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

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
   4 * Copyright (C) 2015 Jakub Kicinski <kubakici@wp.pl>
   5 */
   6
   7#include "mt7601u.h"
   8#include "trace.h"
   9
  10enum mt76_txq_id {
  11        MT_TXQ_VO = IEEE80211_AC_VO,
  12        MT_TXQ_VI = IEEE80211_AC_VI,
  13        MT_TXQ_BE = IEEE80211_AC_BE,
  14        MT_TXQ_BK = IEEE80211_AC_BK,
  15        MT_TXQ_PSD,
  16        MT_TXQ_MCU,
  17        __MT_TXQ_MAX
  18};
  19
  20/* Hardware uses mirrored order of queues with Q0 having the highest priority */
  21static u8 q2hwq(u8 q)
  22{
  23        return q ^ 0x3;
  24}
  25
  26/* Take mac80211 Q id from the skb and translate it to hardware Q id */
  27static u8 skb2q(struct sk_buff *skb)
  28{
  29        int qid = skb_get_queue_mapping(skb);
  30
  31        if (WARN_ON(qid >= MT_TXQ_PSD)) {
  32                qid = MT_TXQ_BE;
  33                skb_set_queue_mapping(skb, qid);
  34        }
  35
  36        return q2hwq(qid);
  37}
  38
  39/* Note: TX retry reporting is a bit broken.
  40 *       Retries are reported only once per AMPDU and often come a frame early
  41 *       i.e. they are reported in the last status preceding the AMPDU. Apart
  42 *       from the fact that it's hard to know the length of the AMPDU (which is
  43 *       required to know to how many consecutive frames retries should be
  44 *       applied), if status comes early on full FIFO it gets lost and retries
  45 *       of the whole AMPDU become invisible.
  46 *       As a work-around encode the desired rate in PKT_ID of TX descriptor
  47 *       and based on that guess the retries (every rate is tried once).
  48 *       Only downside here is that for MCS0 we have to rely solely on
  49 *       transmission failures as no retries can ever be reported.
  50 *       Not having to read EXT_FIFO has a nice effect of doubling the number
  51 *       of reports which can be fetched.
  52 *       Also the vendor driver never uses the EXT_FIFO register so it may be
  53 *       undertested.
  54 */
  55static u8 mt7601u_tx_pktid_enc(struct mt7601u_dev *dev, u8 rate, bool is_probe)
  56{
  57        u8 encoded = (rate + 1) + is_probe *  8;
  58
  59        /* Because PKT_ID 0 disables status reporting only 15 values are
  60         * available but 16 are needed (8 MCS * 2 for encoding is_probe)
  61         * - we need to cram together two rates. MCS0 and MCS7 with is_probe
  62         * share PKT_ID 9.
  63         */
  64        if (is_probe && rate == 7)
  65                return encoded - 7;
  66
  67        return encoded;
  68}
  69
  70static void
  71mt7601u_tx_pktid_dec(struct mt7601u_dev *dev, struct mt76_tx_status *stat)
  72{
  73        u8 req_rate = stat->pktid;
  74        u8 eff_rate = stat->rate & 0x7;
  75
  76        req_rate -= 1;
  77
  78        if (req_rate > 7) {
  79                stat->is_probe = true;
  80                req_rate -= 8;
  81
  82                /* Decide between MCS0 and MCS7 which share pktid 9 */
  83                if (!req_rate && eff_rate)
  84                        req_rate = 7;
  85        }
  86
  87        stat->retry = req_rate - eff_rate;
  88}
  89
  90static void mt7601u_tx_skb_remove_dma_overhead(struct sk_buff *skb,
  91                                               struct ieee80211_tx_info *info)
  92{
  93        int pkt_len = (unsigned long)info->status.status_driver_data[0];
  94
  95        skb_pull(skb, sizeof(struct mt76_txwi) + 4);
  96        if (ieee80211_get_hdrlen_from_skb(skb) % 4)
  97                mt76_remove_hdr_pad(skb);
  98
  99        skb_trim(skb, pkt_len);
 100}
 101
 102void mt7601u_tx_status(struct mt7601u_dev *dev, struct sk_buff *skb)
 103{
 104        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 105
 106        mt7601u_tx_skb_remove_dma_overhead(skb, info);
 107
 108        ieee80211_tx_info_clear_status(info);
 109        info->status.rates[0].idx = -1;
 110        info->flags |= IEEE80211_TX_STAT_ACK;
 111
 112        spin_lock_bh(&dev->mac_lock);
 113        ieee80211_tx_status(dev->hw, skb);
 114        spin_unlock_bh(&dev->mac_lock);
 115}
 116
 117static int mt7601u_skb_rooms(struct mt7601u_dev *dev, struct sk_buff *skb)
 118{
 119        int hdr_len = ieee80211_get_hdrlen_from_skb(skb);
 120        u32 need_head;
 121
 122        need_head = sizeof(struct mt76_txwi) + 4;
 123        if (hdr_len % 4)
 124                need_head += 2;
 125
 126        return skb_cow(skb, need_head);
 127}
 128
 129static struct mt76_txwi *
 130mt7601u_push_txwi(struct mt7601u_dev *dev, struct sk_buff *skb,
 131                  struct ieee80211_sta *sta, struct mt76_wcid *wcid,
 132                  int pkt_len)
 133{
 134        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 135        struct ieee80211_tx_rate *rate = &info->control.rates[0];
 136        struct mt76_txwi *txwi;
 137        unsigned long flags;
 138        bool is_probe;
 139        u32 pkt_id;
 140        u16 rate_ctl;
 141        u8 nss;
 142
 143        txwi = skb_push(skb, sizeof(struct mt76_txwi));
 144        memset(txwi, 0, sizeof(*txwi));
 145
 146        if (!wcid->tx_rate_set)
 147                ieee80211_get_tx_rates(info->control.vif, sta, skb,
 148                                       info->control.rates, 1);
 149
 150        spin_lock_irqsave(&dev->lock, flags);
 151        if (rate->idx < 0 || !rate->count)
 152                rate_ctl = wcid->tx_rate;
 153        else
 154                rate_ctl = mt76_mac_tx_rate_val(dev, rate, &nss);
 155        spin_unlock_irqrestore(&dev->lock, flags);
 156        txwi->rate_ctl = cpu_to_le16(rate_ctl);
 157
 158        if (!(info->flags & IEEE80211_TX_CTL_NO_ACK))
 159                txwi->ack_ctl |= MT_TXWI_ACK_CTL_REQ;
 160        if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ)
 161                txwi->ack_ctl |= MT_TXWI_ACK_CTL_NSEQ;
 162
 163        if ((info->flags & IEEE80211_TX_CTL_AMPDU) && sta) {
 164                u8 ba_size = IEEE80211_MIN_AMPDU_BUF;
 165
 166                ba_size <<= sta->ht_cap.ampdu_factor;
 167                ba_size = min_t(int, 63, ba_size);
 168                if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
 169                        ba_size = 0;
 170                txwi->ack_ctl |= FIELD_PREP(MT_TXWI_ACK_CTL_BA_WINDOW, ba_size);
 171
 172                txwi->flags =
 173                        cpu_to_le16(MT_TXWI_FLAGS_AMPDU |
 174                                    FIELD_PREP(MT_TXWI_FLAGS_MPDU_DENSITY,
 175                                               sta->ht_cap.ampdu_density));
 176                if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
 177                        txwi->flags = 0;
 178        }
 179
 180        txwi->wcid = wcid->idx;
 181
 182        is_probe = !!(info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE);
 183        pkt_id = mt7601u_tx_pktid_enc(dev, rate_ctl & 0x7, is_probe);
 184        pkt_len |= FIELD_PREP(MT_TXWI_LEN_PKTID, pkt_id);
 185        txwi->len_ctl = cpu_to_le16(pkt_len);
 186
 187        return txwi;
 188}
 189
 190void mt7601u_tx(struct ieee80211_hw *hw, struct ieee80211_tx_control *control,
 191                struct sk_buff *skb)
 192{
 193        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 194        struct mt7601u_dev *dev = hw->priv;
 195        struct ieee80211_vif *vif = info->control.vif;
 196        struct ieee80211_sta *sta = control->sta;
 197        struct mt76_sta *msta = NULL;
 198        struct mt76_wcid *wcid = dev->mon_wcid;
 199        struct mt76_txwi *txwi;
 200        int pkt_len = skb->len;
 201        int hw_q = skb2q(skb);
 202
 203        BUILD_BUG_ON(ARRAY_SIZE(info->status.status_driver_data) < 1);
 204        info->status.status_driver_data[0] = (void *)(unsigned long)pkt_len;
 205
 206        if (mt7601u_skb_rooms(dev, skb) || mt76_insert_hdr_pad(skb)) {
 207                ieee80211_free_txskb(dev->hw, skb);
 208                return;
 209        }
 210
 211        if (sta) {
 212                msta = (struct mt76_sta *) sta->drv_priv;
 213                wcid = &msta->wcid;
 214        } else if (vif) {
 215                struct mt76_vif *mvif = (struct mt76_vif *)vif->drv_priv;
 216
 217                wcid = &mvif->group_wcid;
 218        }
 219
 220        txwi = mt7601u_push_txwi(dev, skb, sta, wcid, pkt_len);
 221
 222        if (mt7601u_dma_enqueue_tx(dev, skb, wcid, hw_q))
 223                return;
 224
 225        trace_mt_tx(dev, skb, msta, txwi);
 226}
 227
 228void mt7601u_tx_stat(struct work_struct *work)
 229{
 230        struct mt7601u_dev *dev = container_of(work, struct mt7601u_dev,
 231                                               stat_work.work);
 232        struct mt76_tx_status stat;
 233        unsigned long flags;
 234        int cleaned = 0;
 235
 236        while (!test_bit(MT7601U_STATE_REMOVED, &dev->state)) {
 237                stat = mt7601u_mac_fetch_tx_status(dev);
 238                if (!stat.valid)
 239                        break;
 240
 241                mt7601u_tx_pktid_dec(dev, &stat);
 242                mt76_send_tx_status(dev, &stat);
 243
 244                cleaned++;
 245        }
 246        trace_mt_tx_status_cleaned(dev, cleaned);
 247
 248        spin_lock_irqsave(&dev->tx_lock, flags);
 249        if (cleaned)
 250                queue_delayed_work(dev->stat_wq, &dev->stat_work,
 251                                   msecs_to_jiffies(10));
 252        else if (test_and_clear_bit(MT7601U_STATE_MORE_STATS, &dev->state))
 253                queue_delayed_work(dev->stat_wq, &dev->stat_work,
 254                                   msecs_to_jiffies(20));
 255        else
 256                clear_bit(MT7601U_STATE_READING_STATS, &dev->state);
 257        spin_unlock_irqrestore(&dev->tx_lock, flags);
 258}
 259
 260int mt7601u_conf_tx(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 261                    u16 queue, const struct ieee80211_tx_queue_params *params)
 262{
 263        struct mt7601u_dev *dev = hw->priv;
 264        u8 cw_min = 5, cw_max = 10, hw_q = q2hwq(queue);
 265        u32 val;
 266
 267        /* TODO: should we do funny things with the parameters?
 268         *       See what mt7601u_set_default_edca() used to do in init.c.
 269         */
 270
 271        if (params->cw_min)
 272                cw_min = fls(params->cw_min);
 273        if (params->cw_max)
 274                cw_max = fls(params->cw_max);
 275
 276        WARN_ON(params->txop > 0xff);
 277        WARN_ON(params->aifs > 0xf);
 278        WARN_ON(cw_min > 0xf);
 279        WARN_ON(cw_max > 0xf);
 280
 281        val = FIELD_PREP(MT_EDCA_CFG_AIFSN, params->aifs) |
 282              FIELD_PREP(MT_EDCA_CFG_CWMIN, cw_min) |
 283              FIELD_PREP(MT_EDCA_CFG_CWMAX, cw_max);
 284        /* TODO: based on user-controlled EnableTxBurst var vendor drv sets
 285         *       a really long txop on AC0 (see connect.c:2009) but only on
 286         *       connect? When not connected should be 0.
 287         */
 288        if (!hw_q)
 289                val |= 0x60;
 290        else
 291                val |= FIELD_PREP(MT_EDCA_CFG_TXOP, params->txop);
 292        mt76_wr(dev, MT_EDCA_CFG_AC(hw_q), val);
 293
 294        val = mt76_rr(dev, MT_WMM_TXOP(hw_q));
 295        val &= ~(MT_WMM_TXOP_MASK << MT_WMM_TXOP_SHIFT(hw_q));
 296        val |= params->txop << MT_WMM_TXOP_SHIFT(hw_q);
 297        mt76_wr(dev, MT_WMM_TXOP(hw_q), val);
 298
 299        val = mt76_rr(dev, MT_WMM_AIFSN);
 300        val &= ~(MT_WMM_AIFSN_MASK << MT_WMM_AIFSN_SHIFT(hw_q));
 301        val |= params->aifs << MT_WMM_AIFSN_SHIFT(hw_q);
 302        mt76_wr(dev, MT_WMM_AIFSN, val);
 303
 304        val = mt76_rr(dev, MT_WMM_CWMIN);
 305        val &= ~(MT_WMM_CWMIN_MASK << MT_WMM_CWMIN_SHIFT(hw_q));
 306        val |= cw_min << MT_WMM_CWMIN_SHIFT(hw_q);
 307        mt76_wr(dev, MT_WMM_CWMIN, val);
 308
 309        val = mt76_rr(dev, MT_WMM_CWMAX);
 310        val &= ~(MT_WMM_CWMAX_MASK << MT_WMM_CWMAX_SHIFT(hw_q));
 311        val |= cw_max << MT_WMM_CWMAX_SHIFT(hw_q);
 312        mt76_wr(dev, MT_WMM_CWMAX, val);
 313
 314        return 0;
 315}
 316