diff mbox series

[stable-5.9.y] net: dsa: b53: Correct learning for standalone ports

Message ID 20210225010956.946545-6-f.fainelli@gmail.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series [stable-5.9.y] net: dsa: b53: Correct learning for standalone ports | expand

Checks

Context Check Description
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Florian Fainelli Feb. 25, 2021, 1:09 a.m. UTC
Standalone ports should not have learning enabled since all the frames
are always copied to the CPU port. This is particularly important in
case an user-facing port intentionally spoofs the CPU port's MAC
address. With learning enabled we would end up with the switch having
incorrectly learned the address of the CPU port which typically results
in a complete break down of network connectivity until the address
learned ages out and gets re-learned, from the correct port this time.

There was no control of the BR_LEARNING flag until upstream commit
4098ced4680a485c5953f60ac63dff19f3fb3d42 ("Merge branch 'brport-flags'")
which is why we default to enabling learning when the ports gets added
as a bridge member.

Fixes: 967dd82ffc52 ("net: dsa: b53: Add support for Broadcom RoboSwitch")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/dsa/b53/b53_common.c | 18 ++++++++++++++++++
 drivers/net/dsa/b53/b53_regs.h   |  1 +
 drivers/net/dsa/bcm_sf2.c        | 15 +--------------
 3 files changed, 20 insertions(+), 14 deletions(-)

Comments

Greg Kroah-Hartman Feb. 25, 2021, 8:16 a.m. UTC | #1
On Wed, Feb 24, 2021 at 05:09:54PM -0800, Florian Fainelli wrote:
> Standalone ports should not have learning enabled since all the frames
> are always copied to the CPU port. This is particularly important in
> case an user-facing port intentionally spoofs the CPU port's MAC
> address. With learning enabled we would end up with the switch having
> incorrectly learned the address of the CPU port which typically results
> in a complete break down of network connectivity until the address
> learned ages out and gets re-learned, from the correct port this time.
> 
> There was no control of the BR_LEARNING flag until upstream commit
> 4098ced4680a485c5953f60ac63dff19f3fb3d42 ("Merge branch 'brport-flags'")
> which is why we default to enabling learning when the ports gets added
> as a bridge member.
> 
> Fixes: 967dd82ffc52 ("net: dsa: b53: Add support for Broadcom RoboSwitch")
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
>  drivers/net/dsa/b53/b53_common.c | 18 ++++++++++++++++++
>  drivers/net/dsa/b53/b53_regs.h   |  1 +
>  drivers/net/dsa/bcm_sf2.c        | 15 +--------------
>  3 files changed, 20 insertions(+), 14 deletions(-)

Note, 5.9.y and 5.8.y are long end-of-life.  You can see that at the
front page of www.kernel.org if you ever are curious about it.

thanks,

greg k-h
diff mbox series

Patch

diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index e731db900ee0..23dbb91946a7 100644
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -512,6 +512,19 @@  void b53_imp_vlan_setup(struct dsa_switch *ds, int cpu_port)
 }
 EXPORT_SYMBOL(b53_imp_vlan_setup);
 
+static void b53_port_set_learning(struct b53_device *dev, int port,
+				  bool learning)
+{
+	u16 reg;
+
+	b53_read16(dev, B53_CTRL_PAGE, B53_DIS_LEARNING, &reg);
+	if (learning)
+		reg &= ~BIT(port);
+	else
+		reg |= BIT(port);
+	b53_write16(dev, B53_CTRL_PAGE, B53_DIS_LEARNING, reg);
+}
+
 int b53_enable_port(struct dsa_switch *ds, int port, struct phy_device *phy)
 {
 	struct b53_device *dev = ds->priv;
@@ -525,6 +538,7 @@  int b53_enable_port(struct dsa_switch *ds, int port, struct phy_device *phy)
 	cpu_port = dsa_to_port(ds, port)->cpu_dp->index;
 
 	b53_br_egress_floods(ds, port, true, true);
+	b53_port_set_learning(dev, port, false);
 
 	if (dev->ops->irq_enable)
 		ret = dev->ops->irq_enable(dev, port);
@@ -658,6 +672,7 @@  static void b53_enable_cpu_port(struct b53_device *dev, int port)
 	b53_brcm_hdr_setup(dev->ds, port);
 
 	b53_br_egress_floods(dev->ds, port, true, true);
+	b53_port_set_learning(dev, port, false);
 }
 
 static void b53_enable_mib(struct b53_device *dev)
@@ -1796,6 +1811,8 @@  int b53_br_join(struct dsa_switch *ds, int port, struct net_device *br)
 	b53_write16(dev, B53_PVLAN_PAGE, B53_PVLAN_PORT_MASK(port), pvlan);
 	dev->ports[port].vlan_ctl_mask = pvlan;
 
+	b53_port_set_learning(dev, port, true);
+
 	return 0;
 }
 EXPORT_SYMBOL(b53_br_join);
@@ -1843,6 +1860,7 @@  void b53_br_leave(struct dsa_switch *ds, int port, struct net_device *br)
 		vl->untag |= BIT(port) | BIT(cpu_port);
 		b53_set_vlan_entry(dev, pvid, vl);
 	}
+	b53_port_set_learning(dev, port, false);
 }
 EXPORT_SYMBOL(b53_br_leave);
 
diff --git a/drivers/net/dsa/b53/b53_regs.h b/drivers/net/dsa/b53/b53_regs.h
index c90985c294a2..b2c539a42154 100644
--- a/drivers/net/dsa/b53/b53_regs.h
+++ b/drivers/net/dsa/b53/b53_regs.h
@@ -115,6 +115,7 @@ 
 #define B53_UC_FLOOD_MASK		0x32
 #define B53_MC_FLOOD_MASK		0x34
 #define B53_IPMC_FLOOD_MASK		0x36
+#define B53_DIS_LEARNING		0x3c
 
 /*
  * Override Ports 0-7 State on devices with xMII interfaces (8 bit)
diff --git a/drivers/net/dsa/bcm_sf2.c b/drivers/net/dsa/bcm_sf2.c
index 5ebff986a1ac..99402f769584 100644
--- a/drivers/net/dsa/bcm_sf2.c
+++ b/drivers/net/dsa/bcm_sf2.c
@@ -172,23 +172,10 @@  static int bcm_sf2_port_setup(struct dsa_switch *ds, int port,
 	reg &= ~P_TXQ_PSM_VDD(port);
 	core_writel(priv, reg, CORE_MEM_PSM_VDD_CTRL);
 
-	/* Enable learning */
-	reg = core_readl(priv, CORE_DIS_LEARN);
-	reg &= ~BIT(port);
-	core_writel(priv, reg, CORE_DIS_LEARN);
-
 	/* Enable Broadcom tags for that port if requested */
-	if (priv->brcm_tag_mask & BIT(port)) {
+	if (priv->brcm_tag_mask & BIT(port))
 		b53_brcm_hdr_setup(ds, port);
 
-		/* Disable learning on ASP port */
-		if (port == 7) {
-			reg = core_readl(priv, CORE_DIS_LEARN);
-			reg |= BIT(port);
-			core_writel(priv, reg, CORE_DIS_LEARN);
-		}
-	}
-
 	/* Configure Traffic Class to QoS mapping, allow each priority to map
 	 * to a different queue number
 	 */