mediatek/mt7601u/tx.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
0004  * Copyright (C) 2015 Jakub Kicinski <kubakici@wp.pl>
0005  */
0006
0007 #include "mt7601u.h"
0008 #include "trace.h"
0009
0010 enum mt76_txq_id {
0011     MT_TXQ_VO = IEEE80211_AC_VO,
0012     MT_TXQ_VI = IEEE80211_AC_VI,
0013     MT_TXQ_BE = IEEE80211_AC_BE,
0014     MT_TXQ_BK = IEEE80211_AC_BK,
0015     MT_TXQ_PSD,
0016     MT_TXQ_MCU,
0017     __MT_TXQ_MAX
0018 };
0019
0020 /* Hardware uses mirrored order of queues with Q0 having the highest priority */
0021 static u8 q2hwq(u8 q)
0022 {
0023     return q ^ 0x3;
0024 }
0025
0026 /* Take mac80211 Q id from the skb and translate it to hardware Q id */
0027 static u8 skb2q(struct sk_buff *skb)
0028 {
0029     int qid = skb_get_queue_mapping(skb);
0030
0031     if (WARN_ON(qid >= MT_TXQ_PSD)) {
0032         qid = MT_TXQ_BE;
0033         skb_set_queue_mapping(skb, qid);
0034     }
0035
0036     return q2hwq(qid);
0037 }
0038
0039 /* Note: TX retry reporting is a bit broken.
0040  *   Retries are reported only once per AMPDU and often come a frame early
0041  *   i.e. they are reported in the last status preceding the AMPDU. Apart
0042  *   from the fact that it's hard to know the length of the AMPDU (which is
0043  *   required to know to how many consecutive frames retries should be
0044  *   applied), if status comes early on full FIFO it gets lost and retries
0045  *   of the whole AMPDU become invisible.
0046  *   As a work-around encode the desired rate in PKT_ID of TX descriptor
0047  *   and based on that guess the retries (every rate is tried once).
0048  *   Only downside here is that for MCS0 we have to rely solely on
0049  *   transmission failures as no retries can ever be reported.
0050  *   Not having to read EXT_FIFO has a nice effect of doubling the number
0051  *   of reports which can be fetched.
0052  *   Also the vendor driver never uses the EXT_FIFO register so it may be
0053  *   undertested.
0054  */
0055 static u8 mt7601u_tx_pktid_enc(struct mt7601u_dev *dev, u8 rate, bool is_probe)
0056 {
0057     u8 encoded = (rate + 1) + is_probe *  8;
0058
0059     /* Because PKT_ID 0 disables status reporting only 15 values are
0060      * available but 16 are needed (8 MCS * 2 for encoding is_probe)
0061      * - we need to cram together two rates. MCS0 and MCS7 with is_probe
0062      * share PKT_ID 9.
0063      */
0064     if (is_probe && rate == 7)
0065         return encoded - 7;
0066
0067     return encoded;
0068 }
0069
0070 static void
0071 mt7601u_tx_pktid_dec(struct mt7601u_dev *dev, struct mt76_tx_status *stat)
0072 {
0073     u8 req_rate = stat->pktid;
0074     u8 eff_rate = stat->rate & 0x7;
0075
0076     req_rate -= 1;
0077
0078     if (req_rate > 7) {
0079         stat->is_probe = true;
0080         req_rate -= 8;
0081
0082         /* Decide between MCS0 and MCS7 which share pktid 9 */
0083         if (!req_rate && eff_rate)
0084             req_rate = 7;
0085     }
0086
0087     stat->retry = req_rate - eff_rate;
0088 }
0089
0090 static void mt7601u_tx_skb_remove_dma_overhead(struct sk_buff *skb,
0091                            struct ieee80211_tx_info *info)
0092 {
0093     int pkt_len = (unsigned long)info->status.status_driver_data[0];
0094
0095     skb_pull(skb, sizeof(struct mt76_txwi) + 4);
0096     if (ieee80211_get_hdrlen_from_skb(skb) % 4)
0097         mt76_remove_hdr_pad(skb);
0098
0099     skb_trim(skb, pkt_len);
0100 }
0101
0102 void mt7601u_tx_status(struct mt7601u_dev *dev, struct sk_buff *skb)
0103 {
0104     struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
0105
0106     mt7601u_tx_skb_remove_dma_overhead(skb, info);
0107
0108     ieee80211_tx_info_clear_status(info);
0109     info->status.rates[0].idx = -1;
0110     info->flags |= IEEE80211_TX_STAT_ACK;
0111
0112     spin_lock_bh(&dev->mac_lock);
0113     ieee80211_tx_status(dev->hw, skb);
0114     spin_unlock_bh(&dev->mac_lock);
0115 }
0116
0117 static int mt7601u_skb_rooms(struct mt7601u_dev *dev, struct sk_buff *skb)
0118 {
0119     int hdr_len = ieee80211_get_hdrlen_from_skb(skb);
0120     u32 need_head;
0121
0122     need_head = sizeof(struct mt76_txwi) + 4;
0123     if (hdr_len % 4)
0124         need_head += 2;
0125
0126     return skb_cow(skb, need_head);
0127 }
0128
0129 static struct mt76_txwi *
0130 mt7601u_push_txwi(struct mt7601u_dev *dev, struct sk_buff *skb,
0131           struct ieee80211_sta *sta, struct mt76_wcid *wcid,
0132           int pkt_len)
0133 {
0134     struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
0135     struct ieee80211_tx_rate *rate = &info->control.rates[0];
0136     struct mt76_txwi *txwi;
0137     unsigned long flags;
0138     bool is_probe;
0139     u32 pkt_id;
0140     u16 rate_ctl;
0141     u8 nss;
0142
0143     txwi = skb_push(skb, sizeof(struct mt76_txwi));
0144     memset(txwi, 0, sizeof(*txwi));
0145
0146     if (!wcid->tx_rate_set)
0147         ieee80211_get_tx_rates(info->control.vif, sta, skb,
0148                        info->control.rates, 1);
0149
0150     spin_lock_irqsave(&dev->lock, flags);
0151     if (rate->idx < 0 || !rate->count)
0152         rate_ctl = wcid->tx_rate;
0153     else
0154         rate_ctl = mt76_mac_tx_rate_val(dev, rate, &nss);
0155     spin_unlock_irqrestore(&dev->lock, flags);
0156     txwi->rate_ctl = cpu_to_le16(rate_ctl);
0157
0158     if (!(info->flags & IEEE80211_TX_CTL_NO_ACK))
0159         txwi->ack_ctl |= MT_TXWI_ACK_CTL_REQ;
0160     if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ)
0161         txwi->ack_ctl |= MT_TXWI_ACK_CTL_NSEQ;
0162
0163     if ((info->flags & IEEE80211_TX_CTL_AMPDU) && sta) {
0164         u8 ba_size = IEEE80211_MIN_AMPDU_BUF;
0165
0166         ba_size <<= sta->deflink.ht_cap.ampdu_factor;
0167         ba_size = min_t(int, 63, ba_size);
0168         if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
0169             ba_size = 0;
0170         txwi->ack_ctl |= FIELD_PREP(MT_TXWI_ACK_CTL_BA_WINDOW, ba_size);
0171
0172         txwi->flags =
0173             cpu_to_le16(MT_TXWI_FLAGS_AMPDU |
0174                     FIELD_PREP(MT_TXWI_FLAGS_MPDU_DENSITY,
0175                            sta->deflink.ht_cap.ampdu_density));
0176         if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
0177             txwi->flags = 0;
0178     }
0179
0180     txwi->wcid = wcid->idx;
0181
0182     is_probe = !!(info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE);
0183     pkt_id = mt7601u_tx_pktid_enc(dev, rate_ctl & 0x7, is_probe);
0184     pkt_len |= FIELD_PREP(MT_TXWI_LEN_PKTID, pkt_id);
0185     txwi->len_ctl = cpu_to_le16(pkt_len);
0186
0187     return txwi;
0188 }
0189
0190 void mt7601u_tx(struct ieee80211_hw *hw, struct ieee80211_tx_control *control,
0191         struct sk_buff *skb)
0192 {
0193     struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
0194     struct mt7601u_dev *dev = hw->priv;
0195     struct ieee80211_vif *vif = info->control.vif;
0196     struct ieee80211_sta *sta = control->sta;
0197     struct mt76_sta *msta = NULL;
0198     struct mt76_wcid *wcid = dev->mon_wcid;
0199     struct mt76_txwi *txwi;
0200     int pkt_len = skb->len;
0201     int hw_q = skb2q(skb);
0202
0203     BUILD_BUG_ON(ARRAY_SIZE(info->status.status_driver_data) < 1);
0204     info->status.status_driver_data[0] = (void *)(unsigned long)pkt_len;
0205
0206     if (mt7601u_skb_rooms(dev, skb) || mt76_insert_hdr_pad(skb)) {
0207         ieee80211_free_txskb(dev->hw, skb);
0208         return;
0209     }
0210
0211     if (sta) {
0212         msta = (struct mt76_sta *) sta->drv_priv;
0213         wcid = &msta->wcid;
0214     } else if (vif) {
0215         struct mt76_vif *mvif = (struct mt76_vif *)vif->drv_priv;
0216
0217         wcid = &mvif->group_wcid;
0218     }
0219
0220     txwi = mt7601u_push_txwi(dev, skb, sta, wcid, pkt_len);
0221
0222     if (mt7601u_dma_enqueue_tx(dev, skb, wcid, hw_q))
0223         return;
0224
0225     trace_mt_tx(dev, skb, msta, txwi);
0226 }
0227
0228 void mt7601u_tx_stat(struct work_struct *work)
0229 {
0230     struct mt7601u_dev *dev = container_of(work, struct mt7601u_dev,
0231                            stat_work.work);
0232     struct mt76_tx_status stat;
0233     unsigned long flags;
0234     int cleaned = 0;
0235
0236     while (!test_bit(MT7601U_STATE_REMOVED, &dev->state)) {
0237         stat = mt7601u_mac_fetch_tx_status(dev);
0238         if (!stat.valid)
0239             break;
0240
0241         mt7601u_tx_pktid_dec(dev, &stat);
0242         mt76_send_tx_status(dev, &stat);
0243
0244         cleaned++;
0245     }
0246     trace_mt_tx_status_cleaned(dev, cleaned);
0247
0248     spin_lock_irqsave(&dev->tx_lock, flags);
0249     if (cleaned)
0250         queue_delayed_work(dev->stat_wq, &dev->stat_work,
0251                    msecs_to_jiffies(10));
0252     else if (test_and_clear_bit(MT7601U_STATE_MORE_STATS, &dev->state))
0253         queue_delayed_work(dev->stat_wq, &dev->stat_work,
0254                    msecs_to_jiffies(20));
0255     else
0256         clear_bit(MT7601U_STATE_READING_STATS, &dev->state);
0257     spin_unlock_irqrestore(&dev->tx_lock, flags);
0258 }
0259
0260 int mt7601u_conf_tx(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
0261             unsigned int link_id, u16 queue,
0262             const struct ieee80211_tx_queue_params *params)
0263 {
0264     struct mt7601u_dev *dev = hw->priv;
0265     u8 cw_min = 5, cw_max = 10, hw_q = q2hwq(queue);
0266     u32 val;
0267
0268     /* TODO: should we do funny things with the parameters?
0269      *   See what mt7601u_set_default_edca() used to do in init.c.
0270      */
0271
0272     if (params->cw_min)
0273         cw_min = fls(params->cw_min);
0274     if (params->cw_max)
0275         cw_max = fls(params->cw_max);
0276
0277     WARN_ON(params->txop > 0xff);
0278     WARN_ON(params->aifs > 0xf);
0279     WARN_ON(cw_min > 0xf);
0280     WARN_ON(cw_max > 0xf);
0281
0282     val = FIELD_PREP(MT_EDCA_CFG_AIFSN, params->aifs) |
0283           FIELD_PREP(MT_EDCA_CFG_CWMIN, cw_min) |
0284           FIELD_PREP(MT_EDCA_CFG_CWMAX, cw_max);
0285     /* TODO: based on user-controlled EnableTxBurst var vendor drv sets
0286      *   a really long txop on AC0 (see connect.c:2009) but only on
0287      *   connect? When not connected should be 0.
0288      */
0289     if (!hw_q)
0290         val |= 0x60;
0291     else
0292         val |= FIELD_PREP(MT_EDCA_CFG_TXOP, params->txop);
0293     mt76_wr(dev, MT_EDCA_CFG_AC(hw_q), val);
0294
0295     val = mt76_rr(dev, MT_WMM_TXOP(hw_q));
0296     val &= ~(MT_WMM_TXOP_MASK << MT_WMM_TXOP_SHIFT(hw_q));
0297     val |= params->txop << MT_WMM_TXOP_SHIFT(hw_q);
0298     mt76_wr(dev, MT_WMM_TXOP(hw_q), val);
0299
0300     val = mt76_rr(dev, MT_WMM_AIFSN);
0301     val &= ~(MT_WMM_AIFSN_MASK << MT_WMM_AIFSN_SHIFT(hw_q));
0302     val |= params->aifs << MT_WMM_AIFSN_SHIFT(hw_q);
0303     mt76_wr(dev, MT_WMM_AIFSN, val);
0304
0305     val = mt76_rr(dev, MT_WMM_CWMIN);
0306     val &= ~(MT_WMM_CWMIN_MASK << MT_WMM_CWMIN_SHIFT(hw_q));
0307     val |= cw_min << MT_WMM_CWMIN_SHIFT(hw_q);
0308     mt76_wr(dev, MT_WMM_CWMIN, val);
0309
0310     val = mt76_rr(dev, MT_WMM_CWMAX);
0311     val &= ~(MT_WMM_CWMAX_MASK << MT_WMM_CWMAX_SHIFT(hw_q));
0312     val |= cw_max << MT_WMM_CWMAX_SHIFT(hw_q);
0313     mt76_wr(dev, MT_WMM_CWMAX, val);
0314
0315     return 0;
0316 }