htc_drv_txrx.c

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/*
 * Copyright (c) 2010-2011 Atheros Communications Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "htc.h"

/******/
/* TX */
/******/

static const int subtype_txq_to_hwq[] = {
    [WME_AC_BE] = ATH_TXQ_AC_BE,
    [WME_AC_BK] = ATH_TXQ_AC_BK,
    [WME_AC_VI] = ATH_TXQ_AC_VI,
    [WME_AC_VO] = ATH_TXQ_AC_VO,
};

#define ATH9K_HTC_INIT_TXQ(subtype) do {            \
        qi.tqi_subtype = subtype_txq_to_hwq[subtype];   \
        qi.tqi_aifs = ATH9K_TXQ_USEDEFAULT;     \
        qi.tqi_cwmin = ATH9K_TXQ_USEDEFAULT;        \
        qi.tqi_cwmax = ATH9K_TXQ_USEDEFAULT;        \
        qi.tqi_physCompBuf = 0;             \
        qi.tqi_qflags = TXQ_FLAG_TXEOLINT_ENABLE |  \
            TXQ_FLAG_TXDESCINT_ENABLE;      \
    } while (0)

int get_hw_qnum(u16 queue, int *hwq_map)
{
    switch (queue) {
    case 0:
        return hwq_map[WME_AC_VO];
    case 1:
        return hwq_map[WME_AC_VI];
    case 2:
        return hwq_map[WME_AC_BE];
    case 3:
        return hwq_map[WME_AC_BK];
    default:
        return hwq_map[WME_AC_BE];
    }
}

void ath9k_htc_check_stop_queues(struct ath9k_htc_priv *priv)
{
    spin_lock_bh(&priv->tx.tx_lock);
    priv->tx.queued_cnt++;
    if ((priv->tx.queued_cnt >= ATH9K_HTC_TX_THRESHOLD) &&
        !(priv->tx.flags & ATH9K_HTC_OP_TX_QUEUES_STOP)) {
        priv->tx.flags |= ATH9K_HTC_OP_TX_QUEUES_STOP;
        ieee80211_stop_queues(priv->hw);
    }
    spin_unlock_bh(&priv->tx.tx_lock);
}

void ath9k_htc_check_wake_queues(struct ath9k_htc_priv *priv)
{
    spin_lock_bh(&priv->tx.tx_lock);
    if ((priv->tx.queued_cnt < ATH9K_HTC_TX_THRESHOLD) &&
        (priv->tx.flags & ATH9K_HTC_OP_TX_QUEUES_STOP)) {
        priv->tx.flags &= ~ATH9K_HTC_OP_TX_QUEUES_STOP;
        ieee80211_wake_queues(priv->hw);
    }
    spin_unlock_bh(&priv->tx.tx_lock);
}

int ath9k_htc_tx_get_slot(struct ath9k_htc_priv *priv)
{
    int slot;

    spin_lock_bh(&priv->tx.tx_lock);
    slot = find_first_zero_bit(priv->tx.tx_slot, MAX_TX_BUF_NUM);
    if (slot >= MAX_TX_BUF_NUM) {
        spin_unlock_bh(&priv->tx.tx_lock);
        return -ENOBUFS;
    }
    __set_bit(slot, priv->tx.tx_slot);
    spin_unlock_bh(&priv->tx.tx_lock);

    return slot;
}

void ath9k_htc_tx_clear_slot(struct ath9k_htc_priv *priv, int slot)
{
    spin_lock_bh(&priv->tx.tx_lock);
    __clear_bit(slot, priv->tx.tx_slot);
    spin_unlock_bh(&priv->tx.tx_lock);
}

static inline enum htc_endpoint_id get_htc_epid(struct ath9k_htc_priv *priv,
                        u16 qnum)
{
    enum htc_endpoint_id epid;

    switch (qnum) {
    case 0:
        TX_QSTAT_INC(WME_AC_VO);
        epid = priv->data_vo_ep;
        break;
    case 1:
        TX_QSTAT_INC(WME_AC_VI);
        epid = priv->data_vi_ep;
        break;
    case 2:
        TX_QSTAT_INC(WME_AC_BE);
        epid = priv->data_be_ep;
        break;
    case 3:
    default:
        TX_QSTAT_INC(WME_AC_BK);
        epid = priv->data_bk_ep;
        break;
    }

    return epid;
}

static inline struct sk_buff_head*
get_htc_epid_queue(struct ath9k_htc_priv *priv, u8 epid)
{
    struct ath_common *common = ath9k_hw_common(priv->ah);
    struct sk_buff_head *epid_queue = NULL;

    if (epid == priv->mgmt_ep)
        epid_queue = &priv->tx.mgmt_ep_queue;
    else if (epid == priv->cab_ep)
        epid_queue = &priv->tx.cab_ep_queue;
    else if (epid == priv->data_be_ep)
        epid_queue = &priv->tx.data_be_queue;
    else if (epid == priv->data_bk_ep)
        epid_queue = &priv->tx.data_bk_queue;
    else if (epid == priv->data_vi_ep)
        epid_queue = &priv->tx.data_vi_queue;
    else if (epid == priv->data_vo_ep)
        epid_queue = &priv->tx.data_vo_queue;
    else
        ath_err(common, "Invalid EPID: %d\n", epid);

    return epid_queue;
}

/*
 * Removes the driver header and returns the TX slot number
 */
static inline int strip_drv_header(struct ath9k_htc_priv *priv,
                   struct sk_buff *skb)
{
    struct ath_common *common = ath9k_hw_common(priv->ah);
    struct ath9k_htc_tx_ctl *tx_ctl;
    int slot;

    tx_ctl = HTC_SKB_CB(skb);

    if (tx_ctl->epid == priv->mgmt_ep) {
        struct tx_mgmt_hdr *tx_mhdr =
            (struct tx_mgmt_hdr *)skb->data;
        slot = tx_mhdr->cookie;
        skb_pull(skb, sizeof(struct tx_mgmt_hdr));
    } else if ((tx_ctl->epid == priv->data_bk_ep) ||
           (tx_ctl->epid == priv->data_be_ep) ||
           (tx_ctl->epid == priv->data_vi_ep) ||
           (tx_ctl->epid == priv->data_vo_ep) ||
           (tx_ctl->epid == priv->cab_ep)) {
        struct tx_frame_hdr *tx_fhdr =
            (struct tx_frame_hdr *)skb->data;
        slot = tx_fhdr->cookie;
        skb_pull(skb, sizeof(struct tx_frame_hdr));
    } else {
        ath_err(common, "Unsupported EPID: %d\n", tx_ctl->epid);
        slot = -EINVAL;
    }

    return slot;
}

int ath_htc_txq_update(struct ath9k_htc_priv *priv, int qnum,
               struct ath9k_tx_queue_info *qinfo)
{
    struct ath_hw *ah = priv->ah;
    int error = 0;
    struct ath9k_tx_queue_info qi;

    ath9k_hw_get_txq_props(ah, qnum, &qi);

    qi.tqi_aifs = qinfo->tqi_aifs;
    qi.tqi_cwmin = qinfo->tqi_cwmin / 2; /* XXX */
    qi.tqi_cwmax = qinfo->tqi_cwmax;
    qi.tqi_burstTime = qinfo->tqi_burstTime;
    qi.tqi_readyTime = qinfo->tqi_readyTime;

    if (!ath9k_hw_set_txq_props(ah, qnum, &qi)) {
        ath_err(ath9k_hw_common(ah),
            "Unable to update hardware queue %u!\n", qnum);
        error = -EIO;
    } else {
        ath9k_hw_resettxqueue(ah, qnum);
    }

    return error;
}

static void ath9k_htc_tx_mgmt(struct ath9k_htc_priv *priv,
                  struct ath9k_htc_vif *avp,
                  struct sk_buff *skb,
                  u8 sta_idx, u8 vif_idx, u8 slot)
{
    struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
    struct ieee80211_mgmt *mgmt;
    struct ieee80211_hdr *hdr;
    struct tx_mgmt_hdr mgmt_hdr;
    struct ath9k_htc_tx_ctl *tx_ctl;
    u8 *tx_fhdr;

    tx_ctl = HTC_SKB_CB(skb);
    hdr = (struct ieee80211_hdr *) skb->data;

    memset(tx_ctl, 0, sizeof(*tx_ctl));
    memset(&mgmt_hdr, 0, sizeof(struct tx_mgmt_hdr));

    /*
     * Set the TSF adjust value for probe response
     * frame also.
     */
    if (avp && unlikely(ieee80211_is_probe_resp(hdr->frame_control))) {
        mgmt = (struct ieee80211_mgmt *)skb->data;
        mgmt->u.probe_resp.timestamp = avp->tsfadjust;
    }

    tx_ctl->type = ATH9K_HTC_MGMT;

    mgmt_hdr.node_idx = sta_idx;
    mgmt_hdr.vif_idx = vif_idx;
    mgmt_hdr.tidno = 0;
    mgmt_hdr.flags = 0;
    mgmt_hdr.cookie = slot;

    mgmt_hdr.key_type = ath9k_cmn_get_hw_crypto_keytype(skb);
    if (mgmt_hdr.key_type == ATH9K_KEY_TYPE_CLEAR)
        mgmt_hdr.keyix = (u8) ATH9K_TXKEYIX_INVALID;
    else
        mgmt_hdr.keyix = tx_info->control.hw_key->hw_key_idx;

    tx_fhdr = skb_push(skb, sizeof(mgmt_hdr));
    memcpy(tx_fhdr, (u8 *) &mgmt_hdr, sizeof(mgmt_hdr));
    tx_ctl->epid = priv->mgmt_ep;
}

static void ath9k_htc_tx_data(struct ath9k_htc_priv *priv,
                  struct ieee80211_vif *vif,
                  struct sk_buff *skb,
                  u8 sta_idx, u8 vif_idx, u8 slot,
                  bool is_cab)
{
    struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
    struct ieee80211_hdr *hdr;
    struct ath9k_htc_tx_ctl *tx_ctl;
    struct tx_frame_hdr tx_hdr;
    u32 flags = 0;
    u8 *qc, *tx_fhdr;
    u16 qnum;

    tx_ctl = HTC_SKB_CB(skb);
    hdr = (struct ieee80211_hdr *) skb->data;

    memset(tx_ctl, 0, sizeof(*tx_ctl));
    memset(&tx_hdr, 0, sizeof(struct tx_frame_hdr));

    tx_hdr.node_idx = sta_idx;
    tx_hdr.vif_idx = vif_idx;
    tx_hdr.cookie = slot;

    /*
     * This is a bit redundant but it helps to get
     * the per-packet index quickly when draining the
     * TX queue in the HIF layer. Otherwise we would
     * have to parse the packet contents ...
     */
    tx_ctl->sta_idx = sta_idx;

    if (tx_info->flags & IEEE80211_TX_CTL_AMPDU) {
        tx_ctl->type = ATH9K_HTC_AMPDU;
        tx_hdr.data_type = ATH9K_HTC_AMPDU;
    } else {
        tx_ctl->type = ATH9K_HTC_NORMAL;
        tx_hdr.data_type = ATH9K_HTC_NORMAL;
    }

    if (ieee80211_is_data_qos(hdr->frame_control)) {
        qc = ieee80211_get_qos_ctl(hdr);
        tx_hdr.tidno = qc[0] & IEEE80211_QOS_CTL_TID_MASK;
    }

    /* Check for RTS protection */
    if (priv->hw->wiphy->rts_threshold != (u32) -1)
        if (skb->len > priv->hw->wiphy->rts_threshold)
            flags |= ATH9K_HTC_TX_RTSCTS;

    /* CTS-to-self */
    if (!(flags & ATH9K_HTC_TX_RTSCTS) &&
        (vif && vif->bss_conf.use_cts_prot))
        flags |= ATH9K_HTC_TX_CTSONLY;

    tx_hdr.flags = cpu_to_be32(flags);
    tx_hdr.key_type = ath9k_cmn_get_hw_crypto_keytype(skb);
    if (tx_hdr.key_type == ATH9K_KEY_TYPE_CLEAR)
        tx_hdr.keyix = (u8) ATH9K_TXKEYIX_INVALID;
    else
        tx_hdr.keyix = tx_info->control.hw_key->hw_key_idx;

    tx_fhdr = skb_push(skb, sizeof(tx_hdr));
    memcpy(tx_fhdr, (u8 *) &tx_hdr, sizeof(tx_hdr));

    if (is_cab) {
        CAB_STAT_INC;
        tx_ctl->epid = priv->cab_ep;
        return;
    }

    qnum = skb_get_queue_mapping(skb);
    tx_ctl->epid = get_htc_epid(priv, qnum);
}

int ath9k_htc_tx_start(struct ath9k_htc_priv *priv,
               struct ieee80211_sta *sta,
               struct sk_buff *skb,
               u8 slot, bool is_cab)
{
    struct ieee80211_hdr *hdr;
    struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
    struct ieee80211_vif *vif = tx_info->control.vif;
    struct ath9k_htc_sta *ista;
    struct ath9k_htc_vif *avp = NULL;
    u8 sta_idx, vif_idx;

    hdr = (struct ieee80211_hdr *) skb->data;

    /*
     * Find out on which interface this packet has to be
     * sent out.
     */
    if (vif) {
        avp = (struct ath9k_htc_vif *) vif->drv_priv;
        vif_idx = avp->index;
    } else {
        if (!priv->ah->is_monitoring) {
            ath_dbg(ath9k_hw_common(priv->ah), XMIT,
                "VIF is null, but no monitor interface !\n");
            return -EINVAL;
        }

        vif_idx = priv->mon_vif_idx;
    }

    /*
     * Find out which station this packet is destined for.
     */
    if (sta) {
        ista = (struct ath9k_htc_sta *) sta->drv_priv;
        sta_idx = ista->index;
    } else {
        sta_idx = priv->vif_sta_pos[vif_idx];
    }

    if (ieee80211_is_data(hdr->frame_control))
        ath9k_htc_tx_data(priv, vif, skb,
                  sta_idx, vif_idx, slot, is_cab);
    else
        ath9k_htc_tx_mgmt(priv, avp, skb,
                  sta_idx, vif_idx, slot);


    return htc_send(priv->htc, skb);
}

static inline bool __ath9k_htc_check_tx_aggr(struct ath9k_htc_priv *priv,
                         struct ath9k_htc_sta *ista, u8 tid)
{
    bool ret = false;

    spin_lock_bh(&priv->tx.tx_lock);
    if ((tid < ATH9K_HTC_MAX_TID) && (ista->tid_state[tid] == AGGR_STOP))
        ret = true;
    spin_unlock_bh(&priv->tx.tx_lock);

    return ret;
}

static void ath9k_htc_check_tx_aggr(struct ath9k_htc_priv *priv,
                    struct ieee80211_vif *vif,
                    struct sk_buff *skb)
{
    struct ieee80211_sta *sta;
    struct ieee80211_hdr *hdr;
    __le16 fc;

    hdr = (struct ieee80211_hdr *) skb->data;
    fc = hdr->frame_control;

    rcu_read_lock();

    sta = ieee80211_find_sta(vif, hdr->addr1);
    if (!sta) {
        rcu_read_unlock();
        return;
    }

    if (sta && conf_is_ht(&priv->hw->conf) &&
        !(skb->protocol == cpu_to_be16(ETH_P_PAE))) {
        if (ieee80211_is_data_qos(fc)) {
            u8 *qc, tid;
            struct ath9k_htc_sta *ista;

            qc = ieee80211_get_qos_ctl(hdr);
            tid = qc[0] & 0xf;
            ista = (struct ath9k_htc_sta *)sta->drv_priv;
            if (__ath9k_htc_check_tx_aggr(priv, ista, tid)) {
                ieee80211_start_tx_ba_session(sta, tid, 0);
                spin_lock_bh(&priv->tx.tx_lock);
                ista->tid_state[tid] = AGGR_PROGRESS;
                spin_unlock_bh(&priv->tx.tx_lock);
            }
        }
    }

    rcu_read_unlock();
}

static void ath9k_htc_tx_process(struct ath9k_htc_priv *priv,
                 struct sk_buff *skb,
                 struct __wmi_event_txstatus *txs)
{
    struct ieee80211_vif *vif;
    struct ath9k_htc_tx_ctl *tx_ctl;
    struct ieee80211_tx_info *tx_info;
    struct ieee80211_tx_rate *rate;
    struct ieee80211_conf *cur_conf = &priv->hw->conf;
    bool txok;
    int slot;

    slot = strip_drv_header(priv, skb);
    if (slot < 0) {
        dev_kfree_skb_any(skb);
        return;
    }

    tx_ctl = HTC_SKB_CB(skb);
    txok = tx_ctl->txok;
    tx_info = IEEE80211_SKB_CB(skb);
    vif = tx_info->control.vif;
    rate = &tx_info->status.rates[0];

    memset(&tx_info->status, 0, sizeof(tx_info->status));

    /*
     * URB submission failed for this frame, it never reached
     * the target.
     */
    if (!txok || !vif || !txs)
        goto send_mac80211;

    if (txs->ts_flags & ATH9K_HTC_TXSTAT_ACK)
        tx_info->flags |= IEEE80211_TX_STAT_ACK;

    if (txs->ts_flags & ATH9K_HTC_TXSTAT_FILT)
        tx_info->flags |= IEEE80211_TX_STAT_TX_FILTERED;

    if (txs->ts_flags & ATH9K_HTC_TXSTAT_RTC_CTS)
        rate->flags |= IEEE80211_TX_RC_USE_RTS_CTS;

    rate->count = 1;
    rate->idx = MS(txs->ts_rate, ATH9K_HTC_TXSTAT_RATE);

    if (txs->ts_flags & ATH9K_HTC_TXSTAT_MCS) {
        rate->flags |= IEEE80211_TX_RC_MCS;

        if (txs->ts_flags & ATH9K_HTC_TXSTAT_CW40)
            rate->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
        if (txs->ts_flags & ATH9K_HTC_TXSTAT_SGI)
            rate->flags |= IEEE80211_TX_RC_SHORT_GI;
    } else {
        if (cur_conf->channel->band == IEEE80211_BAND_5GHZ)
            rate->idx += 4; /* No CCK rates */
    }

    ath9k_htc_check_tx_aggr(priv, vif, skb);

send_mac80211:
    spin_lock_bh(&priv->tx.tx_lock);
    if (WARN_ON(--priv->tx.queued_cnt < 0))
        priv->tx.queued_cnt = 0;
    spin_unlock_bh(&priv->tx.tx_lock);

    ath9k_htc_tx_clear_slot(priv, slot);

    /* Send status to mac80211 */
    ieee80211_tx_status(priv->hw, skb);
}

static inline void ath9k_htc_tx_drainq(struct ath9k_htc_priv *priv,
                       struct sk_buff_head *queue)
{
    struct sk_buff *skb;

    while ((skb = skb_dequeue(queue)) != NULL) {
        ath9k_htc_tx_process(priv, skb, NULL);
    }
}

void ath9k_htc_tx_drain(struct ath9k_htc_priv *priv)
{
    struct ath9k_htc_tx_event *event, *tmp;

    spin_lock_bh(&priv->tx.tx_lock);
    priv->tx.flags |= ATH9K_HTC_OP_TX_DRAIN;
    spin_unlock_bh(&priv->tx.tx_lock);

    /*
     * Ensure that all pending TX frames are flushed,
     * and that the TX completion/failed tasklets is killed.
     */
    htc_stop(priv->htc);
    tasklet_kill(&priv->wmi->wmi_event_tasklet);
    tasklet_kill(&priv->tx_failed_tasklet);

    ath9k_htc_tx_drainq(priv, &priv->tx.mgmt_ep_queue);
    ath9k_htc_tx_drainq(priv, &priv->tx.cab_ep_queue);
    ath9k_htc_tx_drainq(priv, &priv->tx.data_be_queue);
    ath9k_htc_tx_drainq(priv, &priv->tx.data_bk_queue);
    ath9k_htc_tx_drainq(priv, &priv->tx.data_vi_queue);
    ath9k_htc_tx_drainq(priv, &priv->tx.data_vo_queue);
    ath9k_htc_tx_drainq(priv, &priv->tx.tx_failed);

    /*
     * The TX cleanup timer has already been killed.
     */
    spin_lock_bh(&priv->wmi->event_lock);
    list_for_each_entry_safe(event, tmp, &priv->wmi->pending_tx_events, list) {
        list_del(&event->list);
        kfree(event);
    }
    spin_unlock_bh(&priv->wmi->event_lock);

    spin_lock_bh(&priv->tx.tx_lock);
    priv->tx.flags &= ~ATH9K_HTC_OP_TX_DRAIN;
    spin_unlock_bh(&priv->tx.tx_lock);
}

void ath9k_tx_failed_tasklet(unsigned long data)
{
    struct ath9k_htc_priv *priv = (struct ath9k_htc_priv *)data;

    spin_lock_bh(&priv->tx.tx_lock);
    if (priv->tx.flags & ATH9K_HTC_OP_TX_DRAIN) {
        spin_unlock_bh(&priv->tx.tx_lock);
        return;
    }
    spin_unlock_bh(&priv->tx.tx_lock);

    ath9k_htc_tx_drainq(priv, &priv->tx.tx_failed);
}

static inline bool check_cookie(struct ath9k_htc_priv *priv,
                struct sk_buff *skb,
                u8 cookie, u8 epid)
{
    u8 fcookie = 0;

    if (epid == priv->mgmt_ep) {
        struct tx_mgmt_hdr *hdr;
        hdr = (struct tx_mgmt_hdr *) skb->data;
        fcookie = hdr->cookie;
    } else if ((epid == priv->data_bk_ep) ||
           (epid == priv->data_be_ep) ||
           (epid == priv->data_vi_ep) ||
           (epid == priv->data_vo_ep) ||
           (epid == priv->cab_ep)) {
        struct tx_frame_hdr *hdr;
        hdr = (struct tx_frame_hdr *) skb->data;
        fcookie = hdr->cookie;
    }

    if (fcookie == cookie)
        return true;

    return false;
}

static struct sk_buff* ath9k_htc_tx_get_packet(struct ath9k_htc_priv *priv,
                           struct __wmi_event_txstatus *txs)
{
    struct ath_common *common = ath9k_hw_common(priv->ah);
    struct sk_buff_head *epid_queue;
    struct sk_buff *skb, *tmp;
    unsigned long flags;
    u8 epid = MS(txs->ts_rate, ATH9K_HTC_TXSTAT_EPID);

    epid_queue = get_htc_epid_queue(priv, epid);
    if (!epid_queue)
        return NULL;

    spin_lock_irqsave(&epid_queue->lock, flags);
    skb_queue_walk_safe(epid_queue, skb, tmp) {
        if (check_cookie(priv, skb, txs->cookie, epid)) {
            __skb_unlink(skb, epid_queue);
            spin_unlock_irqrestore(&epid_queue->lock, flags);
            return skb;
        }
    }
    spin_unlock_irqrestore(&epid_queue->lock, flags);

    ath_dbg(common, XMIT, "No matching packet for cookie: %d, epid: %d\n",
        txs->cookie, epid);

    return NULL;
}

void ath9k_htc_txstatus(struct ath9k_htc_priv *priv, void *wmi_event)
{
    struct wmi_event_txstatus *txs = (struct wmi_event_txstatus *)wmi_event;
    struct __wmi_event_txstatus *__txs;
    struct sk_buff *skb;
    struct ath9k_htc_tx_event *tx_pend;
    int i;

    for (i = 0; i < txs->cnt; i++) {
        WARN_ON(txs->cnt > HTC_MAX_TX_STATUS);

        __txs = &txs->txstatus[i];

        skb = ath9k_htc_tx_get_packet(priv, __txs);
        if (!skb) {
            /*
             * Store this event, so that the TX cleanup
             * routine can check later for the needed packet.
             */
            tx_pend = kzalloc(sizeof(struct ath9k_htc_tx_event),
                      GFP_ATOMIC);
            if (!tx_pend)
                continue;

            memcpy(&tx_pend->txs, __txs,
                   sizeof(struct __wmi_event_txstatus));

            spin_lock(&priv->wmi->event_lock);
            list_add_tail(&tx_pend->list,
                      &priv->wmi->pending_tx_events);
            spin_unlock(&priv->wmi->event_lock);

            continue;
        }

        ath9k_htc_tx_process(priv, skb, __txs);
    }

    /* Wake TX queues if needed */
    ath9k_htc_check_wake_queues(priv);
}

void ath9k_htc_txep(void *drv_priv, struct sk_buff *skb,
            enum htc_endpoint_id ep_id, bool txok)
{
    struct ath9k_htc_priv *priv = (struct ath9k_htc_priv *) drv_priv;
    struct ath9k_htc_tx_ctl *tx_ctl;
    struct sk_buff_head *epid_queue;

    tx_ctl = HTC_SKB_CB(skb);
    tx_ctl->txok = txok;
    tx_ctl->timestamp = jiffies;

    if (!txok) {
        skb_queue_tail(&priv->tx.tx_failed, skb);
        tasklet_schedule(&priv->tx_failed_tasklet);
        return;
    }

    epid_queue = get_htc_epid_queue(priv, ep_id);
    if (!epid_queue) {
        dev_kfree_skb_any(skb);
        return;
    }

    skb_queue_tail(epid_queue, skb);
}

static inline bool check_packet(struct ath9k_htc_priv *priv, struct sk_buff *skb)
{
    struct ath_common *common = ath9k_hw_common(priv->ah);
    struct ath9k_htc_tx_ctl *tx_ctl;

    tx_ctl = HTC_SKB_CB(skb);

    if (time_after(jiffies,
               tx_ctl->timestamp +
               msecs_to_jiffies(ATH9K_HTC_TX_TIMEOUT_INTERVAL))) {
        ath_dbg(common, XMIT, "Dropping a packet due to TX timeout\n");
        return true;
    }

    return false;
}

static void ath9k_htc_tx_cleanup_queue(struct ath9k_htc_priv *priv,
                       struct sk_buff_head *epid_queue)
{
    bool process = false;
    unsigned long flags;
    struct sk_buff *skb, *tmp;
    struct sk_buff_head queue;

    skb_queue_head_init(&queue);

    spin_lock_irqsave(&epid_queue->lock, flags);
    skb_queue_walk_safe(epid_queue, skb, tmp) {
        if (check_packet(priv, skb)) {
            __skb_unlink(skb, epid_queue);
            __skb_queue_tail(&queue, skb);
            process = true;
        }
    }
    spin_unlock_irqrestore(&epid_queue->lock, flags);

    if (process) {
        skb_queue_walk_safe(&queue, skb, tmp) {
            __skb_unlink(skb, &queue);
            ath9k_htc_tx_process(priv, skb, NULL);
        }
    }
}

void ath9k_htc_tx_cleanup_timer(unsigned long data)
{
    struct ath9k_htc_priv *priv = (struct ath9k_htc_priv *) data;
    struct ath_common *common = ath9k_hw_common(priv->ah);
    struct ath9k_htc_tx_event *event, *tmp;
    struct sk_buff *skb;

    spin_lock(&priv->wmi->event_lock);
    list_for_each_entry_safe(event, tmp, &priv->wmi->pending_tx_events, list) {

        skb = ath9k_htc_tx_get_packet(priv, &event->txs);
        if (skb) {
            ath_dbg(common, XMIT,
                "Found packet for cookie: %d, epid: %d\n",
                event->txs.cookie,
                MS(event->txs.ts_rate, ATH9K_HTC_TXSTAT_EPID));

            ath9k_htc_tx_process(priv, skb, &event->txs);
            list_del(&event->list);
            kfree(event);
            continue;
        }

        if (++event->count >= ATH9K_HTC_TX_TIMEOUT_COUNT) {
            list_del(&event->list);
            kfree(event);
        }
    }
    spin_unlock(&priv->wmi->event_lock);

    /*
     * Check if status-pending packets have to be cleaned up.
     */
    ath9k_htc_tx_cleanup_queue(priv, &priv->tx.mgmt_ep_queue);
    ath9k_htc_tx_cleanup_queue(priv, &priv->tx.cab_ep_queue);
    ath9k_htc_tx_cleanup_queue(priv, &priv->tx.data_be_queue);
    ath9k_htc_tx_cleanup_queue(priv, &priv->tx.data_bk_queue);
    ath9k_htc_tx_cleanup_queue(priv, &priv->tx.data_vi_queue);
    ath9k_htc_tx_cleanup_queue(priv, &priv->tx.data_vo_queue);

    /* Wake TX queues if needed */
    ath9k_htc_check_wake_queues(priv);

    mod_timer(&priv->tx.cleanup_timer,
          jiffies + msecs_to_jiffies(ATH9K_HTC_TX_CLEANUP_INTERVAL));
}

int ath9k_tx_init(struct ath9k_htc_priv *priv)
{
    skb_queue_head_init(&priv->tx.mgmt_ep_queue);
    skb_queue_head_init(&priv->tx.cab_ep_queue);
    skb_queue_head_init(&priv->tx.data_be_queue);
    skb_queue_head_init(&priv->tx.data_bk_queue);
    skb_queue_head_init(&priv->tx.data_vi_queue);
    skb_queue_head_init(&priv->tx.data_vo_queue);
    skb_queue_head_init(&priv->tx.tx_failed);
    return 0;
}

void ath9k_tx_cleanup(struct ath9k_htc_priv *priv)
{

}

bool ath9k_htc_txq_setup(struct ath9k_htc_priv *priv, int subtype)
{
    struct ath_hw *ah = priv->ah;
    struct ath_common *common = ath9k_hw_common(ah);
    struct ath9k_tx_queue_info qi;
    int qnum;

    memset(&qi, 0, sizeof(qi));
    ATH9K_HTC_INIT_TXQ(subtype);

    qnum = ath9k_hw_setuptxqueue(priv->ah, ATH9K_TX_QUEUE_DATA, &qi);
    if (qnum == -1)
        return false;

    if (qnum >= ARRAY_SIZE(priv->hwq_map)) {
        ath_err(common, "qnum %u out of range, max %zu!\n",
            qnum, ARRAY_SIZE(priv->hwq_map));
        ath9k_hw_releasetxqueue(ah, qnum);
        return false;
    }

    priv->hwq_map[subtype] = qnum;
    return true;
}

int ath9k_htc_cabq_setup(struct ath9k_htc_priv *priv)
{
    struct ath9k_tx_queue_info qi;

    memset(&qi, 0, sizeof(qi));
    ATH9K_HTC_INIT_TXQ(0);

    return ath9k_hw_setuptxqueue(priv->ah, ATH9K_TX_QUEUE_CAB, &qi);
}

/******/
/* RX */
/******/

/*
 * Calculate the RX filter to be set in the HW.
 */
u32 ath9k_htc_calcrxfilter(struct ath9k_htc_priv *priv)
{
#define RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)

    struct ath_hw *ah = priv->ah;
    u32 rfilt;

    rfilt = (ath9k_hw_getrxfilter(ah) & RX_FILTER_PRESERVE)
        | ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
        | ATH9K_RX_FILTER_MCAST;

    if (priv->rxfilter & FIF_PROBE_REQ)
        rfilt |= ATH9K_RX_FILTER_PROBEREQ;

    /*
     * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
     * mode interface or when in monitor mode. AP mode does not need this
     * since it receives all in-BSS frames anyway.
     */
    if (((ah->opmode != NL80211_IFTYPE_AP) &&
         (priv->rxfilter & FIF_PROMISC_IN_BSS)) ||
        ah->is_monitoring)
        rfilt |= ATH9K_RX_FILTER_PROM;

    if (priv->rxfilter & FIF_CONTROL)
        rfilt |= ATH9K_RX_FILTER_CONTROL;

    if ((ah->opmode == NL80211_IFTYPE_STATION) &&
        (priv->nvifs <= 1) &&
        !(priv->rxfilter & FIF_BCN_PRBRESP_PROMISC))
        rfilt |= ATH9K_RX_FILTER_MYBEACON;
    else
        rfilt |= ATH9K_RX_FILTER_BEACON;

    if (conf_is_ht(&priv->hw->conf)) {
        rfilt |= ATH9K_RX_FILTER_COMP_BAR;
        rfilt |= ATH9K_RX_FILTER_UNCOMP_BA_BAR;
    }

    if (priv->rxfilter & FIF_PSPOLL)
        rfilt |= ATH9K_RX_FILTER_PSPOLL;

    if (priv->nvifs > 1)
        rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;

    return rfilt;

#undef RX_FILTER_PRESERVE
}

/*
 * Recv initialization for opmode change.
 */
static void ath9k_htc_opmode_init(struct ath9k_htc_priv *priv)
{
    struct ath_hw *ah = priv->ah;
    u32 rfilt, mfilt[2];

    /* configure rx filter */
    rfilt = ath9k_htc_calcrxfilter(priv);
    ath9k_hw_setrxfilter(ah, rfilt);

    /* calculate and install multicast filter */
    mfilt[0] = mfilt[1] = ~0;
    ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
}

void ath9k_host_rx_init(struct ath9k_htc_priv *priv)
{
    ath9k_hw_rxena(priv->ah);
    ath9k_htc_opmode_init(priv);
    ath9k_hw_startpcureceive(priv->ah, test_bit(OP_SCANNING, &priv->op_flags));
    priv->rx.last_rssi = ATH_RSSI_DUMMY_MARKER;
}

static void ath9k_process_rate(struct ieee80211_hw *hw,
                   struct ieee80211_rx_status *rxs,
                   u8 rx_rate, u8 rs_flags)
{
    struct ieee80211_supported_band *sband;
    enum ieee80211_band band;
    unsigned int i = 0;

    if (rx_rate & 0x80) {
        /* HT rate */
        rxs->flag |= RX_FLAG_HT;
        if (rs_flags & ATH9K_RX_2040)
            rxs->flag |= RX_FLAG_40MHZ;
        if (rs_flags & ATH9K_RX_GI)
            rxs->flag |= RX_FLAG_SHORT_GI;
        rxs->rate_idx = rx_rate & 0x7f;
        return;
    }

    band = hw->conf.channel->band;
    sband = hw->wiphy->bands[band];

    for (i = 0; i < sband->n_bitrates; i++) {
        if (sband->bitrates[i].hw_value == rx_rate) {
            rxs->rate_idx = i;
            return;
        }
        if (sband->bitrates[i].hw_value_short == rx_rate) {
            rxs->rate_idx = i;
            rxs->flag |= RX_FLAG_SHORTPRE;
            return;
        }
    }

}

static bool ath9k_rx_prepare(struct ath9k_htc_priv *priv,
                 struct ath9k_htc_rxbuf *rxbuf,
                 struct ieee80211_rx_status *rx_status)

{
    struct ieee80211_hdr *hdr;
    struct ieee80211_hw *hw = priv->hw;
    struct sk_buff *skb = rxbuf->skb;
    struct ath_common *common = ath9k_hw_common(priv->ah);
    struct ath_htc_rx_status *rxstatus;
    int hdrlen, padpos, padsize;
    int last_rssi = ATH_RSSI_DUMMY_MARKER;
    __le16 fc;

    if (skb->len < HTC_RX_FRAME_HEADER_SIZE) {
        ath_err(common, "Corrupted RX frame, dropping (len: %d)\n",
            skb->len);
        goto rx_next;
    }

    rxstatus = (struct ath_htc_rx_status *)skb->data;

    if (be16_to_cpu(rxstatus->rs_datalen) -
        (skb->len - HTC_RX_FRAME_HEADER_SIZE) != 0) {
        ath_err(common,
            "Corrupted RX data len, dropping (dlen: %d, skblen: %d)\n",
            rxstatus->rs_datalen, skb->len);
        goto rx_next;
    }

    ath9k_htc_err_stat_rx(priv, rxstatus);

    /* Get the RX status information */
    memcpy(&rxbuf->rxstatus, rxstatus, HTC_RX_FRAME_HEADER_SIZE);
    skb_pull(skb, HTC_RX_FRAME_HEADER_SIZE);

    hdr = (struct ieee80211_hdr *)skb->data;
    fc = hdr->frame_control;
    hdrlen = ieee80211_get_hdrlen_from_skb(skb);

    padpos = ath9k_cmn_padpos(fc);

    padsize = padpos & 3;
    if (padsize && skb->len >= padpos+padsize+FCS_LEN) {
        memmove(skb->data + padsize, skb->data, padpos);
        skb_pull(skb, padsize);
    }

    memset(rx_status, 0, sizeof(struct ieee80211_rx_status));

    if (rxbuf->rxstatus.rs_status != 0) {
        if (rxbuf->rxstatus.rs_status & ATH9K_RXERR_CRC)
            rx_status->flag |= RX_FLAG_FAILED_FCS_CRC;
        if (rxbuf->rxstatus.rs_status & ATH9K_RXERR_PHY)
            goto rx_next;

        if (rxbuf->rxstatus.rs_status & ATH9K_RXERR_DECRYPT) {
            /* FIXME */
        } else if (rxbuf->rxstatus.rs_status & ATH9K_RXERR_MIC) {
            if (ieee80211_is_ctl(fc))
                /*
                 * Sometimes, we get invalid
                 * MIC failures on valid control frames.
                 * Remove these mic errors.
                 */
                rxbuf->rxstatus.rs_status &= ~ATH9K_RXERR_MIC;
            else
                rx_status->flag |= RX_FLAG_MMIC_ERROR;
        }

        /*
         * Reject error frames with the exception of
         * decryption and MIC failures. For monitor mode,
         * we also ignore the CRC error.
         */
        if (priv->ah->opmode == NL80211_IFTYPE_MONITOR) {
            if (rxbuf->rxstatus.rs_status &
                ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
                  ATH9K_RXERR_CRC))
                goto rx_next;
        } else {
            if (rxbuf->rxstatus.rs_status &
                ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
                goto rx_next;
            }
        }
    }

    if (!(rxbuf->rxstatus.rs_status & ATH9K_RXERR_DECRYPT)) {
        u8 keyix;
        keyix = rxbuf->rxstatus.rs_keyix;
        if (keyix != ATH9K_RXKEYIX_INVALID) {
            rx_status->flag |= RX_FLAG_DECRYPTED;
        } else if (ieee80211_has_protected(fc) &&
               skb->len >= hdrlen + 4) {
            keyix = skb->data[hdrlen + 3] >> 6;
            if (test_bit(keyix, common->keymap))
                rx_status->flag |= RX_FLAG_DECRYPTED;
        }
    }

    ath9k_process_rate(hw, rx_status, rxbuf->rxstatus.rs_rate,
               rxbuf->rxstatus.rs_flags);

    if (rxbuf->rxstatus.rs_rssi != ATH9K_RSSI_BAD &&
        !rxbuf->rxstatus.rs_moreaggr)
        ATH_RSSI_LPF(priv->rx.last_rssi,
                 rxbuf->rxstatus.rs_rssi);

    last_rssi = priv->rx.last_rssi;

    if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
        rxbuf->rxstatus.rs_rssi = ATH_EP_RND(last_rssi,
                             ATH_RSSI_EP_MULTIPLIER);

    if (rxbuf->rxstatus.rs_rssi < 0)
        rxbuf->rxstatus.rs_rssi = 0;

    if (ieee80211_is_beacon(fc))
        priv->ah->stats.avgbrssi = rxbuf->rxstatus.rs_rssi;

    rx_status->mactime = be64_to_cpu(rxbuf->rxstatus.rs_tstamp);
    rx_status->band = hw->conf.channel->band;
    rx_status->freq = hw->conf.channel->center_freq;
    rx_status->signal =  rxbuf->rxstatus.rs_rssi + ATH_DEFAULT_NOISE_FLOOR;
    rx_status->antenna = rxbuf->rxstatus.rs_antenna;
    rx_status->flag |= RX_FLAG_MACTIME_MPDU;

    return true;

rx_next:
    return false;
}

/*
 * FIXME: Handle FLUSH later on.
 */
void ath9k_rx_tasklet(unsigned long data)
{
    struct ath9k_htc_priv *priv = (struct ath9k_htc_priv *)data;
    struct ath9k_htc_rxbuf *rxbuf = NULL, *tmp_buf = NULL;
    struct ieee80211_rx_status rx_status;
    struct sk_buff *skb;
    unsigned long flags;
    struct ieee80211_hdr *hdr;

    do {
        spin_lock_irqsave(&priv->rx.rxbuflock, flags);
        list_for_each_entry(tmp_buf, &priv->rx.rxbuf, list) {
            if (tmp_buf->in_process) {
                rxbuf = tmp_buf;
                break;
            }
        }

        if (rxbuf == NULL) {
            spin_unlock_irqrestore(&priv->rx.rxbuflock, flags);
            break;
        }

        if (!rxbuf->skb)
            goto requeue;

        if (!ath9k_rx_prepare(priv, rxbuf, &rx_status)) {
            dev_kfree_skb_any(rxbuf->skb);
            goto requeue;
        }

        memcpy(IEEE80211_SKB_RXCB(rxbuf->skb), &rx_status,
               sizeof(struct ieee80211_rx_status));
        skb = rxbuf->skb;
        hdr = (struct ieee80211_hdr *) skb->data;

        if (ieee80211_is_beacon(hdr->frame_control) && priv->ps_enabled)
                ieee80211_queue_work(priv->hw, &priv->ps_work);

        spin_unlock_irqrestore(&priv->rx.rxbuflock, flags);

        ieee80211_rx(priv->hw, skb);

        spin_lock_irqsave(&priv->rx.rxbuflock, flags);
requeue:
        rxbuf->in_process = false;
        rxbuf->skb = NULL;
        list_move_tail(&rxbuf->list, &priv->rx.rxbuf);
        rxbuf = NULL;
        spin_unlock_irqrestore(&priv->rx.rxbuflock, flags);
    } while (1);

}

void ath9k_htc_rxep(void *drv_priv, struct sk_buff *skb,
            enum htc_endpoint_id ep_id)
{
    struct ath9k_htc_priv *priv = (struct ath9k_htc_priv *)drv_priv;
    struct ath_hw *ah = priv->ah;
    struct ath_common *common = ath9k_hw_common(ah);
    struct ath9k_htc_rxbuf *rxbuf = NULL, *tmp_buf = NULL;

    spin_lock(&priv->rx.rxbuflock);
    list_for_each_entry(tmp_buf, &priv->rx.rxbuf, list) {
        if (!tmp_buf->in_process) {
            rxbuf = tmp_buf;
            break;
        }
    }
    spin_unlock(&priv->rx.rxbuflock);

    if (rxbuf == NULL) {
        ath_dbg(common, ANY, "No free RX buffer\n");
        goto err;
    }

    spin_lock(&priv->rx.rxbuflock);
    rxbuf->skb = skb;
    rxbuf->in_process = true;
    spin_unlock(&priv->rx.rxbuflock);

    tasklet_schedule(&priv->rx_tasklet);
    return;
err:
    dev_kfree_skb_any(skb);
}

/* FIXME: Locking for cleanup/init */

void ath9k_rx_cleanup(struct ath9k_htc_priv *priv)
{
    struct ath9k_htc_rxbuf *rxbuf, *tbuf;

    list_for_each_entry_safe(rxbuf, tbuf, &priv->rx.rxbuf, list) {
        list_del(&rxbuf->list);
        if (rxbuf->skb)
            dev_kfree_skb_any(rxbuf->skb);
        kfree(rxbuf);
    }
}

int ath9k_rx_init(struct ath9k_htc_priv *priv)
{
    struct ath_hw *ah = priv->ah;
    struct ath_common *common = ath9k_hw_common(ah);
    struct ath9k_htc_rxbuf *rxbuf;
    int i = 0;

    INIT_LIST_HEAD(&priv->rx.rxbuf);
    spin_lock_init(&priv->rx.rxbuflock);

    for (i = 0; i < ATH9K_HTC_RXBUF; i++) {
        rxbuf = kzalloc(sizeof(struct ath9k_htc_rxbuf), GFP_KERNEL);
        if (rxbuf == NULL) {
            ath_err(common, "Unable to allocate RX buffers\n");
            goto err;
        }
        list_add_tail(&rxbuf->list, &priv->rx.rxbuf);
    }

    return 0;

err:
    ath9k_rx_cleanup(priv);
    return -ENOMEM;
}