net: dsa: microchip: implement multi-bridge support

Current driver version is able to handle only one bridge at time.
Configuring two bridges on two different ports would end up shorting this
bridges by HW. To reproduce it:

	ip l a name br0 type bridge
	ip l a name br1 type bridge
	ip l s dev br0 up
	ip l s dev br1 up
	ip l s lan1 master br0
	ip l s dev lan1 up
	ip l s lan2 master br1
	ip l s dev lan2 up

	Ping on lan1 and get response on lan2, which should not happen.

This happened, because current driver version is storing one global "Port VLAN
Membership" and applying it to all ports which are members of any
bridge.
To solve this issue, we need to handle each port separately.

This patch is dropping the global port member storage and calculating
membership dynamically depending on STP state and bridge participation.

Note: STP support was broken before this patch and should be fixed
separately.

Fixes: c2e866911e25 ("net: dsa: microchip: break KSZ9477 DSA driver into two files")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20211126123926.2981028-1-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 7 insertions, 49 deletions

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index 43fc3087aeb3..013e9c02be71 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -1002,57 +1002,32 @@ static void ksz8_cfg_port_member(struct ksz_device *dev, int port, u8 member)
 	data &= ~PORT_VLAN_MEMBERSHIP;
 	data |= (member & dev->port_mask);
 	ksz_pwrite8(dev, port, P_MIRROR_CTRL, data);
-	dev->ports[port].member = member;
 }
 
 static void ksz8_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
 {
 	struct ksz_device *dev = ds->priv;
-	int forward = dev->member;
 	struct ksz_port *p;
-	int member = -1;
 	u8 data;
 
-	p = &dev->ports[port];
-
 	ksz_pread8(dev, port, P_STP_CTRL, &data);
 	data &= ~(PORT_TX_ENABLE | PORT_RX_ENABLE | PORT_LEARN_DISABLE);
 
 	switch (state) {
 	case BR_STATE_DISABLED:
 		data |= PORT_LEARN_DISABLE;
-		if (port < dev->phy_port_cnt)
-			member = 0;
 		break;
 	case BR_STATE_LISTENING:
 		data |= (PORT_RX_ENABLE | PORT_LEARN_DISABLE);
-		if (port < dev->phy_port_cnt &&
-		    p->stp_state == BR_STATE_DISABLED)
-			member = dev->host_mask | p->vid_member;
 		break;
 	case BR_STATE_LEARNING:
 		data |= PORT_RX_ENABLE;
 		break;
 	case BR_STATE_FORWARDING:
 		data |= (PORT_TX_ENABLE | PORT_RX_ENABLE);
-
-		/* This function is also used internally. */
-		if (port == dev->cpu_port)
-			break;
-
-		/* Port is a member of a bridge. */
-		if (dev->br_member & BIT(port)) {
-			dev->member |= BIT(port);
-			member = dev->member;
-		} else {
-			member = dev->host_mask | p->vid_member;
-		}
 		break;
 	case BR_STATE_BLOCKING:
 		data |= PORT_LEARN_DISABLE;
-		if (port < dev->phy_port_cnt &&
-		    p->stp_state == BR_STATE_DISABLED)
-			member = dev->host_mask | p->vid_member;
 		break;
 	default:
 		dev_err(ds->dev, "invalid STP state: %d\n", state);
@@ -1060,22 +1035,11 @@ static void ksz8_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
 	}
 
 	ksz_pwrite8(dev, port, P_STP_CTRL, data);
+
+	p = &dev->ports[port];
 	p->stp_state = state;
-	/* Port membership may share register with STP state. */
-	if (member >= 0 && member != p->member)
-		ksz8_cfg_port_member(dev, port, (u8)member);
-
-	/* Check if forwarding needs to be updated. */
-	if (state != BR_STATE_FORWARDING) {
-		if (dev->br_member & BIT(port))
-			dev->member &= ~BIT(port);
-	}
 
-	/* When topology has changed the function ksz_update_port_member
-	 * should be called to modify port forwarding behavior.
-	 */
-	if (forward != dev->member)
-		ksz_update_port_member(dev, port);
+	ksz_update_port_member(dev, port);
 }
 
 static void ksz8_flush_dyn_mac_table(struct ksz_device *dev, int port)
@@ -1341,7 +1305,7 @@ static void ksz8795_cpu_interface_select(struct ksz_device *dev, int port)
 
 static void ksz8_port_setup(struct ksz_device *dev, int port, bool cpu_port)
 {
-	struct ksz_port *p = &dev->ports[port];
+	struct dsa_switch *ds = dev->ds;
 	struct ksz8 *ksz8 = dev->priv;
 	const u32 *masks;
 	u8 member;
@@ -1368,10 +1332,11 @@ static void ksz8_port_setup(struct ksz_device *dev, int port, bool cpu_port)
 		if (!ksz_is_ksz88x3(dev))
 			ksz8795_cpu_interface_select(dev, port);
 
-		member = dev->port_mask;
+		member = dsa_user_ports(ds);
 	} else {
-		member = dev->host_mask | p->vid_member;
+		member = BIT(dsa_upstream_port(ds, port));
 	}
+
 	ksz8_cfg_port_member(dev, port, member);
 }
 
@@ -1392,20 +1357,13 @@ static void ksz8_config_cpu_port(struct dsa_switch *ds)
 	ksz_cfg(dev, regs[S_TAIL_TAG_CTRL], masks[SW_TAIL_TAG_ENABLE], true);
 
 	p = &dev->ports[dev->cpu_port];
-	p->vid_member = dev->port_mask;
 	p->on = 1;
 
 	ksz8_port_setup(dev, dev->cpu_port, true);
-	dev->member = dev->host_mask;
 
 	for (i = 0; i < dev->phy_port_cnt; i++) {
 		p = &dev->ports[i];
 
-		/* Initialize to non-zero so that ksz_cfg_port_member() will
-		 * be called.
-		 */
-		p->vid_member = BIT(i);
-		p->member = dev->port_mask;
 		ksz8_port_stp_state_set(ds, i, BR_STATE_DISABLED);
 
 		/* Last port may be disabled. */