Subject: Re: [PATCH net-next 5/9] net: dsa: mv88e6xxx: rework in-chip bridging

From: Andrew Lunn <[email-masked]>
Date: Thu, 30 Mar 2017 15:57:30 +0200

On Wed, Mar 29, 2017 at 04:30:16PM -0400, Vivien Didelot wrote:
> All ports -- internal and external, for chips featuring a PVT -- have a
> mask restricting to which internal ports a frame is allowed to egress.
> 
> Now that DSA exposes the number of ports and their bridge devices, it is
> possible to extract the code generating the VLAN map and make it generic
> so that it can be shared later with the cross-chip bridging code.
> 
> Signed-off-by: Vivien Didelot <[email-masked]>

Reviewed-by: Andrew Lunn <[email-masked]>

> +static u16 mv88e6xxx_port_vlan(struct mv88e6xxx_chip *chip, int dev, int port)
> +{
> +	struct dsa_switch *ds = NULL;
> +	struct net_device *br;
> +	u16 pvlan;
> +	int i;
> +
> +	if (dev < DSA_MAX_SWITCHES)
> +		ds = chip->ds->dst->ds[dev];
> +
> +	/* Prevent frames from unknown switch or port */
> +	if (!ds || port >= ds->num_ports)
> +		return 0;
> +
> +	/* Frames from DSA links and CPU ports can egress any local port */
> +	if (dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port))
> +		return mv88e6xxx_port_mask(chip);
> +
> +	br = ds->ports[port].bridge_dev;
> +	pvlan = 0;

You could do this where you define the variable, but having it here,
close to where it is used also has its merits.

> +
> +	/* Frames from user ports can egress any local DSA links and CPU ports,
> +	 * as well as any local member of their bridge group.
> +	 */
> +	for (i = 0; i < mv88e6xxx_num_ports(chip); ++i)
> +		if (dsa_is_cpu_port(chip->ds, i) ||
> +		    dsa_is_dsa_port(chip->ds, i) ||
> +		    (br && chip->ds->ports[i].bridge_dev == br))
> +			pvlan |= BIT(i);
> +
> +	return pvlan;

  Andrew