/******************************************************************************
 *
 * Copyright(c) 2003 - 2010 Intel Corporation. All rights reserved.
 *
 * Portions of this file are derived from the ipw3945 project, as well
 * as portions of the ieee80211 subsystem header files.
 *
 * 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 LICENSE.
 *
 * Contact Information:
 *  Intel Linux Wireless <ilw@linux.intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 *****************************************************************************/

#include <net/mac80211.h>
#include <linux/etherdevice.h>
#include <linux/sched.h>
#include <linux/lockdep.h>

#include "iwl-dev.h"
#include "iwl-core.h"
#include "iwl-sta.h"

/* priv->sta_lock must be held */
static void iwl_sta_ucode_activate(struct iwl_priv *priv, u8 sta_id)
{

        if (!(priv->stations[sta_id].used & IWL_STA_DRIVER_ACTIVE))
                IWL_ERR(priv, "ACTIVATE a non DRIVER active station id %u addr %pM\n",
                        sta_id, priv->stations[sta_id].sta.sta.addr);

        if (priv->stations[sta_id].used & IWL_STA_UCODE_ACTIVE) {
                IWL_DEBUG_ASSOC(priv,
                                "STA id %u addr %pM already present in uCode (according to driver)\n",
                                sta_id, priv->stations[sta_id].sta.sta.addr);
        } else {
                priv->stations[sta_id].used |= IWL_STA_UCODE_ACTIVE;
                IWL_DEBUG_ASSOC(priv, "Added STA id %u addr %pM to uCode\n",
                                sta_id, priv->stations[sta_id].sta.sta.addr);
        }
}

static int iwl_process_add_sta_resp(struct iwl_priv *priv,
                                    struct iwl_addsta_cmd *addsta,
                                    struct iwl_rx_packet *pkt,
                                    bool sync)
{
        u8 sta_id = addsta->sta.sta_id;
        unsigned long flags;
        int ret = -EIO;

        if (pkt->hdr.flags & IWL_CMD_FAILED_MSK) {
                IWL_ERR(priv, "Bad return from REPLY_ADD_STA (0x%08X)\n",
                        pkt->hdr.flags);
                return ret;
        }

        IWL_DEBUG_INFO(priv, "Processing response for adding station %u\n",
                       sta_id);

        spin_lock_irqsave(&priv->sta_lock, flags);

        switch (pkt->u.add_sta.status) {
        case ADD_STA_SUCCESS_MSK:
                IWL_DEBUG_INFO(priv, "REPLY_ADD_STA PASSED\n");
                iwl_sta_ucode_activate(priv, sta_id);
                ret = 0;
                break;
        case ADD_STA_NO_ROOM_IN_TABLE:
                IWL_ERR(priv, "Adding station %d failed, no room in table.\n",
                        sta_id);
                break;
        case ADD_STA_NO_BLOCK_ACK_RESOURCE:
                IWL_ERR(priv, "Adding station %d failed, no block ack resource.\n",
                        sta_id);
                break;
        case ADD_STA_MODIFY_NON_EXIST_STA:
                IWL_ERR(priv, "Attempting to modify non-existing station %d\n",
                        sta_id);
                break;
        default:
                IWL_DEBUG_ASSOC(priv, "Received REPLY_ADD_STA:(0x%08X)\n",
                                pkt->u.add_sta.status);
                break;
        }

        IWL_DEBUG_INFO(priv, "%s station id %u addr %pM\n",
                       priv->stations[sta_id].sta.mode ==
                       STA_CONTROL_MODIFY_MSK ?  "Modified" : "Added",
                       sta_id, priv->stations[sta_id].sta.sta.addr);

        /*
         * XXX: The MAC address in the command buffer is often changed from
         * the original sent to the device. That is, the MAC address
         * written to the command buffer often is not the same MAC address
         * read from the command buffer when the command returns. This
         * issue has not yet been resolved and this debugging is left to
         * observe the problem.
         */
        IWL_DEBUG_INFO(priv, "%s station according to cmd buffer %pM\n",
                       priv->stations[sta_id].sta.mode ==
                       STA_CONTROL_MODIFY_MSK ? "Modified" : "Added",
                       addsta->sta.addr);
        spin_unlock_irqrestore(&priv->sta_lock, flags);

        return ret;
}

static void iwl_add_sta_callback(struct iwl_priv *priv,
                                 struct iwl_device_cmd *cmd,
                                 struct iwl_rx_packet *pkt)
{
        struct iwl_addsta_cmd *addsta =
                (struct iwl_addsta_cmd *)cmd->cmd.payload;

        iwl_process_add_sta_resp(priv, addsta, pkt, false);

}

int iwl_send_add_sta(struct iwl_priv *priv,
                     struct iwl_addsta_cmd *sta, u8 flags)
{
        struct iwl_rx_packet *pkt = NULL;
        int ret = 0;
        u8 data[sizeof(*sta)];
        struct iwl_host_cmd cmd = {
                .id = REPLY_ADD_STA,
                .flags = flags,
                .data = data,
        };
        u8 sta_id __maybe_unused = sta->sta.sta_id;

        IWL_DEBUG_INFO(priv, "Adding sta %u (%pM) %ssynchronously\n",
                       sta_id, sta->sta.addr, flags & CMD_ASYNC ?  "a" : "");

        if (flags & CMD_ASYNC)
                cmd.callback = iwl_add_sta_callback;
        else {
                cmd.flags |= CMD_WANT_SKB;
                might_sleep();
        }

        cmd.len = priv->cfg->ops->utils->build_addsta_hcmd(sta, data);
        ret = iwl_send_cmd(priv, &cmd);

        if (ret || (flags & CMD_ASYNC))
                return ret;

        if (ret == 0) {
                pkt = (struct iwl_rx_packet *)cmd.reply_page;
                ret = iwl_process_add_sta_resp(priv, sta, pkt, true);
        }
        iwl_free_pages(priv, cmd.reply_page);

        return ret;
}
EXPORT_SYMBOL(iwl_send_add_sta);

static void iwl_set_ht_add_station(struct iwl_priv *priv, u8 index,
                                   struct ieee80211_sta *sta,
                                   struct iwl_rxon_context *ctx)
{
        struct ieee80211_sta_ht_cap *sta_ht_inf = &sta->ht_cap;
        __le32 sta_flags;
        u8 mimo_ps_mode;

        if (!sta || !sta_ht_inf->ht_supported)
                goto done;

        mimo_ps_mode = (sta_ht_inf->cap & IEEE80211_HT_CAP_SM_PS) >> 2;
        IWL_DEBUG_ASSOC(priv, "spatial multiplexing power save mode: %s\n",
                        (mimo_ps_mode == WLAN_HT_CAP_SM_PS_STATIC) ?
                        "static" :
                        (mimo_ps_mode == WLAN_HT_CAP_SM_PS_DYNAMIC) ?
                        "dynamic" : "disabled");

        sta_flags = priv->stations[index].sta.station_flags;

        sta_flags &= ~(STA_FLG_RTS_MIMO_PROT_MSK | STA_FLG_MIMO_DIS_MSK);

        switch (mimo_ps_mode) {
        case WLAN_HT_CAP_SM_PS_STATIC:
                sta_flags |= STA_FLG_MIMO_DIS_MSK;
                break;
        case WLAN_HT_CAP_SM_PS_DYNAMIC:
                sta_flags |= STA_FLG_RTS_MIMO_PROT_MSK;
                break;
        case WLAN_HT_CAP_SM_PS_DISABLED:
                break;
        default:
                IWL_WARN(priv, "Invalid MIMO PS mode %d\n", mimo_ps_mode);
                break;
        }

        sta_flags |= cpu_to_le32(
              (u32)sta_ht_inf->ampdu_factor << STA_FLG_MAX_AGG_SIZE_POS);

        sta_flags |= cpu_to_le32(
              (u32)sta_ht_inf->ampdu_density << STA_FLG_AGG_MPDU_DENSITY_POS);

        if (iwl_is_ht40_tx_allowed(priv, ctx, &sta->ht_cap))
                sta_flags |= STA_FLG_HT40_EN_MSK;
        else
                sta_flags &= ~STA_FLG_HT40_EN_MSK;

        priv->stations[index].sta.station_flags = sta_flags;
 done:
        return;
}

/**
 * iwl_prep_station - Prepare station information for addition
 *
 * should be called with sta_lock held
 */
u8 iwl_prep_station(struct iwl_priv *priv, struct iwl_rxon_context *ctx,
                    const u8 *addr, bool is_ap, struct ieee80211_sta *sta)
{
        struct iwl_station_entry *station;
        int i;
        u8 sta_id = IWL_INVALID_STATION;
        u16 rate;

        if (is_ap)
                sta_id = ctx->ap_sta_id;
        else if (is_broadcast_ether_addr(addr))
                sta_id = ctx->bcast_sta_id;
        else
                for (i = IWL_STA_ID; i < priv->hw_params.max_stations; i++) {
                        if (!compare_ether_addr(priv->stations[i].sta.sta.addr,
                                                addr)) {
                                sta_id = i;
                                break;
                        }

                        if (!priv->stations[i].used &&
                            sta_id == IWL_INVALID_STATION)
                                sta_id = i;
                }

        /*
         * These two conditions have the same outcome, but keep them
         * separate
         */
        if (unlikely(sta_id == IWL_INVALID_STATION))
                return sta_id;

        /*
         * uCode is not able to deal with multiple requests to add a
         * station. Keep track if one is in progress so that we do not send
         * another.
         */
        if (priv->stations[sta_id].used & IWL_STA_UCODE_INPROGRESS) {
                IWL_DEBUG_INFO(priv, "STA %d already in process of being added.\n",
                                sta_id);
                return sta_id;
        }

        if ((priv->stations[sta_id].used & IWL_STA_DRIVER_ACTIVE) &&
            (priv->stations[sta_id].used & IWL_STA_UCODE_ACTIVE) &&
            !compare_ether_addr(priv->stations[sta_id].sta.sta.addr, addr)) {
                IWL_DEBUG_ASSOC(priv, "STA %d (%pM) already added, not adding again.\n",
                                sta_id, addr);
                return sta_id;
        }

        station = &priv->stations[sta_id];
        station->used = IWL_STA_DRIVER_ACTIVE;
        IWL_DEBUG_ASSOC(priv, "Add STA to driver ID %d: %pM\n",
                        sta_id, addr);
        priv->num_stations++;

        /* Set up the REPLY_ADD_STA command to send to device */
        memset(&station->sta, 0, sizeof(struct iwl_addsta_cmd));
        memcpy(station->sta.sta.addr, addr, ETH_ALEN);
        station->sta.mode = 0;
        station->sta.sta.sta_id = sta_id;
        station->sta.station_flags = ctx->station_flags;
        station->ctxid = ctx->ctxid;

        if (sta) {
                struct iwl_station_priv_common *sta_priv;

                sta_priv = (void *)sta->drv_priv;
                sta_priv->ctx = ctx;
        }

        /*
         * OK to call unconditionally, since local stations (IBSS BSSID
         * STA and broadcast STA) pass in a NULL sta, and mac80211
         * doesn't allow HT IBSS.
         */
        iwl_set_ht_add_station(priv, sta_id, sta, ctx);

        /* 3945 only */
        rate = (priv->band == IEEE80211_BAND_5GHZ) ?
                IWL_RATE_6M_PLCP : IWL_RATE_1M_PLCP;
        /* Turn on both antennas for the station... */
        station->sta.rate_n_flags = cpu_to_le16(rate | RATE_MCS_ANT_AB_MSK);

        return sta_id;

}
EXPORT_SYMBOL_GPL(iwl_prep_station);

#define STA_WAIT_TIMEOUT (HZ/2)

/**
 * iwl_add_station_common -
 */
int iwl_add_station_common(struct iwl_priv *priv, struct iwl_rxon_context *ctx,
                           const u8 *addr, bool is_ap,
                           struct ieee80211_sta *sta, u8 *sta_id_r)
{
        unsigned long flags_spin;
        int ret = 0;
        u8 sta_id;
        struct iwl_addsta_cmd sta_cmd;

        *sta_id_r = 0;
        spin_lock_irqsave(&priv->sta_lock, flags_spin);
        sta_id = iwl_prep_station(priv, ctx, addr, is_ap, sta);
        if (sta_id == IWL_INVALID_STATION) {
                IWL_ERR(priv, "Unable to prepare station %pM for addition\n",
                        addr);
                spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
                return -EINVAL;
        }

        /*
         * uCode is not able to deal with multiple requests to add a
         * station. Keep track if one is in progress so that we do not send
         * another.
         */
        if (priv->stations[sta_id].used & IWL_STA_UCODE_INPROGRESS) {
                IWL_DEBUG_INFO(priv, "STA %d already in process of being added.\n",
                               sta_id);
                spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
                return -EEXIST;
        }

        if ((priv->stations[sta_id].used & IWL_STA_DRIVER_ACTIVE) &&
            (priv->stations[sta_id].used & IWL_STA_UCODE_ACTIVE)) {
                IWL_DEBUG_ASSOC(priv, "STA %d (%pM) already added, not adding again.\n",
                                sta_id, addr);
                spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
                return -EEXIST;
        }

        priv->stations[sta_id].used |= IWL_STA_UCODE_INPROGRESS;
        memcpy(&sta_cmd, &priv->stations[sta_id].sta, sizeof(struct iwl_addsta_cmd));
        spin_unlock_irqrestore(&priv->sta_lock, flags_spin);

        /* Add station to device's station table */
        ret = iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
        if (ret) {
                spin_lock_irqsave(&priv->sta_lock, flags_spin);
                IWL_ERR(priv, "Adding station %pM failed.\n",
                        priv->stations[sta_id].sta.sta.addr);
                priv->stations[sta_id].used &= ~IWL_STA_DRIVER_ACTIVE;
                priv->stations[sta_id].used &= ~IWL_STA_UCODE_INPROGRESS;
                spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
        }
        *sta_id_r = sta_id;
        return ret;
}
EXPORT_SYMBOL(iwl_add_station_common);

/**
 * iwl_sta_ucode_deactivate - deactivate ucode status for a station
 *
 * priv->sta_lock must be held
 */
static void iwl_sta_ucode_deactivate(struct iwl_priv *priv, u8 sta_id)
{
        /* Ucode must be active and driver must be non active */
        if ((priv->stations[sta_id].used &
             (IWL_STA_UCODE_ACTIVE | IWL_STA_DRIVER_ACTIVE)) != IWL_STA_UCODE_ACTIVE)
                IWL_ERR(priv, "removed non active STA %u\n", sta_id);

        priv->stations[sta_id].used &= ~IWL_STA_UCODE_ACTIVE;

        memset(&priv->stations[sta_id], 0, sizeof(struct iwl_station_entry));
        IWL_DEBUG_ASSOC(priv, "Removed STA %u\n", sta_id);
}

static int iwl_send_remove_station(struct iwl_priv *priv,
                                   const u8 *addr, int sta_id,
                                   bool temporary)
{
        struct iwl_rx_packet *pkt;
        int ret;

        unsigned long flags_spin;
        struct iwl_rem_sta_cmd rm_sta_cmd;

        struct iwl_host_cmd cmd = {
                .id = REPLY_REMOVE_STA,
                .len = sizeof(struct iwl_rem_sta_cmd),
                .flags = CMD_SYNC,
                .data = &rm_sta_cmd,
        };

        memset(&rm_sta_cmd, 0, sizeof(rm_sta_cmd));
        rm_sta_cmd.num_sta = 1;
        memcpy(&rm_sta_cmd.addr, addr, ETH_ALEN);

        cmd.flags |= CMD_WANT_SKB;

        ret = iwl_send_cmd(priv, &cmd);

        if (ret)
                return ret;

        pkt = (struct iwl_rx_packet *)cmd.reply_page;
        if (pkt->hdr.flags & IWL_CMD_FAILED_MSK) {
                IWL_ERR(priv, "Bad return from REPLY_REMOVE_STA (0x%08X)\n",
                          pkt->hdr.flags);
                ret = -EIO;
        }

        if (!ret) {
                switch (pkt->u.rem_sta.status) {
                case REM_STA_SUCCESS_MSK:
                        if (!temporary) {
                                spin_lock_irqsave(&priv->sta_lock, flags_spin);
                                iwl_sta_ucode_deactivate(priv, sta_id);
                                spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
                        }
                        IWL_DEBUG_ASSOC(priv, "REPLY_REMOVE_STA PASSED\n");
                        break;
                default:
                        ret = -EIO;
                        IWL_ERR(priv, "REPLY_REMOVE_STA failed\n");
                        break;
                }
        }
        iwl_free_pages(priv, cmd.reply_page);

        return ret;
}

/**
 * iwl_remove_station - Remove driver's knowledge of station.
 */
int iwl_remove_station(struct iwl_priv *priv, const u8 sta_id,
                       const u8 *addr)
{
        unsigned long flags;

        if (!iwl_is_ready(priv)) {
                IWL_DEBUG_INFO(priv,
                        "Unable to remove station %pM, device not ready.\n",
                        addr);
                /*
                 * It is typical for stations to be removed when we are
                 * going down. Return success since device will be down
                 * soon anyway
                 */
                return 0;
        }

        IWL_DEBUG_ASSOC(priv, "Removing STA from driver:%d  %pM\n",
                        sta_id, addr);

        if (WARN_ON(sta_id == IWL_INVALID_STATION))
                return -EINVAL;

        spin_lock_irqsave(&priv->sta_lock, flags);

        if (!(priv->stations[sta_id].used & IWL_STA_DRIVER_ACTIVE)) {
                IWL_DEBUG_INFO(priv, "Removing %pM but non DRIVER active\n",
                                addr);
                goto out_err;
        }

        if (!(priv->stations[sta_id].used & IWL_STA_UCODE_ACTIVE)) {
                IWL_DEBUG_INFO(priv, "Removing %pM but non UCODE active\n",
                                addr);
                goto out_err;
        }

        if (priv->stations[sta_id].used & IWL_STA_LOCAL) {
                kfree(priv->stations[sta_id].lq);
                priv->stations[sta_id].lq = NULL;
        }

        priv->stations[sta_id].used &= ~IWL_STA_DRIVER_ACTIVE;

        priv->num_stations--;

        BUG_ON(priv->num_stations < 0);

        spin_unlock_irqrestore(&priv->sta_lock, flags);

        return iwl_send_remove_station(priv, addr, sta_id, false);
out_err:
        spin_unlock_irqrestore(&priv->sta_lock, flags);
        return -EINVAL;
}
EXPORT_SYMBOL_GPL(iwl_remove_station);

/**
 * iwl_clear_ucode_stations - clear ucode station table bits
 *
 * This function clears all the bits in the driver indicating
 * which stations are active in the ucode. Call when something
 * other than explicit station management would cause this in
 * the ucode, e.g. unassociated RXON.
 */
void iwl_clear_ucode_stations(struct iwl_priv *priv,
                              struct iwl_rxon_context *ctx)
{
        int i;
        unsigned long flags_spin;
        bool cleared = false;

        IWL_DEBUG_INFO(priv, "Clearing ucode stations in driver\n");

        spin_lock_irqsave(&priv->sta_lock, flags_spin);
        for (i = 0; i < priv->hw_params.max_stations; i++) {
                if (ctx && ctx->ctxid != priv->stations[i].ctxid)
                        continue;

                if (priv->stations[i].used & IWL_STA_UCODE_ACTIVE) {
                        IWL_DEBUG_INFO(priv, "Clearing ucode active for station %d\n", i);
                        priv->stations[i].used &= ~IWL_STA_UCODE_ACTIVE;
                        cleared = true;
                }
        }
        spin_unlock_irqrestore(&priv->sta_lock, flags_spin);

        if (!cleared)
                IWL_DEBUG_INFO(priv, "No active stations found to be cleared\n");
}
EXPORT_SYMBOL(iwl_clear_ucode_stations);

/**
 * iwl_restore_stations() - Restore driver known stations to device
 *
 * All stations considered active by driver, but not present in ucode, is
 * restored.
 *
 * Function sleeps.
 */
void iwl_restore_stations(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
{
        struct iwl_addsta_cmd sta_cmd;
        struct iwl_link_quality_cmd lq;
        unsigned long flags_spin;
        int i;
        bool found = false;
        int ret;
        bool send_lq;

        if (!iwl_is_ready(priv)) {
                IWL_DEBUG_INFO(priv, "Not ready yet, not restoring any stations.\n");
                return;
        }

        IWL_DEBUG_ASSOC(priv, "Restoring all known stations ... start.\n");
        spin_lock_irqsave(&priv->sta_lock, flags_spin);
        for (i = 0; i < priv->hw_params.max_stations; i++) {
                if (ctx->ctxid != priv->stations[i].ctxid)
                        continue;
                if ((priv->stations[i].used & IWL_STA_DRIVER_ACTIVE) &&
                            !(priv->stations[i].used & IWL_STA_UCODE_ACTIVE)) {
                        IWL_DEBUG_ASSOC(priv, "Restoring sta %pM\n",
                                        priv->stations[i].sta.sta.addr);
                        priv->stations[i].sta.mode = 0;
                        priv->stations[i].used |= IWL_STA_UCODE_INPROGRESS;
                        found = true;
                }
        }

        for (i = 0; i < priv->hw_params.max_stations; i++) {
                if ((priv->stations[i].used & IWL_STA_UCODE_INPROGRESS)) {
                        memcpy(&sta_cmd, &priv->stations[i].sta,
                               sizeof(struct iwl_addsta_cmd));
                        send_lq = false;
                        if (priv->stations[i].lq) {
                                memcpy(&lq, priv->stations[i].lq,
                                       sizeof(struct iwl_link_quality_cmd));
                                send_lq = true;
                        }
                        spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
                        ret = iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
                        if (ret) {
                                spin_lock_irqsave(&priv->sta_lock, flags_spin);
                                IWL_ERR(priv, "Adding station %pM failed.\n",
                                        priv->stations[i].sta.sta.addr);
                                priv->stations[i].used &= ~IWL_STA_DRIVER_ACTIVE;
                                priv->stations[i].used &= ~IWL_STA_UCODE_INPROGRESS;
                                spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
                        }
                        /*
                         * Rate scaling has already been initialized, send
                         * current LQ command
                         */
                        if (send_lq)
                                iwl_send_lq_cmd(priv, ctx, &lq, CMD_SYNC, true);
                        spin_lock_irqsave(&priv->sta_lock, flags_spin);
                        priv->stations[i].used &= ~IWL_STA_UCODE_INPROGRESS;
                }
        }

        spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
        if (!found)
                IWL_DEBUG_INFO(priv, "Restoring all known stations .... no stations to be restored.\n");
        else
                IWL_DEBUG_INFO(priv, "Restoring all known stations .... complete.\n");
}
EXPORT_SYMBOL(iwl_restore_stations);

void iwl_reprogram_ap_sta(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
{
        unsigned long flags;
        int sta_id = ctx->ap_sta_id;
        int ret;
        struct iwl_addsta_cmd sta_cmd;
        struct iwl_link_quality_cmd lq;
        bool active;

        spin_lock_irqsave(&priv->sta_lock, flags);
        if (!(priv->stations[sta_id].used & IWL_STA_DRIVER_ACTIVE)) {
                spin_unlock_irqrestore(&priv->sta_lock, flags);
                return;
        }

        memcpy(&sta_cmd, &priv->stations[sta_id].sta, sizeof(sta_cmd));
        sta_cmd.mode = 0;
        memcpy(&lq, priv->stations[sta_id].lq, sizeof(lq));

        active = priv->stations[sta_id].used & IWL_STA_UCODE_ACTIVE;
        priv->stations[sta_id].used &= ~IWL_STA_DRIVER_ACTIVE;
        spin_unlock_irqrestore(&priv->sta_lock, flags);

        if (active) {
                ret = iwl_send_remove_station(
                        priv, priv->stations[sta_id].sta.sta.addr,
                        sta_id, true);
                if (ret)
                        IWL_ERR(priv, "failed to remove STA %pM (%d)\n",
                                priv->stations[sta_id].sta.sta.addr, ret);
        }
        spin_lock_irqsave(&priv->sta_lock, flags);
        priv->stations[sta_id].used |= IWL_STA_DRIVER_ACTIVE;
        spin_unlock_irqrestore(&priv->sta_lock, flags);

        ret = iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
        if (ret)
                IWL_ERR(priv, "failed to re-add STA %pM (%d)\n",
                        priv->stations[sta_id].sta.sta.addr, ret);
        iwl_send_lq_cmd(priv, ctx, &lq, CMD_SYNC, true);
}
EXPORT_SYMBOL(iwl_reprogram_ap_sta);

int iwl_get_free_ucode_key_index(struct iwl_priv *priv)
{
        int i;

        for (i = 0; i < priv->sta_key_max_num; i++)
                if (!test_and_set_bit(i, &priv->ucode_key_table))
                        return i;

        return WEP_INVALID_OFFSET;
}
EXPORT_SYMBOL(iwl_get_free_ucode_key_index);

void iwl_dealloc_bcast_stations(struct iwl_priv *priv)
{
        unsigned long flags;
        int i;

        spin_lock_irqsave(&priv->sta_lock, flags);
        for (i = 0; i < priv->hw_params.max_stations; i++) {
                if (!(priv->stations[i].used & IWL_STA_BCAST))
                        continue;

                priv->stations[i].used &= ~IWL_STA_UCODE_ACTIVE;
                priv->num_stations--;
                BUG_ON(priv->num_stations < 0);
                kfree(priv->stations[i].lq);
                priv->stations[i].lq = NULL;
        }
        spin_unlock_irqrestore(&priv->sta_lock, flags);
}
EXPORT_SYMBOL_GPL(iwl_dealloc_bcast_stations);

#ifdef CONFIG_IWLWIFI_DEBUG
static void iwl_dump_lq_cmd(struct iwl_priv *priv,
                           struct iwl_link_quality_cmd *lq)
{
        int i;
        IWL_DEBUG_RATE(priv, "lq station id 0x%x\n", lq->sta_id);
        IWL_DEBUG_RATE(priv, "lq ant 0x%X 0x%X\n",
                       lq->general_params.single_stream_ant_msk,
                       lq->general_params.dual_stream_ant_msk);

        for (i = 0; i < LINK_QUAL_MAX_RETRY_NUM; i++)
                IWL_DEBUG_RATE(priv, "lq index %d 0x%X\n",
                               i, lq->rs_table[i].rate_n_flags);
}
#else
static inline void iwl_dump_lq_cmd(struct iwl_priv *priv,
                                   struct iwl_link_quality_cmd *lq)
{
}
#endif

/**
 * is_lq_table_valid() - Test one aspect of LQ cmd for validity
 *
 * It sometimes happens when a HT rate has been in use and we
 * loose connectivity with AP then mac80211 will first tell us that the
 * current channel is not HT anymore before removing the station. In such a
 * scenario the RXON flags will be updated to indicate we are not
 * communicating HT anymore, but the LQ command may still contain HT rates.
 * Test for this to prevent driver from sending LQ command between the time
 * RXON flags are updated and when LQ command is updated.
 */
static bool is_lq_table_valid(struct iwl_priv *priv,
                              struct iwl_rxon_context *ctx,
                              struct iwl_link_quality_cmd *lq)
{
        int i;

        if (ctx->ht.enabled)
                return true;

        IWL_DEBUG_INFO(priv, "Channel %u is not an HT channel\n",
                       ctx->active.channel);
        for (i = 0; i < LINK_QUAL_MAX_RETRY_NUM; i++) {
                if (le32_to_cpu(lq->rs_table[i].rate_n_flags) & RATE_MCS_HT_MSK) {
                        IWL_DEBUG_INFO(priv,
                                       "index %d of LQ expects HT channel\n",
                                       i);
                        return false;
                }
        }
        return true;
}

/**
 * iwl_send_lq_cmd() - Send link quality command
 * @init: This command is sent as part of station initialization right
 *        after station has been added.
 *
 * The link quality command is sent as the last step of station creation.
 * This is the special case in which init is set and we call a callback in
 * this case to clear the state indicating that station creation is in
 * progress.
 */
int iwl_send_lq_cmd(struct iwl_priv *priv, struct iwl_rxon_context *ctx,
                    struct iwl_link_quality_cmd *lq, u8 flags, bool init)
{
        int ret = 0;
        unsigned long flags_spin;

        struct iwl_host_cmd cmd = {
                .id = REPLY_TX_LINK_QUALITY_CMD,
                .len = sizeof(struct iwl_link_quality_cmd),
                .flags = flags,
                .data = lq,
        };

        if (WARN_ON(lq->sta_id == IWL_INVALID_STATION))
                return -EINVAL;


        spin_lock_irqsave(&priv->sta_lock, flags_spin);
        if (!(priv->stations[lq->sta_id].used & IWL_STA_DRIVER_ACTIVE)) {
                spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
                return -EINVAL;
        }
        spin_unlock_irqrestore(&priv->sta_lock, flags_spin);

        iwl_dump_lq_cmd(priv, lq);
        BUG_ON(init && (cmd.flags & CMD_ASYNC));

        if (is_lq_table_valid(priv, ctx, lq))
                ret = iwl_send_cmd(priv, &cmd);
        else
                ret = -EINVAL;

        if (cmd.flags & CMD_ASYNC)
                return ret;

        if (init) {
                IWL_DEBUG_INFO(priv, "init LQ command complete, clearing sta addition status for sta %d\n",
                               lq->sta_id);
                spin_lock_irqsave(&priv->sta_lock, flags_spin);
                priv->stations[lq->sta_id].used &= ~IWL_STA_UCODE_INPROGRESS;
                spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
        }
        return ret;
}
EXPORT_SYMBOL(iwl_send_lq_cmd);

int iwl_mac_sta_remove(struct ieee80211_hw *hw,
                       struct ieee80211_vif *vif,
                       struct ieee80211_sta *sta)
{
        struct iwl_priv *priv = hw->priv;
        struct iwl_station_priv_common *sta_common = (void *)sta->drv_priv;
        int ret;

        IWL_DEBUG_INFO(priv, "received request to remove station %pM\n",
                        sta->addr);
        mutex_lock(&priv->mutex);
        IWL_DEBUG_INFO(priv, "proceeding to remove station %pM\n",
                        sta->addr);
        ret = iwl_remove_station(priv, sta_common->sta_id, sta->addr);
        if (ret)
                IWL_ERR(priv, "Error removing station %pM\n",
                        sta->addr);
        mutex_unlock(&priv->mutex);
        return ret;
}
EXPORT_SYMBOL(iwl_mac_sta_remove);