net: dsa: mt7530: add support for port mirroring

Add support for configuring port mirroring through the cls_matchall
classifier. We do a full ingress and/or egress capture towards a
capture port.
MT7530 supports one monitor port and multiple mirrored ports.
Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mt7530.c

@@ -1222,6 +1222,64 @@ mt7530_port_vlan_del(struct dsa_switch *ds, int port,
 	return 0;
 }
 
+static int mt7530_port_mirror_add(struct dsa_switch *ds, int port,
+				  struct dsa_mall_mirror_tc_entry *mirror,
+				  bool ingress)
+{
+	struct mt7530_priv *priv = ds->priv;
+	u32 val;
+
+	/* Check for existent entry */
+	if ((ingress ? priv->mirror_rx : priv->mirror_tx) & BIT(port))
+		return -EEXIST;
+
+	val = mt7530_read(priv, MT7530_MFC);
+
+	/* MT7530 only supports one monitor port */
+	if (val & MIRROR_EN && MIRROR_PORT(val) != mirror->to_local_port)
+		return -EEXIST;
+
+	val |= MIRROR_EN;
+	val &= ~MIRROR_MASK;
+	val |= mirror->to_local_port;
+	mt7530_write(priv, MT7530_MFC, val);
+
+	val = mt7530_read(priv, MT7530_PCR_P(port));
+	if (ingress) {
+		val |= PORT_RX_MIR;
+		priv->mirror_rx |= BIT(port);
+	} else {
+		val |= PORT_TX_MIR;
+		priv->mirror_tx |= BIT(port);
+	}
+	mt7530_write(priv, MT7530_PCR_P(port), val);
+
+	return 0;
+}
+
+static void mt7530_port_mirror_del(struct dsa_switch *ds, int port,
+				   struct dsa_mall_mirror_tc_entry *mirror)
+{
+	struct mt7530_priv *priv = ds->priv;
+	u32 val;
+
+	val = mt7530_read(priv, MT7530_PCR_P(port));
+	if (mirror->ingress) {
+		val &= ~PORT_RX_MIR;
+		priv->mirror_rx &= ~BIT(port);
+	} else {
+		val &= ~PORT_TX_MIR;
+		priv->mirror_tx &= ~BIT(port);
+	}
+	mt7530_write(priv, MT7530_PCR_P(port), val);
+
+	if (!priv->mirror_rx && !priv->mirror_tx) {
+		val = mt7530_read(priv, MT7530_MFC);
+		val &= ~MIRROR_EN;
+		mt7530_write(priv, MT7530_MFC, val);
+	}
+}
+
 static enum dsa_tag_protocol
 mtk_get_tag_protocol(struct dsa_switch *ds, int port,
 		     enum dsa_tag_protocol mp)
@@ -1613,6 +1671,8 @@ static const struct dsa_switch_ops mt7530_switch_ops = {
 	.port_vlan_prepare	= mt7530_port_vlan_prepare,
 	.port_vlan_add		= mt7530_port_vlan_add,
 	.port_vlan_del		= mt7530_port_vlan_del,
+	.port_mirror_add	= mt7530_port_mirror_add,
+	.port_mirror_del	= mt7530_port_mirror_del,
 	.phylink_validate	= mt7530_phylink_validate,
 	.phylink_mac_link_state = mt7530_phylink_mac_link_state,
 	.phylink_mac_config	= mt7530_phylink_mac_config,

drivers/net/dsa/mt7530.h

@@ -36,6 +36,9 @@ enum {
 #define  CPU_EN				BIT(7)
 #define  CPU_PORT(x)			((x) << 4)
 #define  CPU_MASK			(0xf << 4)
+#define  MIRROR_EN			BIT(3)
+#define  MIRROR_PORT(x)			((x & 0x7))
+#define  MIRROR_MASK			0x7
 
 /* Registers for address table access */
 #define MT7530_ATA1			0x74
@@ -141,6 +144,8 @@ enum mt7530_stp_state {
 
 /* Register for port control */
 #define MT7530_PCR_P(x)			(0x2004 + ((x) * 0x100))
+#define  PORT_TX_MIR			BIT(9)
+#define  PORT_RX_MIR			BIT(8)
 #define  PORT_VLAN(x)			((x) & 0x3)
 
 enum mt7530_port_mode {
@@ -460,6 +465,8 @@ struct mt7530_priv {
 	phy_interface_t		p6_interface;
 	phy_interface_t		p5_interface;
 	unsigned int		p5_intf_sel;
+	u8			mirror_rx;
+	u8			mirror_tx;
 
 	struct mt7530_port	ports[MT7530_NUM_PORTS];
 	/* protect among processes for registers access*/