Subject: Re: [PATCH v2 net-next] net: ethernet: mtk_ppe_offload: Allow QinQ

From: Michal Swiatkowski <[email-masked]>
Date: Wed, 5 Feb 2025 07:19:37 +0100

On Tue, Feb 04, 2025 at 08:46:24PM +0100, Eric Woudstra wrote:
> mtk_foe_entry_set_vlan() in mtk_ppe.c already seems to support
> double vlan tagging, but mtk_flow_offload_replace() in
> mtk_ppe_offload.c only allows for 1 vlan tag, optionally in
> combination with pppoe and dsa tags.
> 
> This patch adds QinQ support to mtk_flow_offload_replace().
> 
> Only PPPoE-in-Q (as before) and Q-in-Q are allowed. A combination
> of PPPoE and Q-in-Q is not allowed.
> 
> Signed-off-by: Eric Woudstra <[email-masked]>
> ---
> 
> Since the RFC v1 did not recieve any comments, I'm sending v2 as PATCH
> unchanged.
> 
> Tested on the BPI-R3(mini), on non-dsa-ports and dsa-ports.
> 
>  .../net/ethernet/mediatek/mtk_ppe_offload.c   | 21 +++++++++++--------
>  1 file changed, 12 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/ethernet/mediatek/mtk_ppe_offload.c b/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
> index f20bb390df3a..c19789883a9d 100644
> --- a/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
> +++ b/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
> @@ -34,8 +34,10 @@ struct mtk_flow_data {
>  	u16 vlan_in;
>  
>  	struct {
> -		u16 id;
> -		__be16 proto;
> +		struct {
> +			u16 id;
> +			__be16 proto;
> +		} vlans[2];
>  		u8 num;
>  	} vlan;
>  	struct {
> @@ -349,18 +351,19 @@ mtk_flow_offload_replace(struct mtk_eth *eth, struct flow_cls_offload *f,
>  		case FLOW_ACTION_CSUM:
>  			break;
>  		case FLOW_ACTION_VLAN_PUSH:
> -			if (data.vlan.num == 1 ||
> +			if (data.vlan.num + data.pppoe.num == 2 ||
>  			    act->vlan.proto != htons(ETH_P_8021Q))
>  				return -EOPNOTSUPP;
>  
> -			data.vlan.id = act->vlan.vid;
> -			data.vlan.proto = act->vlan.proto;
> +			data.vlan.vlans[data.vlan.num].id = act->vlan.vid;
> +			data.vlan.vlans[data.vlan.num].proto = act->vlan.proto;
>  			data.vlan.num++;
>  			break;
>  		case FLOW_ACTION_VLAN_POP:
>  			break;
>  		case FLOW_ACTION_PPPOE_PUSH:
> -			if (data.pppoe.num == 1)
> +			if (data.pppoe.num == 1 ||
> +			    data.vlan.num == 2)
>  				return -EOPNOTSUPP;
>  
>  			data.pppoe.sid = act->pppoe.sid;
> @@ -450,11 +453,11 @@ mtk_flow_offload_replace(struct mtk_eth *eth, struct flow_cls_offload *f,
>  	if (offload_type == MTK_PPE_PKT_TYPE_BRIDGE)
>  		foe.bridge.vlan = data.vlan_in;
>  
> -	if (data.vlan.num == 1) {
> -		if (data.vlan.proto != htons(ETH_P_8021Q))
> +	for (i = 0; i < data.vlan.num; i++) {
> +		if (data.vlan.vlans[i].proto != htons(ETH_P_8021Q))
It is already checked in FLOW_ACTION_VLAN_PUSH, so data.vlan.num can't be
increased if proto is different. No need to check it again.

Other than that rest looks fine.

>  			return -EOPNOTSUPP;
>  
> -		mtk_foe_entry_set_vlan(eth, &foe, data.vlan.id);
> +		mtk_foe_entry_set_vlan(eth, &foe, data.vlan.vlans[i].id);
>  	}
>  	if (data.pppoe.num == 1)
>  		mtk_foe_entry_set_pppoe(eth, &foe, data.pppoe.sid);
> -- 
> 2.47.1
>