Subject: Re: [PATCH iwl-next v3 3/5] i40e: Add helpers to find VSI and VEB by SEID and use them

From: Simon Horman <[email-masked]>
Date: Mon, 20 Nov 2023 11:42:24 +0000

On Thu, Nov 16, 2023 at 04:21:12PM +0100, Ivan Vecera wrote:
> Add two helpers i40e_(veb|vsi)_get_by_seid() to find corresponding
> VEB or VSI by their SEID value and use these helpers to replace
> existing open-coded loops.
> 
> Reviewed-by: Wojciech Drewek <[email-masked]>
> Signed-off-by: Ivan Vecera <[email-masked]>

Hi Ivan,

some minor feedback from my side.

...

> diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
> index 1e9266de270b..ca8997d29c02 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e.h
> +++ b/drivers/net/ethernet/intel/i40e/i40e.h
> @@ -1360,4 +1360,38 @@ static inline struct i40e_pf *i40e_hw_to_pf(struct i40e_hw *hw)
>  
>  struct device *i40e_hw_to_dev(struct i40e_hw *hw);
>  
> +/**
> + * i40e_pf_get_vsi_by_seid - find VSI by SEID
> + * @pf: pointer to a PF

nit: @seid is missing here

> + **/
> +static inline struct i40e_vsi *
> +i40e_pf_get_vsi_by_seid(struct i40e_pf *pf, u16 seid)
> +{
> +	struct i40e_vsi *vsi;
> +	int i;
> +
> +	i40e_pf_for_each_vsi(pf, i, vsi)
> +		if (vsi->seid == seid)
> +			return vsi;
> +
> +	return NULL;
> +}
> +
> +/**
> + * i40e_pf_get_veb_by_seid - find VEB by SEID
> + * @pf: pointer to a PF

Ditto

...

> diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c

...

> @@ -14848,23 +14831,16 @@ struct i40e_veb *i40e_veb_setup(struct i40e_pf *pf, u16 flags,
>  	}
>  
>  	/* make sure there is such a vsi and uplink */
> -	i40e_pf_for_each_vsi(pf, vsi_idx, vsi)
> -		if (vsi->seid == vsi_seid)
> -			break;
> -
> -	if (vsi_idx == pf->num_alloc_vsi && vsi_seid != 0) {
> -		dev_info(&pf->pdev->dev, "vsi seid %d not found\n",
> -			 vsi_seid);
> -		return NULL;
> +	if (vsi_seid) {
> +		vsi = i40e_pf_get_vsi_by_seid(pf, vsi_seid);
> +		if (!vsi) {
> +			dev_err(&pf->pdev->dev, "vsi seid %d not found\n",
> +				vsi_seid);
> +			return NULL;
> +		}
>  	}
> -
>  	if (uplink_seid && uplink_seid != pf->mac_seid) {
> -		i40e_pf_for_each_veb(pf, veb_idx, veb) {
> -			if (veb->seid == uplink_seid) {
> -				uplink_veb = veb;
> -				break;
> -			}
> -		}
> +		uplink_veb = i40e_pf_get_veb_by_seid(pf, uplink_seid);
>  		if (!uplink_veb) {
>  			dev_info(&pf->pdev->dev,
>  				 "uplink seid %d not found\n", uplink_seid);

The next part of this function looks like this:

		if (!uplink_veb) {
			dev_info(&pf->pdev->dev,
				 "uplink seid %d not found\n", uplink_seid);
			return NULL;
		}
	}
	/* get veb sw struct */
	veb_idx = i40e_veb_mem_alloc(pf);
	if (veb_idx < 0)
		goto err_alloc;
	veb = pf->veb[veb_idx];
	veb->flags = flags;
	veb->uplink_seid = uplink_seid;
	veb->veb_idx = (uplink_veb ? uplink_veb->idx : I40E_NO_VEB);
	veb->enabled_tc = (enabled_tc ? enabled_tc : 0x1);

	/* create the VEB in the switch */
	ret = i40e_add_veb(veb, vsi);

Smatch complains that vsi may be used uninitialised here.
Which does seem possible to me if vsi_seid is 0.

...