2023-03-22 23:40:32

by Vladimir Oltean

Subject: [PATCH net-next 3/9] net: dpaa: avoid one skb_reset_mac_header() in dpaa_enable_tx_csum()

It appears that dpaa_enable_tx_csum() only calls skb_reset_mac_header()
to get to the VLAN header using skb_mac_header().

We can use skb_vlan_eth_hdr() to get to the VLAN header based on
skb->data directly. This avoids spending a few cycles to set
skb->mac_header.

Signed-off-by: Vladimir Oltean <[email protected]>
---
drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
index 9318a2554056..1fa676308c5e 100644
--- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
+++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
@@ -1482,13 +1482,8 @@ static int dpaa_enable_tx_csum(struct dpaa_priv *priv,
parse_result = (struct fman_prs_result *)parse_results;

/* If we're dealing with VLAN, get the real Ethernet type */
- if (ethertype == ETH_P_8021Q) {
- /* We can't always assume the MAC header is set correctly
- * by the stack, so reset to beginning of skb->data
- */
- skb_reset_mac_header(skb);
- ethertype = ntohs(vlan_eth_hdr(skb)->h_vlan_encapsulated_proto);
- }
+ if (ethertype == ETH_P_8021Q)
+ ethertype = ntohs(skb_vlan_eth_hdr(skb)->h_vlan_encapsulated_proto);

/* Fill in the relevant L3 parse result fields
* and read the L4 protocol type
--
2.34.1

2023-03-23 16:10:53

by Simon Horman

Subject: Re: [PATCH net-next 3/9] net: dpaa: avoid one skb_reset_mac_header() in dpaa_enable_tx_csum()

On Thu, Mar 23, 2023 at 01:38:17AM +0200, Vladimir Oltean wrote:
> It appears that dpaa_enable_tx_csum() only calls skb_reset_mac_header()
> to get to the VLAN header using skb_mac_header().
>
> We can use skb_vlan_eth_hdr() to get to the VLAN header based on
> skb->data directly. This avoids spending a few cycles to set
> skb->mac_header.
>
> Signed-off-by: Vladimir Oltean <[email protected]>

Reviewed-by: Simon Horman <[email protected]>

2023-03-23 16:36:19

by Florian Fainelli

Subject: Re: [PATCH net-next 3/9] net: dpaa: avoid one skb_reset_mac_header() in dpaa_enable_tx_csum()

On 3/22/23 16:38, Vladimir Oltean wrote:
> It appears that dpaa_enable_tx_csum() only calls skb_reset_mac_header()
> to get to the VLAN header using skb_mac_header().
>
> We can use skb_vlan_eth_hdr() to get to the VLAN header based on
> skb->data directly. This avoids spending a few cycles to set
> skb->mac_header.
>
> Signed-off-by: Vladimir Oltean <[email protected]>

Reviewed-by: Florian Fainelli <[email protected]>
--
Florian