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
  18 enum 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 */
  29 static 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 */
  35 static 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  */
  63 static 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
  78 static void
  79 mt7601u_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
  98 static 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
 110 void 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
 125 static 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
 137 static struct mt76_txwi *
 138 mt7601u_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 = 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
 198 void 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
 236 void 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
 268 int 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 }