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>

1 files changed, 77 insertions, 0 deletions

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
index 0000000000..b2b94d026b
--- /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;