package/kernel/mac80211/patches/322-mac80211-add-A-MSDU-tx-support.patch

   1 From: Felix Fietkau <nbd@openwrt.org>
   2 Date: Fri, 5 Feb 2016 01:38:51 +0100
   3 Subject: [PATCH] mac80211: add A-MSDU tx support
   4
   5 Requires software tx queueing support. frag_list support (for zero-copy)
   6 is optional.
   7
   8 Signed-off-by: Felix Fietkau <nbd@openwrt.org>
   9 ---
  10
  11 --- a/include/net/mac80211.h
  12 +++ b/include/net/mac80211.h
  13 @@ -709,6 +709,7 @@ enum mac80211_tx_info_flags {
  14   * @IEEE80211_TX_CTRL_PS_RESPONSE: This frame is a response to a poll
  15   *     frame (PS-Poll or uAPSD).
  16   * @IEEE80211_TX_CTRL_RATE_INJECT: This frame is injected with rate information
  17 + * @IEEE80211_TX_CTRL_AMSDU: This frame is an A-MSDU frame
  18   *
  19   * These flags are used in tx_info->control.flags.
  20   */
  21 @@ -716,6 +717,7 @@ enum mac80211_tx_control_flags {
  22         IEEE80211_TX_CTRL_PORT_CTRL_PROTO       = BIT(0),
  23         IEEE80211_TX_CTRL_PS_RESPONSE           = BIT(1),
  24         IEEE80211_TX_CTRL_RATE_INJECT           = BIT(2),
  25 +       IEEE80211_TX_CTRL_AMSDU                 = BIT(3),
  26  };
  27
  28  /*
  29 @@ -1961,6 +1963,12 @@ struct ieee80211_txq {
  30   *     order and does not need to manage its own reorder buffer or BA session
  31   *     timeout.
  32   *
  33 + * @IEEE80211_HW_TX_AMSDU: Hardware (or driver) supports software aggregated
  34 + *     A-MSDU frames. Requires software tx queueing support.
  35 + *
  36 + * @IEEE80211_HW_TX_FRAG_LIST: Hardware (or driver) supports sending frag_list
  37 + *     skbs, needed for zero-copy software A-MSDU.
  38 + *
  39   * @NUM_IEEE80211_HW_FLAGS: number of hardware flags, used for sizing arrays
  40   */
  41  enum ieee80211_hw_flags {
  42 @@ -1998,6 +2006,8 @@ enum ieee80211_hw_flags {
  43         IEEE80211_HW_BEACON_TX_STATUS,
  44         IEEE80211_HW_NEEDS_UNIQUE_STA_ADDR,
  45         IEEE80211_HW_SUPPORTS_REORDERING_BUFFER,
  46 +       IEEE80211_HW_TX_AMSDU,
  47 +       IEEE80211_HW_TX_FRAG_LIST,
  48
  49         /* keep last, obviously */
  50         NUM_IEEE80211_HW_FLAGS
  51 @@ -2070,6 +2080,9 @@ enum ieee80211_hw_flags {
  52   *     size is smaller (an example is LinkSys WRT120N with FW v1.0.07
  53   *     build 002 Jun 18 2012).
  54   *
  55 + * @max_tx_amsdu_subframes: maximum number of subframes used in software
  56 + *     A-MSDU aggregation
  57 + *
  58   * @offchannel_tx_hw_queue: HW queue ID to use for offchannel TX
  59   *     (if %IEEE80211_HW_QUEUE_CONTROL is set)
  60   *
  61 @@ -2124,6 +2137,7 @@ struct ieee80211_hw {
  62         u8 max_rate_tries;
  63         u8 max_rx_aggregation_subframes;
  64         u8 max_tx_aggregation_subframes;
  65 +       u8 max_tx_amsdu_subframes;
  66         u8 offchannel_tx_hw_queue;
  67         u8 radiotap_mcs_details;
  68         u16 radiotap_vht_details;
  69 --- a/net/mac80211/agg-tx.c
  70 +++ b/net/mac80211/agg-tx.c
  71 @@ -935,6 +935,7 @@ void ieee80211_process_addba_resp(struct
  72                                   size_t len)
  73  {
  74         struct tid_ampdu_tx *tid_tx;
  75 +       struct ieee80211_txq *txq;
  76         u16 capab, tid;
  77         u8 buf_size;
  78         bool amsdu;
  79 @@ -945,6 +946,10 @@ void ieee80211_process_addba_resp(struct
  80         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
  81         buf_size = min(buf_size, local->hw.max_tx_aggregation_subframes);
  82
  83 +       txq = sta->sta.txq[tid];
  84 +       if (!amsdu && txq)
  85 +               set_bit(IEEE80211_TXQ_NO_AMSDU, &to_txq_info(txq)->flags);
  86 +
  87         mutex_lock(&sta->ampdu_mlme.mtx);
  88
  89         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
  90 --- a/net/mac80211/debugfs.c
  91 +++ b/net/mac80211/debugfs.c
  92 @@ -127,6 +127,8 @@ static const char *hw_flag_names[NUM_IEE
  93         FLAG(BEACON_TX_STATUS),
  94         FLAG(NEEDS_UNIQUE_STA_ADDR),
  95         FLAG(SUPPORTS_REORDERING_BUFFER),
  96 +       FLAG(TX_AMSDU),
  97 +       FLAG(TX_FRAG_LIST),
  98
  99         /* keep last for the build bug below */
 100         (void *)0x1
 101 --- a/net/mac80211/ieee80211_i.h
 102 +++ b/net/mac80211/ieee80211_i.h
 103 @@ -799,6 +799,7 @@ struct mac80211_qos_map {
 104  enum txq_info_flags {
 105         IEEE80211_TXQ_STOP,
 106         IEEE80211_TXQ_AMPDU,
 107 +       IEEE80211_TXQ_NO_AMSDU,
 108  };
 109
 110  struct txq_info {
 111 --- a/net/mac80211/tx.c
 112 +++ b/net/mac80211/tx.c
 113 @@ -1318,6 +1318,10 @@ struct sk_buff *ieee80211_tx_dequeue(str
 114  out:
 115         spin_unlock_bh(&txqi->queue.lock);
 116
 117 +       if (skb && skb_has_frag_list(skb) &&
 118 +           !ieee80211_hw_check(&local->hw, TX_FRAG_LIST))
 119 +               skb_linearize(skb);
 120 +
 121         return skb;
 122  }
 123  EXPORT_SYMBOL(ieee80211_tx_dequeue);
 124 @@ -2757,6 +2761,149 @@ void ieee80211_clear_fast_xmit(struct st
 125                 kfree_rcu(fast_tx, rcu_head);
 126  }
 127
 128 +static int ieee80211_amsdu_pad(struct sk_buff *skb, int subframe_len)
 129 +{
 130 +       int amsdu_len = subframe_len + sizeof(struct ethhdr);
 131 +       int padding = (4 - amsdu_len) & 3;
 132 +
 133 +       if (padding)
 134 +               memset(skb_put(skb, padding), 0, padding);
 135 +
 136 +       return padding;
 137 +}
 138 +
 139 +static bool ieee80211_amsdu_prepare_head(struct ieee80211_sub_if_data *sdata,
 140 +                                        struct ieee80211_fast_tx *fast_tx,
 141 +                                        struct sk_buff *skb)
 142 +{
 143 +       struct ieee80211_local *local = sdata->local;
 144 +       struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 145 +       struct ieee80211_hdr *hdr;
 146 +       struct ethhdr amsdu_hdr;
 147 +       int hdr_len = fast_tx->hdr_len - sizeof(rfc1042_header);
 148 +       int subframe_len = skb->len - hdr_len;
 149 +       void *data;
 150 +       u8 *qc;
 151 +
 152 +       if (info->control.flags & IEEE80211_TX_CTRL_AMSDU)
 153 +               return true;
 154 +
 155 +       if (skb_headroom(skb) < sizeof(amsdu_hdr) || skb_tailroom(skb) < 3) {
 156 +               I802_DEBUG_INC(local->tx_expand_skb_head);
 157 +
 158 +               if (pskb_expand_head(skb, sizeof(amsdu_hdr), 3, GFP_ATOMIC)) {
 159 +                       wiphy_debug(local->hw.wiphy,
 160 +                                   "failed to reallocate TX buffer\n");
 161 +                       return false;
 162 +               }
 163 +       }
 164 +
 165 +       subframe_len += ieee80211_amsdu_pad(skb, subframe_len);
 166 +
 167 +       amsdu_hdr.h_proto = cpu_to_be16(subframe_len);
 168 +       memcpy(amsdu_hdr.h_source, skb->data + fast_tx->sa_offs, ETH_ALEN);
 169 +       memcpy(amsdu_hdr.h_dest, skb->data + fast_tx->da_offs, ETH_ALEN);
 170 +
 171 +       data = skb_push(skb, sizeof(amsdu_hdr));
 172 +       memmove(data, data + sizeof(amsdu_hdr), hdr_len);
 173 +       memcpy(data + hdr_len, &amsdu_hdr, sizeof(amsdu_hdr));
 174 +
 175 +       hdr = data;
 176 +       qc = ieee80211_get_qos_ctl(hdr);
 177 +       *qc |= IEEE80211_QOS_CTL_A_MSDU_PRESENT;
 178 +
 179 +       info->control.flags |= IEEE80211_TX_CTRL_AMSDU;
 180 +
 181 +       return true;
 182 +}
 183 +
 184 +static bool ieee80211_amsdu_aggregate(struct ieee80211_sub_if_data *sdata,
 185 +                                     struct sta_info *sta,
 186 +                                     struct ieee80211_fast_tx *fast_tx,
 187 +                                     struct sk_buff *skb)
 188 +{
 189 +       struct ieee80211_local *local = sdata->local;
 190 +       u8 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 191 +       struct ieee80211_txq *txq = sta->sta.txq[tid];
 192 +       struct txq_info *txqi;
 193 +       struct sk_buff **frag_tail, *head;
 194 +       int subframe_len = skb->len - ETH_ALEN;
 195 +       int max_amsdu_len;
 196 +       __be16 len;
 197 +       void *data;
 198 +       bool ret = false;
 199 +       int n = 1;
 200 +
 201 +       if (!ieee80211_hw_check(&local->hw, TX_AMSDU))
 202 +               return false;
 203 +
 204 +       if (!txq)
 205 +               return false;
 206 +
 207 +       txqi = to_txq_info(txq);
 208 +       if (test_bit(IEEE80211_TXQ_NO_AMSDU, &txqi->flags))
 209 +               return false;
 210 +
 211 +       /*
 212 +        * A-MPDU limits maximum MPDU size to 4095 bytes. Since aggregation
 213 +        * sessions are started/stopped without txq flush, use the limit here
 214 +        * to avoid having to de-aggregate later.
 215 +        */
 216 +       max_amsdu_len = min_t(int, sta->sta.max_amsdu_len, 4095);
 217 +
 218 +       spin_lock_bh(&txqi->queue.lock);
 219 +
 220 +       head = skb_peek_tail(&txqi->queue);
 221 +       if (!head)
 222 +               goto out;
 223 +
 224 +       if (skb->len + head->len > max_amsdu_len)
 225 +               goto out;
 226 +
 227 +       if (!ieee80211_amsdu_prepare_head(sdata, fast_tx, head))
 228 +               goto out;
 229 +
 230 +       frag_tail = &skb_shinfo(head)->frag_list;
 231 +       while (*frag_tail) {
 232 +            frag_tail = &(*frag_tail)->next;
 233 +                n++;
 234 +       }
 235 +
 236 +       if (local->hw.max_tx_amsdu_subframes &&
 237 +           n > local->hw.max_tx_amsdu_subframes)
 238 +               goto out;
 239 +
 240 +       if (skb_headroom(skb) < 8 || skb_tailroom(skb) < 3) {
 241 +               I802_DEBUG_INC(local->tx_expand_skb_head);
 242 +
 243 +               if (pskb_expand_head(skb, 8, 3, GFP_ATOMIC)) {
 244 +                       wiphy_debug(local->hw.wiphy,
 245 +                                   "failed to reallocate TX buffer\n");
 246 +                       goto out;
 247 +               }
 248 +       }
 249 +
 250 +       subframe_len += ieee80211_amsdu_pad(skb, subframe_len);
 251 +
 252 +       ret = true;
 253 +       data = skb_push(skb, ETH_ALEN + 2);
 254 +       memmove(data, data + ETH_ALEN + 2, 2 * ETH_ALEN);
 255 +
 256 +       data += 2 * ETH_ALEN;
 257 +       len = cpu_to_be16(subframe_len);
 258 +       memcpy(data, &len, 2);
 259 +       memcpy(data + 2, rfc1042_header, ETH_ALEN);
 260 +
 261 +       head->len += skb->len;
 262 +       head->data_len += skb->len;
 263 +       *frag_tail = skb;
 264 +
 265 +out:
 266 +       spin_unlock_bh(&txqi->queue.lock);
 267 +
 268 +       return ret;
 269 +}
 270 +
 271  static bool ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata,
 272                                 struct net_device *dev, struct sta_info *sta,
 273                                 struct ieee80211_fast_tx *fast_tx,
 274 @@ -2811,6 +2958,10 @@ static bool ieee80211_xmit_fast(struct i
 275
 276         ieee80211_tx_stats(dev, skb->len + extra_head);
 277
 278 +       if ((hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) &&
 279 +           ieee80211_amsdu_aggregate(sdata, sta, fast_tx, skb))
 280 +               return true;
 281 +
 282         /* will not be crypto-handled beyond what we do here, so use false
 283          * as the may-encrypt argument for the resize to not account for
 284          * more room than we already have in 'extra_head'