LXR linux/drivers/net/wireless/mediatek/mt7601u/tx.c

   1/*
   2 * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
   3 * Copyright (C) 2015 Jakub Kicinski <kubakici@wp.pl>
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License version 2
   7 * as published by the Free Software Foundation
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12 * GNU General Public License for more details.
  13 */
  14
  15#include "mt7601u.h"
  16#include "trace.h"
  17
  18enum mt76_txq_id {
  19        MT_TXQ_VO = IEEE80211_AC_VO,
  20        MT_TXQ_VI = IEEE80211_AC_VI,
  21        MT_TXQ_BE = IEEE80211_AC_BE,
  22        MT_TXQ_BK = IEEE80211_AC_BK,
  23        MT_TXQ_PSD,
  24        MT_TXQ_MCU,
  25        __MT_TXQ_MAX
  26};
  27
  28/* Hardware uses mirrored order of queues with Q0 having the highest priority */
  29static u8 q2hwq(u8 q)
  30{
  31        return q ^ 0x3;
  32}
  33
  34/* Take mac80211 Q id from the skb and translate it to hardware Q id */
  35static u8 skb2q(struct sk_buff *skb)
  36{
  37        int qid = skb_get_queue_mapping(skb);
  38
  39        if (WARN_ON(qid >= MT_TXQ_PSD)) {
  40                qid = MT_TXQ_BE;
  41                skb_set_queue_mapping(skb, qid);
  42        }
  43
  44        return q2hwq(qid);
  45}
  46
  47/* Note: TX retry reporting is a bit broken.
  48 *       Retries are reported only once per AMPDU and often come a frame early
  49 *       i.e. they are reported in the last status preceding the AMPDU. Apart
  50 *       from the fact that it's hard to know the length of the AMPDU (which is
  51 *       required to know to how many consecutive frames retries should be
  52 *       applied), if status comes early on full FIFO it gets lost and retries
  53 *       of the whole AMPDU become invisible.
  54 *       As a work-around encode the desired rate in PKT_ID of TX descriptor
  55 *       and based on that guess the retries (every rate is tried once).
  56 *       Only downside here is that for MCS0 we have to rely solely on
  57 *       transmission failures as no retries can ever be reported.
  58 *       Not having to read EXT_FIFO has a nice effect of doubling the number
  59 *       of reports which can be fetched.
  60 *       Also the vendor driver never uses the EXT_FIFO register so it may be
  61 *       undertested.
  62 */
  63static u8 mt7601u_tx_pktid_enc(struct mt7601u_dev *dev, u8 rate, bool is_probe)
  64{
  65        u8 encoded = (rate + 1) + is_probe *  8;
  66
  67        /* Because PKT_ID 0 disables status reporting only 15 values are
  68         * available but 16 are needed (8 MCS * 2 for encoding is_probe)
  69         * - we need to cram together two rates. MCS0 and MCS7 with is_probe
  70         * share PKT_ID 9.
  71         */
  72        if (is_probe && rate == 7)
  73                return encoded - 7;
  74
  75        return encoded;
  76}
  77
  78static void
  79mt7601u_tx_pktid_dec(struct mt7601u_dev *dev, struct mt76_tx_status *stat)
  80{
  81        u8 req_rate = stat->pktid;
  82        u8 eff_rate = stat->rate & 0x7;
  83
  84        req_rate -= 1;
  85
  86        if (req_rate > 7) {
  87                stat->is_probe = true;
  88                req_rate -= 8;
  89
  90                /* Decide between MCS0 and MCS7 which share pktid 9 */
  91                if (!req_rate && eff_rate)
  92                        req_rate = 7;
  93        }
  94
  95        stat->retry = req_rate - eff_rate;
  96}
  97
  98static void mt7601u_tx_skb_remove_dma_overhead(struct sk_buff *skb,
  99                                               struct ieee80211_tx_info *info)
 100{
 101        int pkt_len = (unsigned long)info->status.status_driver_data[0];
 102
 103        skb_pull(skb, sizeof(struct mt76_txwi) + 4);
 104        if (ieee80211_get_hdrlen_from_skb(skb) % 4)
 105                mt76_remove_hdr_pad(skb);
 106
 107        skb_trim(skb, pkt_len);
 108}
 109
 110void mt7601u_tx_status(struct mt7601u_dev *dev, struct sk_buff *skb)
 111{
 112        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 113
 114        mt7601u_tx_skb_remove_dma_overhead(skb, info);
 115
 116        ieee80211_tx_info_clear_status(info);
 117        info->status.rates[0].idx = -1;
 118        info->flags |= IEEE80211_TX_STAT_ACK;
 119
 120        spin_lock(&dev->mac_lock);
 121        ieee80211_tx_status(dev->hw, skb);
 122        spin_unlock(&dev->mac_lock);
 123}
 124
 125static int mt7601u_skb_rooms(struct mt7601u_dev *dev, struct sk_buff *skb)
 126{
 127        int hdr_len = ieee80211_get_hdrlen_from_skb(skb);
 128        u32 need_head;
 129
 130        need_head = sizeof(struct mt76_txwi) + 4;
 131        if (hdr_len % 4)
 132                need_head += 2;
 133
 134        return skb_cow(skb, need_head);
 135}
 136
 137static struct mt76_txwi *
 138mt7601u_push_txwi(struct mt7601u_dev *dev, struct sk_buff *skb,
 139                  struct ieee80211_sta *sta, struct mt76_wcid *wcid,
 140                  int pkt_len)
 141{
 142        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 143        struct ieee80211_tx_rate *rate = &info->control.rates[0];
 144        struct mt76_txwi *txwi;
 145        unsigned long flags;
 146        bool is_probe;
 147        u32 pkt_id;
 148        u16 rate_ctl;
 149        u8 nss;
 150
 151        txwi = (struct mt76_txwi *)skb_push(skb, sizeof(struct mt76_txwi));
 152        memset(txwi, 0, sizeof(*txwi));
 153
 154        if (!wcid->tx_rate_set)
 155                ieee80211_get_tx_rates(info->control.vif, sta, skb,
 156                                       info->control.rates, 1);
 157
 158        spin_lock_irqsave(&dev->lock, flags);
 159        if (rate->idx < 0 || !rate->count)
 160                rate_ctl = wcid->tx_rate;
 161        else
 162                rate_ctl = mt76_mac_tx_rate_val(dev, rate, &nss);
 163        spin_unlock_irqrestore(&dev->lock, flags);
 164        txwi->rate_ctl = cpu_to_le16(rate_ctl);
 165
 166        if (!(info->flags & IEEE80211_TX_CTL_NO_ACK))
 167                txwi->ack_ctl |= MT_TXWI_ACK_CTL_REQ;
 168        if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ)
 169                txwi->ack_ctl |= MT_TXWI_ACK_CTL_NSEQ;
 170
 171        if ((info->flags & IEEE80211_TX_CTL_AMPDU) && sta) {
 172                u8 ba_size = IEEE80211_MIN_AMPDU_BUF;
 173
 174                ba_size <<= sta->ht_cap.ampdu_factor;
 175                ba_size = min_t(int, 63, ba_size);
 176                if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
 177                        ba_size = 0;
 178                txwi->ack_ctl |= FIELD_PREP(MT_TXWI_ACK_CTL_BA_WINDOW, ba_size);
 179
 180                txwi->flags =
 181                        cpu_to_le16(MT_TXWI_FLAGS_AMPDU |
 182                                    FIELD_PREP(MT_TXWI_FLAGS_MPDU_DENSITY,
 183                                               sta->ht_cap.ampdu_density));
 184                if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
 185                        txwi->flags = 0;
 186        }
 187
 188        txwi->wcid = wcid->idx;
 189
 190        is_probe = !!(info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE);
 191        pkt_id = mt7601u_tx_pktid_enc(dev, rate_ctl & 0x7, is_probe);
 192        pkt_len |= FIELD_PREP(MT_TXWI_LEN_PKTID, pkt_id);
 193        txwi->len_ctl = cpu_to_le16(pkt_len);
 194
 195        return txwi;
 196}
 197
 198void mt7601u_tx(struct ieee80211_hw *hw, struct ieee80211_tx_control *control,
 199                struct sk_buff *skb)
 200{
 201        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 202        struct mt7601u_dev *dev = hw->priv;
 203        struct ieee80211_vif *vif = info->control.vif;
 204        struct ieee80211_sta *sta = control->sta;
 205        struct mt76_sta *msta = NULL;
 206        struct mt76_wcid *wcid = dev->mon_wcid;
 207        struct mt76_txwi *txwi;
 208        int pkt_len = skb->len;
 209        int hw_q = skb2q(skb);
 210
 211        BUILD_BUG_ON(ARRAY_SIZE(info->status.status_driver_data) < 1);
 212        info->status.status_driver_data[0] = (void *)(unsigned long)pkt_len;
 213
 214        if (mt7601u_skb_rooms(dev, skb) || mt76_insert_hdr_pad(skb)) {
 215                ieee80211_free_txskb(dev->hw, skb);
 216                return;
 217        }
 218
 219        if (sta) {
 220                msta = (struct mt76_sta *) sta->drv_priv;
 221                wcid = &msta->wcid;
 222        } else if (vif) {
 223                struct mt76_vif *mvif = (struct mt76_vif *)vif->drv_priv;
 224
 225                wcid = &mvif->group_wcid;
 226        }
 227
 228        txwi = mt7601u_push_txwi(dev, skb, sta, wcid, pkt_len);
 229
 230        if (mt7601u_dma_enqueue_tx(dev, skb, wcid, hw_q))
 231                return;
 232
 233        trace_mt_tx(dev, skb, msta, txwi);
 234}
 235
 236void mt7601u_tx_stat(struct work_struct *work)
 237{
 238        struct mt7601u_dev *dev = container_of(work, struct mt7601u_dev,
 239                                               stat_work.work);
 240        struct mt76_tx_status stat;
 241        unsigned long flags;
 242        int cleaned = 0;
 243
 244        while (!test_bit(MT7601U_STATE_REMOVED, &dev->state)) {
 245                stat = mt7601u_mac_fetch_tx_status(dev);
 246                if (!stat.valid)
 247                        break;
 248
 249                mt7601u_tx_pktid_dec(dev, &stat);
 250                mt76_send_tx_status(dev, &stat);
 251
 252                cleaned++;
 253        }
 254        trace_mt_tx_status_cleaned(dev, cleaned);
 255
 256        spin_lock_irqsave(&dev->tx_lock, flags);
 257        if (cleaned)
 258                queue_delayed_work(dev->stat_wq, &dev->stat_work,
 259                                   msecs_to_jiffies(10));
 260        else if (test_and_clear_bit(MT7601U_STATE_MORE_STATS, &dev->state))
 261                queue_delayed_work(dev->stat_wq, &dev->stat_work,
 262                                   msecs_to_jiffies(20));
 263        else
 264                clear_bit(MT7601U_STATE_READING_STATS, &dev->state);
 265        spin_unlock_irqrestore(&dev->tx_lock, flags);
 266}
 267
 268int mt7601u_conf_tx(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 269                    u16 queue, const struct ieee80211_tx_queue_params *params)
 270{
 271        struct mt7601u_dev *dev = hw->priv;
 272        u8 cw_min = 5, cw_max = 10, hw_q = q2hwq(queue);
 273        u32 val;
 274
 275        /* TODO: should we do funny things with the parameters?
 276         *       See what mt7601u_set_default_edca() used to do in init.c.
 277         */
 278
 279        if (params->cw_min)
 280                cw_min = fls(params->cw_min);
 281        if (params->cw_max)
 282                cw_max = fls(params->cw_max);
 283
 284        WARN_ON(params->txop > 0xff);
 285        WARN_ON(params->aifs > 0xf);
 286        WARN_ON(cw_min > 0xf);
 287        WARN_ON(cw_max > 0xf);
 288
 289        val = FIELD_PREP(MT_EDCA_CFG_AIFSN, params->aifs) |
 290              FIELD_PREP(MT_EDCA_CFG_CWMIN, cw_min) |
 291              FIELD_PREP(MT_EDCA_CFG_CWMAX, cw_max);
 292        /* TODO: based on user-controlled EnableTxBurst var vendor drv sets
 293         *       a really long txop on AC0 (see connect.c:2009) but only on
 294         *       connect? When not connected should be 0.
 295         */
 296        if (!hw_q)
 297                val |= 0x60;
 298        else
 299                val |= FIELD_PREP(MT_EDCA_CFG_TXOP, params->txop);
 300        mt76_wr(dev, MT_EDCA_CFG_AC(hw_q), val);
 301
 302        val = mt76_rr(dev, MT_WMM_TXOP(hw_q));
 303        val &= ~(MT_WMM_TXOP_MASK << MT_WMM_TXOP_SHIFT(hw_q));
 304        val |= params->txop << MT_WMM_TXOP_SHIFT(hw_q);
 305        mt76_wr(dev, MT_WMM_TXOP(hw_q), val);
 306
 307        val = mt76_rr(dev, MT_WMM_AIFSN);
 308        val &= ~(MT_WMM_AIFSN_MASK << MT_WMM_AIFSN_SHIFT(hw_q));
 309        val |= params->aifs << MT_WMM_AIFSN_SHIFT(hw_q);
 310        mt76_wr(dev, MT_WMM_AIFSN, val);
 311
 312        val = mt76_rr(dev, MT_WMM_CWMIN);
 313        val &= ~(MT_WMM_CWMIN_MASK << MT_WMM_CWMIN_SHIFT(hw_q));
 314        val |= cw_min << MT_WMM_CWMIN_SHIFT(hw_q);
 315        mt76_wr(dev, MT_WMM_CWMIN, val);
 316
 317        val = mt76_rr(dev, MT_WMM_CWMAX);
 318        val &= ~(MT_WMM_CWMAX_MASK << MT_WMM_CWMAX_SHIFT(hw_q));
 319        val |= cw_max << MT_WMM_CWMAX_SHIFT(hw_q);
 320        mt76_wr(dev, MT_WMM_CWMAX, val);
 321
 322        return 0;
 323}
 324