// SPDX-License-Identifier: GPL-2.0-only
/*
 * Datapath implementation for ST-Ericsson CW1200 mac80211 drivers
 *
 * Copyright (c) 2010, ST-Ericsson
 * Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
 */

#include <net/mac80211.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>

#include "cw1200.h"
#include "wsm.h"
#include "bh.h"
#include "sta.h"
#include "debug.h"

#define CW1200_INVALID_RATE_ID (0xFF)

static int cw1200_handle_action_rx(struct cw1200_common *priv,
                                   struct sk_buff *skb);
static const struct ieee80211_rate *
cw1200_get_tx_rate(const struct cw1200_common *priv,
                   const struct ieee80211_tx_rate *rate);

/* ******************************************************************** */
/* TX queue lock / unlock                                               */

static inline void cw1200_tx_queues_lock(struct cw1200_common *priv)
{
        int i;
        for (i = 0; i < 4; ++i)
                cw1200_queue_lock(&priv->tx_queue[i]);
}

static inline void cw1200_tx_queues_unlock(struct cw1200_common *priv)
{
        int i;
        for (i = 0; i < 4; ++i)
                cw1200_queue_unlock(&priv->tx_queue[i]);
}

/* ******************************************************************** */
/* TX policy cache implementation                                       */

static void tx_policy_dump(struct tx_policy *policy)
{
        pr_debug("[TX policy] %.1X%.1X%.1X%.1X%.1X%.1X%.1X%.1X %.1X%.1X%.1X%.1X%.1X%.1X%.1X%.1X %.1X%.1X%.1X%.1X%.1X%.1X%.1X%.1X: %d\n",
                 policy->raw[0] & 0x0F,  policy->raw[0] >> 4,
                 policy->raw[1] & 0x0F,  policy->raw[1] >> 4,
                 policy->raw[2] & 0x0F,  policy->raw[2] >> 4,
                 policy->raw[3] & 0x0F,  policy->raw[3] >> 4,
                 policy->raw[4] & 0x0F,  policy->raw[4] >> 4,
                 policy->raw[5] & 0x0F,  policy->raw[5] >> 4,
                 policy->raw[6] & 0x0F,  policy->raw[6] >> 4,
                 policy->raw[7] & 0x0F,  policy->raw[7] >> 4,
                 policy->raw[8] & 0x0F,  policy->raw[8] >> 4,
                 policy->raw[9] & 0x0F,  policy->raw[9] >> 4,
                 policy->raw[10] & 0x0F,  policy->raw[10] >> 4,
                 policy->raw[11] & 0x0F,  policy->raw[11] >> 4,
                 policy->defined);
}

static void tx_policy_build(const struct cw1200_common *priv,
        /* [out] */ struct tx_policy *policy,
        struct ieee80211_tx_rate *rates, size_t count)
{
        int i, j;
        unsigned limit = priv->short_frame_max_tx_count;
        unsigned total = 0;
        BUG_ON(rates[0].idx < 0);
        memset(policy, 0, sizeof(*policy));

        /* Sort rates in descending order. */
        for (i = 1; i < count; ++i) {
                if (rates[i].idx < 0) {
                        count = i;
                        break;
                }
                if (rates[i].idx > rates[i - 1].idx) {
                        struct ieee80211_tx_rate tmp = rates[i - 1];
                        rates[i - 1] = rates[i];
                        rates[i] = tmp;
                }
        }

        /* Eliminate duplicates. */
        total = rates[0].count;
        for (i = 0, j = 1; j < count; ++j) {
                if (rates[j].idx == rates[i].idx) {
                        rates[i].count += rates[j].count;
                } else if (rates[j].idx > rates[i].idx) {
                        break;
                } else {
                        ++i;
                        if (i != j)
                                rates[i] = rates[j];
                }
                total += rates[j].count;
        }
        count = i + 1;

        /* Re-fill policy trying to keep every requested rate and with
         * respect to the global max tx retransmission count.
         */
        if (limit < count)
                limit = count;
        if (total > limit) {
                for (i = 0; i < count; ++i) {
                        int left = count - i - 1;
                        if (rates[i].count > limit - left)
                                rates[i].count = limit - left;
                        limit -= rates[i].count;
                }
        }

        /* HACK!!! Device has problems (at least) switching from
         * 54Mbps CTS to 1Mbps. This switch takes enormous amount
         * of time (100-200 ms), leading to valuable throughput drop.
         * As a workaround, additional g-rates are injected to the
         * policy.
         */
        if (count == 2 && !(rates[0].flags & IEEE80211_TX_RC_MCS) &&
            rates[0].idx > 4 && rates[0].count > 2 &&
            rates[1].idx < 2) {
                int mid_rate = (rates[0].idx + 4) >> 1;

                /* Decrease number of retries for the initial rate */
                rates[0].count -= 2;

                if (mid_rate != 4) {
                        /* Keep fallback rate at 1Mbps. */
                        rates[3] = rates[1];

                        /* Inject 1 transmission on lowest g-rate */
                        rates[2].idx = 4;
                        rates[2].count = 1;
                        rates[2].flags = rates[1].flags;

                        /* Inject 1 transmission on mid-rate */
                        rates[1].idx = mid_rate;
                        rates[1].count = 1;

                        /* Fallback to 1 Mbps is a really bad thing,
                         * so let's try to increase probability of
                         * successful transmission on the lowest g rate
                         * even more
                         */
                        if (rates[0].count >= 3) {
                                --rates[0].count;
                                ++rates[2].count;
                        }

                        /* Adjust amount of rates defined */
                        count += 2;
                } else {
                        /* Keep fallback rate at 1Mbps. */
                        rates[2] = rates[1];

                        /* Inject 2 transmissions on lowest g-rate */
                        rates[1].idx = 4;
                        rates[1].count = 2;

                        /* Adjust amount of rates defined */
                        count += 1;
                }
        }

        policy->defined = cw1200_get_tx_rate(priv, &rates[0])->hw_value + 1;

        for (i = 0; i < count; ++i) {
                register unsigned rateid, off, shift, retries;

                rateid = cw1200_get_tx_rate(priv, &rates[i])->hw_value;
                off = rateid >> 3;              /* eq. rateid / 8 */
                shift = (rateid & 0x07) << 2;   /* eq. (rateid % 8) * 4 */

                retries = rates[i].count;
                if (retries > 0x0F) {
                        rates[i].count = 0x0f;
                        retries = 0x0F;
                }
                policy->tbl[off] |= __cpu_to_le32(retries << shift);
                policy->retry_count += retries;
        }

        pr_debug("[TX policy] Policy (%zu): %d:%d, %d:%d, %d:%d, %d:%d\n",
                 count,
                 rates[0].idx, rates[0].count,
                 rates[1].idx, rates[1].count,
                 rates[2].idx, rates[2].count,
                 rates[3].idx, rates[3].count);
}

static inline bool tx_policy_is_equal(const struct tx_policy *wanted,
                                        const struct tx_policy *cached)
{
        size_t count = wanted->defined >> 1;
        if (wanted->defined > cached->defined)
                return false;
        if (count) {
                if (memcmp(wanted->raw, cached->raw, count))
                        return false;
        }
        if (wanted->defined & 1) {
                if ((wanted->raw[count] & 0x0F) != (cached->raw[count] & 0x0F))
                        return false;
        }
        return true;
}

static int tx_policy_find(struct tx_policy_cache *cache,
                                const struct tx_policy *wanted)
{
        /* O(n) complexity. Not so good, but there's only 8 entries in
         * the cache.
         * Also lru helps to reduce search time.
         */
        struct tx_policy_cache_entry *it;
        /* First search for policy in "used" list */
        list_for_each_entry(it, &cache->used, link) {
                if (tx_policy_is_equal(wanted, &it->policy))
                        return it - cache->cache;
        }
        /* Then - in "free list" */
        list_for_each_entry(it, &cache->free, link) {
                if (tx_policy_is_equal(wanted, &it->policy))
                        return it - cache->cache;
        }
        return -1;
}

static inline void tx_policy_use(struct tx_policy_cache *cache,
                                 struct tx_policy_cache_entry *entry)
{
        ++entry->policy.usage_count;
        list_move(&entry->link, &cache->used);
}

static inline int tx_policy_release(struct tx_policy_cache *cache,
                                    struct tx_policy_cache_entry *entry)
{
        int ret = --entry->policy.usage_count;
        if (!ret)
                list_move(&entry->link, &cache->free);
        return ret;
}

void tx_policy_clean(struct cw1200_common *priv)
{
        int idx, locked;
        struct tx_policy_cache *cache = &priv->tx_policy_cache;
        struct tx_policy_cache_entry *entry;

        cw1200_tx_queues_lock(priv);
        spin_lock_bh(&cache->lock);
        locked = list_empty(&cache->free);

        for (idx = 0; idx < TX_POLICY_CACHE_SIZE; idx++) {
                entry = &cache->cache[idx];
                /* Policy usage count should be 0 at this time as all queues
                   should be empty
                 */
                if (WARN_ON(entry->policy.usage_count)) {
                        entry->policy.usage_count = 0;
                        list_move(&entry->link, &cache->free);
                }
                memset(&entry->policy, 0, sizeof(entry->policy));
        }
        if (locked)
                cw1200_tx_queues_unlock(priv);

        cw1200_tx_queues_unlock(priv);
        spin_unlock_bh(&cache->lock);
}

/* ******************************************************************** */
/* External TX policy cache API                                         */

void tx_policy_init(struct cw1200_common *priv)
{
        struct tx_policy_cache *cache = &priv->tx_policy_cache;
        int i;

        memset(cache, 0, sizeof(*cache));

        spin_lock_init(&cache->lock);
        INIT_LIST_HEAD(&cache->used);
        INIT_LIST_HEAD(&cache->free);

        for (i = 0; i < TX_POLICY_CACHE_SIZE; ++i)
                list_add(&cache->cache[i].link, &cache->free);
}

static int tx_policy_get(struct cw1200_common *priv,
                  struct ieee80211_tx_rate *rates,
                  size_t count, bool *renew)
{
        int idx;
        struct tx_policy_cache *cache = &priv->tx_policy_cache;
        struct tx_policy wanted;

        tx_policy_build(priv, &wanted, rates, count);

        spin_lock_bh(&cache->lock);
        if (WARN_ON_ONCE(list_empty(&cache->free))) {
                spin_unlock_bh(&cache->lock);
                return CW1200_INVALID_RATE_ID;
        }
        idx = tx_policy_find(cache, &wanted);
        if (idx >= 0) {
                pr_debug("[TX policy] Used TX policy: %d\n", idx);
                *renew = false;
        } else {
                struct tx_policy_cache_entry *entry;
                *renew = true;
                /* If policy is not found create a new one
                 * using the oldest entry in "free" list
                 */
                entry = list_entry(cache->free.prev,
                        struct tx_policy_cache_entry, link);
                entry->policy = wanted;
                idx = entry - cache->cache;
                pr_debug("[TX policy] New TX policy: %d\n", idx);
                tx_policy_dump(&entry->policy);
        }
        tx_policy_use(cache, &cache->cache[idx]);
        if (list_empty(&cache->free)) {
                /* Lock TX queues. */
                cw1200_tx_queues_lock(priv);
        }
        spin_unlock_bh(&cache->lock);
        return idx;
}

static void tx_policy_put(struct cw1200_common *priv, int idx)
{
        int usage, locked;
        struct tx_policy_cache *cache = &priv->tx_policy_cache;

        spin_lock_bh(&cache->lock);
        locked = list_empty(&cache->free);
        usage = tx_policy_release(cache, &cache->cache[idx]);
        if (locked && !usage) {
                /* Unlock TX queues. */
                cw1200_tx_queues_unlock(priv);
        }
        spin_unlock_bh(&cache->lock);
}

static int tx_policy_upload(struct cw1200_common *priv)
{
        struct tx_policy_cache *cache = &priv->tx_policy_cache;
        int i;
        struct wsm_set_tx_rate_retry_policy arg = {
                .num = 0,
        };
        spin_lock_bh(&cache->lock);

        /* Upload only modified entries. */
        for (i = 0; i < TX_POLICY_CACHE_SIZE; ++i) {
                struct tx_policy *src = &cache->cache[i].policy;
                if (src->retry_count && !src->uploaded) {
                        struct wsm_tx_rate_retry_policy *dst =
                                &arg.tbl[arg.num];
                        dst->index = i;
                        dst->short_retries = priv->short_frame_max_tx_count;
                        dst->long_retries = priv->long_frame_max_tx_count;

                        dst->flags = WSM_TX_RATE_POLICY_FLAG_TERMINATE_WHEN_FINISHED |
                                WSM_TX_RATE_POLICY_FLAG_COUNT_INITIAL_TRANSMIT;
                        memcpy(dst->rate_count_indices, src->tbl,
                               sizeof(dst->rate_count_indices));
                        src->uploaded = 1;
                        ++arg.num;
                }
        }
        spin_unlock_bh(&cache->lock);
        cw1200_debug_tx_cache_miss(priv);
        pr_debug("[TX policy] Upload %d policies\n", arg.num);
        return wsm_set_tx_rate_retry_policy(priv, &arg);
}

void tx_policy_upload_work(struct work_struct *work)
{
        struct cw1200_common *priv =
                container_of(work, struct cw1200_common, tx_policy_upload_work);

        pr_debug("[TX] TX policy upload.\n");
        tx_policy_upload(priv);

        wsm_unlock_tx(priv);
        cw1200_tx_queues_unlock(priv);
}

/* ******************************************************************** */
/* cw1200 TX implementation                                             */

struct cw1200_txinfo {
        struct sk_buff *skb;
        unsigned queue;
        struct ieee80211_tx_info *tx_info;
        const struct ieee80211_rate *rate;
        struct ieee80211_hdr *hdr;
        size_t hdrlen;
        const u8 *da;
        struct cw1200_sta_priv *sta_priv;
        struct ieee80211_sta *sta;
        struct cw1200_txpriv txpriv;
};

u32 cw1200_rate_mask_to_wsm(struct cw1200_common *priv, u32 rates)
{
        u32 ret = 0;
        int i;
        for (i = 0; i < 32; ++i) {
                if (rates & BIT(i))
                        ret |= BIT(priv->rates[i].hw_value);
        }
        return ret;
}

static const struct ieee80211_rate *
cw1200_get_tx_rate(const struct cw1200_common *priv,
                   const struct ieee80211_tx_rate *rate)
{
        if (rate->idx < 0)
                return NULL;
        if (rate->flags & IEEE80211_TX_RC_MCS)
                return &priv->mcs_rates[rate->idx];
        return &priv->hw->wiphy->bands[priv->channel->band]->
                bitrates[rate->idx];
}

static int
cw1200_tx_h_calc_link_ids(struct cw1200_common *priv,
                          struct cw1200_txinfo *t)
{
        if (t->sta && t->sta_priv->link_id)
                t->txpriv.raw_link_id =
                                t->txpriv.link_id =
                                t->sta_priv->link_id;
        else if (priv->mode != NL80211_IFTYPE_AP)
                t->txpriv.raw_link_id =
                                t->txpriv.link_id = 0;
        else if (is_multicast_ether_addr(t->da)) {
                if (priv->enable_beacon) {
                        t->txpriv.raw_link_id = 0;
                        t->txpriv.link_id = CW1200_LINK_ID_AFTER_DTIM;
                } else {
                        t->txpriv.raw_link_id = 0;
                        t->txpriv.link_id = 0;
                }
        } else {
                t->txpriv.link_id = cw1200_find_link_id(priv, t->da);
                if (!t->txpriv.link_id)
                        t->txpriv.link_id = cw1200_alloc_link_id(priv, t->da);
                if (!t->txpriv.link_id) {
                        wiphy_err(priv->hw->wiphy,
                                  "No more link IDs available.\n");
                        return -ENOENT;
                }
                t->txpriv.raw_link_id = t->txpriv.link_id;
        }
        if (t->txpriv.raw_link_id)
                priv->link_id_db[t->txpriv.raw_link_id - 1].timestamp =
                                jiffies;
        if (t->sta && (t->sta->uapsd_queues & BIT(t->queue)))
                t->txpriv.link_id = CW1200_LINK_ID_UAPSD;
        return 0;
}

static void
cw1200_tx_h_pm(struct cw1200_common *priv,
               struct cw1200_txinfo *t)
{
        if (ieee80211_is_auth(t->hdr->frame_control)) {
                u32 mask = ~BIT(t->txpriv.raw_link_id);
                spin_lock_bh(&priv->ps_state_lock);
                priv->sta_asleep_mask &= mask;
                priv->pspoll_mask &= mask;
                spin_unlock_bh(&priv->ps_state_lock);
        }
}

static void
cw1200_tx_h_calc_tid(struct cw1200_common *priv,
                     struct cw1200_txinfo *t)
{
        if (ieee80211_is_data_qos(t->hdr->frame_control)) {
                u8 *qos = ieee80211_get_qos_ctl(t->hdr);
                t->txpriv.tid = qos[0] & IEEE80211_QOS_CTL_TID_MASK;
        } else if (ieee80211_is_data(t->hdr->frame_control)) {
                t->txpriv.tid = 0;
        }
}

static int
cw1200_tx_h_crypt(struct cw1200_common *priv,
                  struct cw1200_txinfo *t)
{
        if (!t->tx_info->control.hw_key ||
            !ieee80211_has_protected(t->hdr->frame_control))
                return 0;

        t->hdrlen += t->tx_info->control.hw_key->iv_len;
        skb_put(t->skb, t->tx_info->control.hw_key->icv_len);

        if (t->tx_info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP)
                skb_put(t->skb, 8); /* MIC space */

        return 0;
}

static int
cw1200_tx_h_align(struct cw1200_common *priv,
                  struct cw1200_txinfo *t,
                  u8 *flags)
{
        size_t offset = (size_t)t->skb->data & 3;

        if (!offset)
                return 0;

        if (offset & 1) {
                wiphy_err(priv->hw->wiphy,
                          "Bug: attempt to transmit a frame with wrong alignment: %zu\n",
                          offset);
                return -EINVAL;
        }

        if (skb_headroom(t->skb) < offset) {
                wiphy_err(priv->hw->wiphy,
                          "Bug: no space allocated for DMA alignment. headroom: %d\n",
                          skb_headroom(t->skb));
                return -ENOMEM;
        }
        skb_push(t->skb, offset);
        t->hdrlen += offset;
        t->txpriv.offset += offset;
        *flags |= WSM_TX_2BYTES_SHIFT;
        cw1200_debug_tx_align(priv);
        return 0;
}

static int
cw1200_tx_h_action(struct cw1200_common *priv,
                   struct cw1200_txinfo *t)
{
        struct ieee80211_mgmt *mgmt =
                (struct ieee80211_mgmt *)t->hdr;
        if (ieee80211_is_action(t->hdr->frame_control) &&
            mgmt->u.action.category == WLAN_CATEGORY_BACK)
                return 1;
        else
                return 0;
}

/* Add WSM header */
static struct wsm_tx *
cw1200_tx_h_wsm(struct cw1200_common *priv,
                struct cw1200_txinfo *t)
{
        struct wsm_tx *wsm;

        if (skb_headroom(t->skb) < sizeof(struct wsm_tx)) {
                wiphy_err(priv->hw->wiphy,
                          "Bug: no space allocated for WSM header. headroom: %d\n",
                          skb_headroom(t->skb));
                return NULL;
        }

        wsm = skb_push(t->skb, sizeof(struct wsm_tx));
        t->txpriv.offset += sizeof(struct wsm_tx);
        memset(wsm, 0, sizeof(*wsm));
        wsm->hdr.len = __cpu_to_le16(t->skb->len);
        wsm->hdr.id = __cpu_to_le16(0x0004);
        wsm->queue_id = wsm_queue_id_to_wsm(t->queue);
        return wsm;
}

/* BT Coex specific handling */
static void
cw1200_tx_h_bt(struct cw1200_common *priv,
               struct cw1200_txinfo *t,
               struct wsm_tx *wsm)
{
        u8 priority = 0;

        if (!priv->bt_present)
                return;

        if (ieee80211_is_nullfunc(t->hdr->frame_control)) {
                priority = WSM_EPTA_PRIORITY_MGT;
        } else if (ieee80211_is_data(t->hdr->frame_control)) {
                /* Skip LLC SNAP header (+6) */
                u8 *payload = &t->skb->data[t->hdrlen];
                __be16 *ethertype = (__be16 *)&payload[6];
                if (be16_to_cpu(*ethertype) == ETH_P_PAE)
                        priority = WSM_EPTA_PRIORITY_EAPOL;
        } else if (ieee80211_is_assoc_req(t->hdr->frame_control) ||
                ieee80211_is_reassoc_req(t->hdr->frame_control)) {
                struct ieee80211_mgmt *mgt_frame =
                                (struct ieee80211_mgmt *)t->hdr;

                if (le16_to_cpu(mgt_frame->u.assoc_req.listen_interval) <
                                                priv->listen_interval) {
                        pr_debug("Modified Listen Interval to %d from %d\n",
                                 priv->listen_interval,
                                 mgt_frame->u.assoc_req.listen_interval);
                        /* Replace listen interval derieved from
                         * the one read from SDD
                         */
                        mgt_frame->u.assoc_req.listen_interval = cpu_to_le16(priv->listen_interval);
                }
        }

        if (!priority) {
                if (ieee80211_is_action(t->hdr->frame_control))
                        priority = WSM_EPTA_PRIORITY_ACTION;
                else if (ieee80211_is_mgmt(t->hdr->frame_control))
                        priority = WSM_EPTA_PRIORITY_MGT;
                else if (wsm->queue_id == WSM_QUEUE_VOICE)
                        priority = WSM_EPTA_PRIORITY_VOICE;
                else if (wsm->queue_id == WSM_QUEUE_VIDEO)
                        priority = WSM_EPTA_PRIORITY_VIDEO;
                else
                        priority = WSM_EPTA_PRIORITY_DATA;
        }

        pr_debug("[TX] EPTA priority %d.\n", priority);

        wsm->flags |= priority << 1;
}

static int
cw1200_tx_h_rate_policy(struct cw1200_common *priv,
                        struct cw1200_txinfo *t,
                        struct wsm_tx *wsm)
{
        bool tx_policy_renew = false;

        t->txpriv.rate_id = tx_policy_get(priv,
                t->tx_info->control.rates, IEEE80211_TX_MAX_RATES,
                &tx_policy_renew);
        if (t->txpriv.rate_id == CW1200_INVALID_RATE_ID)
                return -EFAULT;

        wsm->flags |= t->txpriv.rate_id << 4;

        t->rate = cw1200_get_tx_rate(priv,
                &t->tx_info->control.rates[0]);
        wsm->max_tx_rate = t->rate->hw_value;
        if (t->rate->flags & IEEE80211_TX_RC_MCS) {
                if (cw1200_ht_greenfield(&priv->ht_info))
                        wsm->ht_tx_parameters |=
                                __cpu_to_le32(WSM_HT_TX_GREENFIELD);
                else
                        wsm->ht_tx_parameters |=
                                __cpu_to_le32(WSM_HT_TX_MIXED);
        }

        if (tx_policy_renew) {
                pr_debug("[TX] TX policy renew.\n");
                /* It's not so optimal to stop TX queues every now and then.
                 * Better to reimplement task scheduling with
                 * a counter. TODO.
                 */
                wsm_lock_tx_async(priv);
                cw1200_tx_queues_lock(priv);
                if (queue_work(priv->workqueue,
                               &priv->tx_policy_upload_work) <= 0) {
                        cw1200_tx_queues_unlock(priv);
                        wsm_unlock_tx(priv);
                }
        }
        return 0;
}

static bool
cw1200_tx_h_pm_state(struct cw1200_common *priv,
                     struct cw1200_txinfo *t)
{
        int was_buffered = 1;

        if (t->txpriv.link_id == CW1200_LINK_ID_AFTER_DTIM &&
            !priv->buffered_multicasts) {
                priv->buffered_multicasts = true;
                if (priv->sta_asleep_mask)
                        queue_work(priv->workqueue,
                                   &priv->multicast_start_work);
        }

        if (t->txpriv.raw_link_id && t->txpriv.tid < CW1200_MAX_TID)
                was_buffered = priv->link_id_db[t->txpriv.raw_link_id - 1].buffered[t->txpriv.tid]++;

        return !was_buffered;
}

/* ******************************************************************** */

void cw1200_tx(struct ieee80211_hw *dev,
               struct ieee80211_tx_control *control,
               struct sk_buff *skb)
{
        struct cw1200_common *priv = dev->priv;
        struct cw1200_txinfo t = {
                .skb = skb,
                .queue = skb_get_queue_mapping(skb),
                .tx_info = IEEE80211_SKB_CB(skb),
                .hdr = (struct ieee80211_hdr *)skb->data,
                .txpriv.tid = CW1200_MAX_TID,
                .txpriv.rate_id = CW1200_INVALID_RATE_ID,
        };
        struct ieee80211_sta *sta;
        struct wsm_tx *wsm;
        bool tid_update = false;
        u8 flags = 0;
        int ret;

        if (priv->bh_error)
                goto drop;

        t.hdrlen = ieee80211_hdrlen(t.hdr->frame_control);
        t.da = ieee80211_get_DA(t.hdr);
        if (control) {
                t.sta = control->sta;
                t.sta_priv = (struct cw1200_sta_priv *)&t.sta->drv_priv;
        }

        if (WARN_ON(t.queue >= 4))
                goto drop;

        ret = cw1200_tx_h_calc_link_ids(priv, &t);
        if (ret)
                goto drop;

        pr_debug("[TX] TX %d bytes (queue: %d, link_id: %d (%d)).\n",
                 skb->len, t.queue, t.txpriv.link_id,
                 t.txpriv.raw_link_id);

        cw1200_tx_h_pm(priv, &t);
        cw1200_tx_h_calc_tid(priv, &t);
        ret = cw1200_tx_h_crypt(priv, &t);
        if (ret)
                goto drop;
        ret = cw1200_tx_h_align(priv, &t, &flags);
        if (ret)
                goto drop;
        ret = cw1200_tx_h_action(priv, &t);
        if (ret)
                goto drop;
        wsm = cw1200_tx_h_wsm(priv, &t);
        if (!wsm) {
                ret = -ENOMEM;
                goto drop;
        }
        wsm->flags |= flags;
        cw1200_tx_h_bt(priv, &t, wsm);
        ret = cw1200_tx_h_rate_policy(priv, &t, wsm);
        if (ret)
                goto drop;

        sta = t.sta;

        spin_lock_bh(&priv->ps_state_lock);
        {
                tid_update = cw1200_tx_h_pm_state(priv, &t);
                BUG_ON(cw1200_queue_put(&priv->tx_queue[t.queue],
                                        t.skb, &t.txpriv));
        }
        spin_unlock_bh(&priv->ps_state_lock);

        if (tid_update && sta)
                ieee80211_sta_set_buffered(sta, t.txpriv.tid, true);

        cw1200_bh_wakeup(priv);

        return;

drop:
        cw1200_skb_dtor(priv, skb, &t.txpriv);
        return;
}

/* ******************************************************************** */

static int cw1200_handle_action_rx(struct cw1200_common *priv,
                                   struct sk_buff *skb)
{
        struct ieee80211_mgmt *mgmt = (void *)skb->data;

        /* Filter block ACK negotiation: fully controlled by firmware */
        if (mgmt->u.action.category == WLAN_CATEGORY_BACK)
                return 1;

        return 0;
}

static int cw1200_handle_pspoll(struct cw1200_common *priv,
                                struct sk_buff *skb)
{
        struct ieee80211_sta *sta;
        struct ieee80211_pspoll *pspoll = (struct ieee80211_pspoll *)skb->data;
        int link_id = 0;
        u32 pspoll_mask = 0;
        int drop = 1;
        int i;

        if (priv->join_status != CW1200_JOIN_STATUS_AP)
                goto done;
        if (memcmp(priv->vif->addr, pspoll->bssid, ETH_ALEN))
                goto done;

        rcu_read_lock();
        sta = ieee80211_find_sta(priv->vif, pspoll->ta);
        if (sta) {
                struct cw1200_sta_priv *sta_priv;
                sta_priv = (struct cw1200_sta_priv *)&sta->drv_priv;
                link_id = sta_priv->link_id;
                pspoll_mask = BIT(sta_priv->link_id);
        }
        rcu_read_unlock();
        if (!link_id)
                goto done;

        priv->pspoll_mask |= pspoll_mask;
        drop = 0;

        /* Do not report pspols if data for given link id is queued already. */
        for (i = 0; i < 4; ++i) {
                if (cw1200_queue_get_num_queued(&priv->tx_queue[i],
                                                pspoll_mask)) {
                        cw1200_bh_wakeup(priv);
                        drop = 1;
                        break;
                }
        }
        pr_debug("[RX] PSPOLL: %s\n", drop ? "local" : "fwd");
done:
        return drop;
}

/* ******************************************************************** */

void cw1200_tx_confirm_cb(struct cw1200_common *priv,
                          int link_id,
                          struct wsm_tx_confirm *arg)
{
        u8 queue_id = cw1200_queue_get_queue_id(arg->packet_id);
        struct cw1200_queue *queue = &priv->tx_queue[queue_id];
        struct sk_buff *skb;
        const struct cw1200_txpriv *txpriv;

        pr_debug("[TX] TX confirm: %d, %d.\n",
                 arg->status, arg->ack_failures);

        if (priv->mode == NL80211_IFTYPE_UNSPECIFIED) {
                /* STA is stopped. */
                return;
        }

        if (WARN_ON(queue_id >= 4))
                return;

        if (arg->status)
                pr_debug("TX failed: %d.\n", arg->status);

        if ((arg->status == WSM_REQUEUE) &&
            (arg->flags & WSM_TX_STATUS_REQUEUE)) {
                /* "Requeue" means "implicit suspend" */
                struct wsm_suspend_resume suspend = {
                        .link_id = link_id,
                        .stop = 1,
                        .multicast = !link_id,
                };
                cw1200_suspend_resume(priv, &suspend);
                wiphy_warn(priv->hw->wiphy, "Requeue for link_id %d (try %d). STAs asleep: 0x%.8X\n",
                           link_id,
                           cw1200_queue_get_generation(arg->packet_id) + 1,
                           priv->sta_asleep_mask);
                cw1200_queue_requeue(queue, arg->packet_id);
                spin_lock_bh(&priv->ps_state_lock);
                if (!link_id) {
                        priv->buffered_multicasts = true;
                        if (priv->sta_asleep_mask) {
                                queue_work(priv->workqueue,
                                           &priv->multicast_start_work);
                        }
                }
                spin_unlock_bh(&priv->ps_state_lock);
        } else if (!cw1200_queue_get_skb(queue, arg->packet_id,
                                         &skb, &txpriv)) {
                struct ieee80211_tx_info *tx = IEEE80211_SKB_CB(skb);
                int tx_count = arg->ack_failures;
                u8 ht_flags = 0;
                int i;

                if (cw1200_ht_greenfield(&priv->ht_info))
                        ht_flags |= IEEE80211_TX_RC_GREEN_FIELD;

                spin_lock(&priv->bss_loss_lock);
                if (priv->bss_loss_state &&
                    arg->packet_id == priv->bss_loss_confirm_id) {
                        if (arg->status) {
                                /* Recovery failed */
                                __cw1200_cqm_bssloss_sm(priv, 0, 0, 1);
                        } else {
                                /* Recovery succeeded */
                                __cw1200_cqm_bssloss_sm(priv, 0, 1, 0);
                        }
                }
                spin_unlock(&priv->bss_loss_lock);

                if (!arg->status) {
                        tx->flags |= IEEE80211_TX_STAT_ACK;
                        ++tx_count;
                        cw1200_debug_txed(priv);
                        if (arg->flags & WSM_TX_STATUS_AGGREGATION) {
                                /* Do not report aggregation to mac80211:
                                 * it confuses minstrel a lot.
                                 */
                                /* tx->flags |= IEEE80211_TX_STAT_AMPDU; */
                                cw1200_debug_txed_agg(priv);
                        }
                } else {
                        if (tx_count)
                                ++tx_count;
                }

                for (i = 0; i < IEEE80211_TX_MAX_RATES; ++i) {
                        if (tx->status.rates[i].count >= tx_count) {
                                tx->status.rates[i].count = tx_count;
                                break;
                        }
                        tx_count -= tx->status.rates[i].count;
                        if (tx->status.rates[i].flags & IEEE80211_TX_RC_MCS)
                                tx->status.rates[i].flags |= ht_flags;
                }

                for (++i; i < IEEE80211_TX_MAX_RATES; ++i) {
                        tx->status.rates[i].count = 0;
                        tx->status.rates[i].idx = -1;
                }

                /* Pull off any crypto trailers that we added on */
                if (tx->control.hw_key) {
                        skb_trim(skb, skb->len - tx->control.hw_key->icv_len);
                        if (tx->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP)
                                skb_trim(skb, skb->len - 8); /* MIC space */
                }
                cw1200_queue_remove(queue, arg->packet_id);
        }
        /* XXX TODO:  Only wake if there are pending transmits.. */
        cw1200_bh_wakeup(priv);
}

static void cw1200_notify_buffered_tx(struct cw1200_common *priv,
                               struct sk_buff *skb, int link_id, int tid)
{
        struct ieee80211_sta *sta;
        struct ieee80211_hdr *hdr;
        u8 *buffered;
        u8 still_buffered = 0;

        if (link_id && tid < CW1200_MAX_TID) {
                buffered = priv->link_id_db
                                [link_id - 1].buffered;

                spin_lock_bh(&priv->ps_state_lock);
                if (!WARN_ON(!buffered[tid]))
                        still_buffered = --buffered[tid];
                spin_unlock_bh(&priv->ps_state_lock);

                if (!still_buffered && tid < CW1200_MAX_TID) {
                        hdr = (struct ieee80211_hdr *)skb->data;
                        rcu_read_lock();
                        sta = ieee80211_find_sta(priv->vif, hdr->addr1);
                        if (sta)
                                ieee80211_sta_set_buffered(sta, tid, false);
                        rcu_read_unlock();
                }
        }
}

void cw1200_skb_dtor(struct cw1200_common *priv,
                     struct sk_buff *skb,
                     const struct cw1200_txpriv *txpriv)
{
        skb_pull(skb, txpriv->offset);
        if (txpriv->rate_id != CW1200_INVALID_RATE_ID) {
                cw1200_notify_buffered_tx(priv, skb,
                                          txpriv->raw_link_id, txpriv->tid);
                tx_policy_put(priv, txpriv->rate_id);
        }
        ieee80211_tx_status_skb(priv->hw, skb);
}

void cw1200_rx_cb(struct cw1200_common *priv,
                  struct wsm_rx *arg,
                  int link_id,
                  struct sk_buff **skb_p)
{
        struct sk_buff *skb = *skb_p;
        struct ieee80211_rx_status *hdr = IEEE80211_SKB_RXCB(skb);
        struct ieee80211_hdr *frame = (struct ieee80211_hdr *)skb->data;
        struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)skb->data;
        struct cw1200_link_entry *entry = NULL;
        unsigned long grace_period;

        bool early_data = false;
        bool p2p = priv->vif && priv->vif->p2p;
        size_t hdrlen;
        hdr->flag = 0;

        if (priv->mode == NL80211_IFTYPE_UNSPECIFIED) {
                /* STA is stopped. */
                goto drop;
        }

        if (link_id && link_id <= CW1200_MAX_STA_IN_AP_MODE) {
                entry = &priv->link_id_db[link_id - 1];
                if (entry->status == CW1200_LINK_SOFT &&
                    ieee80211_is_data(frame->frame_control))
                        early_data = true;
                entry->timestamp = jiffies;
        } else if (p2p &&
                   ieee80211_is_action(frame->frame_control) &&
                   (mgmt->u.action.category == WLAN_CATEGORY_PUBLIC)) {
                pr_debug("[RX] Going to MAP&RESET link ID\n");
                WARN_ON(work_pending(&priv->linkid_reset_work));
                memcpy(&priv->action_frame_sa[0],
                       ieee80211_get_SA(frame), ETH_ALEN);
                priv->action_linkid = 0;
                schedule_work(&priv->linkid_reset_work);
        }

        if (link_id && p2p &&
            ieee80211_is_action(frame->frame_control) &&
            (mgmt->u.action.category == WLAN_CATEGORY_PUBLIC)) {
                /* Link ID already exists for the ACTION frame.
                 * Reset and Remap
                 */
                WARN_ON(work_pending(&priv->linkid_reset_work));
                memcpy(&priv->action_frame_sa[0],
                       ieee80211_get_SA(frame), ETH_ALEN);
                priv->action_linkid = link_id;
                schedule_work(&priv->linkid_reset_work);
        }
        if (arg->status) {
                if (arg->status == WSM_STATUS_MICFAILURE) {
                        pr_debug("[RX] MIC failure.\n");
                        hdr->flag |= RX_FLAG_MMIC_ERROR;
                } else if (arg->status == WSM_STATUS_NO_KEY_FOUND) {
                        pr_debug("[RX] No key found.\n");
                        goto drop;
                } else {
                        pr_debug("[RX] Receive failure: %d.\n",
                                 arg->status);
                        goto drop;
                }
        }

        if (skb->len < sizeof(struct ieee80211_pspoll)) {
                wiphy_warn(priv->hw->wiphy, "Malformed SDU rx'ed. Size is lesser than IEEE header.\n");
                goto drop;
        }

        if (ieee80211_is_pspoll(frame->frame_control))
                if (cw1200_handle_pspoll(priv, skb))
                        goto drop;

        hdr->band = ((arg->channel_number & 0xff00) ||
                     (arg->channel_number > 14)) ?
                        NL80211_BAND_5GHZ : NL80211_BAND_2GHZ;
        hdr->freq = ieee80211_channel_to_frequency(
                        arg->channel_number,
                        hdr->band);

        if (arg->rx_rate >= 14) {
                hdr->encoding = RX_ENC_HT;
                hdr->rate_idx = arg->rx_rate - 14;
        } else if (arg->rx_rate >= 4) {
                hdr->rate_idx = arg->rx_rate - 2;
        } else {
                hdr->rate_idx = arg->rx_rate;
        }

        hdr->signal = (s8)arg->rcpi_rssi;
        hdr->antenna = 0;

        hdrlen = ieee80211_hdrlen(frame->frame_control);

        if (WSM_RX_STATUS_ENCRYPTION(arg->flags)) {
                size_t iv_len = 0, icv_len = 0;

                hdr->flag |= RX_FLAG_DECRYPTED | RX_FLAG_IV_STRIPPED;

                /* Oops... There is no fast way to ask mac80211 about
                 * IV/ICV lengths. Even defineas are not exposed.
                 */
                switch (WSM_RX_STATUS_ENCRYPTION(arg->flags)) {
                case WSM_RX_STATUS_WEP:
                        iv_len = 4 /* WEP_IV_LEN */;
                        icv_len = 4 /* WEP_ICV_LEN */;
                        break;
                case WSM_RX_STATUS_TKIP:
                        iv_len = 8 /* TKIP_IV_LEN */;
                        icv_len = 4 /* TKIP_ICV_LEN */
                                + 8 /*MICHAEL_MIC_LEN*/;
                        hdr->flag |= RX_FLAG_MMIC_STRIPPED;
                        break;
                case WSM_RX_STATUS_AES:
                        iv_len = 8 /* CCMP_HDR_LEN */;
                        icv_len = 8 /* CCMP_MIC_LEN */;
                        break;
                case WSM_RX_STATUS_WAPI:
                        iv_len = 18 /* WAPI_HDR_LEN */;
                        icv_len = 16 /* WAPI_MIC_LEN */;
                        break;
                default:
                        pr_warn("Unknown encryption type %d\n",
                                WSM_RX_STATUS_ENCRYPTION(arg->flags));
                        goto drop;
                }

                /* Firmware strips ICV in case of MIC failure. */
                if (arg->status == WSM_STATUS_MICFAILURE)
                        icv_len = 0;

                if (skb->len < hdrlen + iv_len + icv_len) {
                        wiphy_warn(priv->hw->wiphy, "Malformed SDU rx'ed. Size is lesser than crypto headers.\n");
                        goto drop;
                }

                /* Remove IV, ICV and MIC */
                skb_trim(skb, skb->len - icv_len);
                memmove(skb->data + iv_len, skb->data, hdrlen);
                skb_pull(skb, iv_len);
        }

        /* Remove TSF from the end of frame */
        if (arg->flags & WSM_RX_STATUS_TSF_INCLUDED) {
                hdr->mactime = get_unaligned_le64(skb->data + skb->len - 8);
                if (skb->len >= 8)
                        skb_trim(skb, skb->len - 8);
        } else {
                hdr->mactime = 0;
        }

        cw1200_debug_rxed(priv);
        if (arg->flags & WSM_RX_STATUS_AGGREGATE)
                cw1200_debug_rxed_agg(priv);

        if (ieee80211_is_action(frame->frame_control) &&
            (arg->flags & WSM_RX_STATUS_ADDRESS1)) {
                if (cw1200_handle_action_rx(priv, skb))
                        return;
        } else if (ieee80211_is_beacon(frame->frame_control) &&
                   !arg->status && priv->vif &&
                   ether_addr_equal(ieee80211_get_SA(frame), priv->vif->bss_conf.bssid)) {
                const u8 *tim_ie;
                u8 *ies = ((struct ieee80211_mgmt *)
                          (skb->data))->u.beacon.variable;
                size_t ies_len = skb->len - (ies - (u8 *)(skb->data));

                tim_ie = cfg80211_find_ie(WLAN_EID_TIM, ies, ies_len);
                if (tim_ie && tim_ie[1] >= sizeof(struct ieee80211_tim_ie)) {
                        struct ieee80211_tim_ie *tim =
                                (struct ieee80211_tim_ie *)&tim_ie[2];

                        if (priv->join_dtim_period != tim->dtim_period) {
                                priv->join_dtim_period = tim->dtim_period;
                                queue_work(priv->workqueue,
                                           &priv->set_beacon_wakeup_period_work);
                        }
                }

                /* Disable beacon filter once we're associated... */
                if (priv->disable_beacon_filter &&
                    (priv->vif->cfg.assoc ||
                     priv->vif->cfg.ibss_joined)) {
                        priv->disable_beacon_filter = false;
                        queue_work(priv->workqueue,
                                   &priv->update_filtering_work);
                }
        }

        /* Stay awake after frame is received to give
         * userspace chance to react and acquire appropriate
         * wakelock.
         */
        if (ieee80211_is_auth(frame->frame_control))
                grace_period = 5 * HZ;
        else if (ieee80211_is_deauth(frame->frame_control))
                grace_period = 5 * HZ;
        else
                grace_period = 1 * HZ;
        cw1200_pm_stay_awake(&priv->pm_state, grace_period);

        if (early_data) {
                spin_lock_bh(&priv->ps_state_lock);
                /* Double-check status with lock held */
                if (entry->status == CW1200_LINK_SOFT)
                        skb_queue_tail(&entry->rx_queue, skb);
                else
                        ieee80211_rx_irqsafe(priv->hw, skb);
                spin_unlock_bh(&priv->ps_state_lock);
        } else {
                ieee80211_rx_irqsafe(priv->hw, skb);
        }
        *skb_p = NULL;

        return;

drop:
        /* TODO: update failure counters */
        return;
}

/* ******************************************************************** */
/* Security                                                             */

int cw1200_alloc_key(struct cw1200_common *priv)
{
        int idx;

        idx = ffs(~priv->key_map) - 1;
        if (idx < 0 || idx > WSM_KEY_MAX_INDEX)
                return -1;

        priv->key_map |= BIT(idx);
        priv->keys[idx].index = idx;
        return idx;
}

void cw1200_free_key(struct cw1200_common *priv, int idx)
{
        BUG_ON(!(priv->key_map & BIT(idx)));
        memset(&priv->keys[idx], 0, sizeof(priv->keys[idx]));
        priv->key_map &= ~BIT(idx);
}

void cw1200_free_keys(struct cw1200_common *priv)
{
        memset(&priv->keys, 0, sizeof(priv->keys));
        priv->key_map = 0;
}

int cw1200_upload_keys(struct cw1200_common *priv)
{
        int idx, ret = 0;
        for (idx = 0; idx <= WSM_KEY_MAX_INDEX; ++idx)
                if (priv->key_map & BIT(idx)) {
                        ret = wsm_add_key(priv, &priv->keys[idx]);
                        if (ret < 0)
                                break;
                }
        return ret;
}

/* Workaround for WFD test case 6.1.10 */
void cw1200_link_id_reset(struct work_struct *work)
{
        struct cw1200_common *priv =
                container_of(work, struct cw1200_common, linkid_reset_work);
        int temp_linkid;

        if (!priv->action_linkid) {
                /* In GO mode we can receive ACTION frames without a linkID */
                temp_linkid = cw1200_alloc_link_id(priv,
                                &priv->action_frame_sa[0]);
                WARN_ON(!temp_linkid);
                if (temp_linkid) {
                        /* Make sure we execute the WQ */
                        flush_workqueue(priv->workqueue);
                        /* Release the link ID */
                        spin_lock_bh(&priv->ps_state_lock);
                        priv->link_id_db[temp_linkid - 1].prev_status =
                                priv->link_id_db[temp_linkid - 1].status;
                        priv->link_id_db[temp_linkid - 1].status =
                                CW1200_LINK_RESET;
                        spin_unlock_bh(&priv->ps_state_lock);
                        wsm_lock_tx_async(priv);
                        if (queue_work(priv->workqueue,
                                       &priv->link_id_work) <= 0)
                                wsm_unlock_tx(priv);
                }
        } else {
                spin_lock_bh(&priv->ps_state_lock);
                priv->link_id_db[priv->action_linkid - 1].prev_status =
                        priv->link_id_db[priv->action_linkid - 1].status;
                priv->link_id_db[priv->action_linkid - 1].status =
                        CW1200_LINK_RESET_REMAP;
                spin_unlock_bh(&priv->ps_state_lock);
                wsm_lock_tx_async(priv);
                if (queue_work(priv->workqueue, &priv->link_id_work) <= 0)
                        wsm_unlock_tx(priv);
                flush_workqueue(priv->workqueue);
        }
}

int cw1200_find_link_id(struct cw1200_common *priv, const u8 *mac)
{
        int i, ret = 0;
        spin_lock_bh(&priv->ps_state_lock);
        for (i = 0; i < CW1200_MAX_STA_IN_AP_MODE; ++i) {
                if (!memcmp(mac, priv->link_id_db[i].mac, ETH_ALEN) &&
                    priv->link_id_db[i].status) {
                        priv->link_id_db[i].timestamp = jiffies;
                        ret = i + 1;
                        break;
                }
        }
        spin_unlock_bh(&priv->ps_state_lock);
        return ret;
}

int cw1200_alloc_link_id(struct cw1200_common *priv, const u8 *mac)
{
        int i, ret = 0;
        unsigned long max_inactivity = 0;
        unsigned long now = jiffies;

        spin_lock_bh(&priv->ps_state_lock);
        for (i = 0; i < CW1200_MAX_STA_IN_AP_MODE; ++i) {
                if (!priv->link_id_db[i].status) {
                        ret = i + 1;
                        break;
                } else if (priv->link_id_db[i].status != CW1200_LINK_HARD &&
                           !priv->tx_queue_stats.link_map_cache[i + 1]) {
                        unsigned long inactivity =
                                now - priv->link_id_db[i].timestamp;
                        if (inactivity < max_inactivity)
                                continue;
                        max_inactivity = inactivity;
                        ret = i + 1;
                }
        }
        if (ret) {
                struct cw1200_link_entry *entry = &priv->link_id_db[ret - 1];
                pr_debug("[AP] STA added, link_id: %d\n", ret);
                entry->status = CW1200_LINK_RESERVE;
                memcpy(&entry->mac, mac, ETH_ALEN);
                memset(&entry->buffered, 0, CW1200_MAX_TID);
                skb_queue_head_init(&entry->rx_queue);
                wsm_lock_tx_async(priv);
                if (queue_work(priv->workqueue, &priv->link_id_work) <= 0)
                        wsm_unlock_tx(priv);
        } else {
                wiphy_info(priv->hw->wiphy,
                           "[AP] Early: no more link IDs available.\n");
        }

        spin_unlock_bh(&priv->ps_state_lock);
        return ret;
}

void cw1200_link_id_work(struct work_struct *work)
{
        struct cw1200_common *priv =
                container_of(work, struct cw1200_common, link_id_work);
        wsm_flush_tx(priv);
        cw1200_link_id_gc_work(&priv->link_id_gc_work.work);
        wsm_unlock_tx(priv);
}

void cw1200_link_id_gc_work(struct work_struct *work)
{
        struct cw1200_common *priv =
                container_of(work, struct cw1200_common, link_id_gc_work.work);
        struct wsm_reset reset = {
                .reset_statistics = false,
        };
        struct wsm_map_link map_link = {
                .link_id = 0,
        };
        unsigned long now = jiffies;
        unsigned long next_gc = -1;
        long ttl;
        bool need_reset;
        u32 mask;
        int i;

        if (priv->join_status != CW1200_JOIN_STATUS_AP)
                return;

        wsm_lock_tx(priv);
        spin_lock_bh(&priv->ps_state_lock);
        for (i = 0; i < CW1200_MAX_STA_IN_AP_MODE; ++i) {
                need_reset = false;
                mask = BIT(i + 1);
                if (priv->link_id_db[i].status == CW1200_LINK_RESERVE ||
                    (priv->link_id_db[i].status == CW1200_LINK_HARD &&
                     !(priv->link_id_map & mask))) {
                        if (priv->link_id_map & mask) {
                                priv->sta_asleep_mask &= ~mask;
                                priv->pspoll_mask &= ~mask;
                                need_reset = true;
                        }
                        priv->link_id_map |= mask;
                        if (priv->link_id_db[i].status != CW1200_LINK_HARD)
                                priv->link_id_db[i].status = CW1200_LINK_SOFT;
                        memcpy(map_link.mac_addr, priv->link_id_db[i].mac,
                               ETH_ALEN);
                        spin_unlock_bh(&priv->ps_state_lock);
                        if (need_reset) {
                                reset.link_id = i + 1;
                                wsm_reset(priv, &reset);
                        }
                        map_link.link_id = i + 1;
                        wsm_map_link(priv, &map_link);
                        next_gc = min(next_gc, CW1200_LINK_ID_GC_TIMEOUT);
                        spin_lock_bh(&priv->ps_state_lock);
                } else if (priv->link_id_db[i].status == CW1200_LINK_SOFT) {
                        ttl = priv->link_id_db[i].timestamp - now +
                                        CW1200_LINK_ID_GC_TIMEOUT;
                        if (ttl <= 0) {
                                need_reset = true;
                                priv->link_id_db[i].status = CW1200_LINK_OFF;
                                priv->link_id_map &= ~mask;
                                priv->sta_asleep_mask &= ~mask;
                                priv->pspoll_mask &= ~mask;
                                eth_zero_addr(map_link.mac_addr);
                                spin_unlock_bh(&priv->ps_state_lock);
                                reset.link_id = i + 1;
                                wsm_reset(priv, &reset);
                                spin_lock_bh(&priv->ps_state_lock);
                        } else {
                                next_gc = min_t(unsigned long, next_gc, ttl);
                        }
                } else if (priv->link_id_db[i].status == CW1200_LINK_RESET ||
                                priv->link_id_db[i].status ==
                                CW1200_LINK_RESET_REMAP) {
                        int status = priv->link_id_db[i].status;
                        priv->link_id_db[i].status =
                                        priv->link_id_db[i].prev_status;
                        priv->link_id_db[i].timestamp = now;
                        reset.link_id = i + 1;
                        spin_unlock_bh(&priv->ps_state_lock);
                        wsm_reset(priv, &reset);
                        if (status == CW1200_LINK_RESET_REMAP) {
                                memcpy(map_link.mac_addr,
                                       priv->link_id_db[i].mac,
                                       ETH_ALEN);
                                map_link.link_id = i + 1;
                                wsm_map_link(priv, &map_link);
                                next_gc = min(next_gc,
                                                CW1200_LINK_ID_GC_TIMEOUT);
                        }
                        spin_lock_bh(&priv->ps_state_lock);
                }
                if (need_reset) {
                        skb_queue_purge(&priv->link_id_db[i].rx_queue);
                        pr_debug("[AP] STA removed, link_id: %d\n",
                                 reset.link_id);
                }
        }
        spin_unlock_bh(&priv->ps_state_lock);
        if (next_gc != -1)
                queue_delayed_work(priv->workqueue,
                                   &priv->link_id_gc_work, next_gc);
        wsm_unlock_tx(priv);
}