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 @@ -1728,6 +1730,7 @@ struct ieee80211_sta_rates {
  30   *               size is min(max_amsdu_len, 7935) bytes.
  31   *     Both additional HT limits must be enforced by the low level driver.
  32   *     This is defined by the spec (IEEE 802.11-2012 section 8.3.2.2 NOTE 2).
  33 + * @max_rc_amsdu_len: Maximum A-MSDU size in bytes recommended by rate control.
  34   * @txq: per-TID data TX queues (if driver uses the TXQ abstraction)
  35   */
  36  struct ieee80211_sta {
  37 @@ -1748,6 +1751,7 @@ struct ieee80211_sta {
  38         bool mfp;
  39         u8 max_amsdu_subframes;
  40         u16 max_amsdu_len;
  41 +       u16 max_rc_amsdu_len;
  42
  43         struct ieee80211_txq *txq[IEEE80211_NUM_TIDS];
  44
  45 @@ -1961,6 +1965,12 @@ struct ieee80211_txq {
  46   *     order and does not need to manage its own reorder buffer or BA session
  47   *     timeout.
  48   *
  49 + * @IEEE80211_HW_TX_AMSDU: Hardware (or driver) supports software aggregated
  50 + *     A-MSDU frames. Requires software tx queueing support.
  51 + *
  52 + * @IEEE80211_HW_TX_FRAG_LIST: Hardware (or driver) supports sending frag_list
  53 + *     skbs, needed for zero-copy software A-MSDU.
  54 + *
  55   * @NUM_IEEE80211_HW_FLAGS: number of hardware flags, used for sizing arrays
  56   */
  57  enum ieee80211_hw_flags {
  58 @@ -1998,6 +2008,8 @@ enum ieee80211_hw_flags {
  59         IEEE80211_HW_BEACON_TX_STATUS,
  60         IEEE80211_HW_NEEDS_UNIQUE_STA_ADDR,
  61         IEEE80211_HW_SUPPORTS_REORDERING_BUFFER,
  62 +       IEEE80211_HW_TX_AMSDU,
  63 +       IEEE80211_HW_TX_FRAG_LIST,
  64
  65         /* keep last, obviously */
  66         NUM_IEEE80211_HW_FLAGS
  67 @@ -2070,6 +2082,8 @@ enum ieee80211_hw_flags {
  68   *     size is smaller (an example is LinkSys WRT120N with FW v1.0.07
  69   *     build 002 Jun 18 2012).
  70   *
  71 + * @max_tx_fragments: maximum fragments per (A-)MSDU.
  72 + *
  73   * @offchannel_tx_hw_queue: HW queue ID to use for offchannel TX
  74   *     (if %IEEE80211_HW_QUEUE_CONTROL is set)
  75   *
  76 @@ -2124,6 +2138,7 @@ struct ieee80211_hw {
  77         u8 max_rate_tries;
  78         u8 max_rx_aggregation_subframes;
  79         u8 max_tx_aggregation_subframes;
  80 +       u8 max_tx_fragments;
  81         u8 offchannel_tx_hw_queue;
  82         u8 radiotap_mcs_details;
  83         u16 radiotap_vht_details;
  84 --- a/net/mac80211/agg-tx.c
  85 +++ b/net/mac80211/agg-tx.c
  86 @@ -935,6 +935,7 @@ void ieee80211_process_addba_resp(struct
  87                                   size_t len)
  88  {
  89         struct tid_ampdu_tx *tid_tx;
  90 +       struct ieee80211_txq *txq;
  91         u16 capab, tid;
  92         u8 buf_size;
  93         bool amsdu;
  94 @@ -945,6 +946,10 @@ void ieee80211_process_addba_resp(struct
  95         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
  96         buf_size = min(buf_size, local->hw.max_tx_aggregation_subframes);
  97
  98 +       txq = sta->sta.txq[tid];
  99 +       if (!amsdu && txq)
 100 +               set_bit(IEEE80211_TXQ_NO_AMSDU, &to_txq_info(txq)->flags);
 101 +
 102         mutex_lock(&sta->ampdu_mlme.mtx);
 103
 104         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 105 --- a/net/mac80211/debugfs.c
 106 +++ b/net/mac80211/debugfs.c
 107 @@ -127,6 +127,8 @@ static const char *hw_flag_names[NUM_IEE
 108         FLAG(BEACON_TX_STATUS),
 109         FLAG(NEEDS_UNIQUE_STA_ADDR),
 110         FLAG(SUPPORTS_REORDERING_BUFFER),
 111 +       FLAG(TX_AMSDU),
 112 +       FLAG(TX_FRAG_LIST),
 113
 114         /* keep last for the build bug below */
 115         (void *)0x1
 116 --- a/net/mac80211/ieee80211_i.h
 117 +++ b/net/mac80211/ieee80211_i.h
 118 @@ -799,6 +799,7 @@ struct mac80211_qos_map {
 119  enum txq_info_flags {
 120         IEEE80211_TXQ_STOP,
 121         IEEE80211_TXQ_AMPDU,
 122 +       IEEE80211_TXQ_NO_AMSDU,
 123  };
 124
 125  struct txq_info {
 126 --- a/net/mac80211/tx.c
 127 +++ b/net/mac80211/tx.c
 128 @@ -1318,6 +1318,10 @@ struct sk_buff *ieee80211_tx_dequeue(str
 129  out:
 130         spin_unlock_bh(&txqi->queue.lock);
 131
 132 +       if (skb && skb_has_frag_list(skb) &&
 133 +           !ieee80211_hw_check(&local->hw, TX_FRAG_LIST))
 134 +               skb_linearize(skb);
 135 +
 136         return skb;
 137  }
 138  EXPORT_SYMBOL(ieee80211_tx_dequeue);
 139 @@ -2757,6 +2761,165 @@ void ieee80211_clear_fast_xmit(struct st
 140                 kfree_rcu(fast_tx, rcu_head);
 141  }
 142
 143 +static int ieee80211_amsdu_pad(struct sk_buff *skb, int subframe_len)
 144 +{
 145 +       int amsdu_len = subframe_len + sizeof(struct ethhdr);
 146 +       int padding = (4 - amsdu_len) & 3;
 147 +
 148 +       if (padding)
 149 +               memset(skb_put(skb, padding), 0, padding);
 150 +
 151 +       return padding;
 152 +}
 153 +
 154 +static bool ieee80211_amsdu_prepare_head(struct ieee80211_sub_if_data *sdata,
 155 +                                        struct ieee80211_fast_tx *fast_tx,
 156 +                                        struct sk_buff *skb)
 157 +{
 158 +       struct ieee80211_local *local = sdata->local;
 159 +       struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 160 +       struct ieee80211_hdr *hdr;
 161 +       struct ethhdr amsdu_hdr;
 162 +       int hdr_len = fast_tx->hdr_len - sizeof(rfc1042_header);
 163 +       int subframe_len = skb->len - hdr_len;
 164 +       void *data;
 165 +       u8 *qc;
 166 +
 167 +       if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
 168 +               return false;
 169 +
 170 +       if (info->control.flags & IEEE80211_TX_CTRL_AMSDU)
 171 +               return true;
 172 +
 173 +       if (skb_headroom(skb) < sizeof(amsdu_hdr) || skb_tailroom(skb) < 3) {
 174 +               I802_DEBUG_INC(local->tx_expand_skb_head);
 175 +
 176 +               if (pskb_expand_head(skb, sizeof(amsdu_hdr), 3, GFP_ATOMIC)) {
 177 +                       wiphy_debug(local->hw.wiphy,
 178 +                                   "failed to reallocate TX buffer\n");
 179 +                       return false;
 180 +               }
 181 +       }
 182 +
 183 +       subframe_len += ieee80211_amsdu_pad(skb, subframe_len);
 184 +
 185 +       amsdu_hdr.h_proto = cpu_to_be16(subframe_len);
 186 +       memcpy(amsdu_hdr.h_source, skb->data + fast_tx->sa_offs, ETH_ALEN);
 187 +       memcpy(amsdu_hdr.h_dest, skb->data + fast_tx->da_offs, ETH_ALEN);
 188 +
 189 +       data = skb_push(skb, sizeof(amsdu_hdr));
 190 +       memmove(data, data + sizeof(amsdu_hdr), hdr_len);
 191 +       memcpy(data + hdr_len, &amsdu_hdr, sizeof(amsdu_hdr));
 192 +
 193 +       hdr = data;
 194 +       qc = ieee80211_get_qos_ctl(hdr);
 195 +       *qc |= IEEE80211_QOS_CTL_A_MSDU_PRESENT;
 196 +
 197 +       info->control.flags |= IEEE80211_TX_CTRL_AMSDU;
 198 +
 199 +       return true;
 200 +}
 201 +
 202 +static bool ieee80211_amsdu_aggregate(struct ieee80211_sub_if_data *sdata,
 203 +                                     struct sta_info *sta,
 204 +                                     struct ieee80211_fast_tx *fast_tx,
 205 +                                     struct sk_buff *skb)
 206 +{
 207 +       struct ieee80211_local *local = sdata->local;
 208 +       u8 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 209 +       struct ieee80211_txq *txq = sta->sta.txq[tid];
 210 +       struct txq_info *txqi;
 211 +       struct sk_buff **frag_tail, *head;
 212 +       int subframe_len = skb->len - ETH_ALEN;
 213 +       u8 max_subframes = sta->sta.max_amsdu_subframes;
 214 +       int max_frags = local->hw.max_tx_fragments;
 215 +       int max_amsdu_len = sta->sta.max_amsdu_len;
 216 +       __be16 len;
 217 +       void *data;
 218 +       bool ret = false;
 219 +       int n = 1, nfrags;
 220 +
 221 +       if (!ieee80211_hw_check(&local->hw, TX_AMSDU))
 222 +               return false;
 223 +
 224 +       if (!txq)
 225 +               return false;
 226 +
 227 +       txqi = to_txq_info(txq);
 228 +       if (test_bit(IEEE80211_TXQ_NO_AMSDU, &txqi->flags))
 229 +               return false;
 230 +
 231 +       if (sta->sta.max_rc_amsdu_len)
 232 +               max_amsdu_len = min_t(int, max_amsdu_len,
 233 +                                     sta->sta.max_rc_amsdu_len);
 234 +
 235 +       spin_lock_bh(&txqi->queue.lock);
 236 +
 237 +       head = skb_peek_tail(&txqi->queue);
 238 +       if (!head)
 239 +               goto out;
 240 +
 241 +       if (skb->len + head->len > max_amsdu_len)
 242 +               goto out;
 243 +
 244 +       /*
 245 +        * HT A-MPDU limits maximum MPDU size to 4095 bytes. Since aggregation
 246 +        * sessions are started/stopped without txq flush, use the limit here
 247 +        * to avoid having to de-aggregate later.
 248 +        */
 249 +       if (skb->len + head->len > 4095 &&
 250 +           !sta->sta.vht_cap.vht_supported)
 251 +               goto out;
 252 +
 253 +       if (!ieee80211_amsdu_prepare_head(sdata, fast_tx, head))
 254 +               goto out;
 255 +
 256 +       nfrags = 1 + skb_shinfo(skb)->nr_frags;
 257 +       nfrags += 1 + skb_shinfo(head)->nr_frags;
 258 +       frag_tail = &skb_shinfo(head)->frag_list;
 259 +       while (*frag_tail) {
 260 +               nfrags += 1 + skb_shinfo(*frag_tail)->nr_frags;
 261 +               frag_tail = &(*frag_tail)->next;
 262 +               n++;
 263 +       }
 264 +
 265 +       if (max_subframes && n > max_subframes)
 266 +               goto out;
 267 +
 268 +       if (max_frags && nfrags > max_frags)
 269 +               goto out;
 270 +
 271 +       if (skb_headroom(skb) < 8 || skb_tailroom(skb) < 3) {
 272 +               I802_DEBUG_INC(local->tx_expand_skb_head);
 273 +
 274 +               if (pskb_expand_head(skb, 8, 3, GFP_ATOMIC)) {
 275 +                       wiphy_debug(local->hw.wiphy,
 276 +                                   "failed to reallocate TX buffer\n");
 277 +                       goto out;
 278 +               }
 279 +       }
 280 +
 281 +       subframe_len += ieee80211_amsdu_pad(skb, subframe_len);
 282 +
 283 +       ret = true;
 284 +       data = skb_push(skb, ETH_ALEN + 2);
 285 +       memmove(data, data + ETH_ALEN + 2, 2 * ETH_ALEN);
 286 +
 287 +       data += 2 * ETH_ALEN;
 288 +       len = cpu_to_be16(subframe_len);
 289 +       memcpy(data, &len, 2);
 290 +       memcpy(data + 2, rfc1042_header, ETH_ALEN);
 291 +
 292 +       head->len += skb->len;
 293 +       head->data_len += skb->len;
 294 +       *frag_tail = skb;
 295 +
 296 +out:
 297 +       spin_unlock_bh(&txqi->queue.lock);
 298 +
 299 +       return ret;
 300 +}
 301 +
 302  static bool ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata,
 303                                 struct net_device *dev, struct sta_info *sta,
 304                                 struct ieee80211_fast_tx *fast_tx,
 305 @@ -2811,6 +2974,10 @@ static bool ieee80211_xmit_fast(struct i
 306
 307         ieee80211_tx_stats(dev, skb->len + extra_head);
 308
 309 +       if ((hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) &&
 310 +           ieee80211_amsdu_aggregate(sdata, sta, fast_tx, skb))
 311 +               return true;
 312 +
 313         /* will not be crypto-handled beyond what we do here, so use false
 314          * as the may-encrypt argument for the resize to not account for
 315          * more room than we already have in 'extra_head'