Re: [PATCH net-next 1/5 v2] net: dsa: rtl8366rb: support bridge offloading

[Florian Fainelli <f.fainelli@gmail.com>]

On 8/30/2021 2:48 PM, Linus Walleij wrote:
> From: DENG Qingfang <dqfext@gmail.com>
> 
> Use port isolation registers to configure bridge offloading.
> 
> Tested on the D-Link DIR-685, switching between ports and
> sniffing ports to make sure no packets leak.
> 
> Cc: Vladimir Oltean <olteanv@gmail.com>
> Cc: Alvin Šipraga <alsi@bang-olufsen.dk>
> Cc: Mauri Sandberg <sandberg@mailfence.com>
> Signed-off-by: DENG Qingfang <dqfext@gmail.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> ChangeLog v1->v2:
> - introduce RTL8366RB_PORT_ISO_PORTS() to shift the port
>    mask into place so we are not confused by the enable
>    bit.
> - Use this with dsa_user_ports() to isolate the CPU port
>    from itself.
> ---
>   drivers/net/dsa/rtl8366rb.c | 87 +++++++++++++++++++++++++++++++++++++
>   1 file changed, 87 insertions(+)
> 
> diff --git a/drivers/net/dsa/rtl8366rb.c b/drivers/net/dsa/rtl8366rb.c
> index a89093bc6c6a..50ee7cd62484 100644
> --- a/drivers/net/dsa/rtl8366rb.c
> +++ b/drivers/net/dsa/rtl8366rb.c
> @@ -300,6 +300,13 @@
>   #define RTL8366RB_INTERRUPT_STATUS_REG	0x0442
>   #define RTL8366RB_NUM_INTERRUPT		14 /* 0..13 */
>   
> +/* Port isolation registers */
> +#define RTL8366RB_PORT_ISO_BASE		0x0F08
> +#define RTL8366RB_PORT_ISO(pnum)	(RTL8366RB_PORT_ISO_BASE + (pnum))
> +#define RTL8366RB_PORT_ISO_EN		BIT(0)
> +#define RTL8366RB_PORT_ISO_PORTS_MASK	GENMASK(7, 1)
> +#define RTL8366RB_PORT_ISO_PORTS(pmask)	(pmask << 1)
> +
>   /* bits 0..5 enable force when cleared */
>   #define RTL8366RB_MAC_FORCE_CTRL_REG	0x0F11
>   
> @@ -835,6 +842,22 @@ static int rtl8366rb_setup(struct dsa_switch *ds)
>   	if (ret)
>   		return ret;
>   
> +	/* Isolate all user ports so only the CPU port can access them */
> +	for (i = 0; i < RTL8366RB_PORT_NUM_CPU; i++) {
> +		ret = regmap_write(smi->map, RTL8366RB_PORT_ISO(i),
> +				   RTL8366RB_PORT_ISO_EN |
> +				   RTL8366RB_PORT_ISO_PORTS(BIT(RTL8366RB_PORT_NUM_CPU)));
> +		if (ret)
> +			return ret;
> +	}
> +	/* CPU port can access all ports */
> +	dev_info(smi->dev, "DSA user port mask: %08x\n", dsa_user_ports(ds));

As mentioned by Alvin, this should be a dev_dbg() or completely eliminated.

> +	ret = regmap_write(smi->map, RTL8366RB_PORT_ISO(RTL8366RB_PORT_NUM_CPU),
> +			   RTL8366RB_PORT_ISO_PORTS(dsa_user_ports(ds))|
> +			   RTL8366RB_PORT_ISO_EN);
> +	if (ret)
> +		return ret;
> +
>   	/* Set up the "green ethernet" feature */
>   	ret = rtl8366rb_jam_table(rtl8366rb_green_jam,
>   				  ARRAY_SIZE(rtl8366rb_green_jam), smi, false);
> @@ -1127,6 +1150,68 @@ rtl8366rb_port_disable(struct dsa_switch *ds, int port)
>   	rb8366rb_set_port_led(smi, port, false);
>   }
>   
> +static int
> +rtl8366rb_port_bridge_join(struct dsa_switch *ds, int port,
> +			   struct net_device *bridge)
> +{
> +	struct realtek_smi *smi = ds->priv;
> +	unsigned int port_bitmap = 0;
> +	int ret, i;
> +
> +	/* Loop over all other ports than this one */

This sentence is a bit weird, how about: Loop over all ports but this one?

> +	for (i = 0; i < RTL8366RB_PORT_NUM_CPU; i++) {
> +		/* Handled last */

This comment is a bit misleading as it would suggest that the loop does 
act on 'port' when really it does that outside of the loop.

With those nitpicks fixed:

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian