mac80211: add mesh fast-rx support

This helps bring down rx CPU usage by avoiding calls to the rx handlers in
the slow path. Supports forwarding and local rx, including A-MSDU.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/package/kernel/mac80211/patches/subsys/326-wifi-mac80211-add-mesh-fast-rx-support.patch b/package/kernel/mac80211/patches/subsys/326-wifi-mac80211-add-mesh-fast-rx-support.patch
new file mode 100644 (file)
index 0000000..b2b94d0
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/326-wifi-mac80211-add-mesh-fast-rx-support.patch
@@ -0,0 +1,77 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Thu, 2 Mar 2023 13:52:29 +0100
+Subject: [PATCH] wifi: mac80211: add mesh fast-rx support
+
+This helps bring down rx CPU usage by avoiding calls to the rx handlers in
+the slow path. Supports forwarding and local rx, including A-MSDU.
+
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+
+--- a/net/mac80211/rx.c
++++ b/net/mac80211/rx.c
+@@ -4572,6 +4572,12 @@ void ieee80211_check_fast_rx(struct sta_
+               }
+ 
+               break;
++      case NL80211_IFTYPE_MESH_POINT:
++              fastrx.expected_ds_bits = cpu_to_le16(IEEE80211_FCTL_FROMDS |
++                                                    IEEE80211_FCTL_TODS);
++              fastrx.da_offs = offsetof(struct ieee80211_hdr, addr3);
++              fastrx.sa_offs = offsetof(struct ieee80211_hdr, addr4);
++              break;
+       default:
+               goto clear;
+       }
+@@ -4780,6 +4786,7 @@ static bool ieee80211_invoke_fast_rx(str
+       struct sk_buff *skb = rx->skb;
+       struct ieee80211_hdr *hdr = (void *)skb->data;
+       struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
++      static ieee80211_rx_result res;
+       int orig_len = skb->len;
+       int hdrlen = ieee80211_hdrlen(hdr->frame_control);
+       int snap_offs = hdrlen;
+@@ -4841,7 +4848,8 @@ static bool ieee80211_invoke_fast_rx(str
+               snap_offs += IEEE80211_CCMP_HDR_LEN;
+       }
+ 
+-      if (!(status->rx_flags & IEEE80211_RX_AMSDU)) {
++      if (!ieee80211_vif_is_mesh(&rx->sdata->vif) &&
++          !(status->rx_flags & IEEE80211_RX_AMSDU)) {
+               if (!pskb_may_pull(skb, snap_offs + sizeof(*payload)))
+                       return false;
+ 
+@@ -4880,13 +4888,29 @@ static bool ieee80211_invoke_fast_rx(str
+       /* do the header conversion - first grab the addresses */
+       ether_addr_copy(addrs.da, skb->data + fast_rx->da_offs);
+       ether_addr_copy(addrs.sa, skb->data + fast_rx->sa_offs);
+-      skb_postpull_rcsum(skb, skb->data + snap_offs,
+-                         sizeof(rfc1042_header) + 2);
+-      /* remove the SNAP but leave the ethertype */
+-      skb_pull(skb, snap_offs + sizeof(rfc1042_header));
++      if (ieee80211_vif_is_mesh(&rx->sdata->vif)) {
++          skb_pull(skb, snap_offs - 2);
++          put_unaligned_be16(skb->len - 2, skb->data);
++      } else {
++          skb_postpull_rcsum(skb, skb->data + snap_offs,
++                             sizeof(rfc1042_header) + 2);
++
++          /* remove the SNAP but leave the ethertype */
++          skb_pull(skb, snap_offs + sizeof(rfc1042_header));
++      }
+       /* push the addresses in front */
+       memcpy(skb_push(skb, sizeof(addrs)), &addrs, sizeof(addrs));
+ 
++      res = ieee80211_rx_mesh_data(rx->sdata, rx->sta, rx->skb);
++      switch (res) {
++      case RX_QUEUED:
++              return true;
++      case RX_CONTINUE:
++              break;
++      default:
++              goto drop;
++      }
++
+       ieee80211_rx_8023(rx, fast_rx, orig_len);
+ 
+       return true;