diff options
| author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2021-08-10 16:13:54 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-08-11 14:44:58 +0100 |
| commit | 6bef794da6d3bd347c18e93ad33483bd8903d9fd (patch) | |
| tree | 1ce71a803cc78ef91d743a51ced9be8606b429aa /net/dsa/dsa_priv.h | |
| parent | f1dacd7aea34333620bd5177a8808a3296a63184 (diff) | |
net: dsa: create a helper which allocates space for EtherType DSA headers
Hide away the memmove used by DSA EtherType header taggers to shift the
MAC SA and DA to the left to make room for the header, after they've
called skb_push(). The call to skb_push() is still left explicit in
drivers, to be symmetric with dsa_strip_etype_header, and because not
all callers can be refactored to do it (for example, brcm_tag_xmit_ll
has common code for a pre-Ethernet DSA tag and an EtherType DSA tag).
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dsa/dsa_priv.h')
| -rw-r--r-- | net/dsa/dsa_priv.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h index 8a12ec1f9d21..28e1fbe64ee0 100644 --- a/net/dsa/dsa_priv.h +++ b/net/dsa/dsa_priv.h @@ -478,6 +478,35 @@ static inline void dsa_strip_etype_header(struct sk_buff *skb, int len) memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - len, 2 * ETH_ALEN); } +/* Helper for creating space for DSA header tags in TX path packets. + * Must not be called before skb_push(len). + * + * Before: + * + * <<<<<<< | | | | | | | | | | | | | | | + * ^ <<<<<<< +-----------------------+-----------------------+-------+ + * | <<<<<<< | Destination MAC | Source MAC | EType | + * | +-----------------------+-----------------------+-------+ + * <----- len -----> + * | + * | + * skb->data + * + * After: + * + * | | | | | | | | | | | | | | | | | | | + * +-----------------------+-----------------------+---------------+-------+ + * | Destination MAC | Source MAC | DSA header | EType | + * +-----------------------+-----------------------+---------------+-------+ + * ^ | | + * | <----- len -----> + * skb->data + */ +static inline void dsa_alloc_etype_header(struct sk_buff *skb, int len) +{ + memmove(skb->data, skb->data + len, 2 * ETH_ALEN); +} + /* switch.c */ int dsa_switch_register_notifier(struct dsa_switch *ds); void dsa_switch_unregister_notifier(struct dsa_switch *ds); |