/*
 * Copyright (c) 2004-2011 Atheros Communications Inc.
 * Copyright (c) 2011-2012 Qualcomm Atheros, 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include "core.h"
#include "debug.h"
#include "htc-ops.h"
#include "trace.h"

/*
 * tid - tid_mux0..tid_mux3
 * aid - tid_mux4..tid_mux7
 */
#define ATH6KL_TID_MASK 0xf
#define ATH6KL_AID_SHIFT 4

static inline u8 ath6kl_get_tid(u8 tid_mux)
{
        return tid_mux & ATH6KL_TID_MASK;
}

static inline u8 ath6kl_get_aid(u8 tid_mux)
{
        return tid_mux >> ATH6KL_AID_SHIFT;
}

static u8 ath6kl_ibss_map_epid(struct sk_buff *skb, struct net_device *dev,
                               u32 *map_no)
{
        struct ath6kl *ar = ath6kl_priv(dev);
        struct ethhdr *eth_hdr;
        u32 i, ep_map = -1;
        u8 *datap;

        *map_no = 0;
        datap = skb->data;
        eth_hdr = (struct ethhdr *) (datap + sizeof(struct wmi_data_hdr));

        if (is_multicast_ether_addr(eth_hdr->h_dest))
                return ENDPOINT_2;

        for (i = 0; i < ar->node_num; i++) {
                if (memcmp(eth_hdr->h_dest, ar->node_map[i].mac_addr,
                           ETH_ALEN) == 0) {
                        *map_no = i + 1;
                        ar->node_map[i].tx_pend++;
                        return ar->node_map[i].ep_id;
                }

                if ((ep_map == -1) && !ar->node_map[i].tx_pend)
                        ep_map = i;
        }

        if (ep_map == -1) {
                ep_map = ar->node_num;
                ar->node_num++;
                if (ar->node_num > MAX_NODE_NUM)
                        return ENDPOINT_UNUSED;
        }

        memcpy(ar->node_map[ep_map].mac_addr, eth_hdr->h_dest, ETH_ALEN);

        for (i = ENDPOINT_2; i <= ENDPOINT_5; i++) {
                if (!ar->tx_pending[i]) {
                        ar->node_map[ep_map].ep_id = i;
                        break;
                }

                /*
                 * No free endpoint is available, start redistribution on
                 * the inuse endpoints.
                 */
                if (i == ENDPOINT_5) {
                        ar->node_map[ep_map].ep_id = ar->next_ep_id;
                        ar->next_ep_id++;
                        if (ar->next_ep_id > ENDPOINT_5)
                                ar->next_ep_id = ENDPOINT_2;
                }
        }

        *map_no = ep_map + 1;
        ar->node_map[ep_map].tx_pend++;

        return ar->node_map[ep_map].ep_id;
}

static bool ath6kl_process_uapsdq(struct ath6kl_sta *conn,
                                struct ath6kl_vif *vif,
                                struct sk_buff *skb,
                                u32 *flags)
{
        struct ath6kl *ar = vif->ar;
        bool is_apsdq_empty = false;
        struct ethhdr *datap = (struct ethhdr *) skb->data;
        u8 up = 0, traffic_class, *ip_hdr;
        u16 ether_type;
        struct ath6kl_llc_snap_hdr *llc_hdr;

        if (conn->sta_flags & STA_PS_APSD_TRIGGER) {
                /*
                 * This tx is because of a uAPSD trigger, determine
                 * more and EOSP bit. Set EOSP if queue is empty
                 * or sufficient frames are delivered for this trigger.
                 */
                spin_lock_bh(&conn->psq_lock);
                if (!skb_queue_empty(&conn->apsdq))
                        *flags |= WMI_DATA_HDR_FLAGS_MORE;
                else if (conn->sta_flags & STA_PS_APSD_EOSP)
                        *flags |= WMI_DATA_HDR_FLAGS_EOSP;
                *flags |= WMI_DATA_HDR_FLAGS_UAPSD;
                spin_unlock_bh(&conn->psq_lock);
                return false;
        } else if (!conn->apsd_info) {
                return false;
        }

        if (test_bit(WMM_ENABLED, &vif->flags)) {
                ether_type = be16_to_cpu(datap->h_proto);
                if (is_ethertype(ether_type)) {
                        /* packet is in DIX format  */
                        ip_hdr = (u8 *)(datap + 1);
                } else {
                        /* packet is in 802.3 format */
                        llc_hdr = (struct ath6kl_llc_snap_hdr *)
                                                        (datap + 1);
                        ether_type = be16_to_cpu(llc_hdr->eth_type);
                        ip_hdr = (u8 *)(llc_hdr + 1);
                }

                if (ether_type == IP_ETHERTYPE)
                        up = ath6kl_wmi_determine_user_priority(
                                                        ip_hdr, 0);
        }

        traffic_class = ath6kl_wmi_get_traffic_class(up);

        if ((conn->apsd_info & (1 << traffic_class)) == 0)
                return false;

        /* Queue the frames if the STA is sleeping */
        spin_lock_bh(&conn->psq_lock);
        is_apsdq_empty = skb_queue_empty(&conn->apsdq);
        skb_queue_tail(&conn->apsdq, skb);
        spin_unlock_bh(&conn->psq_lock);

        /*
         * If this is the first pkt getting queued
         * for this STA, update the PVB for this STA
         */
        if (is_apsdq_empty) {
                ath6kl_wmi_set_apsd_bfrd_traf(ar->wmi,
                                              vif->fw_vif_idx,
                                              conn->aid, 1, 0);
        }
        *flags |= WMI_DATA_HDR_FLAGS_UAPSD;

        return true;
}

static bool ath6kl_process_psq(struct ath6kl_sta *conn,
                                struct ath6kl_vif *vif,
                                struct sk_buff *skb,
                                u32 *flags)
{
        bool is_psq_empty = false;
        struct ath6kl *ar = vif->ar;

        if (conn->sta_flags & STA_PS_POLLED) {
                spin_lock_bh(&conn->psq_lock);
                if (!skb_queue_empty(&conn->psq))
                        *flags |= WMI_DATA_HDR_FLAGS_MORE;
                spin_unlock_bh(&conn->psq_lock);
                return false;
        }

        /* Queue the frames if the STA is sleeping */
        spin_lock_bh(&conn->psq_lock);
        is_psq_empty = skb_queue_empty(&conn->psq);
        skb_queue_tail(&conn->psq, skb);
        spin_unlock_bh(&conn->psq_lock);

        /*
         * If this is the first pkt getting queued
         * for this STA, update the PVB for this
         * STA.
         */
        if (is_psq_empty)
                ath6kl_wmi_set_pvb_cmd(ar->wmi,
                                       vif->fw_vif_idx,
                                       conn->aid, 1);
        return true;
}

static bool ath6kl_powersave_ap(struct ath6kl_vif *vif, struct sk_buff *skb,
                                u32 *flags)
{
        struct ethhdr *datap = (struct ethhdr *) skb->data;
        struct ath6kl_sta *conn = NULL;
        bool ps_queued = false;
        struct ath6kl *ar = vif->ar;

        if (is_multicast_ether_addr(datap->h_dest)) {
                u8 ctr = 0;
                bool q_mcast = false;

                for (ctr = 0; ctr < AP_MAX_NUM_STA; ctr++) {
                        if (ar->sta_list[ctr].sta_flags & STA_PS_SLEEP) {
                                q_mcast = true;
                                break;
                        }
                }

                if (q_mcast) {
                        /*
                         * If this transmit is not because of a Dtim Expiry
                         * q it.
                         */
                        if (!test_bit(DTIM_EXPIRED, &vif->flags)) {
                                bool is_mcastq_empty = false;

                                spin_lock_bh(&ar->mcastpsq_lock);
                                is_mcastq_empty =
                                        skb_queue_empty(&ar->mcastpsq);
                                skb_queue_tail(&ar->mcastpsq, skb);
                                spin_unlock_bh(&ar->mcastpsq_lock);

                                /*
                                 * If this is the first Mcast pkt getting
                                 * queued indicate to the target to set the
                                 * BitmapControl LSB of the TIM IE.
                                 */
                                if (is_mcastq_empty)
                                        ath6kl_wmi_set_pvb_cmd(ar->wmi,
                                                               vif->fw_vif_idx,
                                                               MCAST_AID, 1);

                                ps_queued = true;
                        } else {
                                /*
                                 * This transmit is because of Dtim expiry.
                                 * Determine if MoreData bit has to be set.
                                 */
                                spin_lock_bh(&ar->mcastpsq_lock);
                                if (!skb_queue_empty(&ar->mcastpsq))
                                        *flags |= WMI_DATA_HDR_FLAGS_MORE;
                                spin_unlock_bh(&ar->mcastpsq_lock);
                        }
                }
        } else {
                conn = ath6kl_find_sta(vif, datap->h_dest);
                if (!conn) {
                        dev_kfree_skb(skb);

                        /* Inform the caller that the skb is consumed */
                        return true;
                }

                if (conn->sta_flags & STA_PS_SLEEP) {
                        ps_queued = ath6kl_process_uapsdq(conn,
                                                vif, skb, flags);
                        if (!(*flags & WMI_DATA_HDR_FLAGS_UAPSD))
                                ps_queued = ath6kl_process_psq(conn,
                                                vif, skb, flags);
                }
        }
        return ps_queued;
}

/* Tx functions */

int ath6kl_control_tx(void *devt, struct sk_buff *skb,
                      enum htc_endpoint_id eid)
{
        struct ath6kl *ar = devt;
        int status = 0;
        struct ath6kl_cookie *cookie = NULL;

        trace_ath6kl_wmi_cmd(skb->data, skb->len);

        if (WARN_ON_ONCE(ar->state == ATH6KL_STATE_WOW)) {
                dev_kfree_skb(skb);
                return -EACCES;
        }

        if (WARN_ON_ONCE(eid == ENDPOINT_UNUSED ||
                         eid >= ENDPOINT_MAX)) {
                status = -EINVAL;
                goto fail_ctrl_tx;
        }

        spin_lock_bh(&ar->lock);

        ath6kl_dbg(ATH6KL_DBG_WLAN_TX,
                   "%s: skb=0x%p, len=0x%x eid =%d\n", __func__,
                   skb, skb->len, eid);

        if (test_bit(WMI_CTRL_EP_FULL, &ar->flag) && (eid == ar->ctrl_ep)) {
                /*
                 * Control endpoint is full, don't allocate resources, we
                 * are just going to drop this packet.
                 */
                cookie = NULL;
                ath6kl_err("wmi ctrl ep full, dropping pkt : 0x%p, len:%d\n",
                           skb, skb->len);
        } else {
                cookie = ath6kl_alloc_cookie(ar);
        }

        if (cookie == NULL) {
                spin_unlock_bh(&ar->lock);
                status = -ENOMEM;
                goto fail_ctrl_tx;
        }

        ar->tx_pending[eid]++;

        if (eid != ar->ctrl_ep)
                ar->total_tx_data_pend++;

        spin_unlock_bh(&ar->lock);

        cookie->skb = skb;
        cookie->map_no = 0;
        set_htc_pkt_info(&cookie->htc_pkt, cookie, skb->data, skb->len,
                         eid, ATH6KL_CONTROL_PKT_TAG);
        cookie->htc_pkt.skb = skb;

        /*
         * This interface is asynchronous, if there is an error, cleanup
         * will happen in the TX completion callback.
         */
        ath6kl_htc_tx(ar->htc_target, &cookie->htc_pkt);

        return 0;

fail_ctrl_tx:
        dev_kfree_skb(skb);
        return status;
}

netdev_tx_t ath6kl_data_tx(struct sk_buff *skb, struct net_device *dev)
{
        struct ath6kl *ar = ath6kl_priv(dev);
        struct ath6kl_cookie *cookie = NULL;
        enum htc_endpoint_id eid = ENDPOINT_UNUSED;
        struct ath6kl_vif *vif = netdev_priv(dev);
        u32 map_no = 0;
        u16 htc_tag = ATH6KL_DATA_PKT_TAG;
        u8 ac = 99; /* initialize to unmapped ac */
        bool chk_adhoc_ps_mapping = false;
        int ret;
        struct wmi_tx_meta_v2 meta_v2;
        void *meta;
        u8 csum_start = 0, csum_dest = 0, csum = skb->ip_summed;
        u8 meta_ver = 0;
        u32 flags = 0;

        ath6kl_dbg(ATH6KL_DBG_WLAN_TX,
                   "%s: skb=0x%p, data=0x%p, len=0x%x\n", __func__,
                   skb, skb->data, skb->len);

        /* If target is not associated */
        if (!test_bit(CONNECTED, &vif->flags))
                goto fail_tx;

        if (WARN_ON_ONCE(ar->state != ATH6KL_STATE_ON))
                goto fail_tx;

        if (!test_bit(WMI_READY, &ar->flag))
                goto fail_tx;

        /* AP mode Power saving processing */
        if (vif->nw_type == AP_NETWORK) {
                if (ath6kl_powersave_ap(vif, skb, &flags))
                        return 0;
        }

        if (test_bit(WMI_ENABLED, &ar->flag)) {
                if ((dev->features & NETIF_F_IP_CSUM) &&
                    (csum == CHECKSUM_PARTIAL)) {
                        csum_start = skb->csum_start -
                                        (skb_network_header(skb) - skb->head) +
                                        sizeof(struct ath6kl_llc_snap_hdr);
                        csum_dest = skb->csum_offset + csum_start;
                }

                if (skb_cow_head(skb, dev->needed_headroom)) {
                        dev->stats.tx_dropped++;
                        kfree_skb(skb);
                        return 0;
                }

                if (ath6kl_wmi_dix_2_dot3(ar->wmi, skb)) {
                        ath6kl_err("ath6kl_wmi_dix_2_dot3 failed\n");
                        goto fail_tx;
                }

                if ((dev->features & NETIF_F_IP_CSUM) &&
                    (csum == CHECKSUM_PARTIAL)) {
                        meta_v2.csum_start = csum_start;
                        meta_v2.csum_dest = csum_dest;

                        /* instruct target to calculate checksum */
                        meta_v2.csum_flags = WMI_META_V2_FLAG_CSUM_OFFLOAD;
                        meta_ver = WMI_META_VERSION_2;
                        meta = &meta_v2;
                } else {
                        meta_ver = 0;
                        meta = NULL;
                }

                ret = ath6kl_wmi_data_hdr_add(ar->wmi, skb,
                                DATA_MSGTYPE, flags, 0,
                                meta_ver,
                                meta, vif->fw_vif_idx);

                if (ret) {
                        ath6kl_warn("failed to add wmi data header:%d\n"
                                , ret);
                        goto fail_tx;
                }

                if ((vif->nw_type == ADHOC_NETWORK) &&
                    ar->ibss_ps_enable && test_bit(CONNECTED, &vif->flags))
                        chk_adhoc_ps_mapping = true;
                else {
                        /* get the stream mapping */
                        ret = ath6kl_wmi_implicit_create_pstream(ar->wmi,
                                    vif->fw_vif_idx, skb,
                                    0, test_bit(WMM_ENABLED, &vif->flags), &ac);
                        if (ret)
                                goto fail_tx;
                }
        } else {
                goto fail_tx;
        }

        spin_lock_bh(&ar->lock);

        if (chk_adhoc_ps_mapping)
                eid = ath6kl_ibss_map_epid(skb, dev, &map_no);
        else
                eid = ar->ac2ep_map[ac];

        if (eid == 0 || eid == ENDPOINT_UNUSED) {
                ath6kl_err("eid %d is not mapped!\n", eid);
                spin_unlock_bh(&ar->lock);
                goto fail_tx;
        }

        /* allocate resource for this packet */
        cookie = ath6kl_alloc_cookie(ar);

        if (!cookie) {
                spin_unlock_bh(&ar->lock);
                goto fail_tx;
        }

        /* update counts while the lock is held */
        ar->tx_pending[eid]++;
        ar->total_tx_data_pend++;

        spin_unlock_bh(&ar->lock);

        if (!IS_ALIGNED((unsigned long) skb->data - HTC_HDR_LENGTH, 4) &&
            skb_cloned(skb)) {
                /*
                 * We will touch (move the buffer data to align it. Since the
                 * skb buffer is cloned and not only the header is changed, we
                 * have to copy it to allow the changes. Since we are copying
                 * the data here, we may as well align it by reserving suitable
                 * headroom to avoid the memmove in ath6kl_htc_tx_buf_align().
                 */
                struct sk_buff *nskb;

                nskb = skb_copy_expand(skb, HTC_HDR_LENGTH, 0, GFP_ATOMIC);
                if (nskb == NULL)
                        goto fail_tx;
                kfree_skb(skb);
                skb = nskb;
        }

        cookie->skb = skb;
        cookie->map_no = map_no;
        set_htc_pkt_info(&cookie->htc_pkt, cookie, skb->data, skb->len,
                         eid, htc_tag);
        cookie->htc_pkt.skb = skb;

        ath6kl_dbg_dump(ATH6KL_DBG_RAW_BYTES, __func__, "tx ",
                        skb->data, skb->len);

        /*
         * HTC interface is asynchronous, if this fails, cleanup will
         * happen in the ath6kl_tx_complete callback.
         */
        ath6kl_htc_tx(ar->htc_target, &cookie->htc_pkt);

        return 0;

fail_tx:
        dev_kfree_skb(skb);

        dev->stats.tx_dropped++;
        dev->stats.tx_aborted_errors++;

        return 0;
}

/* indicate tx activity or inactivity on a WMI stream */
void ath6kl_indicate_tx_activity(void *devt, u8 traffic_class, bool active)
{
        struct ath6kl *ar = devt;
        enum htc_endpoint_id eid;
        int i;

        eid = ar->ac2ep_map[traffic_class];

        if (!test_bit(WMI_ENABLED, &ar->flag))
                goto notify_htc;

        spin_lock_bh(&ar->lock);

        ar->ac_stream_active[traffic_class] = active;

        if (active) {
                /*
                 * Keep track of the active stream with the highest
                 * priority.
                 */
                if (ar->ac_stream_pri_map[traffic_class] >
                    ar->hiac_stream_active_pri)
                        /* set the new highest active priority */
                        ar->hiac_stream_active_pri =
                                        ar->ac_stream_pri_map[traffic_class];

        } else {
                /*
                 * We may have to search for the next active stream
                 * that is the highest priority.
                 */
                if (ar->hiac_stream_active_pri ==
                        ar->ac_stream_pri_map[traffic_class]) {
                        /*
                         * The highest priority stream just went inactive
                         * reset and search for the "next" highest "active"
                         * priority stream.
                         */
                        ar->hiac_stream_active_pri = 0;

                        for (i = 0; i < WMM_NUM_AC; i++) {
                                if (ar->ac_stream_active[i] &&
                                    (ar->ac_stream_pri_map[i] >
                                     ar->hiac_stream_active_pri))
                                        /*
                                         * Set the new highest active
                                         * priority.
                                         */
                                        ar->hiac_stream_active_pri =
                                                ar->ac_stream_pri_map[i];
                        }
                }
        }

        spin_unlock_bh(&ar->lock);

notify_htc:
        /* notify HTC, this may cause credit distribution changes */
        ath6kl_htc_activity_changed(ar->htc_target, eid, active);
}

enum htc_send_full_action ath6kl_tx_queue_full(struct htc_target *target,
                                               struct htc_packet *packet)
{
        struct ath6kl *ar = target->dev->ar;
        struct ath6kl_vif *vif;
        enum htc_endpoint_id endpoint = packet->endpoint;
        enum htc_send_full_action action = HTC_SEND_FULL_KEEP;

        if (endpoint == ar->ctrl_ep) {
                /*
                 * Under normal WMI if this is getting full, then something
                 * is running rampant the host should not be exhausting the
                 * WMI queue with too many commands the only exception to
                 * this is during testing using endpointping.
                 */
                set_bit(WMI_CTRL_EP_FULL, &ar->flag);
                ath6kl_err("wmi ctrl ep is full\n");
                ath6kl_recovery_err_notify(ar, ATH6KL_FW_EP_FULL);
                return action;
        }

        if (packet->info.tx.tag == ATH6KL_CONTROL_PKT_TAG)
                return action;

        /*
         * The last MAX_HI_COOKIE_NUM "batch" of cookies are reserved for
         * the highest active stream.
         */
        if (ar->ac_stream_pri_map[ar->ep2ac_map[endpoint]] <
            ar->hiac_stream_active_pri &&
            ar->cookie_count <=
                        target->endpoint[endpoint].tx_drop_packet_threshold)
                /*
                 * Give preference to the highest priority stream by
                 * dropping the packets which overflowed.
                 */
                action = HTC_SEND_FULL_DROP;

        /* FIXME: Locking */
        spin_lock_bh(&ar->list_lock);
        list_for_each_entry(vif, &ar->vif_list, list) {
                if (vif->nw_type == ADHOC_NETWORK ||
                    action != HTC_SEND_FULL_DROP) {
                        spin_unlock_bh(&ar->list_lock);

                        set_bit(NETQ_STOPPED, &vif->flags);
                        netif_stop_queue(vif->ndev);

                        return action;
                }
        }
        spin_unlock_bh(&ar->list_lock);

        return action;
}

/* TODO this needs to be looked at */
static void ath6kl_tx_clear_node_map(struct ath6kl_vif *vif,
                                     enum htc_endpoint_id eid, u32 map_no)
{
        struct ath6kl *ar = vif->ar;
        u32 i;

        if (vif->nw_type != ADHOC_NETWORK)
                return;

        if (!ar->ibss_ps_enable)
                return;

        if (eid == ar->ctrl_ep)
                return;

        if (map_no == 0)
                return;

        map_no--;
        ar->node_map[map_no].tx_pend--;

        if (ar->node_map[map_no].tx_pend)
                return;

        if (map_no != (ar->node_num - 1))
                return;

        for (i = ar->node_num; i > 0; i--) {
                if (ar->node_map[i - 1].tx_pend)
                        break;

                memset(&ar->node_map[i - 1], 0,
                       sizeof(struct ath6kl_node_mapping));
                ar->node_num--;
        }
}

void ath6kl_tx_complete(struct htc_target *target,
                        struct list_head *packet_queue)
{
        struct ath6kl *ar = target->dev->ar;
        struct sk_buff_head skb_queue;
        struct htc_packet *packet;
        struct sk_buff *skb;
        struct ath6kl_cookie *ath6kl_cookie;
        u32 map_no = 0;
        int status;
        enum htc_endpoint_id eid;
        bool wake_event = false;
        bool flushing[ATH6KL_VIF_MAX] = {false};
        u8 if_idx;
        struct ath6kl_vif *vif;

        skb_queue_head_init(&skb_queue);

        /* lock the driver as we update internal state */
        spin_lock_bh(&ar->lock);

        /* reap completed packets */
        while (!list_empty(packet_queue)) {
                packet = list_first_entry(packet_queue, struct htc_packet,
                                          list);
                list_del(&packet->list);

                if (WARN_ON_ONCE(packet->endpoint == ENDPOINT_UNUSED ||
                                 packet->endpoint >= ENDPOINT_MAX))
                        continue;

                ath6kl_cookie = packet->pkt_cntxt;
                if (WARN_ON_ONCE(!ath6kl_cookie))
                        continue;

                status = packet->status;
                skb = ath6kl_cookie->skb;
                eid = packet->endpoint;
                map_no = ath6kl_cookie->map_no;

                if (WARN_ON_ONCE(!skb || !skb->data)) {
                        dev_kfree_skb(skb);
                        ath6kl_free_cookie(ar, ath6kl_cookie);
                        continue;
                }

                __skb_queue_tail(&skb_queue, skb);

                if (WARN_ON_ONCE(!status && (packet->act_len != skb->len))) {
                        ath6kl_free_cookie(ar, ath6kl_cookie);
                        continue;
                }

                ar->tx_pending[eid]--;

                if (eid != ar->ctrl_ep)
                        ar->total_tx_data_pend--;

                if (eid == ar->ctrl_ep) {
                        if (test_bit(WMI_CTRL_EP_FULL, &ar->flag))
                                clear_bit(WMI_CTRL_EP_FULL, &ar->flag);

                        if (ar->tx_pending[eid] == 0)
                                wake_event = true;
                }

                if (eid == ar->ctrl_ep) {
                        if_idx = wmi_cmd_hdr_get_if_idx(
                                (struct wmi_cmd_hdr *) packet->buf);
                } else {
                        if_idx = wmi_data_hdr_get_if_idx(
                                (struct wmi_data_hdr *) packet->buf);
                }

                vif = ath6kl_get_vif_by_index(ar, if_idx);
                if (!vif) {
                        ath6kl_free_cookie(ar, ath6kl_cookie);
                        continue;
                }

                if (status) {
                        if (status == -ECANCELED)
                                /* a packet was flushed  */
                                flushing[if_idx] = true;

                        vif->ndev->stats.tx_errors++;

                        if (status != -ENOSPC && status != -ECANCELED)
                                ath6kl_warn("tx complete error: %d\n", status);

                        ath6kl_dbg(ATH6KL_DBG_WLAN_TX,
                                   "%s: skb=0x%p data=0x%p len=0x%x eid=%d %s\n",
                                   __func__, skb, packet->buf, packet->act_len,
                                   eid, "error!");
                } else {
                        ath6kl_dbg(ATH6KL_DBG_WLAN_TX,
                                   "%s: skb=0x%p data=0x%p len=0x%x eid=%d %s\n",
                                   __func__, skb, packet->buf, packet->act_len,
                                   eid, "OK");

                        flushing[if_idx] = false;
                        vif->ndev->stats.tx_packets++;
                        vif->ndev->stats.tx_bytes += skb->len;
                }

                ath6kl_tx_clear_node_map(vif, eid, map_no);

                ath6kl_free_cookie(ar, ath6kl_cookie);

                if (test_bit(NETQ_STOPPED, &vif->flags))
                        clear_bit(NETQ_STOPPED, &vif->flags);
        }

        spin_unlock_bh(&ar->lock);

        __skb_queue_purge(&skb_queue);

        /* FIXME: Locking */
        spin_lock_bh(&ar->list_lock);
        list_for_each_entry(vif, &ar->vif_list, list) {
                if (test_bit(CONNECTED, &vif->flags) &&
                    !flushing[vif->fw_vif_idx]) {
                        spin_unlock_bh(&ar->list_lock);
                        netif_wake_queue(vif->ndev);
                        spin_lock_bh(&ar->list_lock);
                }
        }
        spin_unlock_bh(&ar->list_lock);

        if (wake_event)
                wake_up(&ar->event_wq);

        return;
}

void ath6kl_tx_data_cleanup(struct ath6kl *ar)
{
        int i;

        /* flush all the data (non-control) streams */
        for (i = 0; i < WMM_NUM_AC; i++)
                ath6kl_htc_flush_txep(ar->htc_target, ar->ac2ep_map[i],
                                      ATH6KL_DATA_PKT_TAG);
}

/* Rx functions */

static void ath6kl_deliver_frames_to_nw_stack(struct net_device *dev,
                                              struct sk_buff *skb)
{
        if (!skb)
                return;

        skb->dev = dev;

        if (!(skb->dev->flags & IFF_UP)) {
                dev_kfree_skb(skb);
                return;
        }

        skb->protocol = eth_type_trans(skb, skb->dev);

        netif_rx(skb);
}

static void ath6kl_alloc_netbufs(struct sk_buff_head *q, u16 num)
{
        struct sk_buff *skb;

        while (num) {
                skb = ath6kl_buf_alloc(ATH6KL_BUFFER_SIZE);
                if (!skb) {
                        ath6kl_err("netbuf allocation failed\n");
                        return;
                }
                skb_queue_tail(q, skb);
                num--;
        }
}

static struct sk_buff *aggr_get_free_skb(struct aggr_info *p_aggr)
{
        struct sk_buff *skb = NULL;

        if (skb_queue_len(&p_aggr->rx_amsdu_freeq) <
            (AGGR_NUM_OF_FREE_NETBUFS >> 2))
                ath6kl_alloc_netbufs(&p_aggr->rx_amsdu_freeq,
                                     AGGR_NUM_OF_FREE_NETBUFS);

        skb = skb_dequeue(&p_aggr->rx_amsdu_freeq);

        return skb;
}

void ath6kl_rx_refill(struct htc_target *target, enum htc_endpoint_id endpoint)
{
        struct ath6kl *ar = target->dev->ar;
        struct sk_buff *skb;
        int rx_buf;
        int n_buf_refill;
        struct htc_packet *packet;
        struct list_head queue;

        n_buf_refill = ATH6KL_MAX_RX_BUFFERS -
                          ath6kl_htc_get_rxbuf_num(ar->htc_target, endpoint);

        if (n_buf_refill <= 0)
                return;

        INIT_LIST_HEAD(&queue);

        ath6kl_dbg(ATH6KL_DBG_WLAN_RX,
                   "%s: providing htc with %d buffers at eid=%d\n",
                   __func__, n_buf_refill, endpoint);

        for (rx_buf = 0; rx_buf < n_buf_refill; rx_buf++) {
                skb = ath6kl_buf_alloc(ATH6KL_BUFFER_SIZE);
                if (!skb)
                        break;

                packet = (struct htc_packet *) skb->head;
                if (!IS_ALIGNED((unsigned long) skb->data, 4)) {
                        size_t len = skb_headlen(skb);
                        skb->data = PTR_ALIGN(skb->data - 4, 4);
                        skb_set_tail_pointer(skb, len);
                }
                set_htc_rxpkt_info(packet, skb, skb->data,
                                   ATH6KL_BUFFER_SIZE, endpoint);
                packet->skb = skb;
                list_add_tail(&packet->list, &queue);
        }

        if (!list_empty(&queue))
                ath6kl_htc_add_rxbuf_multiple(ar->htc_target, &queue);
}

void ath6kl_refill_amsdu_rxbufs(struct ath6kl *ar, int count)
{
        struct htc_packet *packet;
        struct sk_buff *skb;

        while (count) {
                skb = ath6kl_buf_alloc(ATH6KL_AMSDU_BUFFER_SIZE);
                if (!skb)
                        return;

                packet = (struct htc_packet *) skb->head;
                if (!IS_ALIGNED((unsigned long) skb->data, 4)) {
                        size_t len = skb_headlen(skb);
                        skb->data = PTR_ALIGN(skb->data - 4, 4);
                        skb_set_tail_pointer(skb, len);
                }
                set_htc_rxpkt_info(packet, skb, skb->data,
                                   ATH6KL_AMSDU_BUFFER_SIZE, 0);
                packet->skb = skb;

                spin_lock_bh(&ar->lock);
                list_add_tail(&packet->list, &ar->amsdu_rx_buffer_queue);
                spin_unlock_bh(&ar->lock);
                count--;
        }
}

/*
 * Callback to allocate a receive buffer for a pending packet. We use a
 * pre-allocated list of buffers of maximum AMSDU size (4K).
 */
struct htc_packet *ath6kl_alloc_amsdu_rxbuf(struct htc_target *target,
                                            enum htc_endpoint_id endpoint,
                                            int len)
{
        struct ath6kl *ar = target->dev->ar;
        struct htc_packet *packet = NULL;
        struct list_head *pkt_pos;
        int refill_cnt = 0, depth = 0;

        ath6kl_dbg(ATH6KL_DBG_WLAN_RX, "%s: eid=%d, len:%d\n",
                   __func__, endpoint, len);

        if ((len <= ATH6KL_BUFFER_SIZE) ||
            (len > ATH6KL_AMSDU_BUFFER_SIZE))
                return NULL;

        spin_lock_bh(&ar->lock);

        if (list_empty(&ar->amsdu_rx_buffer_queue)) {
                spin_unlock_bh(&ar->lock);
                refill_cnt = ATH6KL_MAX_AMSDU_RX_BUFFERS;
                goto refill_buf;
        }

        packet = list_first_entry(&ar->amsdu_rx_buffer_queue,
                                  struct htc_packet, list);
        list_del(&packet->list);
        list_for_each(pkt_pos, &ar->amsdu_rx_buffer_queue)
                depth++;

        refill_cnt = ATH6KL_MAX_AMSDU_RX_BUFFERS - depth;
        spin_unlock_bh(&ar->lock);

        /* set actual endpoint ID */
        packet->endpoint = endpoint;

refill_buf:
        if (refill_cnt >= ATH6KL_AMSDU_REFILL_THRESHOLD)
                ath6kl_refill_amsdu_rxbufs(ar, refill_cnt);

        return packet;
}

static void aggr_slice_amsdu(struct aggr_info *p_aggr,
                             struct rxtid *rxtid, struct sk_buff *skb)
{
        struct sk_buff *new_skb;
        struct ethhdr *hdr;
        u16 frame_8023_len, payload_8023_len, mac_hdr_len, amsdu_len;
        u8 *framep;

        mac_hdr_len = sizeof(struct ethhdr);
        framep = skb->data + mac_hdr_len;
        amsdu_len = skb->len - mac_hdr_len;

        while (amsdu_len > mac_hdr_len) {
                hdr = (struct ethhdr *) framep;
                payload_8023_len = be16_to_cpu(hdr->h_proto);

                if (payload_8023_len < MIN_MSDU_SUBFRAME_PAYLOAD_LEN ||
                    payload_8023_len > MAX_MSDU_SUBFRAME_PAYLOAD_LEN) {
                        ath6kl_err("802.3 AMSDU frame bound check failed. len %d\n",
                                   payload_8023_len);
                        break;
                }

                frame_8023_len = payload_8023_len + mac_hdr_len;
                new_skb = aggr_get_free_skb(p_aggr);
                if (!new_skb) {
                        ath6kl_err("no buffer available\n");
                        break;
                }

                memcpy(new_skb->data, framep, frame_8023_len);
                skb_put(new_skb, frame_8023_len);
                if (ath6kl_wmi_dot3_2_dix(new_skb)) {
                        ath6kl_err("dot3_2_dix error\n");
                        dev_kfree_skb(new_skb);
                        break;
                }

                skb_queue_tail(&rxtid->q, new_skb);

                /* Is this the last subframe within this aggregate ? */
                if ((amsdu_len - frame_8023_len) == 0)
                        break;

                /* Add the length of A-MSDU subframe padding bytes -
                 * Round to nearest word.
                 */
                frame_8023_len = ALIGN(frame_8023_len, 4);

                framep += frame_8023_len;
                amsdu_len -= frame_8023_len;
        }

        dev_kfree_skb(skb);
}

static void aggr_deque_frms(struct aggr_info_conn *agg_conn, u8 tid,
                            u16 seq_no, u8 order)
{
        struct sk_buff *skb;
        struct rxtid *rxtid;
        struct skb_hold_q *node;
        u16 idx, idx_end, seq_end;
        struct rxtid_stats *stats;

        rxtid = &agg_conn->rx_tid[tid];
        stats = &agg_conn->stat[tid];

        spin_lock_bh(&rxtid->lock);
        idx = AGGR_WIN_IDX(rxtid->seq_next, rxtid->hold_q_sz);

        /*
         * idx_end is typically the last possible frame in the window,
         * but changes to 'the' seq_no, when BAR comes. If seq_no
         * is non-zero, we will go up to that and stop.
         * Note: last seq no in current window will occupy the same
         * index position as index that is just previous to start.
         * An imp point : if win_sz is 7, for seq_no space of 4095,
         * then, there would be holes when sequence wrap around occurs.
         * Target should judiciously choose the win_sz, based on
         * this condition. For 4095, (TID_WINDOW_SZ = 2 x win_sz
         * 2, 4, 8, 16 win_sz works fine).
         * We must deque from "idx" to "idx_end", including both.
         */
        seq_end = seq_no ? seq_no : rxtid->seq_next;
        idx_end = AGGR_WIN_IDX(seq_end, rxtid->hold_q_sz);

        do {
                node = &rxtid->hold_q[idx];
                if ((order == 1) && (!node->skb))
                        break;

                if (node->skb) {
                        if (node->is_amsdu)
                                aggr_slice_amsdu(agg_conn->aggr_info, rxtid,
                                                 node->skb);
                        else
                                skb_queue_tail(&rxtid->q, node->skb);
                        node->skb = NULL;
                } else {
                        stats->num_hole++;
                }

                rxtid->seq_next = ATH6KL_NEXT_SEQ_NO(rxtid->seq_next);
                idx = AGGR_WIN_IDX(rxtid->seq_next, rxtid->hold_q_sz);
        } while (idx != idx_end);

        spin_unlock_bh(&rxtid->lock);

        stats->num_delivered += skb_queue_len(&rxtid->q);

        while ((skb = skb_dequeue(&rxtid->q)))
                ath6kl_deliver_frames_to_nw_stack(agg_conn->dev, skb);
}

static bool aggr_process_recv_frm(struct aggr_info_conn *agg_conn, u8 tid,
                                  u16 seq_no,
                                  bool is_amsdu, struct sk_buff *frame)
{
        struct rxtid *rxtid;
        struct rxtid_stats *stats;
        struct sk_buff *skb;
        struct skb_hold_q *node;
        u16 idx, st, cur, end;
        bool is_queued = false;
        u16 extended_end;

        rxtid = &agg_conn->rx_tid[tid];
        stats = &agg_conn->stat[tid];

        stats->num_into_aggr++;

        if (!rxtid->aggr) {
                if (is_amsdu) {
                        aggr_slice_amsdu(agg_conn->aggr_info, rxtid, frame);
                        is_queued = true;
                        stats->num_amsdu++;
                        while ((skb = skb_dequeue(&rxtid->q)))
                                ath6kl_deliver_frames_to_nw_stack(agg_conn->dev,
                                                                  skb);
                }
                return is_queued;
        }

        /* Check the incoming sequence no, if it's in the window */
        st = rxtid->seq_next;
        cur = seq_no;
        end = (st + rxtid->hold_q_sz-1) & ATH6KL_MAX_SEQ_NO;

        if (((st < end) && (cur < st || cur > end)) ||
            ((st > end) && (cur > end) && (cur < st))) {
                extended_end = (end + rxtid->hold_q_sz - 1) &
                        ATH6KL_MAX_SEQ_NO;

                if (((end < extended_end) &&
                     (cur < end || cur > extended_end)) ||
                    ((end > extended_end) && (cur > extended_end) &&
                     (cur < end))) {
                        aggr_deque_frms(agg_conn, tid, 0, 0);
                        spin_lock_bh(&rxtid->lock);
                        if (cur >= rxtid->hold_q_sz - 1)
                                rxtid->seq_next = cur - (rxtid->hold_q_sz - 1);
                        else
                                rxtid->seq_next = ATH6KL_MAX_SEQ_NO -
                                                  (rxtid->hold_q_sz - 2 - cur);
                        spin_unlock_bh(&rxtid->lock);
                } else {
                        /*
                         * Dequeue only those frames that are outside the
                         * new shifted window.
                         */
                        if (cur >= rxtid->hold_q_sz - 1)
                                st = cur - (rxtid->hold_q_sz - 1);
                        else
                                st = ATH6KL_MAX_SEQ_NO -
                                        (rxtid->hold_q_sz - 2 - cur);

                        aggr_deque_frms(agg_conn, tid, st, 0);
                }

                stats->num_oow++;
        }

        idx = AGGR_WIN_IDX(seq_no, rxtid->hold_q_sz);

        node = &rxtid->hold_q[idx];

        spin_lock_bh(&rxtid->lock);

        /*
         * Is the cur frame duplicate or something beyond our window(hold_q
         * -> which is 2x, already)?
         *
         * 1. Duplicate is easy - drop incoming frame.
         * 2. Not falling in current sliding window.
         *  2a. is the frame_seq_no preceding current tid_seq_no?
         *      -> drop the frame. perhaps sender did not get our ACK.
         *         this is taken care of above.
         *  2b. is the frame_seq_no beyond window(st, TID_WINDOW_SZ);
         *      -> Taken care of it above, by moving window forward.
         */
        dev_kfree_skb(node->skb);
        stats->num_dups++;

        node->skb = frame;
        is_queued = true;
        node->is_amsdu = is_amsdu;
        node->seq_no = seq_no;

        if (node->is_amsdu)
                stats->num_amsdu++;
        else
                stats->num_mpdu++;

        spin_unlock_bh(&rxtid->lock);

        aggr_deque_frms(agg_conn, tid, 0, 1);

        if (agg_conn->timer_scheduled)
                return is_queued;

        spin_lock_bh(&rxtid->lock);
        for (idx = 0; idx < rxtid->hold_q_sz; idx++) {
                if (rxtid->hold_q[idx].skb) {
                        /*
                         * There is a frame in the queue and no
                         * timer so start a timer to ensure that
                         * the frame doesn't remain stuck
                         * forever.
                         */
                        agg_conn->timer_scheduled = true;
                        mod_timer(&agg_conn->timer,
                                  (jiffies + (HZ * AGGR_RX_TIMEOUT) / 1000));
                        rxtid->timer_mon = true;
                        break;
                }
        }
        spin_unlock_bh(&rxtid->lock);

        return is_queued;
}

static void ath6kl_uapsd_trigger_frame_rx(struct ath6kl_vif *vif,
                                                 struct ath6kl_sta *conn)
{
        struct ath6kl *ar = vif->ar;
        bool is_apsdq_empty, is_apsdq_empty_at_start;
        u32 num_frames_to_deliver, flags;
        struct sk_buff *skb = NULL;

        /*
         * If the APSD q for this STA is not empty, dequeue and
         * send a pkt from the head of the q. Also update the
         * More data bit in the WMI_DATA_HDR if there are
         * more pkts for this STA in the APSD q.
         * If there are no more pkts for this STA,
         * update the APSD bitmap for this STA.
         */

        num_frames_to_deliver = (conn->apsd_info >> ATH6KL_APSD_NUM_OF_AC) &
                                                    ATH6KL_APSD_FRAME_MASK;
        /*
         * Number of frames to send in a service period is
         * indicated by the station
         * in the QOS_INFO of the association request
         * If it is zero, send all frames
         */
        if (!num_frames_to_deliver)
                num_frames_to_deliver = ATH6KL_APSD_ALL_FRAME;

        spin_lock_bh(&conn->psq_lock);
        is_apsdq_empty = skb_queue_empty(&conn->apsdq);
        spin_unlock_bh(&conn->psq_lock);
        is_apsdq_empty_at_start = is_apsdq_empty;

        while ((!is_apsdq_empty) && (num_frames_to_deliver)) {
                spin_lock_bh(&conn->psq_lock);
                skb = skb_dequeue(&conn->apsdq);
                is_apsdq_empty = skb_queue_empty(&conn->apsdq);
                spin_unlock_bh(&conn->psq_lock);

                /*
                 * Set the STA flag to Trigger delivery,
                 * so that the frame will go out
                 */
                conn->sta_flags |= STA_PS_APSD_TRIGGER;
                num_frames_to_deliver--;

                /* Last frame in the service period, set EOSP or queue empty */
                if ((is_apsdq_empty) || (!num_frames_to_deliver))
                        conn->sta_flags |= STA_PS_APSD_EOSP;

                ath6kl_data_tx(skb, vif->ndev);
                conn->sta_flags &= ~(STA_PS_APSD_TRIGGER);
                conn->sta_flags &= ~(STA_PS_APSD_EOSP);
        }

        if (is_apsdq_empty) {
                if (is_apsdq_empty_at_start)
                        flags = WMI_AP_APSD_NO_DELIVERY_FRAMES;
                else
                        flags = 0;

                ath6kl_wmi_set_apsd_bfrd_traf(ar->wmi,
                                              vif->fw_vif_idx,
                                              conn->aid, 0, flags);
        }

        return;
}

void ath6kl_rx(struct htc_target *target, struct htc_packet *packet)
{
        struct ath6kl *ar = target->dev->ar;
        struct sk_buff *skb = packet->pkt_cntxt;
        struct wmi_rx_meta_v2 *meta;
        struct wmi_data_hdr *dhdr;
        int min_hdr_len;
        u8 meta_type, dot11_hdr = 0;
        u8 pad_before_data_start;
        int status = packet->status;
        enum htc_endpoint_id ept = packet->endpoint;
        bool is_amsdu, prev_ps, ps_state = false;
        bool trig_state = false;
        struct ath6kl_sta *conn = NULL;
        struct sk_buff *skb1 = NULL;
        struct ethhdr *datap = NULL;
        struct ath6kl_vif *vif;
        struct aggr_info_conn *aggr_conn;
        u16 seq_no, offset;
        u8 tid, if_idx;

        ath6kl_dbg(ATH6KL_DBG_WLAN_RX,
                   "%s: ar=0x%p eid=%d, skb=0x%p, data=0x%p, len=0x%x status:%d",
                   __func__, ar, ept, skb, packet->buf,
                   packet->act_len, status);

        if (status || packet->act_len < HTC_HDR_LENGTH) {
                dev_kfree_skb(skb);
                return;
        }

        skb_put(skb, packet->act_len + HTC_HDR_LENGTH);
        skb_pull(skb, HTC_HDR_LENGTH);

        ath6kl_dbg_dump(ATH6KL_DBG_RAW_BYTES, __func__, "rx ",
                        skb->data, skb->len);

        if (ept == ar->ctrl_ep) {
                if (test_bit(WMI_ENABLED, &ar->flag)) {
                        ath6kl_check_wow_status(ar);
                        ath6kl_wmi_control_rx(ar->wmi, skb);
                        return;
                }
                if_idx =
                wmi_cmd_hdr_get_if_idx((struct wmi_cmd_hdr *) skb->data);
        } else {
                if_idx =
                wmi_data_hdr_get_if_idx((struct wmi_data_hdr *) skb->data);
        }

        vif = ath6kl_get_vif_by_index(ar, if_idx);
        if (!vif) {
                dev_kfree_skb(skb);
                return;
        }

        /*
         * Take lock to protect buffer counts and adaptive power throughput
         * state.
         */
        spin_lock_bh(&vif->if_lock);

        vif->ndev->stats.rx_packets++;
        vif->ndev->stats.rx_bytes += packet->act_len;

        spin_unlock_bh(&vif->if_lock);

        skb->dev = vif->ndev;

        if (!test_bit(WMI_ENABLED, &ar->flag)) {
                if (EPPING_ALIGNMENT_PAD > 0)
                        skb_pull(skb, EPPING_ALIGNMENT_PAD);
                ath6kl_deliver_frames_to_nw_stack(vif->ndev, skb);
                return;
        }

        ath6kl_check_wow_status(ar);

        min_hdr_len = sizeof(struct ethhdr) + sizeof(struct wmi_data_hdr) +
                      sizeof(struct ath6kl_llc_snap_hdr);

        dhdr = (struct wmi_data_hdr *) skb->data;

        /*
         * In the case of AP mode we may receive NULL data frames
         * that do not have LLC hdr. They are 16 bytes in size.
         * Allow these frames in the AP mode.
         */
        if (vif->nw_type != AP_NETWORK &&
            ((packet->act_len < min_hdr_len) ||
             (packet->act_len > WMI_MAX_AMSDU_RX_DATA_FRAME_LENGTH))) {
                ath6kl_info("frame len is too short or too long\n");
                vif->ndev->stats.rx_errors++;
                vif->ndev->stats.rx_length_errors++;
                dev_kfree_skb(skb);
                return;
        }

        pad_before_data_start =
                (le16_to_cpu(dhdr->info3) >> WMI_DATA_HDR_PAD_BEFORE_DATA_SHIFT)
                        & WMI_DATA_HDR_PAD_BEFORE_DATA_MASK;

        /* Get the Power save state of the STA */
        if (vif->nw_type == AP_NETWORK) {
                meta_type = wmi_data_hdr_get_meta(dhdr);

                ps_state = !!((dhdr->info >> WMI_DATA_HDR_PS_SHIFT) &
                              WMI_DATA_HDR_PS_MASK);

                offset = sizeof(struct wmi_data_hdr) + pad_before_data_start;
                trig_state = !!(le16_to_cpu(dhdr->info3) & WMI_DATA_HDR_TRIG);

                switch (meta_type) {
                case 0:
                        break;
                case WMI_META_VERSION_1:
                        offset += sizeof(struct wmi_rx_meta_v1);
                        break;
                case WMI_META_VERSION_2:
                        offset += sizeof(struct wmi_rx_meta_v2);
                        break;
                default:
                        break;
                }

                datap = (struct ethhdr *) (skb->data + offset);
                conn = ath6kl_find_sta(vif, datap->h_source);

                if (!conn) {
                        dev_kfree_skb(skb);
                        return;
                }

                /*
                 * If there is a change in PS state of the STA,
                 * take appropriate steps:
                 *
                 * 1. If Sleep-->Awake, flush the psq for the STA
                 *    Clear the PVB for the STA.
                 * 2. If Awake-->Sleep, Starting queueing frames
                 *    the STA.
                 */
                prev_ps = !!(conn->sta_flags & STA_PS_SLEEP);

                if (ps_state)
                        conn->sta_flags |= STA_PS_SLEEP;
                else
                        conn->sta_flags &= ~STA_PS_SLEEP;

                /* Accept trigger only when the station is in sleep */
                if ((conn->sta_flags & STA_PS_SLEEP) && trig_state)
                        ath6kl_uapsd_trigger_frame_rx(vif, conn);

                if (prev_ps ^ !!(conn->sta_flags & STA_PS_SLEEP)) {
                        if (!(conn->sta_flags & STA_PS_SLEEP)) {
                                struct sk_buff *skbuff = NULL;
                                bool is_apsdq_empty;
                                struct ath6kl_mgmt_buff *mgmt;
                                u8 idx;

                                spin_lock_bh(&conn->psq_lock);
                                while (conn->mgmt_psq_len > 0) {
                                        mgmt = list_first_entry(
                                                        &conn->mgmt_psq,
                                                        struct ath6kl_mgmt_buff,
                                                        list);
                                        list_del(&mgmt->list);
                                        conn->mgmt_psq_len--;
                                        spin_unlock_bh(&conn->psq_lock);
                                        idx = vif->fw_vif_idx;

                                        ath6kl_wmi_send_mgmt_cmd(ar->wmi,
                                                                 idx,
                                                                 mgmt->id,
                                                                 mgmt->freq,
                                                                 mgmt->wait,
                                                                 mgmt->buf,
                                                                 mgmt->len,
                                                                 mgmt->no_cck);

                                        kfree(mgmt);
                                        spin_lock_bh(&conn->psq_lock);
                                }
                                conn->mgmt_psq_len = 0;
                                while ((skbuff = skb_dequeue(&conn->psq))) {
                                        spin_unlock_bh(&conn->psq_lock);
                                        ath6kl_data_tx(skbuff, vif->ndev);
                                        spin_lock_bh(&conn->psq_lock);
                                }

                                is_apsdq_empty = skb_queue_empty(&conn->apsdq);
                                while ((skbuff = skb_dequeue(&conn->apsdq))) {
                                        spin_unlock_bh(&conn->psq_lock);
                                        ath6kl_data_tx(skbuff, vif->ndev);
                                        spin_lock_bh(&conn->psq_lock);
                                }
                                spin_unlock_bh(&conn->psq_lock);

                                if (!is_apsdq_empty)
                                        ath6kl_wmi_set_apsd_bfrd_traf(
                                                        ar->wmi,
                                                        vif->fw_vif_idx,
                                                        conn->aid, 0, 0);

                                /* Clear the PVB for this STA */
                                ath6kl_wmi_set_pvb_cmd(ar->wmi, vif->fw_vif_idx,
                                                       conn->aid, 0);
                        }
                }

                /* drop NULL data frames here */
                if ((packet->act_len < min_hdr_len) ||
                    (packet->act_len >
                     WMI_MAX_AMSDU_RX_DATA_FRAME_LENGTH)) {
                        dev_kfree_skb(skb);
                        return;
                }
        }

        is_amsdu = wmi_data_hdr_is_amsdu(dhdr) ? true : false;
        tid = wmi_data_hdr_get_up(dhdr);
        seq_no = wmi_data_hdr_get_seqno(dhdr);
        meta_type = wmi_data_hdr_get_meta(dhdr);
        dot11_hdr = wmi_data_hdr_get_dot11(dhdr);

        skb_pull(skb, sizeof(struct wmi_data_hdr));

        switch (meta_type) {
        case WMI_META_VERSION_1:
                skb_pull(skb, sizeof(struct wmi_rx_meta_v1));
                break;
        case WMI_META_VERSION_2:
                meta = (struct wmi_rx_meta_v2 *) skb->data;
                if (meta->csum_flags & 0x1) {
                        skb->ip_summed = CHECKSUM_COMPLETE;
                        skb->csum = (__force __wsum) meta->csum;
                }
                skb_pull(skb, sizeof(struct wmi_rx_meta_v2));
                break;
        default:
                break;
        }

        skb_pull(skb, pad_before_data_start);

        if (dot11_hdr)
                status = ath6kl_wmi_dot11_hdr_remove(ar->wmi, skb);
        else if (!is_amsdu)
                status = ath6kl_wmi_dot3_2_dix(skb);

        if (status) {
                /*
                 * Drop frames that could not be processed (lack of
                 * memory, etc.)
                 */
                dev_kfree_skb(skb);
                return;
        }

        if (!(vif->ndev->flags & IFF_UP)) {
                dev_kfree_skb(skb);
                return;
        }

        if (vif->nw_type == AP_NETWORK) {
                datap = (struct ethhdr *) skb->data;
                if (is_multicast_ether_addr(datap->h_dest))
                        /*
                         * Bcast/Mcast frames should be sent to the
                         * OS stack as well as on the air.
                         */
                        skb1 = skb_copy(skb, GFP_ATOMIC);
                else {
                        /*
                         * Search for a connected STA with dstMac
                         * as the Mac address. If found send the
                         * frame to it on the air else send the
                         * frame up the stack.
                         */
                        conn = ath6kl_find_sta(vif, datap->h_dest);

                        if (conn && ar->intra_bss) {
                                skb1 = skb;
                                skb = NULL;
                        } else if (conn && !ar->intra_bss) {
                                dev_kfree_skb(skb);
                                skb = NULL;
                        }
                }
                if (skb1)
                        ath6kl_data_tx(skb1, vif->ndev);

                if (skb == NULL) {
                        /* nothing to deliver up the stack */
                        return;
                }
        }

        datap = (struct ethhdr *) skb->data;

        if (is_unicast_ether_addr(datap->h_dest)) {
                if (vif->nw_type == AP_NETWORK) {
                        conn = ath6kl_find_sta(vif, datap->h_source);
                        if (!conn)
                                return;
                        aggr_conn = conn->aggr_conn;
                } else {
                        aggr_conn = vif->aggr_cntxt->aggr_conn;
                }

                if (aggr_process_recv_frm(aggr_conn, tid, seq_no,
                                          is_amsdu, skb)) {
                        /* aggregation code will handle the skb */
                        return;
                }
        } else if (!is_broadcast_ether_addr(datap->h_dest)) {
                vif->ndev->stats.multicast++;
        }

        ath6kl_deliver_frames_to_nw_stack(vif->ndev, skb);
}

static void aggr_timeout(struct timer_list *t)
{
        u8 i, j;
        struct aggr_info_conn *aggr_conn = timer_container_of(aggr_conn, t,
                                                              timer);
        struct rxtid *rxtid;
        struct rxtid_stats *stats;

        for (i = 0; i < NUM_OF_TIDS; i++) {
                rxtid = &aggr_conn->rx_tid[i];
                stats = &aggr_conn->stat[i];

                if (!rxtid->aggr || !rxtid->timer_mon)
                        continue;

                stats->num_timeouts++;
                ath6kl_dbg(ATH6KL_DBG_AGGR,
                           "aggr timeout (st %d end %d)\n",
                           rxtid->seq_next,
                           ((rxtid->seq_next + rxtid->hold_q_sz-1) &
                            ATH6KL_MAX_SEQ_NO));
                aggr_deque_frms(aggr_conn, i, 0, 0);
        }

        aggr_conn->timer_scheduled = false;

        for (i = 0; i < NUM_OF_TIDS; i++) {
                rxtid = &aggr_conn->rx_tid[i];

                if (rxtid->aggr && rxtid->hold_q) {
                        spin_lock_bh(&rxtid->lock);
                        for (j = 0; j < rxtid->hold_q_sz; j++) {
                                if (rxtid->hold_q[j].skb) {
                                        aggr_conn->timer_scheduled = true;
                                        rxtid->timer_mon = true;
                                        break;
                                }
                        }
                        spin_unlock_bh(&rxtid->lock);

                        if (j >= rxtid->hold_q_sz)
                                rxtid->timer_mon = false;
                }
        }

        if (aggr_conn->timer_scheduled)
                mod_timer(&aggr_conn->timer,
                          jiffies + msecs_to_jiffies(AGGR_RX_TIMEOUT));
}

static void aggr_delete_tid_state(struct aggr_info_conn *aggr_conn, u8 tid)
{
        struct rxtid *rxtid;
        struct rxtid_stats *stats;

        if (!aggr_conn || tid >= NUM_OF_TIDS)
                return;

        rxtid = &aggr_conn->rx_tid[tid];
        stats = &aggr_conn->stat[tid];

        if (rxtid->aggr)
                aggr_deque_frms(aggr_conn, tid, 0, 0);

        rxtid->aggr = false;
        rxtid->timer_mon = false;
        rxtid->win_sz = 0;
        rxtid->seq_next = 0;
        rxtid->hold_q_sz = 0;

        kfree(rxtid->hold_q);
        rxtid->hold_q = NULL;

        memset(stats, 0, sizeof(struct rxtid_stats));
}

void aggr_recv_addba_req_evt(struct ath6kl_vif *vif, u8 tid_mux, u16 seq_no,
                             u8 win_sz)
{
        struct ath6kl_sta *sta;
        struct aggr_info_conn *aggr_conn = NULL;
        struct rxtid *rxtid;
        u16 hold_q_size;
        u8 tid, aid;

        if (vif->nw_type == AP_NETWORK) {
                aid = ath6kl_get_aid(tid_mux);
                sta = ath6kl_find_sta_by_aid(vif->ar, aid);
                if (sta)
                        aggr_conn = sta->aggr_conn;
        } else {
                aggr_conn = vif->aggr_cntxt->aggr_conn;
        }

        if (!aggr_conn)
                return;

        tid = ath6kl_get_tid(tid_mux);
        if (tid >= NUM_OF_TIDS)
                return;

        rxtid = &aggr_conn->rx_tid[tid];

        if (win_sz < AGGR_WIN_SZ_MIN || win_sz > AGGR_WIN_SZ_MAX)
                ath6kl_dbg(ATH6KL_DBG_WLAN_RX, "%s: win_sz %d, tid %d\n",
                           __func__, win_sz, tid);

        if (rxtid->aggr)
                aggr_delete_tid_state(aggr_conn, tid);

        rxtid->seq_next = seq_no;
        hold_q_size = TID_WINDOW_SZ(win_sz) * sizeof(struct skb_hold_q);
        rxtid->hold_q = kzalloc(hold_q_size, GFP_KERNEL);
        if (!rxtid->hold_q)
                return;

        rxtid->win_sz = win_sz;
        rxtid->hold_q_sz = TID_WINDOW_SZ(win_sz);
        if (!skb_queue_empty(&rxtid->q))
                return;

        rxtid->aggr = true;
}

void aggr_conn_init(struct ath6kl_vif *vif, struct aggr_info *aggr_info,
                    struct aggr_info_conn *aggr_conn)
{
        struct rxtid *rxtid;
        u8 i;

        aggr_conn->aggr_sz = AGGR_SZ_DEFAULT;
        aggr_conn->dev = vif->ndev;
        timer_setup(&aggr_conn->timer, aggr_timeout, 0);
        aggr_conn->aggr_info = aggr_info;

        aggr_conn->timer_scheduled = false;

        for (i = 0; i < NUM_OF_TIDS; i++) {
                rxtid = &aggr_conn->rx_tid[i];
                rxtid->aggr = false;
                rxtid->timer_mon = false;
                skb_queue_head_init(&rxtid->q);
                spin_lock_init(&rxtid->lock);
        }
}

struct aggr_info *aggr_init(struct ath6kl_vif *vif)
{
        struct aggr_info *p_aggr = NULL;

        p_aggr = kzalloc_obj(struct aggr_info);
        if (!p_aggr) {
                ath6kl_err("failed to alloc memory for aggr_node\n");
                return NULL;
        }

        p_aggr->aggr_conn = kzalloc_obj(struct aggr_info_conn);
        if (!p_aggr->aggr_conn) {
                ath6kl_err("failed to alloc memory for connection specific aggr info\n");
                kfree(p_aggr);
                return NULL;
        }

        aggr_conn_init(vif, p_aggr, p_aggr->aggr_conn);

        skb_queue_head_init(&p_aggr->rx_amsdu_freeq);
        ath6kl_alloc_netbufs(&p_aggr->rx_amsdu_freeq, AGGR_NUM_OF_FREE_NETBUFS);

        return p_aggr;
}

void aggr_recv_delba_req_evt(struct ath6kl_vif *vif, u8 tid_mux)
{
        struct ath6kl_sta *sta;
        struct rxtid *rxtid;
        struct aggr_info_conn *aggr_conn = NULL;
        u8 tid, aid;

        if (vif->nw_type == AP_NETWORK) {
                aid = ath6kl_get_aid(tid_mux);
                sta = ath6kl_find_sta_by_aid(vif->ar, aid);
                if (sta)
                        aggr_conn = sta->aggr_conn;
        } else {
                aggr_conn = vif->aggr_cntxt->aggr_conn;
        }

        if (!aggr_conn)
                return;

        tid = ath6kl_get_tid(tid_mux);
        if (tid >= NUM_OF_TIDS)
                return;

        rxtid = &aggr_conn->rx_tid[tid];

        if (rxtid->aggr)
                aggr_delete_tid_state(aggr_conn, tid);
}

void aggr_reset_state(struct aggr_info_conn *aggr_conn)
{
        u8 tid;

        if (!aggr_conn)
                return;

        if (aggr_conn->timer_scheduled) {
                timer_delete(&aggr_conn->timer);
                aggr_conn->timer_scheduled = false;
        }

        for (tid = 0; tid < NUM_OF_TIDS; tid++)
                aggr_delete_tid_state(aggr_conn, tid);
}

/* clean up our amsdu buffer list */
void ath6kl_cleanup_amsdu_rxbufs(struct ath6kl *ar)
{
        struct htc_packet *packet, *tmp_pkt;

        spin_lock_bh(&ar->lock);
        if (list_empty(&ar->amsdu_rx_buffer_queue)) {
                spin_unlock_bh(&ar->lock);
                return;
        }

        list_for_each_entry_safe(packet, tmp_pkt, &ar->amsdu_rx_buffer_queue,
                                 list) {
                list_del(&packet->list);
                spin_unlock_bh(&ar->lock);
                dev_kfree_skb(packet->pkt_cntxt);
                spin_lock_bh(&ar->lock);
        }

        spin_unlock_bh(&ar->lock);
}

void aggr_module_destroy(struct aggr_info *aggr_info)
{
        if (!aggr_info)
                return;

        aggr_reset_state(aggr_info->aggr_conn);
        skb_queue_purge(&aggr_info->rx_amsdu_freeq);
        kfree(aggr_info->aggr_conn);
        kfree(aggr_info);
}