// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2009-2012  Realtek Corporation.*/

#include "wifi.h"
#include "base.h"
#include "rc.h"

/*
 *Finds the highest rate index we can use
 *if skb is special data like DHCP/EAPOL, we set should
 *it to lowest rate CCK_1M, otherwise we set rate to
 *highest rate based on wireless mode used for iwconfig
 *show Tx rate.
 */
static u8 _rtl_rc_get_highest_rix(struct rtl_priv *rtlpriv,
                                  struct ieee80211_sta *sta,
                                  struct sk_buff *skb, bool not_data)
{
        struct rtl_hal *rtlhal = rtl_hal(rtlpriv);
        struct rtl_phy *rtlphy = &(rtlpriv->phy);
        struct rtl_sta_info *sta_entry = NULL;
        u16 wireless_mode = 0;
        u8 nss;
        struct ieee80211_tx_rate rate;

        switch (get_rf_type(rtlphy)) {
        case RF_4T4R:
                nss = 4;
                break;
        case RF_3T3R:
                nss = 3;
                break;
        case RF_2T2R:
                nss = 2;
                break;
        default:
                nss = 1;
                break;
        }

        /*
         *this rate is no use for true rate, firmware
         *will control rate at all it just used for
         *1.show in iwconfig in B/G mode
         *2.in rtl_get_tcb_desc when we check rate is
         *      1M we will not use FW rate but user rate.
         */

        if (sta) {
                sta_entry = (struct rtl_sta_info *)sta->drv_priv;
                wireless_mode = sta_entry->wireless_mode;
        }

        if (rtl_is_special_data(rtlpriv->mac80211.hw, skb, true, false) ||
            not_data) {
                return 0;
        } else {
                if (rtlhal->current_bandtype == BAND_ON_2_4G) {
                        if (wireless_mode == WIRELESS_MODE_B) {
                                return B_MODE_MAX_RIX;
                        } else if (wireless_mode == WIRELESS_MODE_G) {
                                return G_MODE_MAX_RIX;
                        } else if (wireless_mode == WIRELESS_MODE_N_24G) {
                                if (nss == 1)
                                        return N_MODE_MCS7_RIX;
                                else
                                        return N_MODE_MCS15_RIX;
                        } else if (wireless_mode == WIRELESS_MODE_AC_24G) {
                                if (sta->deflink.bandwidth == IEEE80211_STA_RX_BW_20) {
                                        ieee80211_rate_set_vht(&rate,
                                                               AC_MODE_MCS8_RIX,
                                                               nss);
                                        goto out;
                                } else {
                                        ieee80211_rate_set_vht(&rate,
                                                               AC_MODE_MCS9_RIX,
                                                               nss);
                                        goto out;
                                }
                        }
                        return 0;
                } else {
                        if (wireless_mode == WIRELESS_MODE_A) {
                                return A_MODE_MAX_RIX;
                        } else if (wireless_mode == WIRELESS_MODE_N_5G) {
                                if (nss == 1)
                                        return N_MODE_MCS7_RIX;
                                else
                                        return N_MODE_MCS15_RIX;
                        } else if (wireless_mode == WIRELESS_MODE_AC_5G) {
                                if (sta->deflink.bandwidth == IEEE80211_STA_RX_BW_20) {
                                        ieee80211_rate_set_vht(&rate,
                                                               AC_MODE_MCS8_RIX,
                                                               nss);
                                        goto out;
                                } else {
                                        ieee80211_rate_set_vht(&rate,
                                                               AC_MODE_MCS9_RIX,
                                                               nss);
                                        goto out;
                                }
                        }
                        return 0;
                }
        }

out:
        return rate.idx;
}

static void _rtl_rc_rate_set_series(struct rtl_priv *rtlpriv,
                                    struct ieee80211_sta *sta,
                                    struct ieee80211_tx_rate *rate,
                                    struct ieee80211_tx_rate_control *txrc,
                                    u8 tries, s8 rix, int rtsctsenable,
                                    bool not_data)
{
        struct rtl_mac *mac = rtl_mac(rtlpriv);
        struct rtl_sta_info *sta_entry = NULL;
        u16 wireless_mode = 0;
        u8 sgi_20 = 0, sgi_40 = 0, sgi_80 = 0;

        if (sta) {
                sgi_20 = sta->deflink.ht_cap.cap & IEEE80211_HT_CAP_SGI_20;
                sgi_40 = sta->deflink.ht_cap.cap & IEEE80211_HT_CAP_SGI_40;
                sgi_80 = sta->deflink.vht_cap.cap & IEEE80211_VHT_CAP_SHORT_GI_80;
                sta_entry = (struct rtl_sta_info *)sta->drv_priv;
                wireless_mode = sta_entry->wireless_mode;
        }
        rate->count = tries;
        rate->idx = rix >= 0x00 ? rix : 0x00;

        if (!not_data) {
                if (txrc->short_preamble)
                        rate->flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
                if (mac->opmode == NL80211_IFTYPE_AP ||
                        mac->opmode == NL80211_IFTYPE_ADHOC) {
                        if (sta && (sta->deflink.ht_cap.cap &
                                    IEEE80211_HT_CAP_SUP_WIDTH_20_40))
                                rate->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
                        if (sta && sta->deflink.vht_cap.vht_supported)
                                rate->flags |= IEEE80211_TX_RC_80_MHZ_WIDTH;
                } else {
                        if (mac->bw_80)
                                rate->flags |= IEEE80211_TX_RC_80_MHZ_WIDTH;
                        else if (mac->bw_40)
                                rate->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
                }

                if (sgi_20 || sgi_40 || sgi_80)
                        rate->flags |= IEEE80211_TX_RC_SHORT_GI;
                if (sta && sta->deflink.ht_cap.ht_supported &&
                    (wireless_mode == WIRELESS_MODE_N_5G ||
                     wireless_mode == WIRELESS_MODE_N_24G))
                        rate->flags |= IEEE80211_TX_RC_MCS;
                if (sta && sta->deflink.vht_cap.vht_supported &&
                    (wireless_mode == WIRELESS_MODE_AC_5G ||
                     wireless_mode == WIRELESS_MODE_AC_24G ||
                     wireless_mode == WIRELESS_MODE_AC_ONLY))
                        rate->flags |= IEEE80211_TX_RC_VHT_MCS;
        }
}

static void rtl_get_rate(void *ppriv, struct ieee80211_sta *sta,
                         void *priv_sta,
                         struct ieee80211_tx_rate_control *txrc)
{
        struct rtl_priv *rtlpriv = ppriv;
        struct sk_buff *skb = txrc->skb;
        struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
        struct ieee80211_tx_rate *rates = tx_info->control.rates;
        __le16 fc = rtl_get_fc(skb);
        u8 try_per_rate, i, rix;
        bool not_data = !ieee80211_is_data(fc);

        rix = _rtl_rc_get_highest_rix(rtlpriv, sta, skb, not_data);
        try_per_rate = 1;
        _rtl_rc_rate_set_series(rtlpriv, sta, &rates[0], txrc,
                                try_per_rate, rix, 1, not_data);

        if (!not_data) {
                for (i = 1; i < 4; i++)
                        _rtl_rc_rate_set_series(rtlpriv, sta, &rates[i],
                                                txrc, i, (rix - i), 1,
                                                not_data);
        }
}

static bool _rtl_tx_aggr_check(struct rtl_priv *rtlpriv,
                               struct rtl_sta_info *sta_entry, u16 tid)
{
        struct rtl_mac *mac = rtl_mac(rtlpriv);

        if (mac->act_scanning)
                return false;

        if (mac->opmode == NL80211_IFTYPE_STATION &&
            mac->cnt_after_linked < 3)
                return false;

        if (sta_entry->tids[tid].agg.agg_state == RTL_AGG_STOP)
                return true;

        return false;
}

/*mac80211 Rate Control callbacks*/
static void rtl_tx_status(void *ppriv,
                          struct ieee80211_supported_band *sband,
                          struct ieee80211_sta *sta, void *priv_sta,
                          struct sk_buff *skb)
{
        struct rtl_priv *rtlpriv = ppriv;
        struct rtl_mac *mac = rtl_mac(rtlpriv);
        struct ieee80211_hdr *hdr = rtl_get_hdr(skb);
        __le16 fc = rtl_get_fc(skb);
        struct rtl_sta_info *sta_entry;

        if (!priv_sta || !ieee80211_is_data(fc))
                return;

        if (rtl_is_special_data(mac->hw, skb, true, true))
                return;

        if (is_multicast_ether_addr(ieee80211_get_DA(hdr)) ||
            is_broadcast_ether_addr(ieee80211_get_DA(hdr)))
                return;

        if (sta) {
                /* Check if aggregation has to be enabled for this tid */
                sta_entry = (struct rtl_sta_info *)sta->drv_priv;
                if (sta->deflink.ht_cap.ht_supported &&
                    !(skb->protocol == cpu_to_be16(ETH_P_PAE))) {
                        if (ieee80211_is_data_qos(fc)) {
                                u8 tid = rtl_get_tid(skb);

                                if (_rtl_tx_aggr_check(rtlpriv, sta_entry,
                                                       tid)) {
                                        sta_entry->tids[tid].agg.agg_state =
                                                RTL_AGG_PROGRESS;
                                        ieee80211_start_tx_ba_session(sta, tid,
                                                                      5000);
                                }
                        }
                }
        }
}

static void rtl_rate_init(void *ppriv,
                          struct ieee80211_supported_band *sband,
                          struct cfg80211_chan_def *chandef,
                          struct ieee80211_sta *sta, void *priv_sta)
{
}

static void rtl_rate_update(void *ppriv,
                            struct ieee80211_supported_band *sband,
                            struct cfg80211_chan_def *chandef,
                            struct ieee80211_sta *sta, void *priv_sta,
                            u32 changed)
{
}

static void *rtl_rate_alloc(struct ieee80211_hw *hw)
{
        struct rtl_priv *rtlpriv = rtl_priv(hw);
        return rtlpriv;
}

static void rtl_rate_free(void *rtlpriv)
{
        return;
}

static void *rtl_rate_alloc_sta(void *ppriv,
                                struct ieee80211_sta *sta, gfp_t gfp)
{
        struct rtl_priv *rtlpriv = ppriv;
        struct rtl_rate_priv *rate_priv;

        rate_priv = kzalloc_obj(*rate_priv, gfp);
        if (!rate_priv)
                return NULL;

        rtlpriv->rate_priv = rate_priv;

        return rate_priv;
}

static void rtl_rate_free_sta(void *rtlpriv,
                              struct ieee80211_sta *sta, void *priv_sta)
{
        struct rtl_rate_priv *rate_priv = priv_sta;

        kfree(rate_priv);
}

static const struct rate_control_ops rtl_rate_ops = {
        .name = "rtl_rc",
        .alloc = rtl_rate_alloc,
        .free = rtl_rate_free,
        .alloc_sta = rtl_rate_alloc_sta,
        .free_sta = rtl_rate_free_sta,
        .rate_init = rtl_rate_init,
        .rate_update = rtl_rate_update,
        .tx_status = rtl_tx_status,
        .get_rate = rtl_get_rate,
};

int rtl_rate_control_register(void)
{
        return ieee80211_rate_control_register(&rtl_rate_ops);
}

void rtl_rate_control_unregister(void)
{
        ieee80211_rate_control_unregister(&rtl_rate_ops);
}