diff options
Diffstat (limited to 'net/dsa')
| -rw-r--r-- | net/dsa/tag_mtk.c | 38 |
1 files changed, 29 insertions, 9 deletions
diff --git a/net/dsa/tag_mtk.c b/net/dsa/tag_mtk.c index 8475434af7d5..11535bc70743 100644 --- a/net/dsa/tag_mtk.c +++ b/net/dsa/tag_mtk.c @@ -13,10 +13,13 @@ */ #include <linux/etherdevice.h> +#include <linux/if_vlan.h> #include "dsa_priv.h" #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) @@ -25,20 +28,37 @@ static struct sk_buff *mtk_tag_xmit(struct sk_buff *skb, { struct dsa_port *dp = dsa_slave_to_port(dev); u8 *mtk_tag; + bool is_vlan_skb = true; - if (skb_cow_head(skb, MTK_HDR_LEN) < 0) - return NULL; - - skb_push(skb, MTK_HDR_LEN); + /* Build the special tag after the MAC Source Address. If VLAN header + * is present, it's required that VLAN header and special tag is + * being combined. Only in this way we can allow the switch can parse + * the both special and VLAN tag at the same time and then look up VLAN + * table with VID. + */ + if (!skb_vlan_tagged(skb)) { + if (skb_cow_head(skb, MTK_HDR_LEN) < 0) + return NULL; - memmove(skb->data, skb->data + MTK_HDR_LEN, 2 * ETH_ALEN); + skb_push(skb, MTK_HDR_LEN); + memmove(skb->data, skb->data + MTK_HDR_LEN, 2 * ETH_ALEN); + is_vlan_skb = false; + } - /* Build the tag after the MAC Source Address */ mtk_tag = skb->data + 2 * ETH_ALEN; - mtk_tag[0] = 0; + + /* Mark tag attribute on special tag insertion to notify hardware + * whether that's a combined special tag with 802.1Q header. + */ + mtk_tag[0] = is_vlan_skb ? MTK_HDR_XMIT_TAGGED_TPID_8100 : + MTK_HDR_XMIT_UNTAGGED; mtk_tag[1] = (1 << dp->index) & MTK_HDR_XMIT_DP_BIT_MASK; - mtk_tag[2] = 0; - mtk_tag[3] = 0; + + /* Tag control information is kept for 802.1Q */ + if (!is_vlan_skb) { + mtk_tag[2] = 0; + mtk_tag[3] = 0; + } return skb; } |