/*
        Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
        <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, see <http://www.gnu.org/licenses/>.
 */

/*
        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)) {
                rt2x00_warn(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, NULL, true);
        if (retval) {
                dev_kfree_skb_any(skb);
                rt2x00_warn(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 &&
            rt2x00_has_cap_flag(rt2x00dev, REQUIRE_ATIM_QUEUE))
                qid = QID_ATIM;

        queue = rt2x00queue_get_tx_queue(rt2x00dev, qid);
        if (unlikely(!queue)) {
                rt2x00_err(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, control->sta, 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 (!rt2x00_has_cap_control_filters(rt2x00dev)) {
                if (*total_flags & FIF_CONTROL || *total_flags & FIF_PSPOLL)
                        *total_flags |= FIF_CONTROL | FIF_PSPOLL;
        }
        if (!rt2x00_has_cap_control_filter_pspoll(rt2x00dev)) {
                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, IEEE80211_IFACE_ITER_RESUME_ALL,
                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 (!rt2x00_has_cap_hw_crypto(rt2x00dev))
                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;
        if (crypto.cipher == CIPHER_TKIP && rt2x00_is_usb(rt2x00dev))
                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 ieee80211_vif *vif,
                             const u8 *mac_addr)
{
        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 ieee80211_vif *vif)
{
        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);

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

                        if (rt2x00dev->intf_beaconing == 0) {
                                /*
                                 * Last beaconing interface disabled
                                 * -> stop beacon queue.
                                 */
                                rt2x00queue_stop_queue(rt2x00dev->bcn);
                        }
                        /*
                         * Clear beacon in the H/W for this vif. This is needed
                         * to disable beaconing on this particular interface
                         * and keep it running on other interfaces.
                         */
                        rt2x00queue_clear_beacon(rt2x00dev, vif);
                } else if (bss_conf->enable_beacon && !intf->enable_beacon) {
                        rt2x00dev->intf_beaconing++;
                        intf->enable_beacon = true;
                        /*
                         * Upload beacon to the H/W. This is only required on
                         * USB devices. PCI devices fetch beacons periodically.
                         */
                        if (rt2x00_is_usb(rt2x00dev))
                                rt2x00queue_update_beacon(rt2x00dev, vif);

                        if (rt2x00dev->intf_beaconing == 1) {
                                /*
                                 * First beaconing interface enabled
                                 * -> start beacon queue.
                                 */
                                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;

        rt2x00_dbg(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, struct ieee80211_vif *vif,
                     u32 queues, bool drop)
{
        struct rt2x00_dev *rt2x00dev = hw->priv;
        struct data_queue *queue;

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

        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;
        setup.rx_chain_num = 0;
        setup.tx_chain_num = 0;

        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);