sta.c

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/******************************************************************************
 *
 * Copyright(c) 2003 - 2012 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 <[email protected]>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 *****************************************************************************/
#include <linux/etherdevice.h>
#include <net/mac80211.h>
#include "iwl-trans.h"
#include "dev.h"
#include "agn.h"

const u8 iwl_bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };

static int iwl_sta_ucode_activate(struct iwl_priv *priv, u8 sta_id)
{
    lockdep_assert_held(&priv->sta_lock);

    if (sta_id >= IWLAGN_STATION_COUNT) {
        IWL_ERR(priv, "invalid sta_id %u", sta_id);
        return -EINVAL;
    }
    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);
    }
    return 0;
}

static int iwl_process_add_sta_resp(struct iwl_priv *priv,
                    struct iwl_addsta_cmd *addsta,
                    struct iwl_rx_packet *pkt)
{
    struct iwl_add_sta_resp *add_sta_resp = (void *)pkt->data;
    u8 sta_id = addsta->sta.sta_id;
    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(&priv->sta_lock);

    switch (add_sta_resp->status) {
    case ADD_STA_SUCCESS_MSK:
        IWL_DEBUG_INFO(priv, "REPLY_ADD_STA PASSED\n");
        ret = iwl_sta_ucode_activate(priv, sta_id);
        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",
                add_sta_resp->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(&priv->sta_lock);

    return ret;
}

int iwl_add_sta_callback(struct iwl_priv *priv, struct iwl_rx_cmd_buffer *rxb,
                   struct iwl_device_cmd *cmd)
{
    struct iwl_rx_packet *pkt = rxb_addr(rxb);

    if (!cmd)
        return 0;

    return iwl_process_add_sta_resp(priv, (void *)cmd->payload, pkt);
}

int iwl_send_add_sta(struct iwl_priv *priv,
             struct iwl_addsta_cmd *sta, u8 flags)
{
    int ret = 0;
    struct iwl_host_cmd cmd = {
        .id = REPLY_ADD_STA,
        .flags = flags,
        .data = { sta, },
        .len = { sizeof(*sta), },
    };
    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.flags |= CMD_WANT_SKB | CMD_WANT_HCMD;
        might_sleep();
    }

    ret = iwl_dvm_send_cmd(priv, &cmd);

    if (ret || (flags & CMD_ASYNC))
        return ret;
    /*else the command was successfully sent in SYNC mode, need to free
     * the reply page */

    iwl_free_resp(&cmd);

    if (cmd.handler_status)
        IWL_ERR(priv, "%s - error in the CMD response %d", __func__,
            cmd.handler_status);

    return cmd.handler_status;
}

bool iwl_is_ht40_tx_allowed(struct iwl_priv *priv,
                struct iwl_rxon_context *ctx,
                struct ieee80211_sta_ht_cap *ht_cap)
{
    if (!ctx->ht.enabled || !ctx->ht.is_40mhz)
        return false;

#ifdef CONFIG_IWLWIFI_DEBUGFS
    if (priv->disable_ht40)
        return false;
#endif

    /*
     * Remainder of this function checks ht_cap, but if it's
     * NULL then we can do HT40 (special case for RXON)
     */
    if (!ht_cap)
        return true;

    if (!ht_cap->ht_supported)
        return false;

    if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40))
        return false;

    return true;
}

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

    *mask = STA_FLG_RTS_MIMO_PROT_MSK |
        STA_FLG_MIMO_DIS_MSK |
        STA_FLG_HT40_EN_MSK |
        STA_FLG_MAX_AGG_SIZE_MSK |
        STA_FLG_AGG_MPDU_DENSITY_MSK;
    *flags = 0;

    if (!sta || !sta_ht_inf->ht_supported)
        return;

    mimo_ps_mode = (sta_ht_inf->cap & IEEE80211_HT_CAP_SM_PS) >> 2;

    IWL_DEBUG_INFO(priv, "STA %pM SM PS mode: %s\n",
            sta->addr,
            (mimo_ps_mode == WLAN_HT_CAP_SM_PS_STATIC) ?
            "static" :
            (mimo_ps_mode == WLAN_HT_CAP_SM_PS_DYNAMIC) ?
            "dynamic" : "disabled");

    switch (mimo_ps_mode) {
    case WLAN_HT_CAP_SM_PS_STATIC:
        *flags |= STA_FLG_MIMO_DIS_MSK;
        break;
    case WLAN_HT_CAP_SM_PS_DYNAMIC:
        *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;
    }

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

    *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))
        *flags |= STA_FLG_HT40_EN_MSK;
}

int iwl_sta_update_ht(struct iwl_priv *priv, struct iwl_rxon_context *ctx,
              struct ieee80211_sta *sta)
{
    u8 sta_id = iwl_sta_id(sta);
    __le32 flags, mask;
    struct iwl_addsta_cmd cmd;

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

    iwl_sta_calc_ht_flags(priv, sta, ctx, &flags, &mask);

    spin_lock_bh(&priv->sta_lock);
    priv->stations[sta_id].sta.station_flags &= ~mask;
    priv->stations[sta_id].sta.station_flags |= flags;
    spin_unlock_bh(&priv->sta_lock);

    memset(&cmd, 0, sizeof(cmd));
    cmd.mode = STA_CONTROL_MODIFY_MSK;
    cmd.station_flags_msk = mask;
    cmd.station_flags = flags;
    cmd.sta.sta_id = sta_id;

    return iwl_send_add_sta(priv, &cmd, CMD_SYNC);
}

static void iwl_set_ht_add_station(struct iwl_priv *priv, u8 index,
                   struct ieee80211_sta *sta,
                   struct iwl_rxon_context *ctx)
{
    __le32 flags, mask;

    iwl_sta_calc_ht_flags(priv, sta, ctx, &flags, &mask);

    lockdep_assert_held(&priv->sta_lock);
    priv->stations[index].sta.station_flags &= ~mask;
    priv->stations[index].sta.station_flags |= flags;
}

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;

    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 < IWLAGN_STATION_COUNT; i++) {
            if (ether_addr_equal(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) &&
        ether_addr_equal(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 *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);

    return sta_id;

}

#define STA_WAIT_TIMEOUT (HZ/2)

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)
{
    int ret = 0;
    u8 sta_id;
    struct iwl_addsta_cmd sta_cmd;

    *sta_id_r = 0;
    spin_lock_bh(&priv->sta_lock);
    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_bh(&priv->sta_lock);
        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_bh(&priv->sta_lock);
        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_bh(&priv->sta_lock);
        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_bh(&priv->sta_lock);

    /* Add station to device's station table */
    ret = iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
    if (ret) {
        spin_lock_bh(&priv->sta_lock);
        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_bh(&priv->sta_lock);
    }
    *sta_id_r = sta_id;
    return ret;
}

static void iwl_sta_ucode_deactivate(struct iwl_priv *priv, u8 sta_id)
{
    lockdep_assert_held(&priv->sta_lock);

    /* 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;
    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_dvm_send_cmd(priv, &cmd);

    if (ret)
        return ret;

    pkt = cmd.resp_pkt;
    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) {
        struct iwl_rem_sta_resp *rem_sta_resp = (void *)pkt->data;
        switch (rem_sta_resp->status) {
        case REM_STA_SUCCESS_MSK:
            if (!temporary) {
                spin_lock_bh(&priv->sta_lock);
                iwl_sta_ucode_deactivate(priv, sta_id);
                spin_unlock_bh(&priv->sta_lock);
            }
            IWL_DEBUG_ASSOC(priv, "REPLY_REMOVE_STA PASSED\n");
            break;
        default:
            ret = -EIO;
            IWL_ERR(priv, "REPLY_REMOVE_STA failed\n");
            break;
        }
    }
    iwl_free_resp(&cmd);

    return ret;
}

int iwl_remove_station(struct iwl_priv *priv, const u8 sta_id,
               const u8 *addr)
{
    u8 tid;

    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_bh(&priv->sta_lock);

    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;
    }

    for (tid = 0; tid < IWL_MAX_TID_COUNT; tid++)
        memset(&priv->tid_data[sta_id][tid], 0,
            sizeof(priv->tid_data[sta_id][tid]));

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

    priv->num_stations--;

    if (WARN_ON(priv->num_stations < 0))
        priv->num_stations = 0;

    spin_unlock_bh(&priv->sta_lock);

    return iwl_send_remove_station(priv, addr, sta_id, false);
out_err:
    spin_unlock_bh(&priv->sta_lock);
    return -EINVAL;
}

void iwl_deactivate_station(struct iwl_priv *priv, const u8 sta_id,
                const u8 *addr)
{
    u8 tid;

    if (!iwl_is_ready(priv)) {
        IWL_DEBUG_INFO(priv,
            "Unable to remove station %pM, device not ready.\n",
            addr);
        return;
    }

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

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

    spin_lock_bh(&priv->sta_lock);

    WARN_ON_ONCE(!(priv->stations[sta_id].used & IWL_STA_DRIVER_ACTIVE));

    for (tid = 0; tid < IWL_MAX_TID_COUNT; tid++)
        memset(&priv->tid_data[sta_id][tid], 0,
            sizeof(priv->tid_data[sta_id][tid]));

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

    priv->num_stations--;

    if (WARN_ON_ONCE(priv->num_stations < 0))
        priv->num_stations = 0;

    spin_unlock_bh(&priv->sta_lock);
}

static void iwl_sta_fill_lq(struct iwl_priv *priv, struct iwl_rxon_context *ctx,
                u8 sta_id, struct iwl_link_quality_cmd *link_cmd)
{
    int i, r;
    u32 rate_flags = 0;
    __le32 rate_n_flags;

    lockdep_assert_held(&priv->mutex);

    memset(link_cmd, 0, sizeof(*link_cmd));

    /* Set up the rate scaling to start at selected rate, fall back
     * all the way down to 1M in IEEE order, and then spin on 1M */
    if (priv->band == IEEE80211_BAND_5GHZ)
        r = IWL_RATE_6M_INDEX;
    else if (ctx && ctx->vif && ctx->vif->p2p)
        r = IWL_RATE_6M_INDEX;
    else
        r = IWL_RATE_1M_INDEX;

    if (r >= IWL_FIRST_CCK_RATE && r <= IWL_LAST_CCK_RATE)
        rate_flags |= RATE_MCS_CCK_MSK;

    rate_flags |= first_antenna(priv->eeprom_data->valid_tx_ant) <<
                RATE_MCS_ANT_POS;
    rate_n_flags = iwl_hw_set_rate_n_flags(iwl_rates[r].plcp, rate_flags);
    for (i = 0; i < LINK_QUAL_MAX_RETRY_NUM; i++)
        link_cmd->rs_table[i].rate_n_flags = rate_n_flags;

    link_cmd->general_params.single_stream_ant_msk =
            first_antenna(priv->eeprom_data->valid_tx_ant);

    link_cmd->general_params.dual_stream_ant_msk =
        priv->eeprom_data->valid_tx_ant &
        ~first_antenna(priv->eeprom_data->valid_tx_ant);
    if (!link_cmd->general_params.dual_stream_ant_msk) {
        link_cmd->general_params.dual_stream_ant_msk = ANT_AB;
    } else if (num_of_ant(priv->eeprom_data->valid_tx_ant) == 2) {
        link_cmd->general_params.dual_stream_ant_msk =
            priv->eeprom_data->valid_tx_ant;
    }

    link_cmd->agg_params.agg_dis_start_th =
        LINK_QUAL_AGG_DISABLE_START_DEF;
    link_cmd->agg_params.agg_time_limit =
        cpu_to_le16(LINK_QUAL_AGG_TIME_LIMIT_DEF);

    link_cmd->sta_id = sta_id;
}

void iwl_clear_ucode_stations(struct iwl_priv *priv,
                  struct iwl_rxon_context *ctx)
{
    int i;
    bool cleared = false;

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

    spin_lock_bh(&priv->sta_lock);
    for (i = 0; i < IWLAGN_STATION_COUNT; 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_bh(&priv->sta_lock);

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

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;
    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_bh(&priv->sta_lock);
    for (i = 0; i < IWLAGN_STATION_COUNT; 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 < IWLAGN_STATION_COUNT; 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) {
                if (priv->wowlan)
                    iwl_sta_fill_lq(priv, ctx, i, &lq);
                else
                    memcpy(&lq, priv->stations[i].lq,
                           sizeof(struct iwl_link_quality_cmd));
                send_lq = true;
            }
            spin_unlock_bh(&priv->sta_lock);
            ret = iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
            if (ret) {
                spin_lock_bh(&priv->sta_lock);
                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;
                continue;
            }
            /*
             * 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_bh(&priv->sta_lock);
            priv->stations[i].used &= ~IWL_STA_UCODE_INPROGRESS;
        }
    }

    spin_unlock_bh(&priv->sta_lock);
    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");
}

int iwl_get_free_ucode_key_offset(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;
}

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

    spin_lock_bh(&priv->sta_lock);
    for (i = 0; i < IWLAGN_STATION_COUNT; i++) {
        if (!(priv->stations[i].used & IWL_STA_BCAST))
            continue;

        priv->stations[i].used &= ~IWL_STA_UCODE_ACTIVE;
        priv->num_stations--;
        if (WARN_ON(priv->num_stations < 0))
            priv->num_stations = 0;
        kfree(priv->stations[i].lq);
        priv->stations[i].lq = NULL;
    }
    spin_unlock_bh(&priv->sta_lock);
}

#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

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;
}

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;
    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_bh(&priv->sta_lock);
    if (!(priv->stations[lq->sta_id].used & IWL_STA_DRIVER_ACTIVE)) {
        spin_unlock_bh(&priv->sta_lock);
        return -EINVAL;
    }
    spin_unlock_bh(&priv->sta_lock);

    iwl_dump_lq_cmd(priv, lq);
    if (WARN_ON(init && (cmd.flags & CMD_ASYNC)))
        return -EINVAL;

    if (is_lq_table_valid(priv, ctx, lq))
        ret = iwl_dvm_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_bh(&priv->sta_lock);
        priv->stations[lq->sta_id].used &= ~IWL_STA_UCODE_INPROGRESS;
        spin_unlock_bh(&priv->sta_lock);
    }
    return ret;
}


static struct iwl_link_quality_cmd *
iwl_sta_alloc_lq(struct iwl_priv *priv, struct iwl_rxon_context *ctx,
         u8 sta_id)
{
    struct iwl_link_quality_cmd *link_cmd;

    link_cmd = kzalloc(sizeof(struct iwl_link_quality_cmd), GFP_KERNEL);
    if (!link_cmd) {
        IWL_ERR(priv, "Unable to allocate memory for LQ cmd.\n");
        return NULL;
    }

    iwl_sta_fill_lq(priv, ctx, sta_id, link_cmd);

    return link_cmd;
}

/*
 * iwlagn_add_bssid_station - Add the special IBSS BSSID station
 *
 * Function sleeps.
 */
int iwlagn_add_bssid_station(struct iwl_priv *priv,
                 struct iwl_rxon_context *ctx,
                 const u8 *addr, u8 *sta_id_r)
{
    int ret;
    u8 sta_id;
    struct iwl_link_quality_cmd *link_cmd;

    if (sta_id_r)
        *sta_id_r = IWL_INVALID_STATION;

    ret = iwl_add_station_common(priv, ctx, addr, 0, NULL, &sta_id);
    if (ret) {
        IWL_ERR(priv, "Unable to add station %pM\n", addr);
        return ret;
    }

    if (sta_id_r)
        *sta_id_r = sta_id;

    spin_lock_bh(&priv->sta_lock);
    priv->stations[sta_id].used |= IWL_STA_LOCAL;
    spin_unlock_bh(&priv->sta_lock);

    /* Set up default rate scaling table in device's station table */
    link_cmd = iwl_sta_alloc_lq(priv, ctx, sta_id);
    if (!link_cmd) {
        IWL_ERR(priv,
            "Unable to initialize rate scaling for station %pM.\n",
            addr);
        return -ENOMEM;
    }

    ret = iwl_send_lq_cmd(priv, ctx, link_cmd, CMD_SYNC, true);
    if (ret)
        IWL_ERR(priv, "Link quality command failed (%d)\n", ret);

    spin_lock_bh(&priv->sta_lock);
    priv->stations[sta_id].lq = link_cmd;
    spin_unlock_bh(&priv->sta_lock);

    return 0;
}

/*
 * static WEP keys
 *
 * For each context, the device has a table of 4 static WEP keys
 * (one for each key index) that is updated with the following
 * commands.
 */

static int iwl_send_static_wepkey_cmd(struct iwl_priv *priv,
                      struct iwl_rxon_context *ctx,
                      bool send_if_empty)
{
    int i, not_empty = 0;
    u8 buff[sizeof(struct iwl_wep_cmd) +
        sizeof(struct iwl_wep_key) * WEP_KEYS_MAX];
    struct iwl_wep_cmd *wep_cmd = (struct iwl_wep_cmd *)buff;
    size_t cmd_size  = sizeof(struct iwl_wep_cmd);
    struct iwl_host_cmd cmd = {
        .id = ctx->wep_key_cmd,
        .data = { wep_cmd, },
        .flags = CMD_SYNC,
    };

    might_sleep();

    memset(wep_cmd, 0, cmd_size +
            (sizeof(struct iwl_wep_key) * WEP_KEYS_MAX));

    for (i = 0; i < WEP_KEYS_MAX ; i++) {
        wep_cmd->key[i].key_index = i;
        if (ctx->wep_keys[i].key_size) {
            wep_cmd->key[i].key_offset = i;
            not_empty = 1;
        } else {
            wep_cmd->key[i].key_offset = WEP_INVALID_OFFSET;
        }

        wep_cmd->key[i].key_size = ctx->wep_keys[i].key_size;
        memcpy(&wep_cmd->key[i].key[3], ctx->wep_keys[i].key,
                ctx->wep_keys[i].key_size);
    }

    wep_cmd->global_key_type = WEP_KEY_WEP_TYPE;
    wep_cmd->num_keys = WEP_KEYS_MAX;

    cmd_size += sizeof(struct iwl_wep_key) * WEP_KEYS_MAX;

    cmd.len[0] = cmd_size;

    if (not_empty || send_if_empty)
        return iwl_dvm_send_cmd(priv, &cmd);
    else
        return 0;
}

int iwl_restore_default_wep_keys(struct iwl_priv *priv,
                 struct iwl_rxon_context *ctx)
{
    lockdep_assert_held(&priv->mutex);

    return iwl_send_static_wepkey_cmd(priv, ctx, false);
}

int iwl_remove_default_wep_key(struct iwl_priv *priv,
                   struct iwl_rxon_context *ctx,
                   struct ieee80211_key_conf *keyconf)
{
    int ret;

    lockdep_assert_held(&priv->mutex);

    IWL_DEBUG_WEP(priv, "Removing default WEP key: idx=%d\n",
              keyconf->keyidx);

    memset(&ctx->wep_keys[keyconf->keyidx], 0, sizeof(ctx->wep_keys[0]));
    if (iwl_is_rfkill(priv)) {
        IWL_DEBUG_WEP(priv,
            "Not sending REPLY_WEPKEY command due to RFKILL.\n");
        /* but keys in device are clear anyway so return success */
        return 0;
    }
    ret = iwl_send_static_wepkey_cmd(priv, ctx, 1);
    IWL_DEBUG_WEP(priv, "Remove default WEP key: idx=%d ret=%d\n",
              keyconf->keyidx, ret);

    return ret;
}

int iwl_set_default_wep_key(struct iwl_priv *priv,
                struct iwl_rxon_context *ctx,
                struct ieee80211_key_conf *keyconf)
{
    int ret;

    lockdep_assert_held(&priv->mutex);

    if (keyconf->keylen != WEP_KEY_LEN_128 &&
        keyconf->keylen != WEP_KEY_LEN_64) {
        IWL_DEBUG_WEP(priv,
                  "Bad WEP key length %d\n", keyconf->keylen);
        return -EINVAL;
    }

    keyconf->hw_key_idx = IWLAGN_HW_KEY_DEFAULT;

    ctx->wep_keys[keyconf->keyidx].key_size = keyconf->keylen;
    memcpy(&ctx->wep_keys[keyconf->keyidx].key, &keyconf->key,
                            keyconf->keylen);

    ret = iwl_send_static_wepkey_cmd(priv, ctx, false);
    IWL_DEBUG_WEP(priv, "Set default WEP key: len=%d idx=%d ret=%d\n",
        keyconf->keylen, keyconf->keyidx, ret);

    return ret;
}

/*
 * dynamic (per-station) keys
 *
 * The dynamic keys are a little more complicated. The device has
 * a key cache of up to STA_KEY_MAX_NUM/STA_KEY_MAX_NUM_PAN keys.
 * These are linked to stations by a table that contains an index
 * into the key table for each station/key index/{mcast,unicast},
 * i.e. it's basically an array of pointers like this:
 *  key_offset_t key_mapping[NUM_STATIONS][4][2];
 * (it really works differently, but you can think of it as such)
 *
 * The key uploading and linking happens in the same command, the
 * add station command with STA_MODIFY_KEY_MASK.
 */

static u8 iwlagn_key_sta_id(struct iwl_priv *priv,
                struct ieee80211_vif *vif,
                struct ieee80211_sta *sta)
{
    struct iwl_vif_priv *vif_priv = (void *)vif->drv_priv;

    if (sta)
        return iwl_sta_id(sta);

    /*
     * The device expects GTKs for station interfaces to be
     * installed as GTKs for the AP station. If we have no
     * station ID, then use the ap_sta_id in that case.
     */
    if (vif->type == NL80211_IFTYPE_STATION && vif_priv->ctx)
        return vif_priv->ctx->ap_sta_id;

    return IWL_INVALID_STATION;
}

static int iwlagn_send_sta_key(struct iwl_priv *priv,
                   struct ieee80211_key_conf *keyconf,
                   u8 sta_id, u32 tkip_iv32, u16 *tkip_p1k,
                   u32 cmd_flags)
{
    __le16 key_flags;
    struct iwl_addsta_cmd sta_cmd;
    int i;

    spin_lock_bh(&priv->sta_lock);
    memcpy(&sta_cmd, &priv->stations[sta_id].sta, sizeof(sta_cmd));
    spin_unlock_bh(&priv->sta_lock);

    key_flags = cpu_to_le16(keyconf->keyidx << STA_KEY_FLG_KEYID_POS);
    key_flags |= STA_KEY_FLG_MAP_KEY_MSK;

    switch (keyconf->cipher) {
    case WLAN_CIPHER_SUITE_CCMP:
        key_flags |= STA_KEY_FLG_CCMP;
        memcpy(sta_cmd.key.key, keyconf->key, keyconf->keylen);
        break;
    case WLAN_CIPHER_SUITE_TKIP:
        key_flags |= STA_KEY_FLG_TKIP;
        sta_cmd.key.tkip_rx_tsc_byte2 = tkip_iv32;
        for (i = 0; i < 5; i++)
            sta_cmd.key.tkip_rx_ttak[i] = cpu_to_le16(tkip_p1k[i]);
        memcpy(sta_cmd.key.key, keyconf->key, keyconf->keylen);
        break;
    case WLAN_CIPHER_SUITE_WEP104:
        key_flags |= STA_KEY_FLG_KEY_SIZE_MSK;
        /* fall through */
    case WLAN_CIPHER_SUITE_WEP40:
        key_flags |= STA_KEY_FLG_WEP;
        memcpy(&sta_cmd.key.key[3], keyconf->key, keyconf->keylen);
        break;
    default:
        WARN_ON(1);
        return -EINVAL;
    }

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

    /* key pointer (offset) */
    sta_cmd.key.key_offset = keyconf->hw_key_idx;

    sta_cmd.key.key_flags = key_flags;
    sta_cmd.mode = STA_CONTROL_MODIFY_MSK;
    sta_cmd.sta.modify_mask = STA_MODIFY_KEY_MASK;

    return iwl_send_add_sta(priv, &sta_cmd, cmd_flags);
}

void iwl_update_tkip_key(struct iwl_priv *priv,
             struct ieee80211_vif *vif,
             struct ieee80211_key_conf *keyconf,
             struct ieee80211_sta *sta, u32 iv32, u16 *phase1key)
{
    u8 sta_id = iwlagn_key_sta_id(priv, vif, sta);

    if (sta_id == IWL_INVALID_STATION)
        return;

    if (iwl_scan_cancel(priv)) {
        /* cancel scan failed, just live w/ bad key and rely
           briefly on SW decryption */
        return;
    }

    iwlagn_send_sta_key(priv, keyconf, sta_id,
                iv32, phase1key, CMD_ASYNC);
}

int iwl_remove_dynamic_key(struct iwl_priv *priv,
               struct iwl_rxon_context *ctx,
               struct ieee80211_key_conf *keyconf,
               struct ieee80211_sta *sta)
{
    struct iwl_addsta_cmd sta_cmd;
    u8 sta_id = iwlagn_key_sta_id(priv, ctx->vif, sta);
    __le16 key_flags;

    /* if station isn't there, neither is the key */
    if (sta_id == IWL_INVALID_STATION)
        return -ENOENT;

    spin_lock_bh(&priv->sta_lock);
    memcpy(&sta_cmd, &priv->stations[sta_id].sta, sizeof(sta_cmd));
    if (!(priv->stations[sta_id].used & IWL_STA_UCODE_ACTIVE))
        sta_id = IWL_INVALID_STATION;
    spin_unlock_bh(&priv->sta_lock);

    if (sta_id == IWL_INVALID_STATION)
        return 0;

    lockdep_assert_held(&priv->mutex);

    ctx->key_mapping_keys--;

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

    if (!test_and_clear_bit(keyconf->hw_key_idx, &priv->ucode_key_table))
        IWL_ERR(priv, "offset %d not used in uCode key table.\n",
            keyconf->hw_key_idx);

    key_flags = cpu_to_le16(keyconf->keyidx << STA_KEY_FLG_KEYID_POS);
    key_flags |= STA_KEY_FLG_MAP_KEY_MSK | STA_KEY_FLG_NO_ENC |
             STA_KEY_FLG_INVALID;

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

    sta_cmd.key.key_flags = key_flags;
    sta_cmd.key.key_offset = keyconf->hw_key_idx;
    sta_cmd.sta.modify_mask = STA_MODIFY_KEY_MASK;
    sta_cmd.mode = STA_CONTROL_MODIFY_MSK;

    return iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
}

int iwl_set_dynamic_key(struct iwl_priv *priv,
            struct iwl_rxon_context *ctx,
            struct ieee80211_key_conf *keyconf,
            struct ieee80211_sta *sta)
{
    struct ieee80211_key_seq seq;
    u16 p1k[5];
    int ret;
    u8 sta_id = iwlagn_key_sta_id(priv, ctx->vif, sta);
    const u8 *addr;

    if (sta_id == IWL_INVALID_STATION)
        return -EINVAL;

    lockdep_assert_held(&priv->mutex);

    keyconf->hw_key_idx = iwl_get_free_ucode_key_offset(priv);
    if (keyconf->hw_key_idx == WEP_INVALID_OFFSET)
        return -ENOSPC;

    ctx->key_mapping_keys++;

    switch (keyconf->cipher) {
    case WLAN_CIPHER_SUITE_TKIP:
        if (sta)
            addr = sta->addr;
        else /* station mode case only */
            addr = ctx->active.bssid_addr;

        /* pre-fill phase 1 key into device cache */
        ieee80211_get_key_rx_seq(keyconf, 0, &seq);
        ieee80211_get_tkip_rx_p1k(keyconf, addr, seq.tkip.iv32, p1k);
        ret = iwlagn_send_sta_key(priv, keyconf, sta_id,
                      seq.tkip.iv32, p1k, CMD_SYNC);
        break;
    case WLAN_CIPHER_SUITE_CCMP:
    case WLAN_CIPHER_SUITE_WEP40:
    case WLAN_CIPHER_SUITE_WEP104:
        ret = iwlagn_send_sta_key(priv, keyconf, sta_id,
                      0, NULL, CMD_SYNC);
        break;
    default:
        IWL_ERR(priv, "Unknown cipher %x\n", keyconf->cipher);
        ret = -EINVAL;
    }

    if (ret) {
        ctx->key_mapping_keys--;
        clear_bit(keyconf->hw_key_idx, &priv->ucode_key_table);
    }

    IWL_DEBUG_WEP(priv, "Set dynamic key: cipher=%x len=%d idx=%d sta=%pM ret=%d\n",
              keyconf->cipher, keyconf->keylen, keyconf->keyidx,
              sta ? sta->addr : NULL, ret);

    return ret;
}

int iwlagn_alloc_bcast_station(struct iwl_priv *priv,
                   struct iwl_rxon_context *ctx)
{
    struct iwl_link_quality_cmd *link_cmd;
    u8 sta_id;

    spin_lock_bh(&priv->sta_lock);
    sta_id = iwl_prep_station(priv, ctx, iwl_bcast_addr, false, NULL);
    if (sta_id == IWL_INVALID_STATION) {
        IWL_ERR(priv, "Unable to prepare broadcast station\n");
        spin_unlock_bh(&priv->sta_lock);

        return -EINVAL;
    }

    priv->stations[sta_id].used |= IWL_STA_DRIVER_ACTIVE;
    priv->stations[sta_id].used |= IWL_STA_BCAST;
    spin_unlock_bh(&priv->sta_lock);

    link_cmd = iwl_sta_alloc_lq(priv, ctx, sta_id);
    if (!link_cmd) {
        IWL_ERR(priv,
            "Unable to initialize rate scaling for bcast station.\n");
        return -ENOMEM;
    }

    spin_lock_bh(&priv->sta_lock);
    priv->stations[sta_id].lq = link_cmd;
    spin_unlock_bh(&priv->sta_lock);

    return 0;
}

int iwl_update_bcast_station(struct iwl_priv *priv,
                 struct iwl_rxon_context *ctx)
{
    struct iwl_link_quality_cmd *link_cmd;
    u8 sta_id = ctx->bcast_sta_id;

    link_cmd = iwl_sta_alloc_lq(priv, ctx, sta_id);
    if (!link_cmd) {
        IWL_ERR(priv, "Unable to initialize rate scaling for bcast station.\n");
        return -ENOMEM;
    }

    spin_lock_bh(&priv->sta_lock);
    if (priv->stations[sta_id].lq)
        kfree(priv->stations[sta_id].lq);
    else
        IWL_DEBUG_INFO(priv, "Bcast station rate scaling has not been initialized yet.\n");
    priv->stations[sta_id].lq = link_cmd;
    spin_unlock_bh(&priv->sta_lock);

    return 0;
}

int iwl_update_bcast_stations(struct iwl_priv *priv)
{
    struct iwl_rxon_context *ctx;
    int ret = 0;

    for_each_context(priv, ctx) {
        ret = iwl_update_bcast_station(priv, ctx);
        if (ret)
            break;
    }

    return ret;
}

int iwl_sta_tx_modify_enable_tid(struct iwl_priv *priv, int sta_id, int tid)
{
    struct iwl_addsta_cmd sta_cmd;

    lockdep_assert_held(&priv->mutex);

    /* Remove "disable" flag, to enable Tx for this TID */
    spin_lock_bh(&priv->sta_lock);
    priv->stations[sta_id].sta.sta.modify_mask = STA_MODIFY_TID_DISABLE_TX;
    priv->stations[sta_id].sta.tid_disable_tx &= cpu_to_le16(~(1 << tid));
    priv->stations[sta_id].sta.mode = STA_CONTROL_MODIFY_MSK;
    memcpy(&sta_cmd, &priv->stations[sta_id].sta, sizeof(struct iwl_addsta_cmd));
    spin_unlock_bh(&priv->sta_lock);

    return iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
}

int iwl_sta_rx_agg_start(struct iwl_priv *priv, struct ieee80211_sta *sta,
             int tid, u16 ssn)
{
    int sta_id;
    struct iwl_addsta_cmd sta_cmd;

    lockdep_assert_held(&priv->mutex);

    sta_id = iwl_sta_id(sta);
    if (sta_id == IWL_INVALID_STATION)
        return -ENXIO;

    spin_lock_bh(&priv->sta_lock);
    priv->stations[sta_id].sta.station_flags_msk = 0;
    priv->stations[sta_id].sta.sta.modify_mask = STA_MODIFY_ADDBA_TID_MSK;
    priv->stations[sta_id].sta.add_immediate_ba_tid = (u8)tid;
    priv->stations[sta_id].sta.add_immediate_ba_ssn = cpu_to_le16(ssn);
    priv->stations[sta_id].sta.mode = STA_CONTROL_MODIFY_MSK;
    memcpy(&sta_cmd, &priv->stations[sta_id].sta, sizeof(struct iwl_addsta_cmd));
    spin_unlock_bh(&priv->sta_lock);

    return iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
}

int iwl_sta_rx_agg_stop(struct iwl_priv *priv, struct ieee80211_sta *sta,
            int tid)
{
    int sta_id;
    struct iwl_addsta_cmd sta_cmd;

    lockdep_assert_held(&priv->mutex);

    sta_id = iwl_sta_id(sta);
    if (sta_id == IWL_INVALID_STATION) {
        IWL_ERR(priv, "Invalid station for AGG tid %d\n", tid);
        return -ENXIO;
    }

    spin_lock_bh(&priv->sta_lock);
    priv->stations[sta_id].sta.station_flags_msk = 0;
    priv->stations[sta_id].sta.sta.modify_mask = STA_MODIFY_DELBA_TID_MSK;
    priv->stations[sta_id].sta.remove_immediate_ba_tid = (u8)tid;
    priv->stations[sta_id].sta.mode = STA_CONTROL_MODIFY_MSK;
    memcpy(&sta_cmd, &priv->stations[sta_id].sta, sizeof(struct iwl_addsta_cmd));
    spin_unlock_bh(&priv->sta_lock);

    return iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
}



void iwl_sta_modify_sleep_tx_count(struct iwl_priv *priv, int sta_id, int cnt)
{
    struct iwl_addsta_cmd cmd = {
        .mode = STA_CONTROL_MODIFY_MSK,
        .station_flags = STA_FLG_PWR_SAVE_MSK,
        .station_flags_msk = STA_FLG_PWR_SAVE_MSK,
        .sta.sta_id = sta_id,
        .sta.modify_mask = STA_MODIFY_SLEEP_TX_COUNT_MSK,
        .sleep_tx_count = cpu_to_le16(cnt),
    };

    iwl_send_add_sta(priv, &cmd, CMD_ASYNC);
}