/*
 * Marvell Wireless LAN device driver: WMM
 *
 * Copyright (C) 2011, Marvell International Ltd.
 *
 * This software file (the "File") is distributed by Marvell International
 * Ltd. under the terms of the GNU General Public License Version 2, June 1991
 * (the "License").  You may use, redistribute and/or modify this File in
 * accordance with the terms and conditions of the License, a copy of which
 * is available by writing to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or on the
 * worldwide web at http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
 * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
 * this warranty disclaimer.
 */

#include "decl.h"
#include "ioctl.h"
#include "util.h"
#include "fw.h"
#include "main.h"
#include "wmm.h"
#include "11n.h"


/* Maximum value FW can accept for driver delay in packet transmission */
#define DRV_PKT_DELAY_TO_FW_MAX   512


#define WMM_QUEUED_PACKET_LOWER_LIMIT   180

#define WMM_QUEUED_PACKET_UPPER_LIMIT   200

/* Offset for TOS field in the IP header */
#define IPTOS_OFFSET 5

static bool enable_tx_amsdu;
module_param(enable_tx_amsdu, bool, 0644);

/* WMM information IE */
static const u8 wmm_info_ie[] = { WLAN_EID_VENDOR_SPECIFIC, 0x07,
        0x00, 0x50, 0xf2, 0x02,
        0x00, 0x01, 0x00
};

static const u8 wmm_aci_to_qidx_map[] = { WMM_AC_BE,
        WMM_AC_BK,
        WMM_AC_VI,
        WMM_AC_VO
};

static u8 tos_to_tid[] = {
        /* TID DSCP_P2 DSCP_P1 DSCP_P0 WMM_AC */
        0x01,                   /* 0 1 0 AC_BK */
        0x02,                   /* 0 0 0 AC_BK */
        0x00,                   /* 0 0 1 AC_BE */
        0x03,                   /* 0 1 1 AC_BE */
        0x04,                   /* 1 0 0 AC_VI */
        0x05,                   /* 1 0 1 AC_VI */
        0x06,                   /* 1 1 0 AC_VO */
        0x07                    /* 1 1 1 AC_VO */
};

/*
 * This table inverses the tos_to_tid operation to get a priority
 * which is in sequential order, and can be compared.
 * Use this to compare the priority of two different TIDs.
 */
static u8 tos_to_tid_inv[] = {
        0x02,  /* from tos_to_tid[2] = 0 */
        0x00,  /* from tos_to_tid[0] = 1 */
        0x01,  /* from tos_to_tid[1] = 2 */
        0x03,
        0x04,
        0x05,
        0x06,
        0x07};

static u8 ac_to_tid[4][2] = { {1, 2}, {0, 3}, {4, 5}, {6, 7} };

/*
 * This function debug prints the priority parameters for a WMM AC.
 */
static void
mwifiex_wmm_ac_debug_print(const struct ieee_types_wmm_ac_parameters *ac_param)
{
        const char *ac_str[] = { "BK", "BE", "VI", "VO" };

        pr_debug("info: WMM AC_%s: ACI=%d, ACM=%d, Aifsn=%d, "
                 "EcwMin=%d, EcwMax=%d, TxopLimit=%d\n",
                 ac_str[wmm_aci_to_qidx_map[(ac_param->aci_aifsn_bitmap
                                             & MWIFIEX_ACI) >> 5]],
                 (ac_param->aci_aifsn_bitmap & MWIFIEX_ACI) >> 5,
                 (ac_param->aci_aifsn_bitmap & MWIFIEX_ACM) >> 4,
                 ac_param->aci_aifsn_bitmap & MWIFIEX_AIFSN,
                 ac_param->ecw_bitmap & MWIFIEX_ECW_MIN,
                 (ac_param->ecw_bitmap & MWIFIEX_ECW_MAX) >> 4,
                 le16_to_cpu(ac_param->tx_op_limit));
}

/*
 * This function allocates a route address list.
 *
 * The function also initializes the list with the provided RA.
 */
static struct mwifiex_ra_list_tbl *
mwifiex_wmm_allocate_ralist_node(struct mwifiex_adapter *adapter, u8 *ra)
{
        struct mwifiex_ra_list_tbl *ra_list;

        ra_list = kzalloc(sizeof(struct mwifiex_ra_list_tbl), GFP_ATOMIC);
        if (!ra_list)
                return NULL;

        INIT_LIST_HEAD(&ra_list->list);
        skb_queue_head_init(&ra_list->skb_head);

        memcpy(ra_list->ra, ra, ETH_ALEN);

        ra_list->total_pkts_size = 0;

        dev_dbg(adapter->dev, "info: allocated ra_list %p\n", ra_list);

        return ra_list;
}

/* This function returns random no between 16 and 32 to be used as threshold
 * for no of packets after which BA setup is initiated.
 */
static u8 mwifiex_get_random_ba_threshold(void)
{
        u32 sec, usec;
        struct timeval ba_tstamp;
        u8 ba_threshold;

        /* setup ba_packet_threshold here random number between
         * [BA_SETUP_PACKET_OFFSET,
         * BA_SETUP_PACKET_OFFSET+BA_SETUP_MAX_PACKET_THRESHOLD-1]
         */

        do_gettimeofday(&ba_tstamp);
        sec = (ba_tstamp.tv_sec & 0xFFFF) + (ba_tstamp.tv_sec >> 16);
        usec = (ba_tstamp.tv_usec & 0xFFFF) + (ba_tstamp.tv_usec >> 16);
        ba_threshold = (((sec << 16) + usec) % BA_SETUP_MAX_PACKET_THRESHOLD)
                                                      + BA_SETUP_PACKET_OFFSET;

        return ba_threshold;
}

/*
 * This function allocates and adds a RA list for all TIDs
 * with the given RA.
 */
void
mwifiex_ralist_add(struct mwifiex_private *priv, u8 *ra)
{
        int i;
        struct mwifiex_ra_list_tbl *ra_list;
        struct mwifiex_adapter *adapter = priv->adapter;
        struct mwifiex_sta_node *node;
        unsigned long flags;

        spin_lock_irqsave(&priv->sta_list_spinlock, flags);
        node = mwifiex_get_sta_entry(priv, ra);
        spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);

        for (i = 0; i < MAX_NUM_TID; ++i) {
                ra_list = mwifiex_wmm_allocate_ralist_node(adapter, ra);
                dev_dbg(adapter->dev, "info: created ra_list %p\n", ra_list);

                if (!ra_list)
                        break;

                ra_list->is_11n_enabled = 0;
                if (!mwifiex_queuing_ra_based(priv)) {
                        ra_list->is_11n_enabled = IS_11N_ENABLED(priv);
                } else {
                        ra_list->is_11n_enabled =
                                      mwifiex_is_sta_11n_enabled(priv, node);
                        if (ra_list->is_11n_enabled)
                                ra_list->max_amsdu = node->max_amsdu;
                }

                dev_dbg(adapter->dev, "data: ralist %p: is_11n_enabled=%d\n",
                        ra_list, ra_list->is_11n_enabled);

                if (ra_list->is_11n_enabled) {
                        ra_list->pkt_count = 0;
                        ra_list->ba_packet_thr =
                                              mwifiex_get_random_ba_threshold();
                }
                list_add_tail(&ra_list->list,
                              &priv->wmm.tid_tbl_ptr[i].ra_list);
        }
}

/*
 * This function sets the WMM queue priorities to their default values.
 */
static void mwifiex_wmm_default_queue_priorities(struct mwifiex_private *priv)
{
        /* Default queue priorities: VO->VI->BE->BK */
        priv->wmm.queue_priority[0] = WMM_AC_VO;
        priv->wmm.queue_priority[1] = WMM_AC_VI;
        priv->wmm.queue_priority[2] = WMM_AC_BE;
        priv->wmm.queue_priority[3] = WMM_AC_BK;
}

/*
 * This function map ACs to TIDs.
 */
static void
mwifiex_wmm_queue_priorities_tid(struct mwifiex_wmm_desc *wmm)
{
        u8 *queue_priority = wmm->queue_priority;
        int i;

        for (i = 0; i < 4; ++i) {
                tos_to_tid[7 - (i * 2)] = ac_to_tid[queue_priority[i]][1];
                tos_to_tid[6 - (i * 2)] = ac_to_tid[queue_priority[i]][0];
        }

        for (i = 0; i < MAX_NUM_TID; ++i)
                tos_to_tid_inv[tos_to_tid[i]] = (u8)i;

        atomic_set(&wmm->highest_queued_prio, HIGH_PRIO_TID);
}

/*
 * This function initializes WMM priority queues.
 */
void
mwifiex_wmm_setup_queue_priorities(struct mwifiex_private *priv,
                                   struct ieee_types_wmm_parameter *wmm_ie)
{
        u16 cw_min, avg_back_off, tmp[4];
        u32 i, j, num_ac;
        u8 ac_idx;

        if (!wmm_ie || !priv->wmm_enabled) {
                /* WMM is not enabled, just set the defaults and return */
                mwifiex_wmm_default_queue_priorities(priv);
                return;
        }

        dev_dbg(priv->adapter->dev, "info: WMM Parameter IE: version=%d, "
                "qos_info Parameter Set Count=%d, Reserved=%#x\n",
                wmm_ie->vend_hdr.version, wmm_ie->qos_info_bitmap &
                IEEE80211_WMM_IE_AP_QOSINFO_PARAM_SET_CNT_MASK,
                wmm_ie->reserved);

        for (num_ac = 0; num_ac < ARRAY_SIZE(wmm_ie->ac_params); num_ac++) {
                u8 ecw = wmm_ie->ac_params[num_ac].ecw_bitmap;
                u8 aci_aifsn = wmm_ie->ac_params[num_ac].aci_aifsn_bitmap;
                cw_min = (1 << (ecw & MWIFIEX_ECW_MIN)) - 1;
                avg_back_off = (cw_min >> 1) + (aci_aifsn & MWIFIEX_AIFSN);

                ac_idx = wmm_aci_to_qidx_map[(aci_aifsn & MWIFIEX_ACI) >> 5];
                priv->wmm.queue_priority[ac_idx] = ac_idx;
                tmp[ac_idx] = avg_back_off;

                dev_dbg(priv->adapter->dev,
                        "info: WMM: CWmax=%d CWmin=%d Avg Back-off=%d\n",
                        (1 << ((ecw & MWIFIEX_ECW_MAX) >> 4)) - 1,
                        cw_min, avg_back_off);
                mwifiex_wmm_ac_debug_print(&wmm_ie->ac_params[num_ac]);
        }

        /* Bubble sort */
        for (i = 0; i < num_ac; i++) {
                for (j = 1; j < num_ac - i; j++) {
                        if (tmp[j - 1] > tmp[j]) {
                                swap(tmp[j - 1], tmp[j]);
                                swap(priv->wmm.queue_priority[j - 1],
                                     priv->wmm.queue_priority[j]);
                        } else if (tmp[j - 1] == tmp[j]) {
                                if (priv->wmm.queue_priority[j - 1]
                                    < priv->wmm.queue_priority[j])
                                        swap(priv->wmm.queue_priority[j - 1],
                                             priv->wmm.queue_priority[j]);
                        }
                }
        }

        mwifiex_wmm_queue_priorities_tid(&priv->wmm);
}

/*
 * This function evaluates whether or not an AC is to be downgraded.
 *
 * In case the AC is not enabled, the highest AC is returned that is
 * enabled and does not require admission control.
 */
static enum mwifiex_wmm_ac_e
mwifiex_wmm_eval_downgrade_ac(struct mwifiex_private *priv,
                              enum mwifiex_wmm_ac_e eval_ac)
{
        int down_ac;
        enum mwifiex_wmm_ac_e ret_ac;
        struct mwifiex_wmm_ac_status *ac_status;

        ac_status = &priv->wmm.ac_status[eval_ac];

        if (!ac_status->disabled)
                /* Okay to use this AC, its enabled */
                return eval_ac;

        /* Setup a default return value of the lowest priority */
        ret_ac = WMM_AC_BK;

        /*
         *  Find the highest AC that is enabled and does not require
         *  admission control. The spec disallows downgrading to an AC,
         *  which is enabled due to a completed admission control.
         *  Unadmitted traffic is not to be sent on an AC with admitted
         *  traffic.
         */
        for (down_ac = WMM_AC_BK; down_ac < eval_ac; down_ac++) {
                ac_status = &priv->wmm.ac_status[down_ac];

                if (!ac_status->disabled && !ac_status->flow_required)
                        /* AC is enabled and does not require admission
                           control */
                        ret_ac = (enum mwifiex_wmm_ac_e) down_ac;
        }

        return ret_ac;
}

/*
 * This function downgrades WMM priority queue.
 */
void
mwifiex_wmm_setup_ac_downgrade(struct mwifiex_private *priv)
{
        int ac_val;

        dev_dbg(priv->adapter->dev, "info: WMM: AC Priorities:"
                        "BK(0), BE(1), VI(2), VO(3)\n");

        if (!priv->wmm_enabled) {
                /* WMM is not enabled, default priorities */
                for (ac_val = WMM_AC_BK; ac_val <= WMM_AC_VO; ac_val++)
                        priv->wmm.ac_down_graded_vals[ac_val] =
                                                (enum mwifiex_wmm_ac_e) ac_val;
        } else {
                for (ac_val = WMM_AC_BK; ac_val <= WMM_AC_VO; ac_val++) {
                        priv->wmm.ac_down_graded_vals[ac_val]
                                = mwifiex_wmm_eval_downgrade_ac(priv,
                                                (enum mwifiex_wmm_ac_e) ac_val);
                        dev_dbg(priv->adapter->dev,
                                "info: WMM: AC PRIO %d maps to %d\n",
                                ac_val, priv->wmm.ac_down_graded_vals[ac_val]);
                }
        }
}

/*
 * This function converts the IP TOS field to an WMM AC
 * Queue assignment.
 */
static enum mwifiex_wmm_ac_e
mwifiex_wmm_convert_tos_to_ac(struct mwifiex_adapter *adapter, u32 tos)
{
        /* Map of TOS UP values to WMM AC */
        const enum mwifiex_wmm_ac_e tos_to_ac[] = { WMM_AC_BE,
                WMM_AC_BK,
                WMM_AC_BK,
                WMM_AC_BE,
                WMM_AC_VI,
                WMM_AC_VI,
                WMM_AC_VO,
                WMM_AC_VO
        };

        if (tos >= ARRAY_SIZE(tos_to_ac))
                return WMM_AC_BE;

        return tos_to_ac[tos];
}

/*
 * This function evaluates a given TID and downgrades it to a lower
 * TID if the WMM Parameter IE received from the AP indicates that the
 * AP is disabled (due to call admission control (ACM bit). Mapping
 * of TID to AC is taken care of internally.
 */
static u8
mwifiex_wmm_downgrade_tid(struct mwifiex_private *priv, u32 tid)
{
        enum mwifiex_wmm_ac_e ac, ac_down;
        u8 new_tid;

        ac = mwifiex_wmm_convert_tos_to_ac(priv->adapter, tid);
        ac_down = priv->wmm.ac_down_graded_vals[ac];

        /* Send the index to tid array, picking from the array will be
         * taken care by dequeuing function
         */
        new_tid = ac_to_tid[ac_down][tid % 2];

        return new_tid;
}

/*
 * This function initializes the WMM state information and the
 * WMM data path queues.
 */
void
mwifiex_wmm_init(struct mwifiex_adapter *adapter)
{
        int i, j;
        struct mwifiex_private *priv;

        for (j = 0; j < adapter->priv_num; ++j) {
                priv = adapter->priv[j];
                if (!priv)
                        continue;

                for (i = 0; i < MAX_NUM_TID; ++i) {
                        priv->aggr_prio_tbl[i].amsdu = tos_to_tid_inv[i];
                        priv->aggr_prio_tbl[i].ampdu_ap = tos_to_tid_inv[i];
                        priv->aggr_prio_tbl[i].ampdu_user = tos_to_tid_inv[i];
                }

                priv->aggr_prio_tbl[6].amsdu
                                        = priv->aggr_prio_tbl[6].ampdu_ap
                                        = priv->aggr_prio_tbl[6].ampdu_user
                                        = BA_STREAM_NOT_ALLOWED;

                priv->aggr_prio_tbl[7].amsdu = priv->aggr_prio_tbl[7].ampdu_ap
                                        = priv->aggr_prio_tbl[7].ampdu_user
                                        = BA_STREAM_NOT_ALLOWED;

                mwifiex_set_ba_params(priv);
                mwifiex_reset_11n_rx_seq_num(priv);

                atomic_set(&priv->wmm.tx_pkts_queued, 0);
                atomic_set(&priv->wmm.highest_queued_prio, HIGH_PRIO_TID);
        }
}

/*
 * This function checks if WMM Tx queue is empty.
 */
int
mwifiex_wmm_lists_empty(struct mwifiex_adapter *adapter)
{
        int i;
        struct mwifiex_private *priv;

        for (i = 0; i < adapter->priv_num; ++i) {
                priv = adapter->priv[i];
                if (priv && atomic_read(&priv->wmm.tx_pkts_queued))
                        return false;
        }

        return true;
}

/*
 * This function deletes all packets in an RA list node.
 *
 * The packet sent completion callback handler are called with
 * status failure, after they are dequeued to ensure proper
 * cleanup. The RA list node itself is freed at the end.
 */
static void
mwifiex_wmm_del_pkts_in_ralist_node(struct mwifiex_private *priv,
                                    struct mwifiex_ra_list_tbl *ra_list)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        struct sk_buff *skb, *tmp;

        skb_queue_walk_safe(&ra_list->skb_head, skb, tmp)
                mwifiex_write_data_complete(adapter, skb, 0, -1);
}

/*
 * This function deletes all packets in an RA list.
 *
 * Each nodes in the RA list are freed individually first, and then
 * the RA list itself is freed.
 */
static void
mwifiex_wmm_del_pkts_in_ralist(struct mwifiex_private *priv,
                               struct list_head *ra_list_head)
{
        struct mwifiex_ra_list_tbl *ra_list;

        list_for_each_entry(ra_list, ra_list_head, list)
                mwifiex_wmm_del_pkts_in_ralist_node(priv, ra_list);
}

/*
 * This function deletes all packets in all RA lists.
 */
static void mwifiex_wmm_cleanup_queues(struct mwifiex_private *priv)
{
        int i;

        for (i = 0; i < MAX_NUM_TID; i++)
                mwifiex_wmm_del_pkts_in_ralist(priv, &priv->wmm.tid_tbl_ptr[i].
                                                                       ra_list);

        atomic_set(&priv->wmm.tx_pkts_queued, 0);
        atomic_set(&priv->wmm.highest_queued_prio, HIGH_PRIO_TID);
}

/*
 * This function deletes all route addresses from all RA lists.
 */
static void mwifiex_wmm_delete_all_ralist(struct mwifiex_private *priv)
{
        struct mwifiex_ra_list_tbl *ra_list, *tmp_node;
        int i;

        for (i = 0; i < MAX_NUM_TID; ++i) {
                dev_dbg(priv->adapter->dev,
                        "info: ra_list: freeing buf for tid %d\n", i);
                list_for_each_entry_safe(ra_list, tmp_node,
                                         &priv->wmm.tid_tbl_ptr[i].ra_list,
                                         list) {
                        list_del(&ra_list->list);
                        kfree(ra_list);
                }

                INIT_LIST_HEAD(&priv->wmm.tid_tbl_ptr[i].ra_list);
        }
}

/*
 * This function cleans up the Tx and Rx queues.
 *
 * Cleanup includes -
 *      - All packets in RA lists
 *      - All entries in Rx reorder table
 *      - All entries in Tx BA stream table
 *      - MPA buffer (if required)
 *      - All RA lists
 */
void
mwifiex_clean_txrx(struct mwifiex_private *priv)
{
        unsigned long flags;

        mwifiex_11n_cleanup_reorder_tbl(priv);
        spin_lock_irqsave(&priv->wmm.ra_list_spinlock, flags);

        mwifiex_wmm_cleanup_queues(priv);
        mwifiex_11n_delete_all_tx_ba_stream_tbl(priv);

        if (priv->adapter->if_ops.cleanup_mpa_buf)
                priv->adapter->if_ops.cleanup_mpa_buf(priv->adapter);

        mwifiex_wmm_delete_all_ralist(priv);
        memcpy(tos_to_tid, ac_to_tid, sizeof(tos_to_tid));

        if (priv->adapter->if_ops.clean_pcie_ring)
                priv->adapter->if_ops.clean_pcie_ring(priv->adapter);
        spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, flags);
}

/*
 * This function retrieves a particular RA list node, matching with the
 * given TID and RA address.
 */
static struct mwifiex_ra_list_tbl *
mwifiex_wmm_get_ralist_node(struct mwifiex_private *priv, u8 tid,
                            u8 *ra_addr)
{
        struct mwifiex_ra_list_tbl *ra_list;

        list_for_each_entry(ra_list, &priv->wmm.tid_tbl_ptr[tid].ra_list,
                            list) {
                if (!memcmp(ra_list->ra, ra_addr, ETH_ALEN))
                        return ra_list;
        }

        return NULL;
}

/*
 * This function retrieves an RA list node for a given TID and
 * RA address pair.
 *
 * If no such node is found, a new node is added first and then
 * retrieved.
 */
static struct mwifiex_ra_list_tbl *
mwifiex_wmm_get_queue_raptr(struct mwifiex_private *priv, u8 tid, u8 *ra_addr)
{
        struct mwifiex_ra_list_tbl *ra_list;

        ra_list = mwifiex_wmm_get_ralist_node(priv, tid, ra_addr);
        if (ra_list)
                return ra_list;
        mwifiex_ralist_add(priv, ra_addr);

        return mwifiex_wmm_get_ralist_node(priv, tid, ra_addr);
}

/*
 * This function checks if a particular RA list node exists in a given TID
 * table index.
 */
int
mwifiex_is_ralist_valid(struct mwifiex_private *priv,
                        struct mwifiex_ra_list_tbl *ra_list, int ptr_index)
{
        struct mwifiex_ra_list_tbl *rlist;

        list_for_each_entry(rlist, &priv->wmm.tid_tbl_ptr[ptr_index].ra_list,
                            list) {
                if (rlist == ra_list)
                        return true;
        }

        return false;
}

/*
 * This function adds a packet to WMM queue.
 *
 * In disconnected state the packet is immediately dropped and the
 * packet send completion callback is called with status failure.
 *
 * Otherwise, the correct RA list node is located and the packet
 * is queued at the list tail.
 */
void
mwifiex_wmm_add_buf_txqueue(struct mwifiex_private *priv,
                            struct sk_buff *skb)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        u32 tid;
        struct mwifiex_ra_list_tbl *ra_list;
        u8 ra[ETH_ALEN], tid_down;
        unsigned long flags;

        if (!priv->media_connected && !mwifiex_is_skb_mgmt_frame(skb)) {
                dev_dbg(adapter->dev, "data: drop packet in disconnect\n");
                mwifiex_write_data_complete(adapter, skb, 0, -1);
                return;
        }

        tid = skb->priority;

        spin_lock_irqsave(&priv->wmm.ra_list_spinlock, flags);

        tid_down = mwifiex_wmm_downgrade_tid(priv, tid);

        /* In case of infra as we have already created the list during
           association we just don't have to call get_queue_raptr, we will
           have only 1 raptr for a tid in case of infra */
        if (!mwifiex_queuing_ra_based(priv) &&
            !mwifiex_is_skb_mgmt_frame(skb)) {
                if (!list_empty(&priv->wmm.tid_tbl_ptr[tid_down].ra_list))
                        ra_list = list_first_entry(
                                &priv->wmm.tid_tbl_ptr[tid_down].ra_list,
                                struct mwifiex_ra_list_tbl, list);
                else
                        ra_list = NULL;
        } else {
                memcpy(ra, skb->data, ETH_ALEN);
                if (ra[0] & 0x01 || mwifiex_is_skb_mgmt_frame(skb))
                        memset(ra, 0xff, ETH_ALEN);
                ra_list = mwifiex_wmm_get_queue_raptr(priv, tid_down, ra);
        }

        if (!ra_list) {
                spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, flags);
                mwifiex_write_data_complete(adapter, skb, 0, -1);
                return;
        }

        skb_queue_tail(&ra_list->skb_head, skb);

        ra_list->total_pkts_size += skb->len;
        ra_list->pkt_count++;

        if (atomic_read(&priv->wmm.highest_queued_prio) <
                                                tos_to_tid_inv[tid_down])
                atomic_set(&priv->wmm.highest_queued_prio,
                           tos_to_tid_inv[tid_down]);

        atomic_inc(&priv->wmm.tx_pkts_queued);

        spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, flags);
}

/*
 * This function processes the get WMM status command response from firmware.
 *
 * The response may contain multiple TLVs -
 *      - AC Queue status TLVs
 *      - Current WMM Parameter IE TLV
 *      - Admission Control action frame TLVs
 *
 * This function parses the TLVs and then calls further specific functions
 * to process any changes in the queue prioritize or state.
 */
int mwifiex_ret_wmm_get_status(struct mwifiex_private *priv,
                               const struct host_cmd_ds_command *resp)
{
        u8 *curr = (u8 *) &resp->params.get_wmm_status;
        uint16_t resp_len = le16_to_cpu(resp->size), tlv_len;
        int valid = true;

        struct mwifiex_ie_types_data *tlv_hdr;
        struct mwifiex_ie_types_wmm_queue_status *tlv_wmm_qstatus;
        struct ieee_types_wmm_parameter *wmm_param_ie = NULL;
        struct mwifiex_wmm_ac_status *ac_status;

        dev_dbg(priv->adapter->dev, "info: WMM: WMM_GET_STATUS cmdresp received: %d\n",
                resp_len);

        while ((resp_len >= sizeof(tlv_hdr->header)) && valid) {
                tlv_hdr = (struct mwifiex_ie_types_data *) curr;
                tlv_len = le16_to_cpu(tlv_hdr->header.len);

                switch (le16_to_cpu(tlv_hdr->header.type)) {
                case TLV_TYPE_WMMQSTATUS:
                        tlv_wmm_qstatus =
                                (struct mwifiex_ie_types_wmm_queue_status *)
                                tlv_hdr;
                        dev_dbg(priv->adapter->dev,
                                "info: CMD_RESP: WMM_GET_STATUS:"
                                " QSTATUS TLV: %d, %d, %d\n",
                                tlv_wmm_qstatus->queue_index,
                                tlv_wmm_qstatus->flow_required,
                                tlv_wmm_qstatus->disabled);

                        ac_status = &priv->wmm.ac_status[tlv_wmm_qstatus->
                                                         queue_index];
                        ac_status->disabled = tlv_wmm_qstatus->disabled;
                        ac_status->flow_required =
                                                tlv_wmm_qstatus->flow_required;
                        ac_status->flow_created = tlv_wmm_qstatus->flow_created;
                        break;

                case WLAN_EID_VENDOR_SPECIFIC:
                        /*
                         * Point the regular IEEE IE 2 bytes into the Marvell IE
                         *   and setup the IEEE IE type and length byte fields
                         */

                        wmm_param_ie =
                                (struct ieee_types_wmm_parameter *) (curr +
                                                                    2);
                        wmm_param_ie->vend_hdr.len = (u8) tlv_len;
                        wmm_param_ie->vend_hdr.element_id =
                                                WLAN_EID_VENDOR_SPECIFIC;

                        dev_dbg(priv->adapter->dev,
                                "info: CMD_RESP: WMM_GET_STATUS:"
                                " WMM Parameter Set Count: %d\n",
                                wmm_param_ie->qos_info_bitmap &
                                IEEE80211_WMM_IE_AP_QOSINFO_PARAM_SET_CNT_MASK);

                        memcpy((u8 *) &priv->curr_bss_params.bss_descriptor.
                               wmm_ie, wmm_param_ie,
                               wmm_param_ie->vend_hdr.len + 2);

                        break;

                default:
                        valid = false;
                        break;
                }

                curr += (tlv_len + sizeof(tlv_hdr->header));
                resp_len -= (tlv_len + sizeof(tlv_hdr->header));
        }

        mwifiex_wmm_setup_queue_priorities(priv, wmm_param_ie);
        mwifiex_wmm_setup_ac_downgrade(priv);

        return 0;
}

/*
 * Callback handler from the command module to allow insertion of a WMM TLV.
 *
 * If the BSS we are associating to supports WMM, this function adds the
 * required WMM Information IE to the association request command buffer in
 * the form of a Marvell extended IEEE IE.
 */
u32
mwifiex_wmm_process_association_req(struct mwifiex_private *priv,
                                    u8 **assoc_buf,
                                    struct ieee_types_wmm_parameter *wmm_ie,
                                    struct ieee80211_ht_cap *ht_cap)
{
        struct mwifiex_ie_types_wmm_param_set *wmm_tlv;
        u32 ret_len = 0;

        /* Null checks */
        if (!assoc_buf)
                return 0;
        if (!(*assoc_buf))
                return 0;

        if (!wmm_ie)
                return 0;

        dev_dbg(priv->adapter->dev,
                "info: WMM: process assoc req: bss->wmm_ie=%#x\n",
                wmm_ie->vend_hdr.element_id);

        if ((priv->wmm_required ||
             (ht_cap && (priv->adapter->config_bands & BAND_GN ||
             priv->adapter->config_bands & BAND_AN))) &&
            wmm_ie->vend_hdr.element_id == WLAN_EID_VENDOR_SPECIFIC) {
                wmm_tlv = (struct mwifiex_ie_types_wmm_param_set *) *assoc_buf;
                wmm_tlv->header.type = cpu_to_le16((u16) wmm_info_ie[0]);
                wmm_tlv->header.len = cpu_to_le16((u16) wmm_info_ie[1]);
                memcpy(wmm_tlv->wmm_ie, &wmm_info_ie[2],
                       le16_to_cpu(wmm_tlv->header.len));
                if (wmm_ie->qos_info_bitmap & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD)
                        memcpy((u8 *) (wmm_tlv->wmm_ie
                                       + le16_to_cpu(wmm_tlv->header.len)
                                       - sizeof(priv->wmm_qosinfo)),
                               &priv->wmm_qosinfo, sizeof(priv->wmm_qosinfo));

                ret_len = sizeof(wmm_tlv->header)
                          + le16_to_cpu(wmm_tlv->header.len);

                *assoc_buf += ret_len;
        }

        return ret_len;
}

/*
 * This function computes the time delay in the driver queues for a
 * given packet.
 *
 * When the packet is received at the OS/Driver interface, the current
 * time is set in the packet structure. The difference between the present
 * time and that received time is computed in this function and limited
 * based on pre-compiled limits in the driver.
 */
u8
mwifiex_wmm_compute_drv_pkt_delay(struct mwifiex_private *priv,
                                  const struct sk_buff *skb)
{
        u8 ret_val;
        struct timeval out_tstamp, in_tstamp;
        u32 queue_delay;

        do_gettimeofday(&out_tstamp);
        in_tstamp = ktime_to_timeval(skb->tstamp);

        queue_delay = (out_tstamp.tv_sec - in_tstamp.tv_sec) * 1000;
        queue_delay += (out_tstamp.tv_usec - in_tstamp.tv_usec) / 1000;

        /*
         * Queue delay is passed as a uint8 in units of 2ms (ms shifted
         *  by 1). Min value (other than 0) is therefore 2ms, max is 510ms.
         *
         * Pass max value if queue_delay is beyond the uint8 range
         */
        ret_val = (u8) (min(queue_delay, priv->wmm.drv_pkt_delay_max) >> 1);

        dev_dbg(priv->adapter->dev, "data: WMM: Pkt Delay: %d ms,"
                                " %d ms sent to FW\n", queue_delay, ret_val);

        return ret_val;
}

/*
 * This function retrieves the highest priority RA list table pointer.
 */
static struct mwifiex_ra_list_tbl *
mwifiex_wmm_get_highest_priolist_ptr(struct mwifiex_adapter *adapter,
                                     struct mwifiex_private **priv, int *tid)
{
        struct mwifiex_private *priv_tmp;
        struct mwifiex_ra_list_tbl *ptr;
        struct mwifiex_tid_tbl *tid_ptr;
        atomic_t *hqp;
        unsigned long flags_bss, flags_ra;
        int i, j;

        /* check the BSS with highest priority first */
        for (j = adapter->priv_num - 1; j >= 0; --j) {
                spin_lock_irqsave(&adapter->bss_prio_tbl[j].bss_prio_lock,
                                  flags_bss);

                /* iterate over BSS with the equal priority */
                list_for_each_entry(adapter->bss_prio_tbl[j].bss_prio_cur,
                                    &adapter->bss_prio_tbl[j].bss_prio_head,
                                    list) {

                        priv_tmp = adapter->bss_prio_tbl[j].bss_prio_cur->priv;

                        if (atomic_read(&priv_tmp->wmm.tx_pkts_queued) == 0)
                                continue;

                        /* iterate over the WMM queues of the BSS */
                        hqp = &priv_tmp->wmm.highest_queued_prio;
                        for (i = atomic_read(hqp); i >= LOW_PRIO_TID; --i) {

                                spin_lock_irqsave(&priv_tmp->wmm.
                                                  ra_list_spinlock, flags_ra);

                                tid_ptr = &(priv_tmp)->wmm.
                                        tid_tbl_ptr[tos_to_tid[i]];

                                /* iterate over receiver addresses */
                                list_for_each_entry(ptr, &tid_ptr->ra_list,
                                                    list) {

                                        if (!skb_queue_empty(&ptr->skb_head))
                                                /* holds both locks */
                                                goto found;
                                }

                                spin_unlock_irqrestore(&priv_tmp->wmm.
                                                       ra_list_spinlock,
                                                       flags_ra);
                        }
                }

                spin_unlock_irqrestore(&adapter->bss_prio_tbl[j].bss_prio_lock,
                                       flags_bss);
        }

        return NULL;

found:
        /* holds bss_prio_lock / ra_list_spinlock */
        if (atomic_read(hqp) > i)
                atomic_set(hqp, i);
        spin_unlock_irqrestore(&priv_tmp->wmm.ra_list_spinlock, flags_ra);
        spin_unlock_irqrestore(&adapter->bss_prio_tbl[j].bss_prio_lock,
                               flags_bss);

        *priv = priv_tmp;
        *tid = tos_to_tid[i];

        return ptr;
}

/* This functions rotates ra and bss lists so packets are picked round robin.
 *
 * After a packet is successfully transmitted, rotate the ra list, so the ra
 * next to the one transmitted, will come first in the list. This way we pick
 * the ra' in a round robin fashion. Same applies to bss nodes of equal
 * priority.
 *
 * Function also increments wmm.packets_out counter.
 */
void mwifiex_rotate_priolists(struct mwifiex_private *priv,
                                 struct mwifiex_ra_list_tbl *ra,
                                 int tid)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        struct mwifiex_bss_prio_tbl *tbl = adapter->bss_prio_tbl;
        struct mwifiex_tid_tbl *tid_ptr = &priv->wmm.tid_tbl_ptr[tid];
        unsigned long flags;

        spin_lock_irqsave(&tbl[priv->bss_priority].bss_prio_lock, flags);
        /*
         * dirty trick: we remove 'head' temporarily and reinsert it after
         * curr bss node. imagine list to stay fixed while head is moved
         */
        list_move(&tbl[priv->bss_priority].bss_prio_head,
                  &tbl[priv->bss_priority].bss_prio_cur->list);
        spin_unlock_irqrestore(&tbl[priv->bss_priority].bss_prio_lock, flags);

        spin_lock_irqsave(&priv->wmm.ra_list_spinlock, flags);
        if (mwifiex_is_ralist_valid(priv, ra, tid)) {
                priv->wmm.packets_out[tid]++;
                /* same as above */
                list_move(&tid_ptr->ra_list, &ra->list);
        }
        spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, flags);
}

/*
 * This function checks if 11n aggregation is possible.
 */
static int
mwifiex_is_11n_aggragation_possible(struct mwifiex_private *priv,
                                    struct mwifiex_ra_list_tbl *ptr,
                                    int max_buf_size)
{
        int count = 0, total_size = 0;
        struct sk_buff *skb, *tmp;
        int max_amsdu_size;

        if (priv->bss_role == MWIFIEX_BSS_ROLE_UAP && priv->ap_11n_enabled &&
            ptr->is_11n_enabled)
                max_amsdu_size = min_t(int, ptr->max_amsdu, max_buf_size);
        else

                max_amsdu_size = max_buf_size;

        skb_queue_walk_safe(&ptr->skb_head, skb, tmp) {
                total_size += skb->len;
                if (total_size >= max_amsdu_size)
                        break;
                if (++count >= MIN_NUM_AMSDU)
                        return true;
        }

        return false;
}

/*
 * This function sends a single packet to firmware for transmission.
 */
static void
mwifiex_send_single_packet(struct mwifiex_private *priv,
                           struct mwifiex_ra_list_tbl *ptr, int ptr_index,
                           unsigned long ra_list_flags)
                           __releases(&priv->wmm.ra_list_spinlock)
{
        struct sk_buff *skb, *skb_next;
        struct mwifiex_tx_param tx_param;
        struct mwifiex_adapter *adapter = priv->adapter;
        struct mwifiex_txinfo *tx_info;

        if (skb_queue_empty(&ptr->skb_head)) {
                spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
                                       ra_list_flags);
                dev_dbg(adapter->dev, "data: nothing to send\n");
                return;
        }

        skb = skb_dequeue(&ptr->skb_head);

        tx_info = MWIFIEX_SKB_TXCB(skb);
        dev_dbg(adapter->dev, "data: dequeuing the packet %p %p\n", ptr, skb);

        ptr->total_pkts_size -= skb->len;

        if (!skb_queue_empty(&ptr->skb_head))
                skb_next = skb_peek(&ptr->skb_head);
        else
                skb_next = NULL;

        spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, ra_list_flags);

        tx_param.next_pkt_len = ((skb_next) ? skb_next->len +
                                sizeof(struct txpd) : 0);

        if (mwifiex_process_tx(priv, skb, &tx_param) == -EBUSY) {
                /* Queue the packet back at the head */
                spin_lock_irqsave(&priv->wmm.ra_list_spinlock, ra_list_flags);

                if (!mwifiex_is_ralist_valid(priv, ptr, ptr_index)) {
                        spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
                                               ra_list_flags);
                        mwifiex_write_data_complete(adapter, skb, 0, -1);
                        return;
                }

                skb_queue_tail(&ptr->skb_head, skb);

                ptr->total_pkts_size += skb->len;
                ptr->pkt_count++;
                tx_info->flags |= MWIFIEX_BUF_FLAG_REQUEUED_PKT;
                spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
                                       ra_list_flags);
        } else {
                mwifiex_rotate_priolists(priv, ptr, ptr_index);
                atomic_dec(&priv->wmm.tx_pkts_queued);
        }
}

/*
 * This function checks if the first packet in the given RA list
 * is already processed or not.
 */
static int
mwifiex_is_ptr_processed(struct mwifiex_private *priv,
                         struct mwifiex_ra_list_tbl *ptr)
{
        struct sk_buff *skb;
        struct mwifiex_txinfo *tx_info;

        if (skb_queue_empty(&ptr->skb_head))
                return false;

        skb = skb_peek(&ptr->skb_head);

        tx_info = MWIFIEX_SKB_TXCB(skb);
        if (tx_info->flags & MWIFIEX_BUF_FLAG_REQUEUED_PKT)
                return true;

        return false;
}

/*
 * This function sends a single processed packet to firmware for
 * transmission.
 */
static void
mwifiex_send_processed_packet(struct mwifiex_private *priv,
                              struct mwifiex_ra_list_tbl *ptr, int ptr_index,
                              unsigned long ra_list_flags)
                                __releases(&priv->wmm.ra_list_spinlock)
{
        struct mwifiex_tx_param tx_param;
        struct mwifiex_adapter *adapter = priv->adapter;
        int ret = -1;
        struct sk_buff *skb, *skb_next;
        struct mwifiex_txinfo *tx_info;

        if (skb_queue_empty(&ptr->skb_head)) {
                spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
                                       ra_list_flags);
                return;
        }

        skb = skb_dequeue(&ptr->skb_head);

        if (!skb_queue_empty(&ptr->skb_head))
                skb_next = skb_peek(&ptr->skb_head);
        else
                skb_next = NULL;

        tx_info = MWIFIEX_SKB_TXCB(skb);

        spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, ra_list_flags);

        if (adapter->iface_type == MWIFIEX_USB) {
                adapter->data_sent = true;
                ret = adapter->if_ops.host_to_card(adapter, MWIFIEX_USB_EP_DATA,
                                                   skb, NULL);
        } else {
                tx_param.next_pkt_len =
                        ((skb_next) ? skb_next->len +
                         sizeof(struct txpd) : 0);
                ret = adapter->if_ops.host_to_card(adapter, MWIFIEX_TYPE_DATA,
                                                   skb, &tx_param);
        }

        switch (ret) {
        case -EBUSY:
                dev_dbg(adapter->dev, "data: -EBUSY is returned\n");
                spin_lock_irqsave(&priv->wmm.ra_list_spinlock, ra_list_flags);

                if (!mwifiex_is_ralist_valid(priv, ptr, ptr_index)) {
                        spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
                                               ra_list_flags);
                        mwifiex_write_data_complete(adapter, skb, 0, -1);
                        return;
                }

                skb_queue_tail(&ptr->skb_head, skb);

                tx_info->flags |= MWIFIEX_BUF_FLAG_REQUEUED_PKT;
                spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock,
                                       ra_list_flags);
                break;
        case -1:
                if (adapter->iface_type != MWIFIEX_PCIE)
                        adapter->data_sent = false;
                dev_err(adapter->dev, "host_to_card failed: %#x\n", ret);
                adapter->dbg.num_tx_host_to_card_failure++;
                mwifiex_write_data_complete(adapter, skb, 0, ret);
                break;
        case -EINPROGRESS:
                if (adapter->iface_type != MWIFIEX_PCIE)
                        adapter->data_sent = false;
        default:
                break;
        }
        if (ret != -EBUSY) {
                mwifiex_rotate_priolists(priv, ptr, ptr_index);
                atomic_dec(&priv->wmm.tx_pkts_queued);
        }
}

/*
 * This function dequeues a packet from the highest priority list
 * and transmits it.
 */
static int
mwifiex_dequeue_tx_packet(struct mwifiex_adapter *adapter)
{
        struct mwifiex_ra_list_tbl *ptr;
        struct mwifiex_private *priv = NULL;
        int ptr_index = 0;
        u8 ra[ETH_ALEN];
        int tid_del = 0, tid = 0;
        unsigned long flags;

        ptr = mwifiex_wmm_get_highest_priolist_ptr(adapter, &priv, &ptr_index);
        if (!ptr)
                return -1;

        tid = mwifiex_get_tid(ptr);

        dev_dbg(adapter->dev, "data: tid=%d\n", tid);

        spin_lock_irqsave(&priv->wmm.ra_list_spinlock, flags);
        if (!mwifiex_is_ralist_valid(priv, ptr, ptr_index)) {
                spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, flags);
                return -1;
        }

        if (mwifiex_is_ptr_processed(priv, ptr)) {
                mwifiex_send_processed_packet(priv, ptr, ptr_index, flags);
                /* ra_list_spinlock has been freed in
                   mwifiex_send_processed_packet() */
                return 0;
        }

        if (!ptr->is_11n_enabled ||
            mwifiex_is_ba_stream_setup(priv, ptr, tid) ||
            priv->wps.session_enable ||
            ((priv->sec_info.wpa_enabled ||
              priv->sec_info.wpa2_enabled) &&
             !priv->wpa_is_gtk_set)) {
                mwifiex_send_single_packet(priv, ptr, ptr_index, flags);
                /* ra_list_spinlock has been freed in
                   mwifiex_send_single_packet() */
        } else {
                if (mwifiex_is_ampdu_allowed(priv, tid) &&
                    ptr->pkt_count > ptr->ba_packet_thr) {
                        if (mwifiex_space_avail_for_new_ba_stream(adapter)) {
                                mwifiex_create_ba_tbl(priv, ptr->ra, tid,
                                                      BA_SETUP_INPROGRESS);
                                mwifiex_send_addba(priv, tid, ptr->ra);
                        } else if (mwifiex_find_stream_to_delete
                                   (priv, tid, &tid_del, ra)) {
                                mwifiex_create_ba_tbl(priv, ptr->ra, tid,
                                                      BA_SETUP_INPROGRESS);
                                mwifiex_send_delba(priv, tid_del, ra, 1);
                        }
                }
                if (enable_tx_amsdu && mwifiex_is_amsdu_allowed(priv, tid) &&
                    mwifiex_is_11n_aggragation_possible(priv, ptr,
                                                        adapter->tx_buf_size))
                        mwifiex_11n_aggregate_pkt(priv, ptr, INTF_HEADER_LEN,
                                                  ptr_index, flags);
                        /* ra_list_spinlock has been freed in
                           mwifiex_11n_aggregate_pkt() */
                else
                        mwifiex_send_single_packet(priv, ptr, ptr_index, flags);
                        /* ra_list_spinlock has been freed in
                           mwifiex_send_single_packet() */
        }
        return 0;
}

/*
 * This function transmits the highest priority packet awaiting in the
 * WMM Queues.
 */
void
mwifiex_wmm_process_tx(struct mwifiex_adapter *adapter)
{
        do {
                /* Check if busy */
                if (adapter->data_sent || adapter->tx_lock_flag)
                        break;

                if (mwifiex_dequeue_tx_packet(adapter))
                        break;
        } while (!mwifiex_wmm_lists_empty(adapter));
}