generic: fix DSA VLAN filtering

Currently enabling VLAN filtering blocks all traffic in the bridge
immediately. That is because DSA ignores all VLAN setup when VLAN
filtering is disabled, and when it is enabled, there is no VLAN entry
in the VLAN table, causing all traffic to be blocked.

Add patches to allow VLAN setup even if VLAN filtering is disabled.

Signed-off-by: DENG Qingfang <dengqf6@mail2.sysu.edu.cn>

3 files changed, 199 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.4/752-v5.8-net-dsa-provide-an-option-for-drivers-to-always-rece.patch b/target/linux/generic/backport-5.4/752-v5.8-net-dsa-provide-an-option-for-drivers-to-always-rece.patch
new file mode 100644
index 0000000000..97ac6e2acd
--- /dev/null
+++ b/target/linux/generic/backport-5.4/752-v5.8-net-dsa-provide-an-option-for-drivers-to-always-rece.patch
@@ -0,0 +1,121 @@
+From 54a0ed0df49609f4e3f098f8943e38e389dc2e15 Mon Sep 17 00:00:00 2001
+From: Russell King <rmk+kernel@armlinux.org.uk>
+Date: Tue, 12 May 2020 20:20:25 +0300
+Subject: net: dsa: provide an option for drivers to always receive bridge
+ VLANs
+
+DSA assumes that a bridge which has vlan filtering disabled is not
+vlan aware, and ignores all vlan configuration. However, the kernel
+software bridge code allows configuration in this state.
+
+This causes the kernel's idea of the bridge vlan state and the
+hardware state to disagree, so "bridge vlan show" indicates a correct
+configuration but the hardware lacks all configuration. Even worse,
+enabling vlan filtering on a DSA bridge immediately blocks all traffic
+which, given the output of "bridge vlan show", is very confusing.
+
+Provide an option that drivers can set to indicate they want to receive
+vlan configuration even when vlan filtering is disabled. At the very
+least, this is safe for Marvell DSA bridges, which do not look up
+ingress traffic in the VTU if the port is in 8021Q disabled state. It is
+also safe for the Ocelot switch family. Whether this change is suitable
+for all DSA bridges is not known.
+
+Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
+Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
+Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ include/net/dsa.h  |  7 +++++++
+ net/dsa/dsa_priv.h |  1 +
+ net/dsa/port.c     | 14 ++++++++++++++
+ net/dsa/slave.c    |  8 ++++----
+ 4 files changed, 26 insertions(+), 4 deletions(-)
+
+--- a/include/net/dsa.h
++++ b/include/net/dsa.h
+@@ -270,6 +270,13 @@ struct dsa_switch {
+ 	 */
+ 	bool			vlan_filtering_is_global;
+ 
++	/* Pass .port_vlan_add and .port_vlan_del to drivers even for bridges
++	 * that have vlan_filtering=0. All drivers should ideally set this (and
++	 * then the option would get removed), but it is unknown whether this
++	 * would break things or not.
++	 */
++	bool			configure_vlan_while_not_filtering;
++
+ 	/* In case vlan_filtering_is_global is set, the VLAN awareness state
+ 	 * should be retrieved from here and not from the per-port settings.
+ 	 */
+--- a/net/dsa/dsa_priv.h
++++ b/net/dsa/dsa_priv.h
+@@ -136,6 +136,7 @@ int dsa_port_bridge_join(struct dsa_port
+ void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br);
+ int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
+ 			    struct switchdev_trans *trans);
++bool dsa_port_skip_vlan_configuration(struct dsa_port *dp);
+ int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock,
+ 			 struct switchdev_trans *trans);
+ int dsa_port_fdb_add(struct dsa_port *dp, const unsigned char *addr,
+--- a/net/dsa/port.c
++++ b/net/dsa/port.c
+@@ -238,6 +238,20 @@ int dsa_port_vlan_filtering(struct dsa_p
+ 	return 0;
+ }
+ 
++/* This enforces legacy behavior for switch drivers which assume they can't
++ * receive VLAN configuration when enslaved to a bridge with vlan_filtering=0
++ */
++bool dsa_port_skip_vlan_configuration(struct dsa_port *dp)
++{
++	struct dsa_switch *ds = dp->ds;
++
++	if (!dp->bridge_dev)
++		return false;
++
++	return (!ds->configure_vlan_while_not_filtering &&
++		!br_vlan_enabled(dp->bridge_dev));
++}
++
+ int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock,
+ 			 struct switchdev_trans *trans)
+ {
+--- a/net/dsa/slave.c
++++ b/net/dsa/slave.c
+@@ -319,7 +319,7 @@ static int dsa_slave_vlan_add(struct net
+ 	if (obj->orig_dev != dev)
+ 		return -EOPNOTSUPP;
+ 
+-	if (dp->bridge_dev && !br_vlan_enabled(dp->bridge_dev))
++	if (dsa_port_skip_vlan_configuration(dp))
+ 		return 0;
+ 
+ 	vlan = *SWITCHDEV_OBJ_PORT_VLAN(obj);
+@@ -386,7 +386,7 @@ static int dsa_slave_vlan_del(struct net
+ 	if (obj->orig_dev != dev)
+ 		return -EOPNOTSUPP;
+ 
+-	if (dp->bridge_dev && !br_vlan_enabled(dp->bridge_dev))
++	if (dsa_port_skip_vlan_configuration(dp))
+ 		return 0;
+ 
+ 	/* Do not deprogram the CPU port as it may be shared with other user
+@@ -1118,7 +1118,7 @@ static int dsa_slave_vlan_rx_add_vid(str
+ 	 * need to emulate the switchdev prepare + commit phase.
+ 	 */
+ 	if (dp->bridge_dev) {
+-		if (!br_vlan_enabled(dp->bridge_dev))
++		if (dsa_port_skip_vlan_configuration(dp))
+ 			return 0;
+ 
+ 		/* br_vlan_get_info() returns -EINVAL or -ENOENT if the
+@@ -1152,7 +1152,7 @@ static int dsa_slave_vlan_rx_kill_vid(st
+ 	 * need to emulate the switchdev prepare + commit phase.
+ 	 */
+ 	if (dp->bridge_dev) {
+-		if (!br_vlan_enabled(dp->bridge_dev))
++		if (dsa_port_skip_vlan_configuration(dp))
+ 			return 0;
+ 
+ 		/* br_vlan_get_info() returns -EINVAL or -ENOENT if the
diff --git a/target/linux/generic/backport-5.4/753-v5.8-net-dsa-mt7530-fix-VLAN-setup.patch b/target/linux/generic/backport-5.4/753-v5.8-net-dsa-mt7530-fix-VLAN-setup.patch
new file mode 100644
index 0000000000..8d64d2e672
--- /dev/null
+++ b/target/linux/generic/backport-5.4/753-v5.8-net-dsa-mt7530-fix-VLAN-setup.patch
@@ -0,0 +1,51 @@
+From 0141792f8b7300006b874dda1c35acd0abd90d9d Mon Sep 17 00:00:00 2001
+From: DENG Qingfang <dqfext@gmail.com>
+Date: Fri, 15 May 2020 23:25:55 +0800
+Subject: net: dsa: mt7530: fix VLAN setup
+
+Allow DSA to add VLAN entries even if VLAN filtering is disabled, so
+enabling it will not block the traffic of existent ports in the bridge
+
+Signed-off-by: DENG Qingfang <dqfext@gmail.com>
+Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ drivers/net/dsa/mt7530.c | 13 +------------
+ 1 file changed, 1 insertion(+), 12 deletions(-)
+
+--- a/drivers/net/dsa/mt7530.c
++++ b/drivers/net/dsa/mt7530.c
+@@ -1096,12 +1096,6 @@ mt7530_port_vlan_add(struct dsa_switch *
+ 	struct mt7530_priv *priv = ds->priv;
+ 	u16 vid;
+ 
+-	/* The port is kept as VLAN-unaware if bridge with vlan_filtering not
+-	 * being set.
+-	 */
+-	if (!dsa_port_is_vlan_filtering(&ds->ports[port]))
+-		return;
+-
+ 	mutex_lock(&priv->reg_mutex);
+ 
+ 	for (vid = vlan->vid_begin; vid <= vlan->vid_end; ++vid) {
+@@ -1127,12 +1121,6 @@ mt7530_port_vlan_del(struct dsa_switch *
+ 	struct mt7530_priv *priv = ds->priv;
+ 	u16 vid, pvid;
+ 
+-	/* The port is kept as VLAN-unaware if bridge with vlan_filtering not
+-	 * being set.
+-	 */
+-	if (!dsa_port_is_vlan_filtering(&ds->ports[port]))
+-		return 0;
+-
+ 	mutex_lock(&priv->reg_mutex);
+ 
+ 	pvid = priv->ports[port].pvid;
+@@ -1245,6 +1233,7 @@ mt7530_setup(struct dsa_switch *ds)
+ 	 * as two netdev instances.
+ 	 */
+ 	dn = ds->ports[MT7530_CPU_PORT].master->dev.of_node->parent;
++	ds->configure_vlan_while_not_filtering = true;
+ 
+ 	if (priv->id == ID_MT7530) {
+ 		regulator_set_voltage(priv->core_pwr, 1000000, 1000000);
diff --git a/target/linux/generic/pending-5.4/760-net-dsa-mv88e6xxx-fix-vlan-setup.patch b/target/linux/generic/pending-5.4/760-net-dsa-mv88e6xxx-fix-vlan-setup.patch
new file mode 100644
index 0000000000..535c753a7b
--- /dev/null
+++ b/target/linux/generic/pending-5.4/760-net-dsa-mv88e6xxx-fix-vlan-setup.patch
@@ -0,0 +1,27 @@
+From a1b291f3f6c80a6c5ccad7283fc472d77a2a4763 Mon Sep 17 00:00:00 2001
+From: Russell King <rmk+kernel@armlinux.org.uk>
+Date: Sun, 22 Dec 2019 12:40:11 +0000
+Subject: [PATCH] net: dsa: mv88e6xxx: fix vlan setup
+
+Provide an option that drivers can set to indicate they want to receive
+vlan configuration even when vlan filtering is disabled. This is safe
+for Marvell DSA bridges, which do not look up ingress traffic in the
+VTU if the port is in 8021Q disabled state. Whether this change is
+suitable for all DSA bridges is not known.
+
+Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
+Signed-off-by: DENG Qingfang <dqfext@gmail.com>
+---
+ drivers/net/dsa/mv88e6xxx/chip.c |  1 +
+ 1 file changed, 1 insertion(+)
+
+--- a/drivers/net/dsa/mv88e6xxx/chip.c
++++ b/drivers/net/dsa/mv88e6xxx/chip.c
+@@ -2657,6 +2657,7 @@ static int mv88e6xxx_setup(struct dsa_sw
+ 
+ 	chip->ds = ds;
+ 	ds->slave_mii_bus = mv88e6xxx_default_mdio_bus(chip);
++	ds->configure_vlan_while_not_filtering = true;
+ 
+ 	mv88e6xxx_reg_lock(chip);
+