Re: [net-next PATCH 11/19] net: dsa: qca8k: add support for mirror mode

[Vladimir Oltean <olteanv@gmail.com>]

On Wed, Nov 17, 2021 at 10:04:43PM +0100, Ansuel Smith wrote:
> The switch support mirror mode. Only one port can set as mirror port and
> every other port can set to both ingress and egress mode. The mirror
> port is disabled and reverted to normal operation once every port is
> removed from sending packet to the mirror mode.

> Also modify the fdb logit to send packet to both destination and mirror
> port by default to support mirror mode.

I don't see any FDB logic being modified by this patch. Also, port-based
mirroring should not require it.

> 
> Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
> ---
>  drivers/net/dsa/qca8k.c | 95 +++++++++++++++++++++++++++++++++++++++++
>  drivers/net/dsa/qca8k.h |  5 +++
>  2 files changed, 100 insertions(+)
> 
> diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
> index d73886b36e6a..a74099131e3d 100644
> --- a/drivers/net/dsa/qca8k.c
> +++ b/drivers/net/dsa/qca8k.c
> @@ -1938,6 +1938,99 @@ qca8k_port_fdb_dump(struct dsa_switch *ds, int port,
>  	return 0;
>  }
>  
> +static int
> +qca8k_port_mirror_add(struct dsa_switch *ds, int port,
> +		      struct dsa_mall_mirror_tc_entry *mirror,
> +		      bool ingress)
> +{
> +	struct qca8k_priv *priv = ds->priv;
> +	int monitor_port, ret;
> +	u32 reg, val;
> +
> +	/* Check for existent entry */
> +	if ((ingress ? priv->mirror_rx : priv->mirror_tx) & BIT(port))
> +		return -EEXIST;
> +
> +	ret = regmap_read(priv->regmap, QCA8K_REG_GLOBAL_FW_CTRL0, &val);
> +	if (ret)
> +		return ret;
> +
> +	/* QCA83xx can have only one port set to mirror mode.
> +	 * Check that the correct port is requested and return error otherwise.
> +	 * When no mirror port is set, the values is set to 0xF
> +	 */
> +	monitor_port = FIELD_GET(QCA8K_GLOBAL_FW_CTRL0_MIRROR_PORT_NUM, val);
> +	if (monitor_port != 0xF && monitor_port != mirror->to_local_port)
> +		return -EEXIST;
> +
> +	/* Set the monitor port */
> +	val = FIELD_PREP(QCA8K_GLOBAL_FW_CTRL0_MIRROR_PORT_NUM,
> +			 mirror->to_local_port);
> +	ret = regmap_update_bits(priv->regmap, QCA8K_REG_GLOBAL_FW_CTRL0,
> +				 QCA8K_GLOBAL_FW_CTRL0_MIRROR_PORT_NUM, val);
> +	if (ret)
> +		return ret;
> +
> +	if (ingress) {
> +		reg = QCA8K_PORT_LOOKUP_CTRL(port);
> +		val = QCA8K_PORT_LOOKUP_ING_MIRROR_EN;
> +	} else {
> +		reg = QCA8K_REG_PORT_HOL_CTRL1(port);
> +		val = QCA8K_PORT_HOL_CTRL1_EG_MIRROR_EN;
> +	}
> +
> +	ret = regmap_update_bits(priv->regmap, reg, val, val);
> +	if (ret)
> +		return ret;
> +
> +	/* Track mirror port for tx and rx to decide when the
> +	 * mirror port has to be disabled.
> +	 */
> +	if (ingress)
> +		priv->mirror_rx |= BIT(port);
> +	else
> +		priv->mirror_tx |= BIT(port);
> +
> +	return 0;
> +}
> +
> +static void
> +qca8k_port_mirror_del(struct dsa_switch *ds, int port,
> +		      struct dsa_mall_mirror_tc_entry *mirror)
> +{
> +	struct qca8k_priv *priv = ds->priv;
> +	u32 reg, val;
> +	int ret;
> +
> +	if (mirror->ingress) {
> +		reg = QCA8K_PORT_LOOKUP_CTRL(port);
> +		val = QCA8K_PORT_LOOKUP_ING_MIRROR_EN;
> +	} else {
> +		reg = QCA8K_REG_PORT_HOL_CTRL1(port);
> +		val = QCA8K_PORT_HOL_CTRL1_EG_MIRROR_EN;
> +	}
> +
> +	ret = regmap_clear_bits(priv->regmap, reg, val);
> +	if (ret)
> +		goto err;
> +
> +	if (mirror->ingress)
> +		priv->mirror_rx &= ~BIT(port);
> +	else
> +		priv->mirror_tx &= ~BIT(port);
> +
> +	/* No port set to send packet to mirror port. Disable mirror port */
> +	if (!priv->mirror_rx && !priv->mirror_tx) {
> +		val = FIELD_PREP(QCA8K_GLOBAL_FW_CTRL0_MIRROR_PORT_NUM, 0xF);
> +		ret = regmap_update_bits(priv->regmap, QCA8K_REG_GLOBAL_FW_CTRL0,
> +					 QCA8K_GLOBAL_FW_CTRL0_MIRROR_PORT_NUM, val);
> +		if (ret)
> +			goto err;
> +	}
> +err:
> +	dev_err(priv->dev, "Failed to del mirror port from %d", port);
> +}
> +
>  static int
>  qca8k_port_vlan_filtering(struct dsa_switch *ds, int port, bool vlan_filtering,
>  			  struct netlink_ext_ack *extack)
> @@ -2045,6 +2138,8 @@ static const struct dsa_switch_ops qca8k_switch_ops = {
>  	.port_fdb_add		= qca8k_port_fdb_add,
>  	.port_fdb_del		= qca8k_port_fdb_del,
>  	.port_fdb_dump		= qca8k_port_fdb_dump,
> +	.port_mirror_add	= qca8k_port_mirror_add,
> +	.port_mirror_del	= qca8k_port_mirror_del,
>  	.port_vlan_filtering	= qca8k_port_vlan_filtering,
>  	.port_vlan_add		= qca8k_port_vlan_add,
>  	.port_vlan_del		= qca8k_port_vlan_del,
> diff --git a/drivers/net/dsa/qca8k.h b/drivers/net/dsa/qca8k.h
> index c5d83514ad2e..d25afdab4dea 100644
> --- a/drivers/net/dsa/qca8k.h
> +++ b/drivers/net/dsa/qca8k.h
> @@ -177,6 +177,7 @@
>  #define   QCA8K_VTU_FUNC1_FULL				BIT(4)
>  #define QCA8K_REG_GLOBAL_FW_CTRL0			0x620
>  #define   QCA8K_GLOBAL_FW_CTRL0_CPU_PORT_EN		BIT(10)
> +#define   QCA8K_GLOBAL_FW_CTRL0_MIRROR_PORT_NUM		GENMASK(7, 4)
>  #define QCA8K_REG_GLOBAL_FW_CTRL1			0x624
>  #define   QCA8K_GLOBAL_FW_CTRL1_IGMP_DP_MASK		GENMASK(30, 24)
>  #define   QCA8K_GLOBAL_FW_CTRL1_BC_DP_MASK		GENMASK(22, 16)
> @@ -198,6 +199,7 @@
>  #define   QCA8K_PORT_LOOKUP_STATE_LEARNING		QCA8K_PORT_LOOKUP_STATE(0x3)
>  #define   QCA8K_PORT_LOOKUP_STATE_FORWARD		QCA8K_PORT_LOOKUP_STATE(0x4)
>  #define   QCA8K_PORT_LOOKUP_LEARN			BIT(20)
> +#define   QCA8K_PORT_LOOKUP_ING_MIRROR_EN		BIT(25)
>  
>  #define QCA8K_REG_GLOBAL_FC_THRESH			0x800
>  #define   QCA8K_GLOBAL_FC_GOL_XON_THRES_MASK		GENMASK(24, 16)
> @@ -262,6 +264,7 @@ enum qca8k_fdb_cmd {
>  	QCA8K_FDB_FLUSH	= 1,
>  	QCA8K_FDB_LOAD = 2,
>  	QCA8K_FDB_PURGE = 3,
> +	QCA8K_FDB_FLUSH_PORT = 5,

This portion seems like the missing piece required for the previous
patch to actually compile.

>  	QCA8K_FDB_NEXT = 6,
>  	QCA8K_FDB_SEARCH = 7,
>  };
> @@ -302,6 +305,8 @@ struct qca8k_ports_config {
>  struct qca8k_priv {
>  	u8 switch_id;
>  	u8 switch_revision;
> +	u8 mirror_rx;
> +	u8 mirror_tx;
>  	bool legacy_phy_port_mapping;
>  	struct qca8k_ports_config ports_config;
>  	struct regmap *regmap;
> -- 
> 2.32.0
>