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

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));

+	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 */
+	for (i = 0; i < RTL8366RB_PORT_NUM_CPU; i++) {
+		/* Handled last */
+		if (i == port)
+			continue;
+		/* Not on this bridge */
+		if (dsa_to_port(ds, i)->bridge_dev != bridge)
+			continue;
+		/* Join this port to each other port on the bridge */
+		ret = regmap_update_bits(smi->map, RTL8366RB_PORT_ISO(i),
+					 RTL8366RB_PORT_ISO_PORTS(BIT(port)),
+					 RTL8366RB_PORT_ISO_PORTS(BIT(port)));
+		if (ret)
+			return ret;
+
+		port_bitmap |= BIT(i);
+	}
+
+	/* Set the bits for the ports we can access */
+	return regmap_update_bits(smi->map, RTL8366RB_PORT_ISO(port),
+				  RTL8366RB_PORT_ISO_PORTS_MASK,
+				  RTL8366RB_PORT_ISO_PORTS(port_bitmap));
+}
+
+static void
+rtl8366rb_port_bridge_leave(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 */
+	for (i = 0; i < RTL8366RB_PORT_NUM_CPU; i++) {
+		/* Handled last */
+		if (i == port)
+			continue;
+		/* Not on this bridge */
+		if (dsa_to_port(ds, i)->bridge_dev != bridge)
+			continue;
+		/* Remove this port from any other port on the bridge */
+		ret = regmap_update_bits(smi->map, RTL8366RB_PORT_ISO(i),
+					 RTL8366RB_PORT_ISO_PORTS(BIT(port)), 0);
+		if (ret)
+			return;
+
+		port_bitmap |= BIT(i);
+	}
+
+	/* Clear the bits for the ports we can access */
+	regmap_update_bits(smi->map, RTL8366RB_PORT_ISO(port),
+			   RTL8366RB_PORT_ISO_PORTS(port_bitmap), 0);
+}
+
  static int rtl8366rb_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
  {
  	struct realtek_smi *smi = ds->priv;

@@ -1510,6 +1595,8 @@ static const struct dsa_switch_ops rtl8366rb_switch_ops = {
  	.get_strings = rtl8366_get_strings,
  	.get_ethtool_stats = rtl8366_get_ethtool_stats,
  	.get_sset_count = rtl8366_get_sset_count,
+	.port_bridge_join = rtl8366rb_port_bridge_join,
+	.port_bridge_leave = rtl8366rb_port_bridge_leave,
  	.port_vlan_filtering = rtl8366_vlan_filtering,
  	.port_vlan_add = rtl8366_vlan_add,
  	.port_vlan_del = rtl8366_vlan_del,