/******************************************************************************
 *
 * 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) 2014 Intel Mobile Communications GmbH
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
 * USA
 *
 * The full GNU General Public License is included in this distribution
 * in the file called COPYING.
 *
 * Contact Information:
 *  Intel Linux Wireless <linuxwifi@intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 * BSD LICENSE
 *
 * Copyright(c) 2014 Intel Mobile Communications GmbH
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  * Neither the name Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *****************************************************************************/

#include <linux/etherdevice.h>
#include "mvm.h"
#include "time-event.h"
#include "iwl-io.h"
#include "iwl-prph.h"

#define TU_TO_US(x) (x * 1024)
#define TU_TO_MS(x) (TU_TO_US(x) / 1000)

void iwl_mvm_teardown_tdls_peers(struct iwl_mvm *mvm)
{
        struct ieee80211_sta *sta;
        struct iwl_mvm_sta *mvmsta;
        int i;

        lockdep_assert_held(&mvm->mutex);

        for (i = 0; i < IWL_MVM_STATION_COUNT; i++) {
                sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[i],
                                                lockdep_is_held(&mvm->mutex));
                if (!sta || IS_ERR(sta) || !sta->tdls)
                        continue;

                mvmsta = iwl_mvm_sta_from_mac80211(sta);
                ieee80211_tdls_oper_request(mvmsta->vif, sta->addr,
                                NL80211_TDLS_TEARDOWN,
                                WLAN_REASON_TDLS_TEARDOWN_UNSPECIFIED,
                                GFP_KERNEL);
        }
}

int iwl_mvm_tdls_sta_count(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
{
        struct ieee80211_sta *sta;
        struct iwl_mvm_sta *mvmsta;
        int count = 0;
        int i;

        lockdep_assert_held(&mvm->mutex);

        for (i = 0; i < IWL_MVM_STATION_COUNT; i++) {
                sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[i],
                                                lockdep_is_held(&mvm->mutex));
                if (!sta || IS_ERR(sta) || !sta->tdls)
                        continue;

                if (vif) {
                        mvmsta = iwl_mvm_sta_from_mac80211(sta);
                        if (mvmsta->vif != vif)
                                continue;
                }

                count++;
        }

        return count;
}

static void iwl_mvm_tdls_config(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
{
        struct iwl_rx_packet *pkt;
        struct iwl_tdls_config_res *resp;
        struct iwl_tdls_config_cmd tdls_cfg_cmd = {};
        struct iwl_host_cmd cmd = {
                .id = TDLS_CONFIG_CMD,
                .flags = CMD_WANT_SKB,
                .data = { &tdls_cfg_cmd, },
                .len = { sizeof(struct iwl_tdls_config_cmd), },
        };
        struct ieee80211_sta *sta;
        int ret, i, cnt;
        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);

        lockdep_assert_held(&mvm->mutex);

        tdls_cfg_cmd.id_and_color =
                cpu_to_le32(FW_CMD_ID_AND_COLOR(mvmvif->id, mvmvif->color));
        tdls_cfg_cmd.tx_to_ap_tid = IWL_MVM_TDLS_FW_TID;
        tdls_cfg_cmd.tx_to_ap_ssn = cpu_to_le16(0); /* not used for now */

        /* for now the Tx cmd is empty and unused */

        /* populate TDLS peer data */
        cnt = 0;
        for (i = 0; i < IWL_MVM_STATION_COUNT; i++) {
                sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[i],
                                                lockdep_is_held(&mvm->mutex));
                if (IS_ERR_OR_NULL(sta) || !sta->tdls)
                        continue;

                tdls_cfg_cmd.sta_info[cnt].sta_id = i;
                tdls_cfg_cmd.sta_info[cnt].tx_to_peer_tid =
                                                        IWL_MVM_TDLS_FW_TID;
                tdls_cfg_cmd.sta_info[cnt].tx_to_peer_ssn = cpu_to_le16(0);
                tdls_cfg_cmd.sta_info[cnt].is_initiator =
                                cpu_to_le32(sta->tdls_initiator ? 1 : 0);

                cnt++;
        }

        tdls_cfg_cmd.tdls_peer_count = cnt;
        IWL_DEBUG_TDLS(mvm, "send TDLS config to FW for %d peers\n", cnt);

        ret = iwl_mvm_send_cmd(mvm, &cmd);
        if (WARN_ON_ONCE(ret))
                return;

        pkt = cmd.resp_pkt;

        WARN_ON_ONCE(iwl_rx_packet_payload_len(pkt) != sizeof(*resp));

        /* we don't really care about the response at this point */

        iwl_free_resp(&cmd);
}

void iwl_mvm_recalc_tdls_state(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
                               bool sta_added)
{
        int tdls_sta_cnt = iwl_mvm_tdls_sta_count(mvm, vif);

        /* when the first peer joins, send a power update first */
        if (tdls_sta_cnt == 1 && sta_added)
                iwl_mvm_power_update_mac(mvm);

        /* configure the FW with TDLS peer info */
        iwl_mvm_tdls_config(mvm, vif);

        /* when the last peer leaves, send a power update last */
        if (tdls_sta_cnt == 0 && !sta_added)
                iwl_mvm_power_update_mac(mvm);
}

void iwl_mvm_mac_mgd_protect_tdls_discover(struct ieee80211_hw *hw,
                                           struct ieee80211_vif *vif)
{
        struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
        u32 duration = 2 * vif->bss_conf.dtim_period * vif->bss_conf.beacon_int;

        /*
         * iwl_mvm_protect_session() reads directly from the device
         * (the system time), so make sure it is available.
         */
        if (iwl_mvm_ref_sync(mvm, IWL_MVM_REF_PROTECT_TDLS))
                return;

        mutex_lock(&mvm->mutex);
        /* Protect the session to hear the TDLS setup response on the channel */
        iwl_mvm_protect_session(mvm, vif, duration, duration, 100, true);
        mutex_unlock(&mvm->mutex);

        iwl_mvm_unref(mvm, IWL_MVM_REF_PROTECT_TDLS);
}

static const char *
iwl_mvm_tdls_cs_state_str(enum iwl_mvm_tdls_cs_state state)
{
        switch (state) {
        case IWL_MVM_TDLS_SW_IDLE:
                return "IDLE";
        case IWL_MVM_TDLS_SW_REQ_SENT:
                return "REQ SENT";
        case IWL_MVM_TDLS_SW_RESP_RCVD:
                return "RESP RECEIVED";
        case IWL_MVM_TDLS_SW_REQ_RCVD:
                return "REQ RECEIVED";
        case IWL_MVM_TDLS_SW_ACTIVE:
                return "ACTIVE";
        }

        return NULL;
}

static void iwl_mvm_tdls_update_cs_state(struct iwl_mvm *mvm,
                                         enum iwl_mvm_tdls_cs_state state)
{
        if (mvm->tdls_cs.state == state)
                return;

        IWL_DEBUG_TDLS(mvm, "TDLS channel switch state: %s -> %s\n",
                       iwl_mvm_tdls_cs_state_str(mvm->tdls_cs.state),
                       iwl_mvm_tdls_cs_state_str(state));
        mvm->tdls_cs.state = state;

        /* we only send requests to our switching peer - update sent time */
        if (state == IWL_MVM_TDLS_SW_REQ_SENT)
                mvm->tdls_cs.peer.sent_timestamp =
                        iwl_read_prph(mvm->trans, DEVICE_SYSTEM_TIME_REG);

        if (state == IWL_MVM_TDLS_SW_IDLE)
                mvm->tdls_cs.cur_sta_id = IWL_MVM_STATION_COUNT;
}

void iwl_mvm_rx_tdls_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb)
{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_tdls_channel_switch_notif *notif = (void *)pkt->data;
        struct ieee80211_sta *sta;
        unsigned int delay;
        struct iwl_mvm_sta *mvmsta;
        struct ieee80211_vif *vif;
        u32 sta_id = le32_to_cpu(notif->sta_id);

        lockdep_assert_held(&mvm->mutex);

        /* can fail sometimes */
        if (!le32_to_cpu(notif->status)) {
                iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_IDLE);
                return;
        }

        if (WARN_ON(sta_id >= IWL_MVM_STATION_COUNT))
                return;

        sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[sta_id],
                                        lockdep_is_held(&mvm->mutex));
        /* the station may not be here, but if it is, it must be a TDLS peer */
        if (IS_ERR_OR_NULL(sta) || WARN_ON(!sta->tdls))
                return;

        mvmsta = iwl_mvm_sta_from_mac80211(sta);
        vif = mvmsta->vif;

        /*
         * Update state and possibly switch again after this is over (DTIM).
         * Also convert TU to msec.
         */
        delay = TU_TO_MS(vif->bss_conf.dtim_period * vif->bss_conf.beacon_int);
        mod_delayed_work(system_wq, &mvm->tdls_cs.dwork,
                         msecs_to_jiffies(delay));

        iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_ACTIVE);
}

static int
iwl_mvm_tdls_check_action(struct iwl_mvm *mvm,
                          enum iwl_tdls_channel_switch_type type,
                          const u8 *peer, bool peer_initiator, u32 timestamp)
{
        bool same_peer = false;
        int ret = 0;

        /* get the existing peer if it's there */
        if (mvm->tdls_cs.state != IWL_MVM_TDLS_SW_IDLE &&
            mvm->tdls_cs.cur_sta_id != IWL_MVM_STATION_COUNT) {
                struct ieee80211_sta *sta = rcu_dereference_protected(
                                mvm->fw_id_to_mac_id[mvm->tdls_cs.cur_sta_id],
                                lockdep_is_held(&mvm->mutex));
                if (!IS_ERR_OR_NULL(sta))
                        same_peer = ether_addr_equal(peer, sta->addr);
        }

        switch (mvm->tdls_cs.state) {
        case IWL_MVM_TDLS_SW_IDLE:
                /*
                 * might be spurious packet from the peer after the switch is
                 * already done
                 */
                if (type == TDLS_MOVE_CH)
                        ret = -EINVAL;
                break;
        case IWL_MVM_TDLS_SW_REQ_SENT:
                /* only allow requests from the same peer */
                if (!same_peer)
                        ret = -EBUSY;
                else if (type == TDLS_SEND_CHAN_SW_RESP_AND_MOVE_CH &&
                         !peer_initiator)
                        /*
                         * We received a ch-switch request while an outgoing
                         * one is pending. Allow it if the peer is the link
                         * initiator.
                         */
                        ret = -EBUSY;
                else if (type == TDLS_SEND_CHAN_SW_REQ)
                        /* wait for idle before sending another request */
                        ret = -EBUSY;
                else if (timestamp <= mvm->tdls_cs.peer.sent_timestamp)
                        /* we got a stale response - ignore it */
                        ret = -EINVAL;
                break;
        case IWL_MVM_TDLS_SW_RESP_RCVD:
                /*
                 * we are waiting for the FW to give an "active" notification,
                 * so ignore requests in the meantime
                 */
                ret = -EBUSY;
                break;
        case IWL_MVM_TDLS_SW_REQ_RCVD:
                /* as above, allow the link initiator to proceed */
                if (type == TDLS_SEND_CHAN_SW_REQ) {
                        if (!same_peer)
                                ret = -EBUSY;
                        else if (peer_initiator) /* they are the initiator */
                                ret = -EBUSY;
                } else if (type == TDLS_MOVE_CH) {
                        ret = -EINVAL;
                }
                break;
        case IWL_MVM_TDLS_SW_ACTIVE:
                /*
                 * the only valid request when active is a request to return
                 * to the base channel by the current off-channel peer
                 */
                if (type != TDLS_MOVE_CH || !same_peer)
                        ret = -EBUSY;
                break;
        }

        if (ret)
                IWL_DEBUG_TDLS(mvm,
                               "Invalid TDLS action %d state %d peer %pM same_peer %d initiator %d\n",
                               type, mvm->tdls_cs.state, peer, same_peer,
                               peer_initiator);

        return ret;
}

static int
iwl_mvm_tdls_config_channel_switch(struct iwl_mvm *mvm,
                                   struct ieee80211_vif *vif,
                                   enum iwl_tdls_channel_switch_type type,
                                   const u8 *peer, bool peer_initiator,
                                   u8 oper_class,
                                   struct cfg80211_chan_def *chandef,
                                   u32 timestamp, u16 switch_time,
                                   u16 switch_timeout, struct sk_buff *skb,
                                   u32 ch_sw_tm_ie)
{
        struct ieee80211_sta *sta;
        struct iwl_mvm_sta *mvmsta;
        struct ieee80211_tx_info *info;
        struct ieee80211_hdr *hdr;
        struct iwl_tdls_channel_switch_cmd cmd = {0};
        int ret;

        lockdep_assert_held(&mvm->mutex);

        ret = iwl_mvm_tdls_check_action(mvm, type, peer, peer_initiator,
                                        timestamp);
        if (ret)
                return ret;

        if (!skb || WARN_ON(skb->len > IWL_TDLS_CH_SW_FRAME_MAX_SIZE)) {
                ret = -EINVAL;
                goto out;
        }

        cmd.switch_type = type;
        cmd.timing.frame_timestamp = cpu_to_le32(timestamp);
        cmd.timing.switch_time = cpu_to_le32(switch_time);
        cmd.timing.switch_timeout = cpu_to_le32(switch_timeout);

        rcu_read_lock();
        sta = ieee80211_find_sta(vif, peer);
        if (!sta) {
                rcu_read_unlock();
                ret = -ENOENT;
                goto out;
        }
        mvmsta = iwl_mvm_sta_from_mac80211(sta);
        cmd.peer_sta_id = cpu_to_le32(mvmsta->sta_id);

        if (!chandef) {
                if (mvm->tdls_cs.state == IWL_MVM_TDLS_SW_REQ_SENT &&
                    mvm->tdls_cs.peer.chandef.chan) {
                        /* actually moving to the channel */
                        chandef = &mvm->tdls_cs.peer.chandef;
                } else if (mvm->tdls_cs.state == IWL_MVM_TDLS_SW_ACTIVE &&
                           type == TDLS_MOVE_CH) {
                        /* we need to return to base channel */
                        struct ieee80211_chanctx_conf *chanctx =
                                        rcu_dereference(vif->chanctx_conf);

                        if (WARN_ON_ONCE(!chanctx)) {
                                rcu_read_unlock();
                                goto out;
                        }

                        chandef = &chanctx->def;
                }
        }

        if (chandef) {
                cmd.ci.band = (chandef->chan->band == IEEE80211_BAND_2GHZ ?
                               PHY_BAND_24 : PHY_BAND_5);
                cmd.ci.channel = chandef->chan->hw_value;
                cmd.ci.width = iwl_mvm_get_channel_width(chandef);
                cmd.ci.ctrl_pos = iwl_mvm_get_ctrl_pos(chandef);
        }

        /* keep quota calculation simple for now - 50% of DTIM for TDLS */
        cmd.timing.max_offchan_duration =
                        cpu_to_le32(TU_TO_US(vif->bss_conf.dtim_period *
                                             vif->bss_conf.beacon_int) / 2);

        /* Switch time is the first element in the switch-timing IE. */
        cmd.frame.switch_time_offset = cpu_to_le32(ch_sw_tm_ie + 2);

        info = IEEE80211_SKB_CB(skb);
        hdr = (void *)skb->data;
        if (info->control.hw_key) {
                if (info->control.hw_key->cipher != WLAN_CIPHER_SUITE_CCMP) {
                        rcu_read_unlock();
                        ret = -EINVAL;
                        goto out;
                }
                iwl_mvm_set_tx_cmd_ccmp(info, &cmd.frame.tx_cmd);
        }

        iwl_mvm_set_tx_cmd(mvm, skb, &cmd.frame.tx_cmd, info,
                           mvmsta->sta_id);

        iwl_mvm_set_tx_cmd_rate(mvm, &cmd.frame.tx_cmd, info, sta,
                                hdr->frame_control);
        rcu_read_unlock();

        memcpy(cmd.frame.data, skb->data, skb->len);

        ret = iwl_mvm_send_cmd_pdu(mvm, TDLS_CHANNEL_SWITCH_CMD, 0,
                                   sizeof(cmd), &cmd);
        if (ret) {
                IWL_ERR(mvm, "Failed to send TDLS_CHANNEL_SWITCH cmd: %d\n",
                        ret);
                goto out;
        }

        /* channel switch has started, update state */
        if (type != TDLS_MOVE_CH) {
                mvm->tdls_cs.cur_sta_id = mvmsta->sta_id;
                iwl_mvm_tdls_update_cs_state(mvm,
                                             type == TDLS_SEND_CHAN_SW_REQ ?
                                             IWL_MVM_TDLS_SW_REQ_SENT :
                                             IWL_MVM_TDLS_SW_REQ_RCVD);
        } else {
                iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_RESP_RCVD);
        }

out:

        /* channel switch failed - we are idle */
        if (ret)
                iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_IDLE);

        return ret;
}

void iwl_mvm_tdls_ch_switch_work(struct work_struct *work)
{
        struct iwl_mvm *mvm;
        struct ieee80211_sta *sta;
        struct iwl_mvm_sta *mvmsta;
        struct ieee80211_vif *vif;
        unsigned int delay;
        int ret;

        mvm = container_of(work, struct iwl_mvm, tdls_cs.dwork.work);
        mutex_lock(&mvm->mutex);

        /* called after an active channel switch has finished or timed-out */
        iwl_mvm_tdls_update_cs_state(mvm, IWL_MVM_TDLS_SW_IDLE);

        /* station might be gone, in that case do nothing */
        if (mvm->tdls_cs.peer.sta_id == IWL_MVM_STATION_COUNT)
                goto out;

        sta = rcu_dereference_protected(
                                mvm->fw_id_to_mac_id[mvm->tdls_cs.peer.sta_id],
                                lockdep_is_held(&mvm->mutex));
        /* the station may not be here, but if it is, it must be a TDLS peer */
        if (!sta || IS_ERR(sta) || WARN_ON(!sta->tdls))
                goto out;

        mvmsta = iwl_mvm_sta_from_mac80211(sta);
        vif = mvmsta->vif;
        ret = iwl_mvm_tdls_config_channel_switch(mvm, vif,
                                                 TDLS_SEND_CHAN_SW_REQ,
                                                 sta->addr,
                                                 mvm->tdls_cs.peer.initiator,
                                                 mvm->tdls_cs.peer.op_class,
                                                 &mvm->tdls_cs.peer.chandef,
                                                 0, 0, 0,
                                                 mvm->tdls_cs.peer.skb,
                                                 mvm->tdls_cs.peer.ch_sw_tm_ie);
        if (ret)
                IWL_ERR(mvm, "Not sending TDLS channel switch: %d\n", ret);

        /* retry after a DTIM if we failed sending now */
        delay = TU_TO_MS(vif->bss_conf.dtim_period * vif->bss_conf.beacon_int);
        queue_delayed_work(system_wq, &mvm->tdls_cs.dwork,
                           msecs_to_jiffies(delay));
out:
        mutex_unlock(&mvm->mutex);
}

int
iwl_mvm_tdls_channel_switch(struct ieee80211_hw *hw,
                            struct ieee80211_vif *vif,
                            struct ieee80211_sta *sta, u8 oper_class,
                            struct cfg80211_chan_def *chandef,
                            struct sk_buff *tmpl_skb, u32 ch_sw_tm_ie)
{
        struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
        struct iwl_mvm_sta *mvmsta;
        unsigned int delay;
        int ret;

        mutex_lock(&mvm->mutex);

        IWL_DEBUG_TDLS(mvm, "TDLS channel switch with %pM ch %d width %d\n",
                       sta->addr, chandef->chan->center_freq, chandef->width);

        /* we only support a single peer for channel switching */
        if (mvm->tdls_cs.peer.sta_id != IWL_MVM_STATION_COUNT) {
                IWL_DEBUG_TDLS(mvm,
                               "Existing peer. Can't start switch with %pM\n",
                               sta->addr);
                ret = -EBUSY;
                goto out;
        }

        ret = iwl_mvm_tdls_config_channel_switch(mvm, vif,
                                                 TDLS_SEND_CHAN_SW_REQ,
                                                 sta->addr, sta->tdls_initiator,
                                                 oper_class, chandef, 0, 0, 0,
                                                 tmpl_skb, ch_sw_tm_ie);
        if (ret)
                goto out;

        /*
         * Mark the peer as "in tdls switch" for this vif. We only allow a
         * single such peer per vif.
         */
        mvm->tdls_cs.peer.skb = skb_copy(tmpl_skb, GFP_KERNEL);
        if (!mvm->tdls_cs.peer.skb) {
                ret = -ENOMEM;
                goto out;
        }

        mvmsta = iwl_mvm_sta_from_mac80211(sta);
        mvm->tdls_cs.peer.sta_id = mvmsta->sta_id;
        mvm->tdls_cs.peer.chandef = *chandef;
        mvm->tdls_cs.peer.initiator = sta->tdls_initiator;
        mvm->tdls_cs.peer.op_class = oper_class;
        mvm->tdls_cs.peer.ch_sw_tm_ie = ch_sw_tm_ie;

        /*
         * Wait for 2 DTIM periods before attempting the next switch. The next
         * switch will be made sooner if the current one completes before that.
         */
        delay = 2 * TU_TO_MS(vif->bss_conf.dtim_period *
                             vif->bss_conf.beacon_int);
        mod_delayed_work(system_wq, &mvm->tdls_cs.dwork,
                         msecs_to_jiffies(delay));

out:
        mutex_unlock(&mvm->mutex);
        return ret;
}

void iwl_mvm_tdls_cancel_channel_switch(struct ieee80211_hw *hw,
                                        struct ieee80211_vif *vif,
                                        struct ieee80211_sta *sta)
{
        struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
        struct ieee80211_sta *cur_sta;
        bool wait_for_phy = false;

        mutex_lock(&mvm->mutex);

        IWL_DEBUG_TDLS(mvm, "TDLS cancel channel switch with %pM\n", sta->addr);

        /* we only support a single peer for channel switching */
        if (mvm->tdls_cs.peer.sta_id == IWL_MVM_STATION_COUNT) {
                IWL_DEBUG_TDLS(mvm, "No ch switch peer - %pM\n", sta->addr);
                goto out;
        }

        cur_sta = rcu_dereference_protected(
                                mvm->fw_id_to_mac_id[mvm->tdls_cs.peer.sta_id],
                                lockdep_is_held(&mvm->mutex));
        /* make sure it's the same peer */
        if (cur_sta != sta)
                goto out;

        /*
         * If we're currently in a switch because of the now canceled peer,
         * wait a DTIM here to make sure the phy is back on the base channel.
         * We can't otherwise force it.
         */
        if (mvm->tdls_cs.cur_sta_id == mvm->tdls_cs.peer.sta_id &&
            mvm->tdls_cs.state != IWL_MVM_TDLS_SW_IDLE)
                wait_for_phy = true;

        mvm->tdls_cs.peer.sta_id = IWL_MVM_STATION_COUNT;
        dev_kfree_skb(mvm->tdls_cs.peer.skb);
        mvm->tdls_cs.peer.skb = NULL;

out:
        mutex_unlock(&mvm->mutex);

        /* make sure the phy is on the base channel */
        if (wait_for_phy)
                msleep(TU_TO_MS(vif->bss_conf.dtim_period *
                                vif->bss_conf.beacon_int));

        /* flush the channel switch state */
        flush_delayed_work(&mvm->tdls_cs.dwork);

        IWL_DEBUG_TDLS(mvm, "TDLS ending channel switch with %pM\n", sta->addr);
}

void
iwl_mvm_tdls_recv_channel_switch(struct ieee80211_hw *hw,
                                 struct ieee80211_vif *vif,
                                 struct ieee80211_tdls_ch_sw_params *params)
{
        struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
        enum iwl_tdls_channel_switch_type type;
        unsigned int delay;
        const char *action_str =
                params->action_code == WLAN_TDLS_CHANNEL_SWITCH_REQUEST ?
                "REQ" : "RESP";

        mutex_lock(&mvm->mutex);

        IWL_DEBUG_TDLS(mvm,
                       "Received TDLS ch switch action %s from %pM status %d\n",
                       action_str, params->sta->addr, params->status);

        /*
         * we got a non-zero status from a peer we were switching to - move to
         * the idle state and retry again later
         */
        if (params->action_code == WLAN_TDLS_CHANNEL_SWITCH_RESPONSE &&
            params->status != 0 &&
            mvm->tdls_cs.state == IWL_MVM_TDLS_SW_REQ_SENT &&
            mvm->tdls_cs.cur_sta_id != IWL_MVM_STATION_COUNT) {
                struct ieee80211_sta *cur_sta;

                /* make sure it's the same peer */
                cur_sta = rcu_dereference_protected(
                                mvm->fw_id_to_mac_id[mvm->tdls_cs.cur_sta_id],
                                lockdep_is_held(&mvm->mutex));
                if (cur_sta == params->sta) {
                        iwl_mvm_tdls_update_cs_state(mvm,
                                                     IWL_MVM_TDLS_SW_IDLE);
                        goto retry;
                }
        }

        type = (params->action_code == WLAN_TDLS_CHANNEL_SWITCH_REQUEST) ?
               TDLS_SEND_CHAN_SW_RESP_AND_MOVE_CH : TDLS_MOVE_CH;

        iwl_mvm_tdls_config_channel_switch(mvm, vif, type, params->sta->addr,
                                           params->sta->tdls_initiator, 0,
                                           params->chandef, params->timestamp,
                                           params->switch_time,
                                           params->switch_timeout,
                                           params->tmpl_skb,
                                           params->ch_sw_tm_ie);

retry:
        /* register a timeout in case we don't succeed in switching */
        delay = vif->bss_conf.dtim_period * vif->bss_conf.beacon_int *
                1024 / 1000;
        mod_delayed_work(system_wq, &mvm->tdls_cs.dwork,
                         msecs_to_jiffies(delay));
        mutex_unlock(&mvm->mutex);
}