rt2x00mac.c

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/*
    Copyright (C) 2004 - 2009 Ivo van Doorn <[email protected]>
    <http://rt2x00.serialmonkey.com>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    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.,
    59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*
    Module: rt2x00mac
    Abstract: rt2x00 generic mac80211 routines.
 */

#include <linux/kernel.h>
#include <linux/module.h>

#include "rt2x00.h"
#include "rt2x00lib.h"

static int rt2x00mac_tx_rts_cts(struct rt2x00_dev *rt2x00dev,
                struct data_queue *queue,
                struct sk_buff *frag_skb)
{
    struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(frag_skb);
    struct ieee80211_tx_info *rts_info;
    struct sk_buff *skb;
    unsigned int data_length;
    int retval = 0;

    if (tx_info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
        data_length = sizeof(struct ieee80211_cts);
    else
        data_length = sizeof(struct ieee80211_rts);

    skb = dev_alloc_skb(data_length + rt2x00dev->hw->extra_tx_headroom);
    if (unlikely(!skb)) {
        WARNING(rt2x00dev, "Failed to create RTS/CTS frame.\n");
        return -ENOMEM;
    }

    skb_reserve(skb, rt2x00dev->hw->extra_tx_headroom);
    skb_put(skb, data_length);

    /*
     * Copy TX information over from original frame to
     * RTS/CTS frame. Note that we set the no encryption flag
     * since we don't want this frame to be encrypted.
     * RTS frames should be acked, while CTS-to-self frames
     * should not. The ready for TX flag is cleared to prevent
     * it being automatically send when the descriptor is
     * written to the hardware.
     */
    memcpy(skb->cb, frag_skb->cb, sizeof(skb->cb));
    rts_info = IEEE80211_SKB_CB(skb);
    rts_info->control.rates[0].flags &= ~IEEE80211_TX_RC_USE_RTS_CTS;
    rts_info->control.rates[0].flags &= ~IEEE80211_TX_RC_USE_CTS_PROTECT;

    if (tx_info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
        rts_info->flags |= IEEE80211_TX_CTL_NO_ACK;
    else
        rts_info->flags &= ~IEEE80211_TX_CTL_NO_ACK;

    /* Disable hardware encryption */
    rts_info->control.hw_key = NULL;

    /*
     * RTS/CTS frame should use the length of the frame plus any
     * encryption overhead that will be added by the hardware.
     */
    data_length += rt2x00crypto_tx_overhead(rt2x00dev, skb);

    if (tx_info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
        ieee80211_ctstoself_get(rt2x00dev->hw, tx_info->control.vif,
                    frag_skb->data, data_length, tx_info,
                    (struct ieee80211_cts *)(skb->data));
    else
        ieee80211_rts_get(rt2x00dev->hw, tx_info->control.vif,
                  frag_skb->data, data_length, tx_info,
                  (struct ieee80211_rts *)(skb->data));

    retval = rt2x00queue_write_tx_frame(queue, skb, true);
    if (retval) {
        dev_kfree_skb_any(skb);
        WARNING(rt2x00dev, "Failed to send RTS/CTS frame.\n");
    }

    return retval;
}

void rt2x00mac_tx(struct ieee80211_hw *hw,
          struct ieee80211_tx_control *control,
          struct sk_buff *skb)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
    enum data_queue_qid qid = skb_get_queue_mapping(skb);
    struct data_queue *queue = NULL;

    /*
     * Mac80211 might be calling this function while we are trying
     * to remove the device or perhaps suspending it.
     * Note that we can only stop the TX queues inside the TX path
     * due to possible race conditions in mac80211.
     */
    if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
        goto exit_free_skb;

    /*
     * Use the ATIM queue if appropriate and present.
     */
    if (tx_info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM &&
        test_bit(REQUIRE_ATIM_QUEUE, &rt2x00dev->cap_flags))
        qid = QID_ATIM;

    queue = rt2x00queue_get_tx_queue(rt2x00dev, qid);
    if (unlikely(!queue)) {
        ERROR(rt2x00dev,
              "Attempt to send packet over invalid queue %d.\n"
              "Please file bug report to %s.\n", qid, DRV_PROJECT);
        goto exit_free_skb;
    }

    /*
     * If CTS/RTS is required. create and queue that frame first.
     * Make sure we have at least enough entries available to send
     * this CTS/RTS frame as well as the data frame.
     * Note that when the driver has set the set_rts_threshold()
     * callback function it doesn't need software generation of
     * either RTS or CTS-to-self frame and handles everything
     * inside the hardware.
     */
    if (!rt2x00dev->ops->hw->set_rts_threshold &&
        (tx_info->control.rates[0].flags & (IEEE80211_TX_RC_USE_RTS_CTS |
                        IEEE80211_TX_RC_USE_CTS_PROTECT))) {
        if (rt2x00queue_available(queue) <= 1)
            goto exit_fail;

        if (rt2x00mac_tx_rts_cts(rt2x00dev, queue, skb))
            goto exit_fail;
    }

    if (unlikely(rt2x00queue_write_tx_frame(queue, skb, false)))
        goto exit_fail;

    /*
     * Pausing queue has to be serialized with rt2x00lib_txdone(). Note
     * we should not use spin_lock_bh variant as bottom halve was already
     * disabled before ieee80211_xmit() call.
     */
    spin_lock(&queue->tx_lock);
    if (rt2x00queue_threshold(queue))
        rt2x00queue_pause_queue(queue);
    spin_unlock(&queue->tx_lock);

    return;

 exit_fail:
    spin_lock(&queue->tx_lock);
    rt2x00queue_pause_queue(queue);
    spin_unlock(&queue->tx_lock);
 exit_free_skb:
    ieee80211_free_txskb(hw, skb);
}
EXPORT_SYMBOL_GPL(rt2x00mac_tx);

int rt2x00mac_start(struct ieee80211_hw *hw)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;

    if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
        return 0;

    return rt2x00lib_start(rt2x00dev);
}
EXPORT_SYMBOL_GPL(rt2x00mac_start);

void rt2x00mac_stop(struct ieee80211_hw *hw)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;

    if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
        return;

    rt2x00lib_stop(rt2x00dev);
}
EXPORT_SYMBOL_GPL(rt2x00mac_stop);

int rt2x00mac_add_interface(struct ieee80211_hw *hw,
                struct ieee80211_vif *vif)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    struct rt2x00_intf *intf = vif_to_intf(vif);
    struct data_queue *queue = rt2x00dev->bcn;
    struct queue_entry *entry = NULL;
    unsigned int i;

    /*
     * Don't allow interfaces to be added
     * the device has disappeared.
     */
    if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) ||
        !test_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
        return -ENODEV;

    /*
     * Loop through all beacon queues to find a free
     * entry. Since there are as much beacon entries
     * as the maximum interfaces, this search shouldn't
     * fail.
     */
    for (i = 0; i < queue->limit; i++) {
        entry = &queue->entries[i];
        if (!test_and_set_bit(ENTRY_BCN_ASSIGNED, &entry->flags))
            break;
    }

    if (unlikely(i == queue->limit))
        return -ENOBUFS;

    /*
     * We are now absolutely sure the interface can be created,
     * increase interface count and start initialization.
     */

    if (vif->type == NL80211_IFTYPE_AP)
        rt2x00dev->intf_ap_count++;
    else
        rt2x00dev->intf_sta_count++;

    mutex_init(&intf->beacon_skb_mutex);
    intf->beacon = entry;

    /*
     * The MAC address must be configured after the device
     * has been initialized. Otherwise the device can reset
     * the MAC registers.
     * The BSSID address must only be configured in AP mode,
     * however we should not send an empty BSSID address for
     * STA interfaces at this time, since this can cause
     * invalid behavior in the device.
     */
    rt2x00lib_config_intf(rt2x00dev, intf, vif->type,
                  vif->addr, NULL);

    /*
     * Some filters depend on the current working mode. We can force
     * an update during the next configure_filter() run by mac80211 by
     * resetting the current packet_filter state.
     */
    rt2x00dev->packet_filter = 0;

    return 0;
}
EXPORT_SYMBOL_GPL(rt2x00mac_add_interface);

void rt2x00mac_remove_interface(struct ieee80211_hw *hw,
                struct ieee80211_vif *vif)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    struct rt2x00_intf *intf = vif_to_intf(vif);

    /*
     * Don't allow interfaces to be remove while
     * either the device has disappeared or when
     * no interface is present.
     */
    if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) ||
        (vif->type == NL80211_IFTYPE_AP && !rt2x00dev->intf_ap_count) ||
        (vif->type != NL80211_IFTYPE_AP && !rt2x00dev->intf_sta_count))
        return;

    if (vif->type == NL80211_IFTYPE_AP)
        rt2x00dev->intf_ap_count--;
    else
        rt2x00dev->intf_sta_count--;

    /*
     * Release beacon entry so it is available for
     * new interfaces again.
     */
    clear_bit(ENTRY_BCN_ASSIGNED, &intf->beacon->flags);

    /*
     * Make sure the bssid and mac address registers
     * are cleared to prevent false ACKing of frames.
     */
    rt2x00lib_config_intf(rt2x00dev, intf,
                  NL80211_IFTYPE_UNSPECIFIED, NULL, NULL);
}
EXPORT_SYMBOL_GPL(rt2x00mac_remove_interface);

int rt2x00mac_config(struct ieee80211_hw *hw, u32 changed)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    struct ieee80211_conf *conf = &hw->conf;

    /*
     * mac80211 might be calling this function while we are trying
     * to remove the device or perhaps suspending it.
     */
    if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
        return 0;

    /*
     * Some configuration parameters (e.g. channel and antenna values) can
     * only be set when the radio is enabled, but do require the RX to
     * be off. During this period we should keep link tuning enabled,
     * if for any reason the link tuner must be reset, this will be
     * handled by rt2x00lib_config().
     */
    rt2x00queue_stop_queue(rt2x00dev->rx);

    /*
     * When we've just turned on the radio, we want to reprogram
     * everything to ensure a consistent state
     */
    rt2x00lib_config(rt2x00dev, conf, changed);

    /*
     * After the radio has been enabled we need to configure
     * the antenna to the default settings. rt2x00lib_config_antenna()
     * should determine if any action should be taken based on
     * checking if diversity has been enabled or no antenna changes
     * have been made since the last configuration change.
     */
    rt2x00lib_config_antenna(rt2x00dev, rt2x00dev->default_ant);

    /* Turn RX back on */
    rt2x00queue_start_queue(rt2x00dev->rx);

    return 0;
}
EXPORT_SYMBOL_GPL(rt2x00mac_config);

void rt2x00mac_configure_filter(struct ieee80211_hw *hw,
                unsigned int changed_flags,
                unsigned int *total_flags,
                u64 multicast)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;

    /*
     * Mask off any flags we are going to ignore
     * from the total_flags field.
     */
    *total_flags &=
        FIF_ALLMULTI |
        FIF_FCSFAIL |
        FIF_PLCPFAIL |
        FIF_CONTROL |
        FIF_PSPOLL |
        FIF_OTHER_BSS |
        FIF_PROMISC_IN_BSS;

    /*
     * Apply some rules to the filters:
     * - Some filters imply different filters to be set.
     * - Some things we can't filter out at all.
     * - Multicast filter seems to kill broadcast traffic so never use it.
     */
    *total_flags |= FIF_ALLMULTI;
    if (*total_flags & FIF_OTHER_BSS ||
        *total_flags & FIF_PROMISC_IN_BSS)
        *total_flags |= FIF_PROMISC_IN_BSS | FIF_OTHER_BSS;

    /*
     * If the device has a single filter for all control frames,
     * FIF_CONTROL and FIF_PSPOLL flags imply each other.
     * And if the device has more than one filter for control frames
     * of different types, but has no a separate filter for PS Poll frames,
     * FIF_CONTROL flag implies FIF_PSPOLL.
     */
    if (!test_bit(CAPABILITY_CONTROL_FILTERS, &rt2x00dev->cap_flags)) {
        if (*total_flags & FIF_CONTROL || *total_flags & FIF_PSPOLL)
            *total_flags |= FIF_CONTROL | FIF_PSPOLL;
    }
    if (!test_bit(CAPABILITY_CONTROL_FILTER_PSPOLL, &rt2x00dev->cap_flags)) {
        if (*total_flags & FIF_CONTROL)
            *total_flags |= FIF_PSPOLL;
    }

    /*
     * Check if there is any work left for us.
     */
    if (rt2x00dev->packet_filter == *total_flags)
        return;
    rt2x00dev->packet_filter = *total_flags;

    rt2x00dev->ops->lib->config_filter(rt2x00dev, *total_flags);
}
EXPORT_SYMBOL_GPL(rt2x00mac_configure_filter);

static void rt2x00mac_set_tim_iter(void *data, u8 *mac,
                   struct ieee80211_vif *vif)
{
    struct rt2x00_intf *intf = vif_to_intf(vif);

    if (vif->type != NL80211_IFTYPE_AP &&
        vif->type != NL80211_IFTYPE_ADHOC &&
        vif->type != NL80211_IFTYPE_MESH_POINT &&
        vif->type != NL80211_IFTYPE_WDS)
        return;

    set_bit(DELAYED_UPDATE_BEACON, &intf->delayed_flags);
}

int rt2x00mac_set_tim(struct ieee80211_hw *hw, struct ieee80211_sta *sta,
              bool set)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;

    if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
        return 0;

    ieee80211_iterate_active_interfaces_atomic(rt2x00dev->hw,
                           rt2x00mac_set_tim_iter,
                           rt2x00dev);

    /* queue work to upodate the beacon template */
    ieee80211_queue_work(rt2x00dev->hw, &rt2x00dev->intf_work);
    return 0;
}
EXPORT_SYMBOL_GPL(rt2x00mac_set_tim);

#ifdef CONFIG_RT2X00_LIB_CRYPTO
static void memcpy_tkip(struct rt2x00lib_crypto *crypto, u8 *key, u8 key_len)
{
    if (key_len > NL80211_TKIP_DATA_OFFSET_ENCR_KEY)
        memcpy(crypto->key,
               &key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY],
               sizeof(crypto->key));

    if (key_len > NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY)
        memcpy(crypto->tx_mic,
               &key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY],
               sizeof(crypto->tx_mic));

    if (key_len > NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY)
        memcpy(crypto->rx_mic,
               &key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY],
               sizeof(crypto->rx_mic));
}

int rt2x00mac_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
              struct ieee80211_vif *vif, struct ieee80211_sta *sta,
              struct ieee80211_key_conf *key)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    int (*set_key) (struct rt2x00_dev *rt2x00dev,
            struct rt2x00lib_crypto *crypto,
            struct ieee80211_key_conf *key);
    struct rt2x00lib_crypto crypto;
    static const u8 bcast_addr[ETH_ALEN] =
        { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, };
    struct rt2x00_sta *sta_priv = NULL;

    if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
        return 0;

    if (!test_bit(CAPABILITY_HW_CRYPTO, &rt2x00dev->cap_flags))
        return -EOPNOTSUPP;

    /*
     * To support IBSS RSN, don't program group keys in IBSS, the
     * hardware will then not attempt to decrypt the frames.
     */
    if (vif->type == NL80211_IFTYPE_ADHOC &&
        !(key->flags & IEEE80211_KEY_FLAG_PAIRWISE))
        return -EOPNOTSUPP;

    if (key->keylen > 32)
        return -ENOSPC;

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

    crypto.bssidx = rt2x00lib_get_bssidx(rt2x00dev, vif);
    crypto.cipher = rt2x00crypto_key_to_cipher(key);
    if (crypto.cipher == CIPHER_NONE)
        return -EOPNOTSUPP;

    crypto.cmd = cmd;

    if (sta) {
        crypto.address = sta->addr;
        sta_priv = sta_to_rt2x00_sta(sta);
        crypto.wcid = sta_priv->wcid;
    } else
        crypto.address = bcast_addr;

    if (crypto.cipher == CIPHER_TKIP)
        memcpy_tkip(&crypto, &key->key[0], key->keylen);
    else
        memcpy(crypto.key, &key->key[0], key->keylen);
    /*
     * Each BSS has a maximum of 4 shared keys.
     * Shared key index values:
     *  0) BSS0 key0
     *  1) BSS0 key1
     *  ...
     *  4) BSS1 key0
     *  ...
     *  8) BSS2 key0
     *  ...
     * Both pairwise as shared key indeces are determined by
     * driver. This is required because the hardware requires
     * keys to be assigned in correct order (When key 1 is
     * provided but key 0 is not, then the key is not found
     * by the hardware during RX).
     */
    if (cmd == SET_KEY)
        key->hw_key_idx = 0;

    if (key->flags & IEEE80211_KEY_FLAG_PAIRWISE)
        set_key = rt2x00dev->ops->lib->config_pairwise_key;
    else
        set_key = rt2x00dev->ops->lib->config_shared_key;

    if (!set_key)
        return -EOPNOTSUPP;

    return set_key(rt2x00dev, &crypto, key);
}
EXPORT_SYMBOL_GPL(rt2x00mac_set_key);
#endif /* CONFIG_RT2X00_LIB_CRYPTO */

int rt2x00mac_sta_add(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
              struct ieee80211_sta *sta)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    struct rt2x00_sta *sta_priv = sta_to_rt2x00_sta(sta);

    /*
     * If there's no space left in the device table store
     * -1 as wcid but tell mac80211 everything went ok.
     */
    if (rt2x00dev->ops->lib->sta_add(rt2x00dev, vif, sta))
        sta_priv->wcid = -1;

    return 0;
}
EXPORT_SYMBOL_GPL(rt2x00mac_sta_add);

int rt2x00mac_sta_remove(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
             struct ieee80211_sta *sta)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    struct rt2x00_sta *sta_priv = sta_to_rt2x00_sta(sta);

    /*
     * If we never sent the STA to the device no need to clean it up.
     */
    if (sta_priv->wcid < 0)
        return 0;

    return rt2x00dev->ops->lib->sta_remove(rt2x00dev, sta_priv->wcid);
}
EXPORT_SYMBOL_GPL(rt2x00mac_sta_remove);

void rt2x00mac_sw_scan_start(struct ieee80211_hw *hw)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    set_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags);
    rt2x00link_stop_tuner(rt2x00dev);
}
EXPORT_SYMBOL_GPL(rt2x00mac_sw_scan_start);

void rt2x00mac_sw_scan_complete(struct ieee80211_hw *hw)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    clear_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags);
    rt2x00link_start_tuner(rt2x00dev);
}
EXPORT_SYMBOL_GPL(rt2x00mac_sw_scan_complete);

int rt2x00mac_get_stats(struct ieee80211_hw *hw,
            struct ieee80211_low_level_stats *stats)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;

    /*
     * The dot11ACKFailureCount, dot11RTSFailureCount and
     * dot11RTSSuccessCount are updated in interrupt time.
     * dot11FCSErrorCount is updated in the link tuner.
     */
    memcpy(stats, &rt2x00dev->low_level_stats, sizeof(*stats));

    return 0;
}
EXPORT_SYMBOL_GPL(rt2x00mac_get_stats);

void rt2x00mac_bss_info_changed(struct ieee80211_hw *hw,
                struct ieee80211_vif *vif,
                struct ieee80211_bss_conf *bss_conf,
                u32 changes)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    struct rt2x00_intf *intf = vif_to_intf(vif);

    /*
     * mac80211 might be calling this function while we are trying
     * to remove the device or perhaps suspending it.
     */
    if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
        return;

    /*
     * Update the BSSID.
     */
    if (changes & BSS_CHANGED_BSSID)
        rt2x00lib_config_intf(rt2x00dev, intf, vif->type, NULL,
                      bss_conf->bssid);

    /*
     * Update the beacon. This is only required on USB devices. PCI
     * devices fetch beacons periodically.
     */
    if (changes & BSS_CHANGED_BEACON && rt2x00_is_usb(rt2x00dev))
        rt2x00queue_update_beacon(rt2x00dev, vif);

    /*
     * Start/stop beaconing.
     */
    if (changes & BSS_CHANGED_BEACON_ENABLED) {
        if (!bss_conf->enable_beacon && intf->enable_beacon) {
            rt2x00queue_clear_beacon(rt2x00dev, vif);
            rt2x00dev->intf_beaconing--;
            intf->enable_beacon = false;

            if (rt2x00dev->intf_beaconing == 0) {
                /*
                 * Last beaconing interface disabled
                 * -> stop beacon queue.
                 */
                mutex_lock(&intf->beacon_skb_mutex);
                rt2x00queue_stop_queue(rt2x00dev->bcn);
                mutex_unlock(&intf->beacon_skb_mutex);
            }


        } else if (bss_conf->enable_beacon && !intf->enable_beacon) {
            rt2x00dev->intf_beaconing++;
            intf->enable_beacon = true;

            if (rt2x00dev->intf_beaconing == 1) {
                /*
                 * First beaconing interface enabled
                 * -> start beacon queue.
                 */
                mutex_lock(&intf->beacon_skb_mutex);
                rt2x00queue_start_queue(rt2x00dev->bcn);
                mutex_unlock(&intf->beacon_skb_mutex);
            }
        }
    }

    /*
     * When the association status has changed we must reset the link
     * tuner counter. This is because some drivers determine if they
     * should perform link tuning based on the number of seconds
     * while associated or not associated.
     */
    if (changes & BSS_CHANGED_ASSOC) {
        rt2x00dev->link.count = 0;

        if (bss_conf->assoc)
            rt2x00dev->intf_associated++;
        else
            rt2x00dev->intf_associated--;

        rt2x00leds_led_assoc(rt2x00dev, !!rt2x00dev->intf_associated);

        clear_bit(CONFIG_QOS_DISABLED, &rt2x00dev->flags);
    }

    /*
     * Check for access point which do not support 802.11e . We have to
     * generate data frames sequence number in S/W for such AP, because
     * of H/W bug.
     */
    if (changes & BSS_CHANGED_QOS && !bss_conf->qos)
        set_bit(CONFIG_QOS_DISABLED, &rt2x00dev->flags);

    /*
     * When the erp information has changed, we should perform
     * additional configuration steps. For all other changes we are done.
     */
    if (changes & (BSS_CHANGED_ERP_CTS_PROT | BSS_CHANGED_ERP_PREAMBLE |
               BSS_CHANGED_ERP_SLOT | BSS_CHANGED_BASIC_RATES |
               BSS_CHANGED_BEACON_INT | BSS_CHANGED_HT))
        rt2x00lib_config_erp(rt2x00dev, intf, bss_conf, changes);
}
EXPORT_SYMBOL_GPL(rt2x00mac_bss_info_changed);

int rt2x00mac_conf_tx(struct ieee80211_hw *hw,
              struct ieee80211_vif *vif, u16 queue_idx,
              const struct ieee80211_tx_queue_params *params)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    struct data_queue *queue;

    queue = rt2x00queue_get_tx_queue(rt2x00dev, queue_idx);
    if (unlikely(!queue))
        return -EINVAL;

    /*
     * The passed variables are stored as real value ((2^n)-1).
     * Ralink registers require to know the bit number 'n'.
     */
    if (params->cw_min > 0)
        queue->cw_min = fls(params->cw_min);
    else
        queue->cw_min = 5; /* cw_min: 2^5 = 32. */

    if (params->cw_max > 0)
        queue->cw_max = fls(params->cw_max);
    else
        queue->cw_max = 10; /* cw_min: 2^10 = 1024. */

    queue->aifs = params->aifs;
    queue->txop = params->txop;

    INFO(rt2x00dev,
         "Configured TX queue %d - CWmin: %d, CWmax: %d, Aifs: %d, TXop: %d.\n",
         queue_idx, queue->cw_min, queue->cw_max, queue->aifs, queue->txop);

    return 0;
}
EXPORT_SYMBOL_GPL(rt2x00mac_conf_tx);

void rt2x00mac_rfkill_poll(struct ieee80211_hw *hw)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    bool active = !!rt2x00dev->ops->lib->rfkill_poll(rt2x00dev);

    wiphy_rfkill_set_hw_state(hw->wiphy, !active);
}
EXPORT_SYMBOL_GPL(rt2x00mac_rfkill_poll);

void rt2x00mac_flush(struct ieee80211_hw *hw, bool drop)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    struct data_queue *queue;

    tx_queue_for_each(rt2x00dev, queue)
        rt2x00queue_flush_queue(queue, drop);
}
EXPORT_SYMBOL_GPL(rt2x00mac_flush);

int rt2x00mac_set_antenna(struct ieee80211_hw *hw, u32 tx_ant, u32 rx_ant)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    struct link_ant *ant = &rt2x00dev->link.ant;
    struct antenna_setup *def = &rt2x00dev->default_ant;
    struct antenna_setup setup;

    // The antenna value is not supposed to be 0,
    // or exceed the maximum number of antenna's.
    if (!tx_ant || (tx_ant & ~3) || !rx_ant || (rx_ant & ~3))
        return -EINVAL;

    // When the client tried to configure the antenna to or from
    // diversity mode, we must reset the default antenna as well
    // as that controls the diversity switch.
    if (ant->flags & ANTENNA_TX_DIVERSITY && tx_ant != 3)
        ant->flags &= ~ANTENNA_TX_DIVERSITY;
    if (ant->flags & ANTENNA_RX_DIVERSITY && rx_ant != 3)
        ant->flags &= ~ANTENNA_RX_DIVERSITY;

    // If diversity is being enabled, check if we need hardware
    // or software diversity. In the latter case, reset the value,
    // and make sure we update the antenna flags to have the
    // link tuner pick up the diversity tuning.
    if (tx_ant == 3 && def->tx == ANTENNA_SW_DIVERSITY) {
        tx_ant = ANTENNA_SW_DIVERSITY;
        ant->flags |= ANTENNA_TX_DIVERSITY;
    }

    if (rx_ant == 3 && def->rx == ANTENNA_SW_DIVERSITY) {
        rx_ant = ANTENNA_SW_DIVERSITY;
        ant->flags |= ANTENNA_RX_DIVERSITY;
    }

    setup.tx = tx_ant;
    setup.rx = rx_ant;

    rt2x00lib_config_antenna(rt2x00dev, setup);

    return 0;
}
EXPORT_SYMBOL_GPL(rt2x00mac_set_antenna);

int rt2x00mac_get_antenna(struct ieee80211_hw *hw, u32 *tx_ant, u32 *rx_ant)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    struct link_ant *ant = &rt2x00dev->link.ant;
    struct antenna_setup *active = &rt2x00dev->link.ant.active;

    // When software diversity is active, we must report this to the
    // client and not the current active antenna state.
    if (ant->flags & ANTENNA_TX_DIVERSITY)
        *tx_ant = ANTENNA_HW_DIVERSITY;
    else
        *tx_ant = active->tx;

    if (ant->flags & ANTENNA_RX_DIVERSITY)
        *rx_ant = ANTENNA_HW_DIVERSITY;
    else
        *rx_ant = active->rx;

    return 0;
}
EXPORT_SYMBOL_GPL(rt2x00mac_get_antenna);

void rt2x00mac_get_ringparam(struct ieee80211_hw *hw,
                 u32 *tx, u32 *tx_max, u32 *rx, u32 *rx_max)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    struct data_queue *queue;

    tx_queue_for_each(rt2x00dev, queue) {
        *tx += queue->length;
        *tx_max += queue->limit;
    }

    *rx = rt2x00dev->rx->length;
    *rx_max = rt2x00dev->rx->limit;
}
EXPORT_SYMBOL_GPL(rt2x00mac_get_ringparam);

bool rt2x00mac_tx_frames_pending(struct ieee80211_hw *hw)
{
    struct rt2x00_dev *rt2x00dev = hw->priv;
    struct data_queue *queue;

    tx_queue_for_each(rt2x00dev, queue) {
        if (!rt2x00queue_empty(queue))
            return true;
    }

    return false;
}
EXPORT_SYMBOL_GPL(rt2x00mac_tx_frames_pending);