[PATCH net-next v1 1/1] net: dsa: microchip: Add support for bridge port isolation

[Oleksij Rempel]

Implement bridge port isolation for KSZ switches. Enabling the isolation
of switch ports from each other while maintaining connectivity with the
CPU and other forwarding ports. For instance, to isolate swp1 and swp2
from each other, use the following commands:
- bridge link set dev swp1 isolated on
- bridge link set dev swp2 isolated on

Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
---
 drivers/net/dsa/microchip/ksz_common.c | 16 +++++++++++-----
 drivers/net/dsa/microchip/ksz_common.h |  1 +
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 7cd37133ec05..10e4a14671e2 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -1926,7 +1926,8 @@ static void ksz_update_port_member(struct ksz_device *dev, int port)
 		if (other_p->stp_state != BR_STATE_FORWARDING)
 			continue;
 
-		if (p->stp_state == BR_STATE_FORWARDING) {
+		if (p->stp_state == BR_STATE_FORWARDING &&
+		    !(p->isolated && other_p->isolated)) {
 			val |= BIT(port);
 			port_member |= BIT(i);
 		}
@@ -1946,7 +1947,8 @@ static void ksz_update_port_member(struct ksz_device *dev, int port)
 			if (third_p->stp_state != BR_STATE_FORWARDING)
 				continue;
 			third_dp = dsa_to_port(ds, j);
-			if (dsa_port_bridge_same(other_dp, third_dp))
+			if (dsa_port_bridge_same(other_dp, third_dp) &&
+			    !(other_p->isolated && third_p->isolated))
 				val |= BIT(j);
 		}
 
@@ -2699,7 +2701,7 @@ static int ksz_port_pre_bridge_flags(struct dsa_switch *ds, int port,
 				     struct switchdev_brport_flags flags,
 				     struct netlink_ext_ack *extack)
 {
-	if (flags.mask & ~BR_LEARNING)
+	if (flags.mask & ~(BR_LEARNING | BR_ISOLATED))
 		return -EINVAL;
 
 	return 0;
@@ -2712,8 +2714,12 @@ static int ksz_port_bridge_flags(struct dsa_switch *ds, int port,
 	struct ksz_device *dev = ds->priv;
 	struct ksz_port *p = &dev->ports[port];
 
-	if (flags.mask & BR_LEARNING) {
-		p->learning = !!(flags.val & BR_LEARNING);
+	if (flags.mask & (BR_LEARNING | BR_ISOLATED)) {
+		if (flags.mask & BR_LEARNING)
+			p->learning = !!(flags.val & BR_LEARNING);
+
+		if (flags.mask & BR_ISOLATED)
+			p->isolated = !!(flags.val & BR_ISOLATED);
 
 		/* Make the change take effect immediately */
 		ksz_port_stp_state_set(ds, port, p->stp_state);
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index a3f69a036fa9..fb76637596fc 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -111,6 +111,7 @@ struct ksz_switch_macaddr {
 struct ksz_port {
 	bool remove_tag;		/* Remove Tag flag set, for ksz8795 only */
 	bool learning;
+	bool isolated;
 	int stp_state;
 	struct phy_device phydev;
 
-- 
2.39.2