rc.c

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/******************************************************************************
 *
 * Copyright(c) 2009-2012  Realtek Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
 *
 * The full GNU General Public License is included in this distribution in the
 * file called LICENSE.
 *
 * Contact Information:
 * wlanfae <[email protected]>
 * Realtek Corporation, No. 2, Innovation Road II, Hsinchu Science Park,
 * Hsinchu 300, Taiwan.
 *
 * Larry Finger <[email protected]>
 *
 *****************************************************************************/

#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
 *CCK11M or OFDM_54M based on wireless mode.
 */
static u8 _rtl_rc_get_highest_rix(struct rtl_priv *rtlpriv,
                  struct ieee80211_sta *sta,
                  struct sk_buff *skb, bool not_data)
{
    struct rtl_mac *rtlmac = rtl_mac(rtlpriv);
    struct rtl_hal *rtlhal = rtl_hal(rtlpriv);
    struct rtl_phy *rtlphy = &(rtlpriv->phy);
    struct rtl_sta_info *sta_entry = NULL;
    u8 wireless_mode = 0;

    /*
     *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 (rtlmac->opmode == NL80211_IFTYPE_AP ||
        rtlmac->opmode == NL80211_IFTYPE_ADHOC) {
        if (sta) {
            sta_entry = (struct rtl_sta_info *) sta->drv_priv;
            wireless_mode = sta_entry->wireless_mode;
        } else {
            return 0;
        }
    } else {
        wireless_mode = rtlmac->mode;
    }

    if (rtl_is_special_data(rtlpriv->mac80211.hw, skb, true) ||
            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 (get_rf_type(rtlphy) != RF_2T2R)
                    return N_MODE_MCS7_RIX;
                else
                    return N_MODE_MCS15_RIX;
            }
        } else {
            if (wireless_mode == WIRELESS_MODE_A) {
                return A_MODE_MAX_RIX;
            } else {
                if (get_rf_type(rtlphy) != RF_2T2R)
                    return N_MODE_MCS7_RIX;
                else
                    return N_MODE_MCS15_RIX;
            }
        }
    }
}

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, char rix, int rtsctsenable,
                    bool not_data)
{
    struct rtl_mac *mac = rtl_mac(rtlpriv);
    u8 sgi_20 = 0, sgi_40 = 0;

    if (sta) {
        sgi_20 = sta->ht_cap.cap & IEEE80211_HT_CAP_SGI_20;
        sgi_40 = sta->ht_cap.cap & IEEE80211_HT_CAP_SGI_40;
    }
    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->ht_cap.cap &
                IEEE80211_HT_CAP_SUP_WIDTH_20_40))
                rate->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
        } else {
            if (mac->bw_40)
                rate->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
        }
        if (sgi_20 || sgi_40)
            rate->flags |= IEEE80211_TX_RC_SHORT_GI;
        if (sta && sta->ht_cap.ht_supported)
            rate->flags |= IEEE80211_TX_RC_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);

    if (rate_control_send_low(sta, priv_sta, txrc))
        return;

    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))
        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->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 ieee80211_sta *sta, void *priv_sta)
{
}

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

static void *rtl_rate_alloc(struct ieee80211_hw *hw,
        struct dentry *debugfsdir)
{
    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(sizeof(struct rtl_rate_priv), gfp);
    if (!rate_priv) {
        RT_TRACE(rtlpriv, COMP_ERR, DBG_EMERG,
             "Unable to allocate private rc structure\n");
        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 struct rate_control_ops rtl_rate_ops = {
    .module = NULL,
    .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);
}