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From:   Felix Fietkau <nbd@nbd.name>
To:     netdev@vger.kernel.org, Sean Wang <sean.wang@mediatek.com>,
        Landen Chao <Landen.Chao@mediatek.com>,
        DENG Qingfang <dqfext@gmail.com>, Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Matthias Brugger <matthias.bgg@gmail.com>
Cc:     linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 10/14] net: dsa: tag_mtk: parse hwaccel VLAN tags
Date:   Mon,  7 Nov 2022 19:54:48 +0100
Message-Id: <20221107185452.90711-10-nbd@nbd.name>
In-Reply-To: <20221107185452.90711-1-nbd@nbd.name>
References: <20221107185452.90711-1-nbd@nbd.name>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Pull the port information from the VLAN protocol ID field

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/dsa/tag_mtk.c | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/net/dsa/tag_mtk.c b/net/dsa/tag_mtk.c
index 445d6113227f..0dfa2354f77d 100644
--- a/net/dsa/tag_mtk.c
+++ b/net/dsa/tag_mtk.c
@@ -73,13 +73,18 @@ static struct sk_buff *mtk_tag_rcv(struct sk_buff *skb, struct net_device *dev)
 	if (unlikely(!pskb_may_pull(skb, MTK_HDR_LEN)))
 		return NULL;
 
-	phdr = dsa_etype_header_pos_rx(skb);
-	hdr = ntohs(*phdr);
+	if (skb_vlan_tag_present(skb)) {
+		hdr = ntohs(skb->vlan_proto);
+		__vlan_hwaccel_clear_tag(skb);
+	} else {
+		phdr = dsa_etype_header_pos_rx(skb);
+		hdr = ntohs(*phdr);
 
-	/* Remove MTK tag and recalculate checksum. */
-	skb_pull_rcsum(skb, MTK_HDR_LEN);
+		/* Remove MTK tag and recalculate checksum. */
+		skb_pull_rcsum(skb, MTK_HDR_LEN);
 
-	dsa_strip_etype_header(skb, MTK_HDR_LEN);
+		dsa_strip_etype_header(skb, MTK_HDR_LEN);
+	}
 
 	/* Get source port information */
 	port = (hdr & MTK_HDR_RECV_SOURCE_PORT_MASK);
@@ -93,11 +98,22 @@ static struct sk_buff *mtk_tag_rcv(struct sk_buff *skb, struct net_device *dev)
 	return skb;
 }
 
+static void mtk_tag_flow_dissect(const struct sk_buff *skb, __be16 *proto,
+				 int *offset)
+{
+	if (!skb_vlan_tag_present(skb))
+		return dsa_tag_generic_flow_dissect(skb, proto, offset);
+
+	*offset = 0;
+	*proto = ((__be16 *)skb->data)[-1];
+}
+
 static const struct dsa_device_ops mtk_netdev_ops = {
 	.name		= "mtk",
 	.proto		= DSA_TAG_PROTO_MTK,
 	.xmit		= mtk_tag_xmit,
 	.rcv		= mtk_tag_rcv,
+	.flow_dissect	= mtk_tag_flow_dissect,
 	.needed_headroom = MTK_HDR_LEN,
 };
 
-- 
2.38.1