Re: [PATCH net-next v7 07/16] net: dsa: vsc73xx: Add vlan filtering

[Simon Horman]

On Mon, Mar 25, 2024 at 09:43:32PM +0100, Pawel Dembicki wrote:
> This patch implements VLAN filtering for the vsc73xx driver.
> 
> After starting VLAN filtering, the switch is reconfigured from QinQ to
> a simple VLAN aware mode. This is required because VSC73XX chips do not
> support inner VLAN tag filtering.
> 
> Signed-off-by: Pawel Dembicki <paweldembicki@xxxxxxxxx>

..

> +static int vsc73xx_port_vlan_add(struct dsa_switch *ds, int port,
> +				 const struct switchdev_obj_port_vlan *vlan,
> +				 struct netlink_ext_ack *extack)
> +{
> +	bool untagged = vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED;
> +	bool pvid = vlan->flags & BRIDGE_VLAN_INFO_PVID;
> +	struct dsa_port *dp = dsa_to_port(ds, port);
> +	enum vsc73xx_port_vlan_conf port_vlan_conf;
> +	struct vsc73xx_bridge_vlan *vsc73xx_vlan;
> +	struct vsc73xx_vlan_summary summary;
> +	struct vsc73xx *vsc = ds->priv;
> +	bool operate_on_storage;
> +	int ret;
> +	u16 vid;
> +
> +	/* Be sure to deny alterations to the configuration done by tag_8021q.
> +	 */
> +	if (vid_is_dsa_8021q(vlan->vid)) {
> +		NL_SET_ERR_MSG_MOD(extack,
> +				   "Range 3072-4095 reserved for dsa_8021q operation");
> +		return -EBUSY;
> +	}
> +
> +	/* The processed vlan->vid is excluded from the search because the VLAN
> +	 * can be re-added with a different set of flags, so it's easiest to
> +	 * ignore its old flags from the VLAN database software copy.
> +	 */
> +	vsc73xx_bridge_vlan_summary(vsc, port, &summary, vlan->vid);
> +
> +	/* VSC73XX allow only three untagged states: none, one or all */
> +	if ((untagged && summary.num_tagged > 0 && summary.num_untagged > 0) ||
> +	    (!untagged && summary.num_untagged > 1)) {
> +		NL_SET_ERR_MSG_MOD(extack,
> +				   "Port can have only none, one or all untagged vlan");
> +		return -EBUSY;
> +	}
> +
> +	vsc73xx_vlan = vsc73xx_bridge_vlan_find(vsc, vlan->vid);
> +
> +	if (!vsc73xx_vlan) {
> +		vsc73xx_vlan = kzalloc(sizeof(*vsc73xx_vlan), GFP_KERNEL);
> +		if (!vsc73xx_vlan)
> +			return -ENOMEM;
> +
> +		vsc73xx_vlan->vid = vlan->vid;
> +		vsc73xx_vlan->portmask = 0;
> +		vsc73xx_vlan->untagged = 0;
> +
> +		INIT_LIST_HEAD(&vsc73xx_vlan->list);
> +		list_add_tail(&vsc73xx_vlan->list, &vsc->vlans);
> +	}
> +
> +	vsc73xx_vlan->portmask |= BIT(port);
> +
> +	if (untagged)
> +		vsc73xx_vlan->untagged |= BIT(port);
> +	else
> +		vsc73xx_vlan->untagged &= ~BIT(port);
> +
> +	/* CPU port must be always tagged because port separation is based on
> +	 * tag_8021q.
> +	 */
> +	if (port == CPU_PORT)
> +		goto update_vlan_table;
> +
> +	operate_on_storage = vsc73xx_tag_8021q_active(dp);
> +
> +	if (pvid)
> +		ret = vsc73xx_vlan_set_pvid(vsc, port, vlan->vid,
> +					    operate_on_storage, false);
> +	else if (vsc73xx_port_get_pvid(vsc, port, &vid, false) &&
> +		 vid == vlan->vid)
> +		ret = vsc73xx_vlan_clear_pvid(vsc, port, operate_on_storage,
> +					      false);

Hi Pawel,

some minor feedback from my side.

If neither of the above conditions immediately above is met,
then ret will be used ininitialised on the line below.

Flagged by clang-17 W=1 build, and Smatch.

> +	if (ret)
> +		goto err;

..

-- 
pw-bot: changes-requested