+From: Janusz Dziedzic <janusz.dziedzic@tieto.com>
+Date: Fri, 19 Feb 2016 11:01:50 +0100
+Subject: [PATCH] mac80211: add NEED_ALIGNED4_SKBS hw flag
+
+HW/driver should set NEED_ALIGNED4_SKBS flag in case
+require aligned skbs to four-byte boundaries.
+This affect only TX direction.
+
+Padding is added after ieee80211_hdr, before IV/LLC.
+
+Before we have to do memmove(hdrlen) twice in the
+dirver. Once before we pass this to HW and next
+in tx completion (to be sure monitor will report
+this tx frame correctly).
+
+With this patch we can skip this memmove() and save CPU.
+
+Currently this was tested with ath9k, both hw/sw crypt for
+wep/tkip/ccmp.
+
+Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
+---
+
+--- a/include/net/mac80211.h
++++ b/include/net/mac80211.h
+@@ -2014,6 +2014,9 @@ struct ieee80211_txq {
+ * @IEEE80211_HW_TX_FRAG_LIST: Hardware (or driver) supports sending frag_list
+ * skbs, needed for zero-copy software A-MSDU.
+ *
++ * @IEEE80211_HW_NEEDS_ALIGNED4_SKBS: Driver need aligned skbs to four-byte.
++ * Padding will be added after ieee80211_hdr, before IV/LLC.
++ *
+ * @NUM_IEEE80211_HW_FLAGS: number of hardware flags, used for sizing arrays
+ */
+ enum ieee80211_hw_flags {
+@@ -2054,6 +2057,7 @@ enum ieee80211_hw_flags {
+ IEEE80211_HW_USES_RSS,
+ IEEE80211_HW_TX_AMSDU,
+ IEEE80211_HW_TX_FRAG_LIST,
++ IEEE80211_HW_NEEDS_ALIGNED4_SKBS,
+
+ /* keep last, obviously */
+ NUM_IEEE80211_HW_FLAGS
+--- a/net/mac80211/debugfs.c
++++ b/net/mac80211/debugfs.c
+@@ -302,6 +302,7 @@ static const char *hw_flag_names[] = {
+ FLAG(USES_RSS),
+ FLAG(TX_AMSDU),
+ FLAG(TX_FRAG_LIST),
++ FLAG(NEEDS_ALIGNED4_SKBS),
+ #undef FLAG
+ };
+
+--- a/net/mac80211/ieee80211_i.h
++++ b/net/mac80211/ieee80211_i.h
+@@ -1497,6 +1497,29 @@ ieee80211_have_rx_timestamp(struct ieee8
+ return false;
+ }
+
++static inline unsigned int
++ieee80211_hdr_padsize(struct ieee80211_hw *hw, unsigned int hdrlen)
++{
++ /*
++ * While hdrlen is already aligned to two-byte boundaries,
++ * simple check with & 2 will return correct padsize.
++ */
++ if (ieee80211_hw_check(hw, NEEDS_ALIGNED4_SKBS))
++ return hdrlen & 2;
++ return 0;
++}
++
++static inline unsigned int
++ieee80211_padded_hdrlen(struct ieee80211_hw *hw, __le16 fc)
++{
++ unsigned int hdrlen;
++
++ hdrlen = ieee80211_hdrlen(fc);
++ hdrlen += ieee80211_hdr_padsize(hw, hdrlen);
++
++ return hdrlen;
++}
++
+ u64 ieee80211_calculate_rx_timestamp(struct ieee80211_local *local,
+ struct ieee80211_rx_status *status,
+ unsigned int mpdu_len,
+--- a/net/mac80211/sta_info.h
++++ b/net/mac80211/sta_info.h
+@@ -279,7 +279,7 @@ struct ieee80211_fast_tx {
+ u8 hdr_len;
+ u8 sa_offs, da_offs, pn_offs;
+ u8 band;
+- u8 hdr[30 + 2 + IEEE80211_FAST_XMIT_MAX_IV +
++ u8 hdr[30 + 2 + 2 + IEEE80211_FAST_XMIT_MAX_IV +
+ sizeof(rfc1042_header)] __aligned(2);
+
+ struct rcu_head rcu_head;
+--- a/net/mac80211/status.c
++++ b/net/mac80211/status.c
+@@ -683,9 +683,22 @@ void ieee80211_tx_monitor(struct ieee802
+ struct sk_buff *skb2;
+ struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+ struct ieee80211_sub_if_data *sdata;
++ struct ieee80211_hdr *hdr = (void *)skb->data;
+ struct net_device *prev_dev = NULL;
++ unsigned int hdrlen, padsize;
+ int rtap_len;
+
++ /* Remove padding if was added */
++ if (ieee80211_hw_check(&local->hw, NEEDS_ALIGNED4_SKBS)) {
++ hdrlen = ieee80211_hdrlen(hdr->frame_control);
++ padsize = ieee80211_hdr_padsize(&local->hw, hdrlen);
++
++ if (padsize && skb->len > hdrlen + padsize) {
++ memmove(skb->data + padsize, skb->data, hdrlen);
++ skb_pull(skb, padsize);
++ }
++ }
++
+ /* send frame to monitor interfaces now */
+ rtap_len = ieee80211_tx_radiotap_len(info);
+ if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
+--- a/net/mac80211/tkip.c
++++ b/net/mac80211/tkip.c
+@@ -201,10 +201,12 @@ void ieee80211_get_tkip_p2k(struct ieee8
+ {
+ struct ieee80211_key *key = (struct ieee80211_key *)
+ container_of(keyconf, struct ieee80211_key, conf);
++ struct ieee80211_hw *hw = &key->local->hw;
+ const u8 *tk = &key->conf.key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY];
+ struct tkip_ctx *ctx = &key->u.tkip.tx;
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+- const u8 *data = (u8 *)hdr + ieee80211_hdrlen(hdr->frame_control);
++ const u8 *data = (u8 *)hdr + ieee80211_padded_hdrlen(hw,
++ hdr->frame_control);
+ u32 iv32 = get_unaligned_le32(&data[4]);
+ u16 iv16 = data[2] | (data[0] << 8);
+
+--- a/net/mac80211/tx.c
++++ b/net/mac80211/tx.c
+@@ -1173,8 +1173,7 @@ ieee80211_tx_prepare(struct ieee80211_su
+ info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
+
+ hdr = (struct ieee80211_hdr *) skb->data;
+-
+- tx->hdrlen = ieee80211_hdrlen(hdr->frame_control);
++ tx->hdrlen = ieee80211_padded_hdrlen(&local->hw, hdr->frame_control);
+
+ if (likely(sta)) {
+ if (!IS_ERR(sta))
+@@ -2108,7 +2107,7 @@ netdev_tx_t ieee80211_monitor_start_xmit
+ goto fail;
+
+ hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
+- hdrlen = ieee80211_hdrlen(hdr->frame_control);
++ hdrlen = ieee80211_padded_hdrlen(&local->hw, hdr->frame_control);
+
+ if (skb->len < len_rthdr + hdrlen)
+ goto fail;
+@@ -2334,7 +2333,7 @@ static struct sk_buff *ieee80211_build_h
+ struct ieee80211_chanctx_conf *chanctx_conf;
+ struct ieee80211_sub_if_data *ap_sdata;
+ enum nl80211_band band;
+- int ret;
++ int padsize, ret;
+
+ if (IS_ERR(sta))
+ sta = NULL;
+@@ -2554,6 +2553,9 @@ static struct sk_buff *ieee80211_build_h
+ hdrlen += 2;
+ }
+
++ /* Check aligned4 skb required */
++ padsize = ieee80211_hdr_padsize(&sdata->local->hw, hdrlen);
++
+ /*
+ * Drop unicast frames to unauthorised stations unless they are
+ * EAPOL frames from the local station.
+@@ -2640,6 +2642,7 @@ static struct sk_buff *ieee80211_build_h
+ h_pos -= skip_header_bytes;
+
+ head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
++ head_need += padsize;
+
+ /*
+ * So we need to modify the skb header and hence need a copy of
+@@ -2678,6 +2681,9 @@ static struct sk_buff *ieee80211_build_h
+ }
+ #endif
+
++ if (padsize)
++ memset(skb_push(skb, padsize), 0, padsize);
++
+ if (ieee80211_is_data_qos(fc)) {
+ __le16 *qos_control;
+
+@@ -2691,8 +2697,8 @@ static struct sk_buff *ieee80211_build_h
+ } else
+ memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
+
+- nh_pos += hdrlen;
+- h_pos += hdrlen;
++ nh_pos += hdrlen + padsize;
++ h_pos += hdrlen + padsize;
+
+ /* Update skb pointers to various headers since this modified frame
+ * is going to go through Linux networking code that may potentially
+@@ -2861,6 +2867,9 @@ void ieee80211_check_fast_xmit(struct st
+ fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
+ }
+
++ /* Check aligned4 skb required */
++ build.hdr_len += ieee80211_hdr_padsize(&local->hw, build.hdr_len);
++
+ /* We store the key here so there's no point in using rcu_dereference()
+ * but that's fine because the code that changes the pointers will call
+ * this function after doing so. For a single CPU that would be enough,
+--- a/net/mac80211/util.c
++++ b/net/mac80211/util.c
+@@ -1224,6 +1224,7 @@ void ieee80211_send_auth(struct ieee8021
+ u32 tx_flags)
+ {
+ struct ieee80211_local *local = sdata->local;
++ struct ieee80211_hw *hw = &local->hw;
+ struct sk_buff *skb;
+ struct ieee80211_mgmt *mgmt;
+ unsigned int hdrlen;
+@@ -1251,7 +1252,7 @@ void ieee80211_send_auth(struct ieee8021
+ memcpy(skb_put(skb, extra_len), extra, extra_len);
+
+ if (auth_alg == WLAN_AUTH_SHARED_KEY && transaction == 3) {
+- hdrlen = ieee80211_hdrlen(mgmt->frame_control);
++ hdrlen = ieee80211_padded_hdrlen(hw, mgmt->frame_control);
+ mgmt->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
+ err = ieee80211_wep_encrypt(local, skb, hdrlen, key,
+ key_len, key_idx);
projects / openwrt / staging / chunkeey.git / commitdiff