calls the drain worker.
         */
        spin_lock_bh(&mvm_sta->lock);
        spin_unlock_bh(&mvm_sta->lock);

        ret = iwl_mvm_rm_sta_common(mvm, mvm_sta->sta_id);
        RCU_INIT_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_INIT_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, enum nl80211_iftype iftype,
                             enum iwl_sta_type type)
{
        if (!test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status) ||
            sta->sta_id == IWL_MVM_INVALID_STA) {
                sta->sta_id = iwl_mvm_find_free_sta_id(mvm, iftype);
                if (WARN_ON_ONCE(sta->sta_id == IWL_MVM_INVALID_STA))
                        return -ENOSPC;
        }

        sta->tfd_queue_msk = qmask;
        sta->type = type;

        /* 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_INIT_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_INVALID_STA;
}

static void iwl_mvm_enable_aux_snif_queue(struct iwl_mvm *mvm, u16 *queue,
                                          u8 sta_id, u8 fifo)
{
        unsigned int wdg_timeout = iwlmvm_mod_params.tfd_q_hang_detect ?
                                        mvm->cfg->base_params->wd_timeout :
                                        IWL_WATCHDOG_DISABLED;

        if (iwl_mvm_has_new_tx_api(mvm)) {
                int tvqm_queue =
                        iwl_mvm_tvqm_enable_txq(mvm, sta_id,
                                                IWL_MAX_TID_COUNT,
                                                wdg_timeout);
                *queue = tvqm_queue;
        } else {
                struct iwl_trans_txq_scd_cfg cfg = {
                        .fifo = fifo,
                        .sta_id = sta_id,
                        .tid = IWL_MAX_TID_COUNT,
                        .aggregate = false,
                        .frame_limit = IWL_FRAME_LIMIT,
                };

                iwl_mvm_enable_txq(mvm, NULL, *queue, 0, &cfg, wdg_timeout);
        }
}

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

        lockdep_assert_held(&mvm->mutex);

        /* Allocate aux station and assign to it the aux queue */
        ret = iwl_mvm_allocate_int_sta(mvm, &mvm->aux_sta, BIT(mvm->aux_queue),
                                       NL80211_IFTYPE_UNSPECIFIED,
                                       IWL_STA_AUX_ACTIVITY);

        if (ret)
                return ret;

        /* Map Aux queue to fifo - needs to happen before adding Aux station */
        if (!iwl_mvm_has_new_tx_api(mvm))
                iwl_mvm_enable_aux_snif_queue(mvm, &mvm->aux_queue,
                                              mvm->aux_sta.sta_id,
                                              IWL_MVM_TX_FIFO_MCAST);

        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;
        }

        /*
         * For 22000 firmware and on we cannot add queue to a station unknown
         * to firmware so enable queue here - after the station was added
         */
        if (iwl_mvm_has_new_tx_api(mvm))
                iwl_mvm_enable_aux_snif_queue(mvm, &mvm->aux_queue,
                                              mvm->aux_sta.sta_id,
                                              IWL_MVM_TX_FIFO_MCAST);

        return 0;
}

int iwl_mvm_add_snif_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
{
        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
        int ret;

        lockdep_assert_held(&mvm->mutex);

        /* Map snif queue to fifo - must happen before adding snif station */
        if (!iwl_mvm_has_new_tx_api(mvm))
                iwl_mvm_enable_aux_snif_queue(mvm, &mvm->snif_queue,
                                              mvm->snif_sta.sta_id,
                                              IWL_MVM_TX_FIFO_BE);

        ret = iwl_mvm_add_int_sta_common(mvm, &mvm->snif_sta, vif->addr,
                                         mvmvif->id, 0);
        if (ret)
                return ret;

        /*
         * For 22000 firmware and on we cannot add queue to a station unknown
         * to firmware so enable queue here - after the station was added
         */
        if (iwl_mvm_has_new_tx_api(mvm))
                iwl_mvm_enable_aux_snif_queue(mvm, &mvm->snif_queue,
                                              mvm->snif_sta.sta_id,
                                              IWL_MVM_TX_FIFO_BE);

        return 0;
}

int iwl_mvm_rm_snif_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
{
        int ret;

        lockdep_assert_held(&mvm->mutex);

        iwl_mvm_disable_txq(mvm, NULL, mvm->snif_queue, IWL_MAX_TID_COUNT, 0);
        ret = iwl_mvm_rm_sta_common(mvm, mvm->snif_sta.sta_id);
        if (ret)
                IWL_WARN(mvm, "Failed sending remove station\n");

        return ret;
}

void iwl_mvm_dealloc_snif_sta(struct iwl_mvm *mvm)
{
        iwl_mvm_dealloc_int_sta(mvm, &mvm->snif_sta);
}

void iwl_mvm_del_aux_sta(struct iwl_mvm *mvm)
{
        lockdep_assert_held(&mvm->mutex);

        iwl_mvm_dealloc_int_sta(mvm, &mvm->aux_sta);
}

/*
 * 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_add_bcast_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
{
        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
        struct iwl_mvm_int_sta *bsta = &mvmvif->bcast_sta;
        static const u8 _baddr[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
        const u8 *baddr = _baddr;
        int queue;
        int ret;
        unsigned int wdg_timeout =
                iwl_mvm_get_wd_timeout(mvm, vif, false, false);
        struct iwl_trans_txq_scd_cfg cfg = {
                .fifo = IWL_MVM_TX_FIFO_VO,
                .sta_id = mvmvif->bcast_sta.sta_id,
                .tid = IWL_MAX_TID_COUNT,
                .aggregate = false,
                .frame_limit = IWL_FRAME_LIMIT,
        };

        lockdep_assert_held(&mvm->mutex);

        if (!iwl_mvm_has_new_tx_api(mvm)) {
                if (vif->type == NL80211_IFTYPE_AP ||
                    vif->type == NL80211_IFTYPE_ADHOC) {
                        queue = mvm->probe_queue;
                } else if (vif->type == NL80211_IFTYPE_P2P_DEVICE) {
                        queue = mvm->p2p_dev_queue;
                } else {
                        WARN(1, "Missing required TXQ for adding bcast STA\n");
                        return -EINVAL;
                }

                bsta->tfd_queue_msk |= BIT(queue);

                iwl_mvm_enable_txq(mvm, NULL, queue, 0, &cfg, wdg_timeout);
        }

        if (vif->type == NL80211_IFTYPE_ADHOC)
                baddr = vif->bss_conf.bssid;

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

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

        /*
         * For 22000 firmware and on we cannot add queue to a station unknown
         * to firmware so enable queue here - after the station was added
         */
        if (iwl_mvm_has_new_tx_api(mvm)) {
                queue = iwl_mvm_tvqm_enable_txq(mvm, bsta->sta_id,
                                                IWL_MAX_TID_COUNT,
                                                wdg_timeout);

                if (vif->type == NL80211_IFTYPE_AP ||
                    vif->type == NL80211_IFTYPE_ADHOC)
                        mvm->probe_queue = queue;
                else if (vif->type == NL80211_IFTYPE_P2P_DEVICE)
                        mvm->p2p_dev_queue = queue;
        }

        return 0;
}

static void iwl_mvm_free_bcast_sta_queues(struct iwl_mvm *mvm,
                                          struct ieee80211_vif *vif)
{
        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
        int queue;

        lockdep_assert_held(&mvm->mutex);

        iwl_mvm_flush_sta(mvm, &mvmvif->bcast_sta, true, 0);

        switch (vif->type) {
        case NL80211_IFTYPE_AP:
        case NL80211_IFTYPE_ADHOC:
                queue = mvm->probe_queue;
                break;
        case NL80211_IFTYPE_P2P_DEVICE:
                queue = mvm->p2p_dev_queue;
                break;
        default:
                WARN(1, "Can't free bcast queue on vif type %d\n",
                     vif->type);
                return;
        }

        iwl_mvm_disable_txq(mvm, NULL, queue, IWL_MAX_TID_COUNT, 0);
        if (iwl_mvm_has_new_tx_api(mvm))
                return;

        WARN_ON(!(mvmvif->bcast_sta.tfd_queue_msk & BIT(queue)));
        mvmvif->bcast_sta.tfd_queue_msk &= ~BIT(queue);
}

/* 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 ieee80211_vif *vif)
{
        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
        int ret;

        lockdep_assert_held(&mvm->mutex);

        iwl_mvm_free_bcast_sta_queues(mvm, vif);

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

int iwl_mvm_alloc_bcast_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
{
        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);

        lockdep_assert_held(&mvm->mutex);

        return iwl_mvm_allocate_int_sta(mvm, &mvmvif->bcast_sta, 0,
                                        ieee80211_vif_type_p2p(vif),
                                        IWL_STA_GENERAL_PURPOSE);
}

/* 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_p2p_bcast_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
{
        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
        struct iwl_mvm_int_sta *bsta = &mvmvif->bcast_sta;
        int ret;

        lockdep_assert_held(&mvm->mutex);

        ret = iwl_mvm_alloc_bcast_sta(mvm, vif);
        if (ret)
                return ret;

        ret = iwl_mvm_send_add_bcast_sta(mvm, vif);

        if (ret)
                iwl_mvm_dealloc_int_sta(mvm, bsta);

        return ret;
}

void iwl_mvm_dealloc_bcast_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
{
        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);

        iwl_mvm_dealloc_int_sta(mvm, &mvmvif->bcast_sta);
}

/*
 * 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_p2p_bcast_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
{
        int ret;

        lockdep_assert_held(&mvm->mutex);

        ret = iwl_mvm_send_rm_bcast_sta(mvm, vif);

        iwl_mvm_dealloc_bcast_sta(mvm, vif);

        return ret;
}

/*
 * Allocate a new station entry for the multicast station to the given vif,
 * and send it to the FW.
 * Note that each AP/GO mac should have its own multicast station.
 *
 * @mvm: the mvm component
 * @vif: the interface to which the multicast station is added
 */
int iwl_mvm_add_mcast_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
{
        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
        struct iwl_mvm_int_sta *msta = &mvmvif->mcast_sta;
        static const u8 _maddr[] = {0x03, 0x00, 0x00, 0x00, 0x00, 0x00};
        const u8 *maddr = _maddr;
        struct iwl_trans_txq_scd_cfg cfg = {
                .fifo = vif->type == NL80211_IFTYPE_AP ?
                        IWL_MVM_TX_FIFO_MCAST : IWL_MVM_TX_FIFO_BE,
                .sta_id = msta->sta_id,
                .tid = 0,
                .aggregate = false,
                .frame_limit = IWL_FRAME_LIMIT,
        };
        unsigned int timeout = iwl_mvm_get_wd_timeout(mvm, vif, false, false);
        int ret;

        lockdep_assert_held(&mvm->mutex);

        if (WARN_ON(vif->type != NL80211_IFTYPE_AP &&
                    vif->type != NL80211_IFTYPE_ADHOC))
                return -ENOTSUPP;

        /*
         * In IBSS, ieee80211_check_queues() sets the cab_queue to be
         * invalid, so make sure we use the queue we want.
         * Note that this is done here as we want to avoid making DQA
         * changes in mac80211 layer.
         */
        if (vif->type == NL80211_IFTYPE_ADHOC)
                mvmvif->cab_queue = IWL_MVM_DQA_GCAST_QUEUE;

        /*
         * While in previous FWs we had to exclude cab queue from TFD queue
         * mask, now it is needed as any other queue.
         */
        if (!iwl_mvm_has_new_tx_api(mvm) &&
            fw_has_api(&mvm->fw->ucode_capa, IWL_UCODE_TLV_API_STA_TYPE)) {
                iwl_mvm_enable_txq(mvm, NULL, mvmvif->cab_queue, 0, &cfg,
                                   timeout);
                msta->tfd_queue_msk |= BIT(mvmvif->cab_queue);
        }
        ret = iwl_mvm_add_int_sta_common(mvm, msta, maddr,
                                         mvmvif->id, mvmvif->color);
        if (ret) {
                iwl_mvm_dealloc_int_sta(mvm, msta);
                return ret;
        }

        /*
         * Enable cab queue after the ADD_STA command is sent.
         * This is needed for 22000 firmware which won't accept SCD_QUEUE_CFG
         * command with unknown station id, and for FW that doesn't support
         * station API since the cab queue is not included in the
         * tfd_queue_mask.
         */
        if (iwl_mvm_has_new_tx_api(mvm)) {
                int queue = iwl_mvm_tvqm_enable_txq(mvm, msta->sta_id,
                                                    0,
                                                    timeout);
                mvmvif->cab_queue = queue;
        } else if (!fw_has_api(&mvm->fw->ucode_capa,
                               IWL_UCODE_TLV_API_STA_TYPE))
                iwl_mvm_enable_txq(mvm, NULL, mvmvif->cab_queue, 0, &cfg,
                                   timeout);

        return 0;
}

static int __iwl_mvm_remove_sta_key(struct iwl_mvm *mvm, u8 sta_id,
                                    struct ieee80211_key_conf *keyconf,
                                    bool mcast)
{
        union {
                struct iwl_mvm_add_sta_key_cmd_v1 cmd_v1;
                struct iwl_mvm_add_sta_key_cmd cmd;
        } u = {};
        bool new_api = fw_has_api(&mvm->fw->ucode_capa,
                                  IWL_UCODE_TLV_API_TKIP_MIC_KEYS);
        __le16 key_flags;
        int ret, size;
        u32 status;

        /* This is a valid situation for GTK removal */
        if (sta_id == IWL_MVM_INVALID_STA)
                return 0;

        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 (mcast)
                key_flags |= cpu_to_le16(STA_KEY_MULTICAST);

        /*
         * The fields assigned here are in the same location at the start
         * of the command, so we can do this union trick.
         */
        u.cmd.common.key_flags = key_flags;
        u.cmd.common.key_offset = keyconf->hw_key_idx;
        u.cmd.common.sta_id = sta_id;

        size = new_api ? sizeof(u.cmd) : sizeof(u.cmd_v1);

        status = ADD_STA_SUCCESS;
        ret = iwl_mvm_send_cmd_pdu_status(mvm, ADD_STA_KEY, size, &u.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;
}

/*
 * 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_mcast_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
{
        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
        int ret;

        lockdep_assert_held(&mvm->mutex);

        iwl_mvm_flush_sta(mvm, &mvmvif->mcast_sta, true, 0);

        iwl_mvm_disable_txq(mvm, NULL, mvmvif->cab_queue, 0, 0);

        ret = iwl_mvm_rm_sta_common(mvm, mvmvif->mcast_sta.sta_id);
        if (ret)
                IWL_WARN(mvm, "Failed sending remove station\n");

        return ret;
}

#define IWL_MAX_RX_BA_SESSIONS 16

static void iwl_mvm_sync_rxq_del_ba(struct iwl_mvm *mvm, u8 baid)
{
        struct iwl_mvm_rss_sync_notif notif = {
                .metadata.type = IWL_MVM_RXQ_NOTIF_DEL_BA,
                .metadata.sync = 1,
                .delba.baid = baid,
        };
        iwl_mvm_sync_rx_queues_internal(mvm, (void *)&notif, sizeof(notif));
};

static void iwl_mvm_free_reorder(struct iwl_mvm *mvm,
                                 struct iwl_mvm_baid_data *data)
{
        int i;

        iwl_mvm_sync_rxq_del_ba(mvm, data->baid);

        for (i = 0; i < mvm->trans->num_rx_queues; i++) {
                int j;
                struct iwl_mvm_reorder_buffer *reorder_buf =
                        &data->reorder_buf[i];
                struct iwl_mvm_reorder_buf_entry *entries =
                        &data->entries[i * data->entries_per_queue];

                spin_lock_bh(&reorder_buf->lock);
                if (likely(!reorder_buf->num_stored)) {
                        spin_unlock_bh(&reorder_buf->lock);
                        continue;
                }

                /*
                 * This shouldn't happen in regular DELBA since the internal
                 * delBA notification should trigger a release of all frames in
                 * the reorder buffer.
                 */
                WARN_ON(1);

                for (j = 0; j < reorder_buf->buf_size; j++)
                        __skb_queue_purge(&entries[j].e.frames);
                /*
                 * Prevent timer re-arm. This prevents a very far fetched case
                 * where we timed out on the notification. There may be prior
                 * RX frames pending in the RX queue before the notification
                 * that might get processed between now and the actual deletion
                 * and we would re-arm the timer although we are deleting the
                 * reorder buffer.
                 */
                reorder_buf->removed = true;
                spin_unlock_bh(&reorder_buf->lock);
                del_timer_sync(&reorder_buf->reorder_timer);
        }
}

static void iwl_mvm_init_reorder_buffer(struct iwl_mvm *mvm,
                                        struct iwl_mvm_baid_data *data,
                                        u16 ssn, u16 buf_size)
{
        int i;

        for (i = 0; i < mvm->trans->num_rx_queues; i++) {
                struct iwl_mvm_reorder_buffer *reorder_buf =
                        &data->reorder_buf[i];
                struct iwl_mvm_reorder_buf_entry *entries =
                        &data->entries[i * data->entries_per_queue];
                int j;

                reorder_buf->num_stored = 0;
                reorder_buf->head_sn = ssn;
                reorder_buf->buf_size = buf_size;
                /* rx reorder timer */
                timer_setup(&reorder_buf->reorder_timer,
                            iwl_mvm_reorder_timer_expired, 0);
                spin_lock_init(&reorder_buf->lock);
                reorder_buf->mvm = mvm;
                reorder_buf->queue = i;
                reorder_buf->valid = false;
                for (j = 0; j < reorder_buf->buf_size; j++)
                        __skb_queue_head_init(&entries[j].e.frames);
        }
}

int iwl_mvm_sta_rx_agg(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
                       int tid, u16 ssn, bool start, u16 buf_size, u16 timeout)
{
        struct iwl_mvm_sta *mvm_sta = iwl_mvm_sta_from_mac80211(sta);
        struct iwl_mvm_add_sta_cmd cmd = {};
        struct iwl_mvm_baid_data *baid_data = NULL;
        int ret;
        u32 status;

        lockdep_assert_held(&mvm->mutex);

        if (start && mvm->rx_ba_sessions >= IWL_MAX_RX_BA_SESSIONS) {
                IWL_WARN(mvm, "Not enough RX BA SESSIONS\n");
                return -ENOSPC;
        }

        if (iwl_mvm_has_new_rx_api(mvm) && start) {
                u16 reorder_buf_size = buf_size * sizeof(baid_data->entries[0]);

                /* sparse doesn't like the __align() so don't check */
#ifndef __CHECKER__
                /*
                 * The division below will be OK if either the cache line size
                 * can be divided by the entry size (ALIGN will round up) or if
                 * if the entry size can be divided by the cache line size, in
                 * which case the ALIGN() will do nothing.
                 */
                BUILD_BUG_ON(SMP_CACHE_BYTES % sizeof(baid_data->entries[0]) &&
                             sizeof(baid_data->entries[0]) % SMP_CACHE_BYTES);
#endif

                /*
                 * Upward align the reorder buffer size to fill an entire cache
                 * line for each queue, to avoid sharing cache lines between
                 * different queues.
                 */
                reorder_buf_size = ALIGN(reorder_buf_size, SMP_CACHE_BYTES);

                /*
                 * Allocate here so if allocation fails we can bail out early
                 * before starting the BA session in the firmware
                 */
                baid_data = kzalloc(sizeof(*baid_data) +
                                    mvm->trans->num_rx_queues *
                                    reorder_buf_size,
                                    GFP_KERNEL);
                if (!baid_data)
                        return -ENOMEM;

                /*
                 * This division is why we need the above BUILD_BUG_ON(),
                 * if that doesn't hold then this will not be right.
                 */
                baid_data->entries_per_queue =
                        reorder_buf_size / sizeof(baid_data->entries[0]);
        }

        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;
        if (start) {
                cmd.add_immediate_ba_tid = (u8) tid;
                cmd.add_immediate_ba_ssn = cpu_to_le16(ssn);
                cmd.rx_ba_window = cpu_to_le16(buf_size);
        } else {
                cmd.remove_immediate_ba_tid = (u8) tid;
        }
        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,
                                          iwl_mvm_add_sta_cmd_size(mvm),
                                          &cmd, &status);
        if (ret)
                goto out_free;

        switch (status & IWL_ADD_STA_STATUS_MASK) {
        case ADD_STA_SUCCESS:
                IWL_DEBUG_HT(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;
        }

        if (ret)
                goto out_free;

        if (start) {
                u8 baid;

                mvm->rx_ba_sessions++;

                if (!iwl_mvm_has_new_rx_api(mvm))
                        return 0;

                if (WARN_ON(!(status & IWL_ADD_STA_BAID_VALID_MASK))) {
                        ret = -EINVAL;
                        goto out_free;
                }
                baid = (u8)((status & IWL_ADD_STA_BAID_MASK) >>
                            IWL_ADD_STA_BAID_SHIFT);
                baid_data->baid = baid;
                baid_data->timeout = timeout;
                baid_data->last_rx = jiffies;
                baid_data->rcu_ptr = &mvm->baid_map[baid];
                timer_setup(&baid_data->session_timer,
                            iwl_mvm_rx_agg_session_expired, 0);
                baid_data->mvm = mvm;
                baid_data->tid = tid;
                baid_data->sta_id = mvm_sta->sta_id;

                mvm_sta->tid_to_baid[tid] = baid;
                if (timeout)
                        mod_timer(&baid_data->session_timer,
                                  TU_TO_EXP_TIME(timeout * 2));

                iwl_mvm_init_reorder_buffer(mvm, baid_data, ssn, buf_size);
                /*
                 * protect the BA data with RCU to cover a case where our
                 * internal RX sync mechanism will timeout (not that it's
                 * supposed to happen) and we will free the session data while
                 * RX is being processed in parallel
                 */
                IWL_DEBUG_HT(mvm, "Sta %d(%d) is assigned to BAID %d\n",
                             mvm_sta->sta_id, tid, baid);
                WARN_ON(rcu_access_pointer(mvm->baid_map[baid]));
                rcu_assign_pointer(mvm->baid_map[baid], baid_data);
        } else  {
                u8 baid = mvm_sta->tid_to_baid[tid];

                if (mvm->rx_ba_sessions > 0)
                        /* check that restart flow didn't zero the counter */
                        mvm->rx_ba_sessions--;
                if (!iwl_mvm_has_new_rx_api(mvm))
                        return 0;

                if (WARN_ON(baid == IWL_RX_REORDER_DATA_INVALID_BAID))
                        return -EINVAL;

                baid_data = rcu_access_pointer(mvm->baid_map[baid]);
                if (WARN_ON(!baid_data))
                        return -EINVAL;

                /* synchronize all rx queues so we can safely delete */
                iwl_mvm_free_reorder(mvm, baid_data);
                del_timer_sync(&baid_data->session_timer);
                RCU_INIT_POINTER(mvm->baid_map[baid], NULL);
                kfree_rcu(baid_data, rcu_head);
                IWL_DEBUG_HT(mvm, "BAID %d is free\n", baid);
        }
        return 0;

out_free:
        kfree(baid_data);
        return ret;
}

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 = iwl_mvm_sta_from_mac80211(sta);
        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 {
                /* In DQA-mode the queue isn't removed on agg termination */
                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;
        if (!iwl_mvm_has_new_tx_api(mvm))
                cmd.modify_mask = STA_MODIFY_QUEUES;
        cmd.modify_mask |= 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,
                                          iwl_mvm_add_sta_cmd_size(mvm),
                                          &cmd, &status);
        if (ret)
                return ret;

        switch (status & IWL_ADD_STA_STATUS_MASK) {
        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;
}

const u8 tid_to_mac80211_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,
        IEEE80211_AC_VO, /* We treat MGMT as TID 8, which is set as AC_VO */
};

static const u8 tid_to_ucode_ac[] = {
        AC_BE,
        AC_BK,
        AC_BK,
        AC_BE,
        AC_VI,
        AC_VI,
        AC_VO,
        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 = iwl_mvm_sta_from_mac80211(sta);
        struct iwl_mvm_tid_data *tid_data;
        u16 normalized_ssn;
        u16 txq_id;
        int ret;

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

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

        lockdep_assert_held(&mvm->mutex);

        if (mvmsta->tid_data[tid].txq_id == IWL_MVM_INVALID_QUEUE &&
            iwl_mvm_has_new_tx_api(mvm)) {
                u8 ac = tid_to_mac80211_ac[tid];

                ret = iwl_mvm_sta_alloc_queue_tvqm(mvm, sta, ac, tid);
                if (ret)
                        return ret;
        }

        spin_lock_bh(&mvmsta->lock);

        /* possible race condition - we entered D0i3 while starting agg */
        if (test_bit(IWL_MVM_STATUS_IN_D0I3, &mvm->status)) {
                spin_unlock_bh(&mvmsta->lock);
                IWL_ERR(mvm, "Entered D0i3 while starting Tx agg\n");
                return -EIO;
        }

        /*
         * Note the possible cases:
         *  1. An enabled TXQ - TXQ needs to become agg'ed
         *  2. The TXQ hasn't yet been enabled, so find a free one and mark
         *      it as reserved
         */
        txq_id = mvmsta->tid_data[tid].txq_id;
        if (txq_id == IWL_MVM_INVALID_QUEUE) {
                ret = iwl_mvm_find_free_queue(mvm, mvmsta->sta_id,
                                              IWL_MVM_DQA_MIN_DATA_QUEUE,
                                              IWL_MVM_DQA_MAX_DATA_QUEUE);
                if (ret < 0) {
                        IWL_ERR(mvm, "Failed to allocate agg queue\n");
                        goto out;
                }

                txq_id = ret;

                /* TXQ hasn't yet been enabled, so mark it only as reserved */
                mvm->queue_info[txq_id].status = IWL_MVM_QUEUE_RESERVED;
        } else if (WARN_ON(txq_id >= IWL_MAX_HW_QUEUES)) {
                ret = -ENXIO;
                IWL_ERR(mvm, "tid_id %d out of range (0, %d)!\n",
                        tid, IWL_MAX_HW_QUEUES - 1);
                goto out;

        } else if (unlikely(mvm->queue_info[txq_id].status ==
                            IWL_MVM_QUEUE_SHARED)) {
                ret = -ENXIO;
                IWL_DEBUG_TX_QUEUES(mvm,
                                    "Can't start tid %d agg on shared queue!\n",
                                    tid);
                goto out;
        }

        IWL_DEBUG_TX_QUEUES(mvm,
                            "AGG for tid %d will be on queue #%d\n",
                            tid, txq_id);

        tid_data = &mvmsta->tid_data[tid];
        tid_data->ssn = IEEE80211_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);

        /*
         * In 22000 HW, the next_reclaimed index is only 8 bit, so we'll need
         * to align the wrap around of ssn so we compare relevant values.
         */
        normalized_ssn = tid_data->ssn;
        if (mvm->trans->cfg->gen2)
                normalized_ssn &= 0xff;

        if (normalized_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;
        }

        ret = 0;

out:
        spin_unlock_bh(&mvmsta->lock);

        return ret;
}

int iwl_mvm_sta_tx_agg_oper(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
                            struct ieee80211_sta *sta, u16 tid, u16 buf_size,
                            bool amsdu)
{
        struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
        struct iwl_mvm_tid_data *tid_data = &mvmsta->tid_data[tid];
        unsigned int wdg_timeout =
                iwl_mvm_get_wd_timeout(mvm, vif, sta->tdls, false);
        int queue, ret;
        bool alloc_queue = true;
        enum iwl_mvm_queue_status queue_status;
        u16 ssn;

        struct iwl_trans_txq_scd_cfg cfg = {
                .sta_id = mvmsta->sta_id,
                .tid = tid,
                .frame_limit = buf_size,
                .aggregate = true,
        };

        /*
         * When FW supports TLC_OFFLOAD, it also implements Tx aggregation
         * manager, so this function should never be called in this case.
         */
        if (WARN_ON_ONCE(iwl_mvm_has_tlc_offload(mvm)))
                return -EINVAL;

        BUILD_BUG_ON((sizeof(mvmsta->agg_tids) * BITS_PER_BYTE)
                     != IWL_MAX_TID_COUNT);

        spin_lock_bh(&mvmsta->lock);
        ssn = tid_data->ssn;
        queue = tid_data->txq_id;
        tid_data->state = IWL_AGG_ON;
        mvmsta->agg_tids |= BIT(tid);
        tid_data->ssn = 0xffff;
        tid_data->amsdu_in_ampdu_allowed = amsdu;
        spin_unlock_bh(&mvmsta->lock);

        if (iwl_mvm_has_new_tx_api(mvm)) {
                /*
                 * If there is no queue for this tid, iwl_mvm_sta_tx_agg_start()
                 * would have failed, so if we are here there is no need to
                 * allocate a queue.
                 * However, if aggregation size is different than the default
                 * size, the scheduler should be reconfigured.
                 * We cannot do this with the new TX API, so return unsupported
                 * for now, until it will be offloaded to firmware..
                 * Note that if SCD default value changes - this condition
                 * should be updated as well.
                 */
                if (buf_size < IWL_FRAME_LIMIT)
                        return -ENOTSUPP;

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

        cfg.fifo = iwl_mvm_ac_to_tx_fifo[tid_to_mac80211_ac[tid]];

        queue_status = mvm->queue_info[queue].status;

        /* Maybe there is no need to even alloc a queue... */
        if (mvm->queue_info[queue].status == IWL_MVM_QUEUE_READY)
                alloc_queue = false;

        /*
         * Only reconfig the SCD for the queue if the window size has
         * changed from current (become smaller)
         */
        if (!alloc_queue && buf_size < IWL_FRAME_LIMIT) {
                /*
                 * If reconfiguring an existing queue, it first must be
                 * drained
                 */
                ret = iwl_trans_wait_tx_queues_empty(mvm->trans,
                                                     BIT(queue));
                if (ret) {
                        IWL_ERR(mvm,
                                "Error draining queue before reconfig\n");
                        return ret;
                }

                ret = iwl_mvm_reconfig_scd(mvm, queue, cfg.fifo,
                                           mvmsta->sta_id, tid,
                                           buf_size, ssn);
                if (ret) {
                        IWL_ERR(mvm,
                                "Error reconfiguring TXQ #%d\n", queue);
                        return ret;
                }
        }

        if (alloc_queue)
                iwl_mvm_enable_txq(mvm, sta, queue, ssn,
                                   &cfg, wdg_timeout);

        /* Send ADD_STA command to enable aggs only if the queue isn't shared */
        if (queue_status != IWL_MVM_QUEUE_SHARED) {
                ret = iwl_mvm_sta_tx_agg(mvm, sta, tid, queue, true);
                if (ret)
                        return -EIO;
        }

        /* No need to mark as reserved */
        mvm->queue_info[queue].status = IWL_MVM_QUEUE_READY;

out:
        /*
         * 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.rs_drv.lq.agg_frame_cnt_limit = mvmsta->max_agg_bufsize;

        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.rs_drv.lq);
}

static void iwl_mvm_unreserve_agg_queue(struct iwl_mvm *mvm,
                                        struct iwl_mvm_sta *mvmsta,
                                        struct iwl_mvm_tid_data *tid_data)
{
        u16 txq_id = tid_data->txq_id;

        lockdep_assert_held(&mvm->mutex);

        if (iwl_mvm_has_new_tx_api(mvm))
                return;

        /*
         * The TXQ is marked as reserved only if no traffic came through yet
         * This means no traffic has been sent on this TID (agg'd or not), so
         * we no longer have use for the queue. Since it hasn't even been
         * allocated through iwl_mvm_enable_txq, so we can just mark it back as
         * free.
         */
        if (mvm->queue_info[txq_id].status == IWL_MVM_QUEUE_RESERVED) {
                mvm->queue_info[txq_id].status = IWL_MVM_QUEUE_FREE;
                tid_data->txq_id = IWL_MVM_INVALID_QUEUE;