package/kernel/mac80211/patches/subsys/351-mac80211-add-TX_NEEDS_ALIGNED4_SKBS-hw-flag.patch

   1 From: Janusz Dziedzic <janusz.dziedzic@tieto.com>
   2 Date: Sun, 10 Mar 2019 17:22:08 +0100
   3 Subject: [PATCH] mac80211: add TX_NEEDS_ALIGNED4_SKBS hw flag
   4
   5 The driver should set this flag if the hardware requires tx skb data
   6 (starting with the LLC header) to be aligned to 4 bytes.
   7
   8 Padding is added after ieee80211_hdr, before IV/LLC.
   9
  10 Before this patch, we have to do memmove(hdrlen) twice in the driver:
  11 Once before we pass this to HW and once again in tx completion
  12 (to fix up the skb for monitor mode).
  13
  14 With this patch we can skip this memmove() and thus reduce CPU cycles in
  15 the data path.
  16
  17 Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
  18 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  19 ---
  20
  21 --- a/include/net/mac80211.h
  22 +++ b/include/net/mac80211.h
  23 @@ -2134,6 +2134,9 @@ struct ieee80211_txq {
  24   * @IEEE80211_HW_TX_STATUS_NO_AMPDU_LEN: Driver does not report accurate A-MPDU
  25   *     length in tx status information
  26   *
  27 + * @IEEE80211_HW_TX_NEEDS_ALIGNED4_SKBS: Driver need aligned skbs to four-byte.
  28 + *     Padding will be added after ieee80211_hdr, before IV/LLC.
  29 + *
  30   * @NUM_IEEE80211_HW_FLAGS: number of hardware flags, used for sizing arrays
  31   */
  32  enum ieee80211_hw_flags {
  33 @@ -2180,6 +2183,7 @@ enum ieee80211_hw_flags {
  34         IEEE80211_HW_DEAUTH_NEED_MGD_TX_PREP,
  35         IEEE80211_HW_DOESNT_SUPPORT_QOS_NDP,
  36         IEEE80211_HW_TX_STATUS_NO_AMPDU_LEN,
  37 +       IEEE80211_HW_TX_NEEDS_ALIGNED4_SKBS,
  38
  39         /* keep last, obviously */
  40         NUM_IEEE80211_HW_FLAGS
  41 @@ -2462,6 +2466,40 @@ ieee80211_get_alt_retry_rate(const struc
  42  void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb);
  43
  44  /**
  45 + * ieee80211_hdr_padsize - get size of padding between 802.11 header and LLC
  46 + * @hw: the hardware
  47 + * @hdrlen: 802.11 header length
  48 + */
  49 +static inline unsigned int
  50 +ieee80211_hdr_padsize(struct ieee80211_hw *hw, unsigned int hdrlen)
  51 +{
  52 +       /*
  53 +        * While hdrlen is already aligned to two-byte boundaries,
  54 +        * simple check with & 2 will return correct padsize.
  55 +        */
  56 +       if (ieee80211_hw_check(hw, TX_NEEDS_ALIGNED4_SKBS))
  57 +               return hdrlen & 2;
  58 +       return 0;
  59 +}
  60 +
  61 +/**
  62 + * ieee80211_padded_hdrlen - get padded 802.11 header size
  63 + * @hw: the hardware
  64 + * @fc: frame control field in little-endian format
  65 + */
  66 +static inline unsigned int
  67 +ieee80211_padded_hdrlen(struct ieee80211_hw *hw, __le16 fc)
  68 +{
  69 +       unsigned int hdrlen;
  70 +
  71 +       hdrlen = ieee80211_hdrlen(fc);
  72 +       hdrlen += ieee80211_hdr_padsize(hw, hdrlen);
  73 +
  74 +       return hdrlen;
  75 +}
  76 +
  77 +
  78 +/**
  79   * DOC: Hardware crypto acceleration
  80   *
  81   * mac80211 is capable of taking advantage of many hardware
  82 --- a/net/mac80211/iface.c
  83 +++ b/net/mac80211/iface.c
  84 @@ -1871,6 +1871,10 @@ int ieee80211_if_add(struct ieee80211_lo
  85                                         + 8 /* rfc1042/bridge tunnel */
  86                                         - ETH_HLEN /* ethernet hard_header_len */
  87                                         + IEEE80211_ENCRYPT_HEADROOM;
  88 +
  89 +               if (ieee80211_hw_check(&local->hw, TX_NEEDS_ALIGNED4_SKBS))
  90 +                       ndev->needed_headroom += 2; /* padding */
  91 +
  92                 ndev->needed_tailroom = IEEE80211_ENCRYPT_TAILROOM;
  93
  94                 ret = dev_alloc_name(ndev, ndev->name);
  95 --- a/net/mac80211/mesh_pathtbl.c
  96 +++ b/net/mac80211/mesh_pathtbl.c
  97 @@ -103,13 +103,15 @@ void mesh_path_assign_nexthop(struct mes
  98  static void prepare_for_gate(struct sk_buff *skb, char *dst_addr,
  99                              struct mesh_path *gate_mpath)
 100  {
 101 +       struct ieee80211_sub_if_data *sdata = gate_mpath->sdata;
 102 +       struct ieee80211_hw *hw = &sdata->local->hw;
 103         struct ieee80211_hdr *hdr;
 104         struct ieee80211s_hdr *mshdr;
 105         int mesh_hdrlen, hdrlen;
 106         char *next_hop;
 107
 108         hdr = (struct ieee80211_hdr *) skb->data;
 109 -       hdrlen = ieee80211_hdrlen(hdr->frame_control);
 110 +       hdrlen = ieee80211_padded_hdrlen(hw, hdr->frame_control);
 111         mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
 112
 113         if (!(mshdr->flags & MESH_FLAGS_AE)) {
 114 --- a/net/mac80211/rx.c
 115 +++ b/net/mac80211/rx.c
 116 @@ -2597,7 +2597,7 @@ ieee80211_rx_h_mesh_fwding(struct ieee80
 117         struct ieee80211_local *local = rx->local;
 118         struct ieee80211_sub_if_data *sdata = rx->sdata;
 119         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 120 -       u16 ac, q, hdrlen;
 121 +       u16 ac, q, hdrlen, padsize;
 122         int tailroom = 0;
 123
 124         hdr = (struct ieee80211_hdr *) skb->data;
 125 @@ -2688,7 +2688,9 @@ ieee80211_rx_h_mesh_fwding(struct ieee80
 126         if (sdata->crypto_tx_tailroom_needed_cnt)
 127                 tailroom = IEEE80211_ENCRYPT_TAILROOM;
 128
 129 -       fwd_skb = skb_copy_expand(skb, local->tx_headroom +
 130 +       padsize = ieee80211_hdr_padsize(&local->hw, hdrlen);
 131 +
 132 +       fwd_skb = skb_copy_expand(skb, local->tx_headroom + padsize +
 133                                        sdata->encrypt_headroom,
 134                                   tailroom, GFP_ATOMIC);
 135         if (!fwd_skb)
 136 @@ -2720,6 +2722,12 @@ ieee80211_rx_h_mesh_fwding(struct ieee80
 137                 return RX_DROP_MONITOR;
 138         }
 139
 140 +       if (padsize) {
 141 +               skb_push(fwd_skb, padsize);
 142 +               memmove(fwd_skb->data, skb->data + padsize, hdrlen);
 143 +               memset(fwd_skb->data + hdrlen, 0, padsize);
 144 +       }
 145 +
 146         IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_frames);
 147         ieee80211_add_pending_skb(local, fwd_skb);
 148   out:
 149 --- a/net/mac80211/sta_info.h
 150 +++ b/net/mac80211/sta_info.h
 151 @@ -301,7 +301,7 @@ struct ieee80211_fast_tx {
 152         u8 hdr_len;
 153         u8 sa_offs, da_offs, pn_offs;
 154         u8 band;
 155 -       u8 hdr[30 + 2 + IEEE80211_FAST_XMIT_MAX_IV +
 156 +       u8 hdr[30 + 2 + 2 + IEEE80211_FAST_XMIT_MAX_IV +
 157                sizeof(rfc1042_header)] __aligned(2);
 158
 159         struct rcu_head rcu_head;
 160 --- a/net/mac80211/status.c
 161 +++ b/net/mac80211/status.c
 162 @@ -515,6 +515,7 @@ static void ieee80211_report_used_skb(st
 163  {
 164         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 165         struct ieee80211_hdr *hdr = (void *)skb->data;
 166 +       struct ieee80211_hw *hw = &local->hw;
 167         bool acked = info->flags & IEEE80211_TX_STAT_ACK;
 168
 169         if (dropped)
 170 @@ -531,7 +532,7 @@ static void ieee80211_report_used_skb(st
 171                         skb->dev = NULL;
 172                 } else {
 173                         unsigned int hdr_size =
 174 -                               ieee80211_hdrlen(hdr->frame_control);
 175 +                               ieee80211_padded_hdrlen(hw, hdr->frame_control);
 176
 177                         /* Check to see if packet is a TDLS teardown packet */
 178                         if (ieee80211_is_data(hdr->frame_control) &&
 179 @@ -655,9 +656,22 @@ void ieee80211_tx_monitor(struct ieee802
 180         struct sk_buff *skb2;
 181         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 182         struct ieee80211_sub_if_data *sdata;
 183 +       struct ieee80211_hdr *hdr = (void *)skb->data;
 184         struct net_device *prev_dev = NULL;
 185 +       unsigned int hdrlen, padsize;
 186         int rtap_len;
 187
 188 +       /* Remove padding if was added */
 189 +       if (ieee80211_hw_check(&local->hw, TX_NEEDS_ALIGNED4_SKBS)) {
 190 +               hdrlen = ieee80211_hdrlen(hdr->frame_control);
 191 +               padsize = ieee80211_hdr_padsize(&local->hw, hdrlen);
 192 +
 193 +               if (padsize && skb->len > hdrlen + padsize) {
 194 +                       memmove(skb->data + padsize, skb->data, hdrlen);
 195 +                       skb_pull(skb, padsize);
 196 +               }
 197 +       }
 198 +
 199         /* send frame to monitor interfaces now */
 200         rtap_len = ieee80211_tx_radiotap_len(info);
 201         if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
 202 --- a/net/mac80211/tkip.c
 203 +++ b/net/mac80211/tkip.c
 204 @@ -201,10 +201,12 @@ void ieee80211_get_tkip_p2k(struct ieee8
 205  {
 206         struct ieee80211_key *key = (struct ieee80211_key *)
 207                         container_of(keyconf, struct ieee80211_key, conf);
 208 +       struct ieee80211_hw *hw = &key->local->hw;
 209         const u8 *tk = &key->conf.key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY];
 210         struct tkip_ctx *ctx = &key->u.tkip.tx;
 211         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 212 -       const u8 *data = (u8 *)hdr + ieee80211_hdrlen(hdr->frame_control);
 213 +       const u8 *data = (u8 *)hdr + ieee80211_padded_hdrlen(hw,
 214 +                                                       hdr->frame_control);
 215         u32 iv32 = get_unaligned_le32(&data[4]);
 216         u16 iv16 = data[2] | (data[0] << 8);
 217
 218 --- a/net/mac80211/tx.c
 219 +++ b/net/mac80211/tx.c
 220 @@ -1175,8 +1175,7 @@ ieee80211_tx_prepare(struct ieee80211_su
 221         info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
 222
 223         hdr = (struct ieee80211_hdr *) skb->data;
 224 -
 225 -       tx->hdrlen = ieee80211_hdrlen(hdr->frame_control);
 226 +       tx->hdrlen = ieee80211_padded_hdrlen(&local->hw, hdr->frame_control);
 227
 228         if (likely(sta)) {
 229                 if (!IS_ERR(sta))
 230 @@ -2215,7 +2214,7 @@ netdev_tx_t ieee80211_monitor_start_xmit
 231                 goto fail;
 232
 233         hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
 234 -       hdrlen = ieee80211_hdrlen(hdr->frame_control);
 235 +       hdrlen = ieee80211_padded_hdrlen(&local->hw, hdr->frame_control);
 236
 237         if (skb->len < len_rthdr + hdrlen)
 238                 goto fail;
 239 @@ -2433,7 +2432,7 @@ static struct sk_buff *ieee80211_build_h
 240         struct ieee80211_chanctx_conf *chanctx_conf;
 241         struct ieee80211_sub_if_data *ap_sdata;
 242         enum nl80211_band band;
 243 -       int ret;
 244 +       int padsize, ret;
 245
 246         if (IS_ERR(sta))
 247                 sta = NULL;
 248 @@ -2732,7 +2731,9 @@ static struct sk_buff *ieee80211_build_h
 249         }
 250
 251         skb_pull(skb, skip_header_bytes);
 252 +       padsize = ieee80211_hdr_padsize(&local->hw, hdrlen);
 253         head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
 254 +       head_need += padsize;
 255
 256         /*
 257          * So we need to modify the skb header and hence need a copy of
 258 @@ -2765,6 +2766,9 @@ static struct sk_buff *ieee80211_build_h
 259                 memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
 260  #endif
 261
 262 +       if (padsize)
 263 +               memset(skb_push(skb, padsize), 0, padsize);
 264 +
 265         if (ieee80211_is_data_qos(fc)) {
 266                 __le16 *qos_control;
 267
 268 @@ -2940,6 +2944,8 @@ void ieee80211_check_fast_xmit(struct st
 269                 fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
 270         }
 271
 272 +       build.hdr_len += ieee80211_hdr_padsize(&local->hw, build.hdr_len);
 273 +
 274         /* We store the key here so there's no point in using rcu_dereference()
 275          * but that's fine because the code that changes the pointers will call
 276          * this function after doing so. For a single CPU that would be enough,
 277 @@ -3518,7 +3524,7 @@ begin:
 278         tx.local = local;
 279         tx.skb = skb;
 280         tx.sdata = vif_to_sdata(info->control.vif);
 281 -       tx.hdrlen = ieee80211_hdrlen(hdr->frame_control);
 282 +       tx.hdrlen = ieee80211_padded_hdrlen(hw, hdr->frame_control);
 283
 284         if (txq->sta)
 285                 tx.sta = container_of(txq->sta, struct sta_info, sta);
 286 @@ -3856,7 +3862,7 @@ ieee80211_build_data_template(struct iee
 287         hdr = (void *)skb->data;
 288         tx.sta = sta_info_get(sdata, hdr->addr1);
 289         tx.skb = skb;
 290 -       tx.hdrlen = ieee80211_hdrlen(hdr->frame_control);
 291 +       tx.hdrlen = ieee80211_padded_hdrlen(&tx.local->hw, hdr->frame_control);
 292
 293         if (ieee80211_tx_h_select_key(&tx) != TX_CONTINUE) {
 294                 rcu_read_unlock();
 295 --- a/net/mac80211/debugfs.c
 296 +++ b/net/mac80211/debugfs.c
 297 @@ -215,6 +215,7 @@ static const char *hw_flag_names[] = {
 298         FLAG(DEAUTH_NEED_MGD_TX_PREP),
 299         FLAG(DOESNT_SUPPORT_QOS_NDP),
 300         FLAG(TX_STATUS_NO_AMPDU_LEN),
 301 +       FLAG(TX_NEEDS_ALIGNED4_SKBS),
 302  #undef FLAG
 303  };
 304