Re: [PATCH v9 net-next 09/11] net: dsa: microchip: add support for port mirror operations

[Vladimir Oltean <olteanv@gmail.com>]

On Fri, Mar 18, 2022 at 02:25:38PM +0530, Prasanna Vengateshan wrote:
> Added support for port_mirror_add() and port_mirror_del operations
> 
> Sniffing is limited to one port & alert the user if any new
> sniffing port is selected
> 
> Signed-off-by: Prasanna Vengateshan <prasanna.vengateshan@microchip.com>
> Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
>  drivers/net/dsa/microchip/lan937x_main.c | 84 ++++++++++++++++++++++++
>  1 file changed, 84 insertions(+)
> 
> diff --git a/drivers/net/dsa/microchip/lan937x_main.c b/drivers/net/dsa/microchip/lan937x_main.c
> index c54aba6a05b5..5a57a2ce8992 100644
> --- a/drivers/net/dsa/microchip/lan937x_main.c
> +++ b/drivers/net/dsa/microchip/lan937x_main.c
> @@ -98,6 +98,88 @@ static void lan937x_port_stp_state_set(struct dsa_switch *ds, int port,
>  	ksz_update_port_member(dev, port);
>  }
>  
> +static int lan937x_port_mirror_add(struct dsa_switch *ds, int port,
> +				   struct dsa_mall_mirror_tc_entry *mirror,
> +				   bool ingress)

This function gained a new extack argument yesterday => your patch
doesn't compile. Maybe you could even use the extack to propagate the
"existing sniffer port" error.

> +{
> +	struct ksz_device *dev = ds->priv;
> +	int ret, p;
> +	u8 data;
> +
> +	/* Limit to one sniffer port
> +	 * Check if any of the port is already set for sniffing
> +	 * If yes, instruct the user to remove the previous entry & exit
> +	 */
> +	for (p = 0; p < dev->port_cnt; p++) {
> +		/* Skip the current sniffing port */
> +		if (p == mirror->to_local_port)
> +			continue;
> +
> +		ret = lan937x_pread8(dev, p, P_MIRROR_CTRL, &data);
> +		if (ret < 0)
> +			return ret;
> +
> +		if (data & PORT_MIRROR_SNIFFER) {
> +			dev_err(dev->dev,
> +				"Delete existing rules towards %s & try\n",
> +				dsa_to_port(ds, p)->name);
> +			return -EBUSY;
> +		}
> +	}
> +
> +	/* Configure ingress/egress mirroring */
> +	if (ingress)
> +		ret = lan937x_port_cfg(dev, port, P_MIRROR_CTRL, PORT_MIRROR_RX,
> +				       true);
> +	else
> +		ret = lan937x_port_cfg(dev, port, P_MIRROR_CTRL, PORT_MIRROR_TX,
> +				       true);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Configure sniffer port as other ports do not have
> +	 * PORT_MIRROR_SNIFFER is set
> +	 */
> +	ret = lan937x_port_cfg(dev, mirror->to_local_port, P_MIRROR_CTRL,
> +			       PORT_MIRROR_SNIFFER, true);
> +	if (ret < 0)
> +		return ret;
> +
> +	return lan937x_cfg(dev, S_MIRROR_CTRL, SW_MIRROR_RX_TX, false);
> +}
> +
> +static void lan937x_port_mirror_del(struct dsa_switch *ds, int port,
> +				    struct dsa_mall_mirror_tc_entry *mirror)
> +{
> +	struct ksz_device *dev = ds->priv;
> +	bool in_use = false;
> +	u8 data;
> +	int p;
> +
> +	/* clear ingress/egress mirroring port */
> +	if (mirror->ingress)
> +		lan937x_port_cfg(dev, port, P_MIRROR_CTRL, PORT_MIRROR_RX,
> +				 false);
> +	else
> +		lan937x_port_cfg(dev, port, P_MIRROR_CTRL, PORT_MIRROR_TX,
> +				 false);
> +
> +	/* Check if any of the port is still referring to sniffer port */
> +	for (p = 0; p < dev->port_cnt; p++) {
> +		lan937x_pread8(dev, p, P_MIRROR_CTRL, &data);
> +
> +		if ((data & (PORT_MIRROR_RX | PORT_MIRROR_TX))) {
> +			in_use = true;
> +			break;
> +		}
> +	}
> +
> +	/* delete sniffing if there are no other mirroring rule exist */
> +	if (!in_use)
> +		lan937x_port_cfg(dev, mirror->to_local_port, P_MIRROR_CTRL,
> +				 PORT_MIRROR_SNIFFER, false);
> +}
> +
>  static void lan937x_config_cpu_port(struct dsa_switch *ds)
>  {
>  	struct ksz_device *dev = ds->priv;
> @@ -508,6 +590,8 @@ const struct dsa_switch_ops lan937x_switch_ops = {
>  	.port_bridge_leave = ksz_port_bridge_leave,
>  	.port_stp_state_set = lan937x_port_stp_state_set,
>  	.port_fast_age = ksz_port_fast_age,
> +	.port_mirror_add = lan937x_port_mirror_add,
> +	.port_mirror_del = lan937x_port_mirror_del,
>  	.port_max_mtu = lan937x_get_max_mtu,
>  	.port_change_mtu = lan937x_change_mtu,
>  	.phylink_get_caps = lan937x_phylink_get_caps,
> -- 
> 2.30.2
>