mac80211: add performance improvements for A-MSDU rx

[openwrt/svn-archive/archive.git] / package / kernel / mac80211 / patches / 320-cfg80211-add-support-for-non-linear-skbs-in-ieee8021.patch

diff --git a/package/kernel/mac80211/patches/320-cfg80211-add-support-for-non-linear-skbs-in-ieee8021.patch b/package/kernel/mac80211/patches/320-cfg80211-add-support-for-non-linear-skbs-in-ieee8021.patch
new file mode 100644 (file)
index 0000000..2eeed22
--- /dev/null
+++ b/package/kernel/mac80211/patches/320-cfg80211-add-support-for-non-linear-skbs-in-ieee8021.patch
@@ -0,0 +1,159 @@
+From: Felix Fietkau <nbd@openwrt.org>
+Date: Tue, 2 Feb 2016 14:39:10 +0100
+Subject: [PATCH] cfg80211: add support for non-linear skbs in
+ ieee80211_amsdu_to_8023s
+
+Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+Signed-off-by: Johannes Berg <johannes.berg@intel.com>
+---
+
+--- a/net/wireless/util.c
++++ b/net/wireless/util.c
+@@ -644,73 +644,75 @@ int ieee80211_data_from_8023(struct sk_b
+ }
+ EXPORT_SYMBOL(ieee80211_data_from_8023);
+ 
++static struct sk_buff *
++__ieee80211_amsdu_copy(struct sk_buff *skb, unsigned int hlen,
++                     int offset, int len)
++{
++      struct sk_buff *frame;
++
++      if (skb->len - offset < len)
++              return NULL;
++
++      /*
++       * Allocate and reserve two bytes more for payload
++       * alignment since sizeof(struct ethhdr) is 14.
++       */
++      frame = dev_alloc_skb(hlen + sizeof(struct ethhdr) + 2 + len);
++
++      skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2);
++      skb_copy_bits(skb, offset, skb_put(frame, len), len);
++
++      return frame;
++}
+ 
+ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
+                             const u8 *addr, enum nl80211_iftype iftype,
+                             const unsigned int extra_headroom,
+                             bool has_80211_header)
+ {
++      unsigned int hlen = ALIGN(extra_headroom, 4);
+       struct sk_buff *frame = NULL;
+       u16 ethertype;
+       u8 *payload;
+-      const struct ethhdr *eth;
+-      int remaining, err;
+-      u8 dst[ETH_ALEN], src[ETH_ALEN];
+-
+-      if (skb_linearize(skb))
+-              goto out;
++      int offset = 0, remaining, err;
++      struct ethhdr eth;
++      bool reuse_skb = true;
++      bool last = false;
+ 
+       if (has_80211_header) {
+-              err = ieee80211_data_to_8023(skb, addr, iftype);
++              err = __ieee80211_data_to_8023(skb, &eth, addr, iftype);
+               if (err)
+                       goto out;
+-
+-              /* skip the wrapping header */
+-              eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
+-              if (!eth)
+-                      goto out;
+-      } else {
+-              eth = (struct ethhdr *) skb->data;
+       }
+ 
+-      while (skb != frame) {
++      while (!last) {
++              unsigned int subframe_len;
++              int len;
+               u8 padding;
+-              __be16 len = eth->h_proto;
+-              unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
+-
+-              remaining = skb->len;
+-              memcpy(dst, eth->h_dest, ETH_ALEN);
+-              memcpy(src, eth->h_source, ETH_ALEN);
+ 
++              skb_copy_bits(skb, offset, &eth, sizeof(eth));
++              len = ntohs(eth.h_proto);
++              subframe_len = sizeof(struct ethhdr) + len;
+               padding = (4 - subframe_len) & 0x3;
++
+               /* the last MSDU has no padding */
++              remaining = skb->len - offset;
+               if (subframe_len > remaining)
+                       goto purge;
+ 
+-              skb_pull(skb, sizeof(struct ethhdr));
++              offset += sizeof(struct ethhdr);
+               /* reuse skb for the last subframe */
+-              if (remaining <= subframe_len + padding)
++              last = remaining <= subframe_len + padding;
++              if (!skb_is_nonlinear(skb) && last) {
++                      skb_pull(skb, offset);
+                       frame = skb;
+-              else {
+-                      unsigned int hlen = ALIGN(extra_headroom, 4);
+-                      /*
+-                       * Allocate and reserve two bytes more for payload
+-                       * alignment since sizeof(struct ethhdr) is 14.
+-                       */
+-                      frame = dev_alloc_skb(hlen + subframe_len + 2);
++                      reuse_skb = true;
++              } else {
++                      frame = __ieee80211_amsdu_copy(skb, hlen, offset, len);
+                       if (!frame)
+                               goto purge;
+ 
+-                      skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2);
+-                      memcpy(skb_put(frame, ntohs(len)), skb->data,
+-                              ntohs(len));
+-
+-                      eth = (struct ethhdr *)skb_pull(skb, ntohs(len) +
+-                                                      padding);
+-                      if (!eth) {
+-                              dev_kfree_skb(frame);
+-                              goto purge;
+-                      }
++                      offset += len + padding;
+               }
+ 
+               skb_reset_network_header(frame);
+@@ -719,24 +721,20 @@ void ieee80211_amsdu_to_8023s(struct sk_
+ 
+               payload = frame->data;
+               ethertype = (payload[6] << 8) | payload[7];
+-
+               if (likely((ether_addr_equal(payload, rfc1042_header) &&
+                           ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
+                          ether_addr_equal(payload, bridge_tunnel_header))) {
+-                      /* remove RFC1042 or Bridge-Tunnel
+-                       * encapsulation and replace EtherType */
+-                      skb_pull(frame, 6);
+-                      memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
+-                      memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
+-              } else {
+-                      memcpy(skb_push(frame, sizeof(__be16)), &len,
+-                              sizeof(__be16));
+-                      memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
+-                      memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
++                      eth.h_proto = htons(ethertype);
++                      skb_pull(frame, ETH_ALEN + 2);
+               }
++
++              memcpy(skb_push(frame, sizeof(eth)), &eth, sizeof(eth));
+               __skb_queue_tail(list, frame);
+       }
+ 
++      if (!reuse_skb)
++              dev_kfree_skb(skb);
++
+       return;
+ 
+  purge: