[PATCH RFC net-next 14/19] net: dsa: tag_mtk: split out common tag accessors
From: Alexander Lobakin
Date: Mon Dec 30 2019 - 09:32:28 EST
Misc: fix identation of MTK_HDR_LEN and make use of it in
mtk_tag_flow_dissect() instead of open-coded value.
Signed-off-by: Alexander Lobakin <alobakin@xxxxxxxx>
---
net/dsa/tag_mtk.c | 40 +++++++++++++++++++++++-----------------
1 file changed, 23 insertions(+), 17 deletions(-)
diff --git a/net/dsa/tag_mtk.c b/net/dsa/tag_mtk.c
index c3ad7b7b142a..b926ffdf5fb5 100644
--- a/net/dsa/tag_mtk.c
+++ b/net/dsa/tag_mtk.c
@@ -10,12 +10,27 @@
#include "dsa_priv.h"
-#define MTK_HDR_LEN 4
+#define MTK_HDR_LEN 4
#define MTK_HDR_XMIT_UNTAGGED 0
#define MTK_HDR_XMIT_TAGGED_TPID_8100 1
#define MTK_HDR_RECV_SOURCE_PORT_MASK GENMASK(2, 0)
#define MTK_HDR_XMIT_DP_BIT_MASK GENMASK(5, 0)
+static inline int mtk_tag_source_port(const u8 *data)
+{
+ /* The MTK header is added by the switch between src addr
+ * and ethertype at this point, skb->data points to 2 bytes
+ * after src addr so header should be 2 bytes right before.
+ * The source port field is in the second byte of the tag.
+ */
+ return *(data - 1) & MTK_HDR_RECV_SOURCE_PORT_MASK;
+}
+
+static inline __be16 mtk_tag_encap_proto(const u8 *data)
+{
+ return *(__be16 *)(data + 2);
+}
+
static struct sk_buff *mtk_tag_xmit(struct sk_buff *skb,
struct net_device *dev)
{
@@ -60,17 +75,15 @@ static struct sk_buff *mtk_tag_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt)
{
int port;
- __be16 *phdr, hdr;
if (unlikely(!pskb_may_pull(skb, MTK_HDR_LEN)))
return NULL;
- /* The MTK header is added by the switch between src addr
- * and ethertype at this point, skb->data points to 2 bytes
- * after src addr so header should be 2 bytes right before.
- */
- phdr = (__be16 *)(skb->data - 2);
- hdr = ntohs(*phdr);
+ port = mtk_tag_source_port(skb->data);
+
+ skb->dev = dsa_master_find_slave(dev, 0, port);
+ if (!skb->dev)
+ return NULL;
/* Remove MTK tag and recalculate checksum. */
skb_pull_rcsum(skb, MTK_HDR_LEN);
@@ -79,21 +92,14 @@ static struct sk_buff *mtk_tag_rcv(struct sk_buff *skb, struct net_device *dev,
skb->data - ETH_HLEN - MTK_HDR_LEN,
2 * ETH_ALEN);
- /* Get source port information */
- port = (hdr & MTK_HDR_RECV_SOURCE_PORT_MASK);
-
- skb->dev = dsa_master_find_slave(dev, 0, port);
- if (!skb->dev)
- return NULL;
-
return skb;
}
static void mtk_tag_flow_dissect(const struct sk_buff *skb, __be16 *proto,
int *offset)
{
- *offset = 4;
- *proto = ((__be16 *)skb->data)[1];
+ *offset = MTK_HDR_LEN;
+ *proto = mtk_tag_encap_proto(skb->data);
}
static const struct dsa_device_ops mtk_netdev_ops = {
--
2.24.1