Re: [PATCH net-next v2 2/2] net: dsa: b53: Configure VLANs while not filtering

[Vladimir Oltean]

On Wed, Sep 23, 2020 at 01:45:14PM -0700, Florian Fainelli wrote:
> Update the B53 driver to support VLANs while not filtering. This
> requires us to enable VLAN globally within the switch upon driver
> initial configuration (dev->vlan_enabled).
> 
> We also need to remove the code that dealt with PVID re-configuration in
> b53_vlan_filtering() since that function worked under the assumption
> that it would only be called to make a bridge VLAN filtering, or not
> filtering, and we would attempt to move the port's PVID accordingly.
> 
> Now that VLANs are programmed all the time, even in the case of a
> non-VLAN filtering bridge, we would be programming a default_pvid for
> the bridged switch ports.
> 
> We need the DSA receive path to pop the VLAN tag if it is the bridge's
> default_pvid because the CPU port is always programmed tagged in the
> programmed VLANs. In order to do so we utilize the
> dsa_untag_bridge_pvid() helper introduced in the commit before by
> setting ds->untag_bridge_pvid to true.
> 
> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> ---

Acked-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>

>  drivers/net/dsa/b53/b53_common.c | 19 ++-----------------
>  drivers/net/dsa/b53/b53_priv.h   |  1 -
>  net/dsa/tag_brcm.c               | 16 ++++++++++++++--
>  3 files changed, 16 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
> index 6a5796c32721..73507cff3bc4 100644
> --- a/drivers/net/dsa/b53/b53_common.c
> +++ b/drivers/net/dsa/b53/b53_common.c
> @@ -1377,23 +1377,6 @@ EXPORT_SYMBOL(b53_phylink_mac_link_up);
>  int b53_vlan_filtering(struct dsa_switch *ds, int port, bool vlan_filtering)
>  {
>  	struct b53_device *dev = ds->priv;
> -	u16 pvid, new_pvid;
> -
> -	b53_read16(dev, B53_VLAN_PAGE, B53_VLAN_PORT_DEF_TAG(port), &pvid);
> -	if (!vlan_filtering) {
> -		/* Filtering is currently enabled, use the default PVID since
> -		 * the bridge does not expect tagging anymore
> -		 */
> -		dev->ports[port].pvid = pvid;
> -		new_pvid = b53_default_pvid(dev);
> -	} else {
> -		/* Filtering is currently disabled, restore the previous PVID */
> -		new_pvid = dev->ports[port].pvid;
> -	}
> -
> -	if (pvid != new_pvid)
> -		b53_write16(dev, B53_VLAN_PAGE, B53_VLAN_PORT_DEF_TAG(port),
> -			    new_pvid);
>  
>  	b53_enable_vlan(dev, dev->vlan_enabled, vlan_filtering);
>  
> @@ -2619,6 +2602,8 @@ struct b53_device *b53_switch_alloc(struct device *base,
>  	dev->priv = priv;
>  	dev->ops = ops;
>  	ds->ops = &b53_switch_ops;
> +	ds->configure_vlan_while_not_filtering = true;
> +	dev->vlan_enabled = ds->configure_vlan_while_not_filtering;
>  	mutex_init(&dev->reg_mutex);
>  	mutex_init(&dev->stats_mutex);
>  
> diff --git a/drivers/net/dsa/b53/b53_priv.h b/drivers/net/dsa/b53/b53_priv.h
> index c55c0a9f1b47..24893b592216 100644
> --- a/drivers/net/dsa/b53/b53_priv.h
> +++ b/drivers/net/dsa/b53/b53_priv.h
> @@ -91,7 +91,6 @@ enum {
>  struct b53_port {
>  	u16		vlan_ctl_mask;
>  	struct ethtool_eee eee;
> -	u16		pvid;
>  };
>  
>  struct b53_vlan {
> diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c
> index cc8512b5f9e2..703770161738 100644
> --- a/net/dsa/tag_brcm.c
> +++ b/net/dsa/tag_brcm.c
> @@ -7,6 +7,7 @@
>  
>  #include <linux/etherdevice.h>
>  #include <linux/list.h>
> +#include <linux/if_vlan.h>
>  #include <linux/slab.h>
>  
>  #include "dsa_priv.h"
> @@ -140,6 +141,11 @@ static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb,
>  	/* Remove Broadcom tag and update checksum */
>  	skb_pull_rcsum(skb, BRCM_TAG_LEN);
>  
> +	/* Set the MAC header to where it should point for
> +	 * dsa_untag_bridge_pvid() to parse the correct VLAN header.
> +	 */
> +	skb_set_mac_header(skb, -ETH_HLEN);
> +
>  	skb->offload_fwd_mark = 1;
>  
>  	return skb;
> @@ -191,7 +197,7 @@ static struct sk_buff *brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev,
>  		nskb->data - ETH_HLEN - BRCM_TAG_LEN,
>  		2 * ETH_ALEN);
>  
> -	return nskb;
> +	return dsa_untag_bridge_pvid(nskb);
>  }
>  
>  static const struct dsa_device_ops brcm_netdev_ops = {
> @@ -219,8 +225,14 @@ static struct sk_buff *brcm_tag_rcv_prepend(struct sk_buff *skb,
>  					    struct net_device *dev,
>  					    struct packet_type *pt)
>  {
> +	struct sk_buff *nskb;
> +
>  	/* tag is prepended to the packet */
> -	return brcm_tag_rcv_ll(skb, dev, pt, ETH_HLEN);
> +	nskb = brcm_tag_rcv_ll(skb, dev, pt, ETH_HLEN);
> +	if (!nskb)
> +		return nskb;
> +
> +	return dsa_untag_bridge_pvid(nskb);
>  }
>  
>  static const struct dsa_device_ops brcm_prepend_netdev_ops = {
> -- 
> 2.25.1
>