diff options
| author | Tom Herbert <therbert@google.com> | 2014-08-27 21:26:56 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-08-29 20:41:11 -0700 |
| commit | 662880f4420340aad4f9a62a349c6c9d4faa1a5d (patch) | |
| tree | d62876eeef140de3256a22f0632571dc00c9745c /include/linux/netdevice.h | |
| parent | 77cffe23c1f88835f6bd7b47bfa0c060c2969828 (diff) | |
| download | lwn-662880f4420340aad4f9a62a349c6c9d4faa1a5d.tar.gz lwn-662880f4420340aad4f9a62a349c6c9d4faa1a5d.zip | |
net: Allow GRO to use and set levels of checksum unnecessary
Allow GRO path to "consume" checksums provided in CHECKSUM_UNNECESSARY
and to report new checksums verfied for use in fallback to normal
path.
Change GRO checksum path to track csum_level using a csum_cnt field
in NAPI_GRO_CB. On GRO initialization, if ip_summed is
CHECKSUM_UNNECESSARY set NAPI_GRO_CB(skb)->csum_cnt to
skb->csum_level + 1. For each checksum verified, decrement
NAPI_GRO_CB(skb)->csum_cnt while its greater than zero. If a checksum
is verfied and NAPI_GRO_CB(skb)->csum_cnt == 0, we have verified a
deeper checksum than originally indicated in skbuf so increment
csum_level (or initialize to CHECKSUM_UNNECESSARY if ip_summed is
CHECKSUM_NONE or CHECKSUM_COMPLETE).
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/netdevice.h')
| -rw-r--r-- | include/linux/netdevice.h | 26 |
1 files changed, 12 insertions, 14 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index dfc1d8b8bd0f..456eb1fe51e8 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1883,8 +1883,8 @@ struct napi_gro_cb { /* GRO checksum is valid */ u8 csum_valid:1; - /* Number encapsulation layers crossed */ - u8 encapsulation; + /* Number of checksums via CHECKSUM_UNNECESSARY */ + u8 csum_cnt:3; /* used to support CHECKSUM_COMPLETE for tunneling protocols */ __wsum csum; @@ -2179,8 +2179,7 @@ static inline bool __skb_gro_checksum_validate_needed(struct sk_buff *skb, __sum16 check) { return (skb->ip_summed != CHECKSUM_PARTIAL && - (skb->ip_summed != CHECKSUM_UNNECESSARY || - (NAPI_GRO_CB(skb)->encapsulation > skb->encapsulation)) && + NAPI_GRO_CB(skb)->csum_cnt == 0 && (!zero_okay || check)); } @@ -2196,18 +2195,17 @@ static inline __sum16 __skb_gro_checksum_validate_complete(struct sk_buff *skb, return __skb_gro_checksum_complete(skb); } -/* Update skb for CHECKSUM_UNNECESSARY when we verified a top level - * checksum or an encapsulated one during GRO. This saves work - * if we fallback to normal path with the packet. - */ static inline void skb_gro_incr_csum_unnecessary(struct sk_buff *skb) { - if (skb->ip_summed == CHECKSUM_UNNECESSARY) { - if (NAPI_GRO_CB(skb)->encapsulation) - skb->encapsulation = 1; - } else if (skb->ip_summed != CHECKSUM_PARTIAL) { - skb->ip_summed = CHECKSUM_UNNECESSARY; - skb->encapsulation = 0; + if (NAPI_GRO_CB(skb)->csum_cnt > 0) { + /* Consume a checksum from CHECKSUM_UNNECESSARY */ + NAPI_GRO_CB(skb)->csum_cnt--; + } else { + /* Update skb for CHECKSUM_UNNECESSARY and csum_level when we + * verified a new top level checksum or an encapsulated one + * during GRO. This saves work if we fallback to normal path. + */ + __skb_incr_checksum_unnecessary(skb); } } |