KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted

Manually perform cache maintenance on the source VM during intra-host
migration to ensure no stale data is left in CPU caches after the VM is
destroyed.  Because the source VM is "converted" to a non-SEV VM, KVM's
memory reclaim flows won't trigger cache maintenance, e.g. when all guest
memory is reclaimed in response to detaching from the mmu_notifier.

Note, relying on the destination VM to do cache maintenance isn't an option
as KVM doesn't require identical guest memory configurations, i.e. the
source VM may have access to memory that the destination VM does not.
Enforcing equivalent memory configurations is infeasible, as it would
require a *deep* comparison of memslots, e.g. to verify that not only are
the memslot identical, but what the memslots point at is also identical.

Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration")
Cc: stable@vger.kernel.org
Reported-by: Stefan Teodorescu <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

47 files changed, 16988 insertions, 0 deletions

diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
new file mode 100644
index 000000000..23b4b7400
--- /dev/null
+++ b/net/dsa/Kconfig
@@ -0,0 +1,230 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menuconfig NET_DSA
+	tristate "Distributed Switch Architecture"
+	depends on BRIDGE || BRIDGE=n
+	depends on HSR || HSR=n
+	depends on INET && NETDEVICES
+	select GRO_CELLS
+	select NET_SWITCHDEV
+	select PHYLINK
+	select NET_DEVLINK
+	imply NET_SELFTESTS
+	help
+	  Say Y if you want to enable support for the hardware switches supported
+	  by the Distributed Switch Architecture.
+
+if NET_DSA
+
+# Drivers must select the appropriate tagging format(s)
+
+config NET_DSA_TAG_NONE
+	tristate "No-op tag driver"
+	help
+	  Say Y or M if you want to enable support for switches which don't tag
+	  frames over the CPU port.
+
+config NET_DSA_TAG_AR9331
+	tristate "Tag driver for Atheros AR9331 SoC with built-in switch"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  the Atheros AR9331 SoC with built-in switch.
+
+config NET_DSA_TAG_BRCM_COMMON
+	tristate
+	default n
+
+config NET_DSA_TAG_BRCM
+	tristate "Tag driver for Broadcom switches using in-frame headers"
+	select NET_DSA_TAG_BRCM_COMMON
+	help
+	  Say Y if you want to enable support for tagging frames for the
+	  Broadcom switches which place the tag after the MAC source address.
+
+config NET_DSA_TAG_BRCM_LEGACY
+	tristate "Tag driver for BCM63xx legacy switches using in-frame headers"
+	select NET_DSA_TAG_BRCM_COMMON
+	help
+	  Say Y if you want to enable support for tagging frames for the
+	  BCM63xx legacy switches which place the tag after the MAC source
+	  address.
+	  This tag is used in BCM63xx legacy switches which work without the
+	  original FCS and length before the tag insertion.
+
+config NET_DSA_TAG_BRCM_LEGACY_FCS
+	tristate "Tag driver for BCM53xx legacy switches using in-frame headers"
+	select NET_DSA_TAG_BRCM_COMMON
+	help
+	  Say Y if you want to enable support for tagging frames for the
+	  BCM53xx legacy switches which place the tag after the MAC source
+	  address.
+	  This tag is used in BCM53xx legacy switches which expect original
+	  FCS and length before the tag insertion to be present.
+
+config NET_DSA_TAG_BRCM_PREPEND
+	tristate "Tag driver for Broadcom switches using prepended headers"
+	select NET_DSA_TAG_BRCM_COMMON
+	help
+	  Say Y if you want to enable support for tagging frames for the
+	  Broadcom switches which places the tag before the Ethernet header
+	  (prepended).
+
+config NET_DSA_TAG_HELLCREEK
+	tristate "Tag driver for Hirschmann Hellcreek TSN switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames
+	  for the Hirschmann Hellcreek TSN switches.
+
+config NET_DSA_TAG_GSWIP
+	tristate "Tag driver for Lantiq / Intel GSWIP switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for the
+	  Lantiq / Intel GSWIP switches.
+
+config NET_DSA_TAG_DSA_COMMON
+	tristate
+
+config NET_DSA_TAG_DSA
+	tristate "Tag driver for Marvell switches using DSA headers"
+	select NET_DSA_TAG_DSA_COMMON
+	help
+	  Say Y or M if you want to enable support for tagging frames for the
+	  Marvell switches which use DSA headers.
+
+config NET_DSA_TAG_EDSA
+	tristate "Tag driver for Marvell switches using EtherType DSA headers"
+	select NET_DSA_TAG_DSA_COMMON
+	help
+	  Say Y or M if you want to enable support for tagging frames for the
+	  Marvell switches which use EtherType DSA headers.
+
+config NET_DSA_TAG_MT7628
+	tristate "Tag driver for the MT7628 embedded switch"
+	help
+	  Say Y or M if you want to enable support for tagging frames for the
+	  switch embedded in the MT7628 SoC.
+
+config NET_DSA_TAG_MTK
+	tristate "Tag driver for Mediatek switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  Mediatek switches.
+
+config NET_DSA_TAG_MXL_862XX
+	tristate "Tag driver for MaxLinear MxL862xx switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for the
+	  MaxLinear MxL86252 and MxL86282 switches using their native 8-byte
+	  tagging protocol.
+
+config NET_DSA_TAG_MXL_GSW1XX
+	tristate "Tag driver for MaxLinear GSW1xx switches"
+	help
+	  The GSW1xx family of switches supports an 8-byte special tag which
+	  can be used on the CPU port of the switch.
+	  Say Y or M if you want to enable support for tagging frames for
+	  MaxLinear GSW1xx switches.
+
+config NET_DSA_TAG_KSZ
+	tristate "Tag driver for Microchip 8795/937x/9477/9893 families of switches"
+	help
+	  Say Y if you want to enable support for tagging frames for the
+	  Microchip 8795/937x/9477/9893 families of switches.
+
+config NET_DSA_TAG_NETC
+	tristate "Tag driver for NXP NETC switches"
+	help
+	  Say Y or M if you want to enable support for the NXP Switch Tag (NST),
+	  as implemented by NXP NETC switches having version 4.3 or later. The
+	  switch tag is a proprietary header added to frames after the source
+	  MAC address, it has 3 types and each type has different subtypes, so
+	  its length depends on the type and subtype of the tag, the maximum
+	  length is 14 bytes.
+
+config NET_DSA_TAG_OCELOT
+	tristate "Tag driver for Ocelot family of switches, using NPI port"
+	select PACKING
+	help
+	  Say Y or M if you want to enable NPI tagging for the Ocelot switches
+	  (VSC7511, VSC7512, VSC7513, VSC7514, VSC9953, VSC9959). In this mode,
+	  the frames over the Ethernet CPU port are prepended with a
+	  hardware-defined injection/extraction frame header.  Flow control
+	  (PAUSE frames) over the CPU port is not supported when operating in
+	  this mode.
+
+config NET_DSA_TAG_OCELOT_8021Q
+	tristate "Tag driver for Ocelot family of switches, using VLAN"
+	help
+	  Say Y or M if you want to enable support for tagging frames with a
+	  custom VLAN-based header. Frames that require timestamping, such as
+	  PTP, are not delivered over Ethernet but over register-based MMIO.
+	  Flow control over the CPU port is functional in this mode. When using
+	  this mode, less TCAM resources (VCAP IS1, IS2, ES0) are available for
+	  use with tc-flower.
+
+config NET_DSA_TAG_QCA
+	tristate "Tag driver for Qualcomm Atheros QCA8K switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  the Qualcomm Atheros QCA8K switches.
+
+config NET_DSA_TAG_RTL4_A
+	tristate "Tag driver for Realtek 4 byte protocol A tags"
+	help
+	  Say Y or M if you want to enable support for tagging frames for the
+	  Realtek switches with 4 byte protocol A tags, such as found in
+	  the Realtek RTL8366RB.
+
+config NET_DSA_TAG_RTL8_4
+	tristate "Tag driver for Realtek 8 byte protocol 4 tags"
+	help
+	  Say Y or M if you want to enable support for tagging frames for Realtek
+	  switches with 8 byte protocol 4 tags, such as the Realtek RTL8365MB-VC.
+
+config NET_DSA_TAG_RZN1_A5PSW
+	tristate "Tag driver for Renesas RZ/N1 A5PSW switch"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  Renesas RZ/N1 embedded switch that uses an 8 byte tag located after
+	  destination MAC address.
+
+config NET_DSA_TAG_LAN9303
+	tristate "Tag driver for SMSC/Microchip LAN9303 family of switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for the
+	  SMSC/Microchip LAN9303 family of switches.
+
+config NET_DSA_TAG_SJA1105
+	tristate "Tag driver for NXP SJA1105 switches"
+	select PACKING
+	help
+	  Say Y or M if you want to enable support for tagging frames with the
+	  NXP SJA1105 switch family. Both the native tagging protocol (which
+	  is only for link-local traffic) as well as non-native tagging (based
+	  on a custom 802.1Q VLAN header) are available.
+
+config NET_DSA_TAG_TRAILER
+	tristate "Tag driver for switches using a trailer tag"
+	help
+	  Say Y or M if you want to enable support for tagging frames at
+	  with a trailed. e.g. Marvell 88E6060.
+
+config NET_DSA_TAG_VSC73XX_8021Q
+	tristate "Tag driver for Microchip/Vitesse VSC73xx family of switches, using VLAN"
+	help
+	  Say Y or M if you want to enable support for tagging frames with a
+	  custom VLAN-based header.
+
+config NET_DSA_TAG_XRS700X
+	tristate "Tag driver for XRS700x switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  Arrow SpeedChips XRS700x switches that use a single byte tag trailer.
+
+config NET_DSA_TAG_YT921X
+	tristate "Tag driver for Motorcomm YT921x switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  Motorcomm YT921x switches.
+
+endif
diff --git a/net/dsa/Makefile b/net/dsa/Makefile
new file mode 100644
index 000000000..d15bcf5c6
--- /dev/null
+++ b/net/dsa/Makefile
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# the stubs are built-in whenever DSA is built-in or module
+ifdef CONFIG_NET_DSA
+obj-y := stubs.o
+endif
+
+# the core
+obj-$(CONFIG_NET_DSA) += dsa_core.o
+dsa_core-y += \
+	conduit.o \
+	devlink.o \
+	dsa.o \
+	netlink.o \
+	port.o \
+	switch.o \
+	tag.o \
+	tag_8021q.o \
+	trace.o \
+	user.o
+
+# tagging formats
+obj-$(CONFIG_NET_DSA_TAG_AR9331) += tag_ar9331.o
+obj-$(CONFIG_NET_DSA_TAG_BRCM_COMMON) += tag_brcm.o
+obj-$(CONFIG_NET_DSA_TAG_DSA_COMMON) += tag_dsa.o
+obj-$(CONFIG_NET_DSA_TAG_GSWIP) += tag_gswip.o
+obj-$(CONFIG_NET_DSA_TAG_HELLCREEK) += tag_hellcreek.o
+obj-$(CONFIG_NET_DSA_TAG_KSZ) += tag_ksz.o
+obj-$(CONFIG_NET_DSA_TAG_LAN9303) += tag_lan9303.o
+obj-$(CONFIG_NET_DSA_TAG_MT7628) += tag_mt7628.o
+obj-$(CONFIG_NET_DSA_TAG_MTK) += tag_mtk.o
+obj-$(CONFIG_NET_DSA_TAG_MXL_862XX) += tag_mxl862xx.o
+obj-$(CONFIG_NET_DSA_TAG_MXL_GSW1XX) += tag_mxl-gsw1xx.o
+obj-$(CONFIG_NET_DSA_TAG_NETC) += tag_netc.o
+obj-$(CONFIG_NET_DSA_TAG_NONE) += tag_none.o
+obj-$(CONFIG_NET_DSA_TAG_OCELOT) += tag_ocelot.o
+obj-$(CONFIG_NET_DSA_TAG_OCELOT_8021Q) += tag_ocelot_8021q.o
+obj-$(CONFIG_NET_DSA_TAG_QCA) += tag_qca.o
+obj-$(CONFIG_NET_DSA_TAG_RTL4_A) += tag_rtl4_a.o
+obj-$(CONFIG_NET_DSA_TAG_RTL8_4) += tag_rtl8_4.o
+obj-$(CONFIG_NET_DSA_TAG_RZN1_A5PSW) += tag_rzn1_a5psw.o
+obj-$(CONFIG_NET_DSA_TAG_SJA1105) += tag_sja1105.o
+obj-$(CONFIG_NET_DSA_TAG_TRAILER) += tag_trailer.o
+obj-$(CONFIG_NET_DSA_TAG_VSC73XX_8021Q) += tag_vsc73xx_8021q.o
+obj-$(CONFIG_NET_DSA_TAG_XRS700X) += tag_xrs700x.o
+obj-$(CONFIG_NET_DSA_TAG_YT921X) += tag_yt921x.o
+
+# for tracing framework to find trace.h
+CFLAGS_trace.o := -I$(src)
diff --git a/net/dsa/conduit.c b/net/dsa/conduit.c
new file mode 100644
index 000000000..8398d72d7
--- /dev/null
+++ b/net/dsa/conduit.c
@@ -0,0 +1,535 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Handling of a conduit device, switching frames via its switch fabric CPU port
+ *
+ * Copyright (c) 2017 Savoir-faire Linux Inc.
+ *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
+ */
+
+#include <linux/ethtool.h>
+#include <linux/netdevice.h>
+#include <linux/netlink.h>
+#include <net/dsa.h>
+#include <net/netdev_lock.h>
+
+#include "conduit.h"
+#include "dsa.h"
+#include "port.h"
+#include "tag.h"
+
+static int dsa_conduit_get_regs_len(struct net_device *dev)
+{
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
+	struct dsa_switch *ds = cpu_dp->ds;
+	int port = cpu_dp->index;
+	int ret = 0;
+	int len;
+
+	if (ops && ops->get_regs_len) {
+		len = ops->get_regs_len(dev);
+		if (len < 0)
+			return len;
+		ret += len;
+	}
+
+	ret += sizeof(struct ethtool_drvinfo);
+	ret += sizeof(struct ethtool_regs);
+
+	if (ds->ops->get_regs_len) {
+		len = ds->ops->get_regs_len(ds, port);
+		if (len < 0)
+			return len;
+		ret += len;
+	}
+
+	return ret;
+}
+
+static void dsa_conduit_get_regs(struct net_device *dev,
+				 struct ethtool_regs *regs, void *data)
+{
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
+	struct dsa_switch *ds = cpu_dp->ds;
+	struct ethtool_drvinfo *cpu_info;
+	struct ethtool_regs *cpu_regs;
+	int port = cpu_dp->index;
+	int len;
+
+	if (ops && ops->get_regs_len && ops->get_regs) {
+		len = ops->get_regs_len(dev);
+		if (len < 0)
+			return;
+		regs->len = len;
+		ops->get_regs(dev, regs, data);
+		data += regs->len;
+	}
+
+	cpu_info = (struct ethtool_drvinfo *)data;
+	strscpy(cpu_info->driver, "dsa", sizeof(cpu_info->driver));
+	data += sizeof(*cpu_info);
+	cpu_regs = (struct ethtool_regs *)data;
+	data += sizeof(*cpu_regs);
+
+	if (ds->ops->get_regs_len && ds->ops->get_regs) {
+		len = ds->ops->get_regs_len(ds, port);
+		if (len < 0)
+			return;
+		cpu_regs->len = len;
+		ds->ops->get_regs(ds, port, cpu_regs, data);
+	}
+}
+
+static ssize_t dsa_conduit_append_port_stats(struct dsa_switch *ds, int port,
+					     u64 *data, size_t start)
+{
+	int count;
+
+	if (!ds->ops->get_sset_count)
+		return 0;
+
+	count = ds->ops->get_sset_count(ds, port, ETH_SS_STATS);
+	if (count < 0)
+		return count;
+
+	if (ds->ops->get_ethtool_stats)
+		ds->ops->get_ethtool_stats(ds, port, data + start);
+
+	return count;
+}
+
+static void dsa_conduit_get_ethtool_stats(struct net_device *dev,
+					  struct ethtool_stats *stats,
+					  u64 *data)
+{
+	struct dsa_port *dp, *cpu_dp = dev->dsa_ptr;
+	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
+	struct dsa_switch_tree *dst = cpu_dp->dst;
+	int count, mcount = 0;
+
+	if (ops && ops->get_sset_count && ops->get_ethtool_stats) {
+		mcount = ops->get_sset_count(dev, ETH_SS_STATS);
+		ops->get_ethtool_stats(dev, stats, data);
+	}
+
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (!dsa_port_is_dsa(dp) && !dsa_port_is_cpu(dp))
+			continue;
+
+		count = dsa_conduit_append_port_stats(dp->ds, dp->index,
+						      data, mcount);
+		if (count < 0)
+			return;
+
+		mcount += count;
+	}
+}
+
+static void dsa_conduit_get_ethtool_phy_stats(struct net_device *dev,
+					      struct ethtool_stats *stats,
+					      u64 *data)
+{
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
+	struct dsa_switch *ds = cpu_dp->ds;
+	int port = cpu_dp->index;
+	int count = 0;
+
+	if (dev->phydev && (!ops || !ops->get_ethtool_phy_stats)) {
+		count = phy_ethtool_get_sset_count(dev->phydev);
+		if (count >= 0)
+			phy_ethtool_get_stats(dev->phydev, stats, data);
+	} else if (ops && ops->get_sset_count && ops->get_ethtool_phy_stats) {
+		count = ops->get_sset_count(dev, ETH_SS_PHY_STATS);
+		ops->get_ethtool_phy_stats(dev, stats, data);
+	}
+
+	if (count < 0)
+		count = 0;
+
+	if (ds->ops->get_ethtool_phy_stats)
+		ds->ops->get_ethtool_phy_stats(ds, port, data + count);
+}
+
+static void dsa_conduit_append_port_sset_count(struct dsa_switch *ds, int port,
+					       int sset, int *count)
+{
+	if (ds->ops->get_sset_count)
+		*count += ds->ops->get_sset_count(ds, port, sset);
+}
+
+static int dsa_conduit_get_sset_count(struct net_device *dev, int sset)
+{
+	struct dsa_port *dp, *cpu_dp = dev->dsa_ptr;
+	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
+	struct dsa_switch_tree *dst = cpu_dp->dst;
+	int count = 0;
+
+	if (sset == ETH_SS_PHY_STATS && dev->phydev &&
+	    (!ops || !ops->get_ethtool_phy_stats))
+		count = phy_ethtool_get_sset_count(dev->phydev);
+	else if (ops && ops->get_sset_count)
+		count = ops->get_sset_count(dev, sset);
+
+	if (count < 0)
+		count = 0;
+
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (!dsa_port_is_dsa(dp) && !dsa_port_is_cpu(dp))
+			continue;
+
+		dsa_conduit_append_port_sset_count(dp->ds, dp->index, sset,
+						   &count);
+	}
+
+	return count;
+}
+
+static ssize_t dsa_conduit_append_port_strings(struct dsa_switch *ds, int port,
+					       u32 stringset, u8 *data,
+					       size_t start)
+{
+	int len = ETH_GSTRING_LEN;
+	u8 pfx[8], *ndata;
+	int count, i;
+
+	if (!ds->ops->get_strings)
+		return 0;
+
+	snprintf(pfx, sizeof(pfx), "s%.2d_p%.2d", ds->index, port);
+	/* We do not want to be NULL-terminated, since this is a prefix */
+	pfx[sizeof(pfx) - 1] = '_';
+	ndata = data + start * len;
+	/* This function copies ETH_GSTRINGS_LEN bytes, we will mangle
+	 * the output after to prepend our CPU port prefix we
+	 * constructed earlier
+	 */
+	ds->ops->get_strings(ds, port, stringset, ndata);
+	count = ds->ops->get_sset_count(ds, port, stringset);
+	if (count < 0)
+		return count;
+
+	for (i = 0; i < count; i++) {
+		memmove(ndata + (i * len + sizeof(pfx)),
+			ndata + i * len, len - sizeof(pfx));
+		memcpy(ndata + i * len, pfx, sizeof(pfx));
+	}
+
+	return count;
+}
+
+static void dsa_conduit_get_strings(struct net_device *dev, u32 stringset,
+				    u8 *data)
+{
+	struct dsa_port *dp, *cpu_dp = dev->dsa_ptr;
+	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
+	struct dsa_switch_tree *dst = cpu_dp->dst;
+	int count, mcount = 0;
+
+	if (stringset == ETH_SS_PHY_STATS && dev->phydev &&
+	    !ops->get_ethtool_phy_stats) {
+		mcount = phy_ethtool_get_sset_count(dev->phydev);
+		if (mcount < 0)
+			mcount = 0;
+		else
+			phy_ethtool_get_strings(dev->phydev, data);
+	} else if (ops->get_sset_count && ops->get_strings) {
+		mcount = ops->get_sset_count(dev, stringset);
+		if (mcount < 0)
+			mcount = 0;
+		ops->get_strings(dev, stringset, data);
+	}
+
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (!dsa_port_is_dsa(dp) && !dsa_port_is_cpu(dp))
+			continue;
+
+		count = dsa_conduit_append_port_strings(dp->ds, dp->index,
+							stringset, data,
+							mcount);
+		if (count < 0)
+			return;
+
+		mcount += count;
+	}
+}
+
+/* Deny PTP operations on conduit if there is at least one switch in the tree
+ * that is PTP capable.
+ */
+int __dsa_conduit_hwtstamp_validate(struct net_device *dev,
+				    const struct kernel_hwtstamp_config *config,
+				    struct netlink_ext_ack *extack)
+{
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+	struct dsa_switch *ds = cpu_dp->ds;
+	struct dsa_switch_tree *dst;
+	struct dsa_port *dp;
+
+	dst = ds->dst;
+
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (dsa_port_supports_hwtstamp(dp)) {
+			NL_SET_ERR_MSG(extack,
+				       "HW timestamping not allowed on DSA conduit when switch supports the operation");
+			return -EBUSY;
+		}
+	}
+
+	return 0;
+}
+
+static int dsa_conduit_ethtool_setup(struct net_device *dev)
+{
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+	struct dsa_switch *ds = cpu_dp->ds;
+	struct ethtool_ops *ops;
+
+	if (netif_is_lag_master(dev))
+		return 0;
+
+	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
+	if (!ops)
+		return -ENOMEM;
+
+	cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
+	if (cpu_dp->orig_ethtool_ops)
+		memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
+
+	ops->get_regs_len = dsa_conduit_get_regs_len;
+	ops->get_regs = dsa_conduit_get_regs;
+	ops->get_sset_count = dsa_conduit_get_sset_count;
+	ops->get_ethtool_stats = dsa_conduit_get_ethtool_stats;
+	ops->get_strings = dsa_conduit_get_strings;
+	ops->get_ethtool_phy_stats = dsa_conduit_get_ethtool_phy_stats;
+
+	dev->ethtool_ops = ops;
+
+	return 0;
+}
+
+static void dsa_conduit_ethtool_teardown(struct net_device *dev)
+{
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+
+	if (netif_is_lag_master(dev))
+		return;
+
+	dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
+	cpu_dp->orig_ethtool_ops = NULL;
+}
+
+/* Keep the conduit always promiscuous if the tagging protocol requires that
+ * (garbles MAC DA) or if it doesn't support unicast filtering, case in which
+ * it would revert to promiscuous mode as soon as we call dev_uc_add() on it
+ * anyway.
+ */
+static void dsa_conduit_set_promiscuity(struct net_device *dev, int inc)
+{
+	const struct dsa_device_ops *ops = dev->dsa_ptr->tag_ops;
+
+	if ((dev->priv_flags & IFF_UNICAST_FLT) && !ops->promisc_on_conduit)
+		return;
+
+	ASSERT_RTNL();
+
+	dev_set_promiscuity(dev, inc);
+}
+
+static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
+			    char *buf)
+{
+	struct net_device *dev = to_net_dev(d);
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+
+	return sysfs_emit(buf, "%s\n",
+		       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
+}
+
+static ssize_t tagging_store(struct device *d, struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	const struct dsa_device_ops *new_tag_ops, *old_tag_ops;
+	const char *end = strchrnul(buf, '\n'), *name;
+	struct net_device *dev = to_net_dev(d);
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+	size_t len = end - buf;
+	int err;
+
+	/* Empty string passed */
+	if (!len)
+		return -ENOPROTOOPT;
+
+	name = kstrndup(buf, len, GFP_KERNEL);
+	if (!name)
+		return -ENOMEM;
+
+	old_tag_ops = cpu_dp->tag_ops;
+	new_tag_ops = dsa_tag_driver_get_by_name(name);
+	kfree(name);
+	/* Bad tagger name? */
+	if (IS_ERR(new_tag_ops))
+		return PTR_ERR(new_tag_ops);
+
+	if (new_tag_ops == old_tag_ops)
+		/* Drop the temporarily held duplicate reference, since
+		 * the DSA switch tree uses this tagger.
+		 */
+		goto out;
+
+	err = dsa_tree_change_tag_proto(cpu_dp->ds->dst, new_tag_ops,
+					old_tag_ops);
+	if (err) {
+		/* On failure the old tagger is restored, so we don't need the
+		 * driver for the new one.
+		 */
+		dsa_tag_driver_put(new_tag_ops);
+		return err;
+	}
+
+	/* On success we no longer need the module for the old tagging protocol
+	 */
+out:
+	dsa_tag_driver_put(old_tag_ops);
+	return count;
+}
+static DEVICE_ATTR_RW(tagging);
+
+static struct attribute *dsa_user_attrs[] = {
+	&dev_attr_tagging.attr,
+	NULL
+};
+
+static const struct attribute_group dsa_group = {
+	.name	= "dsa",
+	.attrs	= dsa_user_attrs,
+};
+
+static void dsa_conduit_reset_mtu(struct net_device *dev)
+{
+	int err;
+
+	err = dev_set_mtu(dev, ETH_DATA_LEN);
+	if (err)
+		netdev_dbg(dev,
+			   "Unable to reset MTU to exclude DSA overheads\n");
+}
+
+int dsa_conduit_setup(struct net_device *dev, struct dsa_port *cpu_dp)
+{
+	const struct dsa_device_ops *tag_ops = cpu_dp->tag_ops;
+	struct dsa_switch *ds = cpu_dp->ds;
+	struct device_link *consumer_link;
+	int mtu, ret;
+
+	mtu = ETH_DATA_LEN + dsa_tag_protocol_overhead(tag_ops);
+
+	/* The DSA conduit must use SET_NETDEV_DEV for this to work. */
+	if (!netif_is_lag_master(dev)) {
+		consumer_link = device_link_add(ds->dev, dev->dev.parent,
+						DL_FLAG_AUTOREMOVE_CONSUMER);
+		if (!consumer_link)
+			netdev_err(dev,
+				   "Failed to create a device link to DSA switch %s\n",
+				   dev_name(ds->dev));
+	}
+
+	/* The switch driver may not implement ->port_change_mtu(), case in
+	 * which dsa_user_change_mtu() will not update the conduit MTU either,
+	 * so we need to do that here.
+	 */
+	ret = dev_set_mtu(dev, mtu);
+	if (ret)
+		netdev_warn(dev, "error %d setting MTU to %d to include DSA overhead\n",
+			    ret, mtu);
+
+	/* If we use a tagging format that doesn't have an ethertype
+	 * field, make sure that all packets from this point on get
+	 * sent to the tag format's receive function.
+	 */
+	wmb();
+
+	dev->dsa_ptr = cpu_dp;
+
+	dsa_conduit_set_promiscuity(dev, 1);
+
+	ret = dsa_conduit_ethtool_setup(dev);
+	if (ret)
+		goto out_err_reset_promisc;
+
+	ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
+	if (ret)
+		goto out_err_ethtool_teardown;
+
+	return ret;
+
+out_err_ethtool_teardown:
+	dsa_conduit_ethtool_teardown(dev);
+out_err_reset_promisc:
+	dsa_conduit_set_promiscuity(dev, -1);
+	return ret;
+}
+
+void dsa_conduit_teardown(struct net_device *dev)
+{
+	sysfs_remove_group(&dev->dev.kobj, &dsa_group);
+	dsa_conduit_ethtool_teardown(dev);
+	dsa_conduit_reset_mtu(dev);
+	dsa_conduit_set_promiscuity(dev, -1);
+
+	dev->dsa_ptr = NULL;
+
+	/* If we used a tagging format that doesn't have an ethertype
+	 * field, make sure that all packets from this point get sent
+	 * without the tag and go through the regular receive path.
+	 */
+	wmb();
+}
+
+int dsa_conduit_lag_setup(struct net_device *lag_dev, struct dsa_port *cpu_dp,
+			  struct netdev_lag_upper_info *uinfo,
+			  struct netlink_ext_ack *extack)
+{
+	bool conduit_setup = false;
+	int err;
+
+	if (!netdev_uses_dsa(lag_dev)) {
+		err = dsa_conduit_setup(lag_dev, cpu_dp);
+		if (err)
+			return err;
+
+		conduit_setup = true;
+	}
+
+	err = dsa_port_lag_join(cpu_dp, lag_dev, uinfo, extack);
+	if (err) {
+		NL_SET_ERR_MSG_WEAK_MOD(extack, "CPU port failed to join LAG");
+		goto out_conduit_teardown;
+	}
+
+	return 0;
+
+out_conduit_teardown:
+	if (conduit_setup)
+		dsa_conduit_teardown(lag_dev);
+	return err;
+}
+
+/* Tear down a conduit if there isn't any other user port on it,
+ * optionally also destroying LAG information.
+ */
+void dsa_conduit_lag_teardown(struct net_device *lag_dev,
+			      struct dsa_port *cpu_dp)
+{
+	struct net_device *upper;
+	struct list_head *iter;
+
+	dsa_port_lag_leave(cpu_dp, lag_dev);
+
+	netdev_for_each_upper_dev_rcu(lag_dev, upper, iter)
+		if (dsa_user_dev_check(upper))
+			return;
+
+	dsa_conduit_teardown(lag_dev);
+}
diff --git a/net/dsa/conduit.h b/net/dsa/conduit.h
new file mode 100644
index 000000000..31f8834f5
--- /dev/null
+++ b/net/dsa/conduit.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __DSA_CONDUIT_H
+#define __DSA_CONDUIT_H
+
+struct dsa_port;
+struct net_device;
+struct netdev_lag_upper_info;
+struct netlink_ext_ack;
+
+int dsa_conduit_setup(struct net_device *dev, struct dsa_port *cpu_dp);
+void dsa_conduit_teardown(struct net_device *dev);
+int dsa_conduit_lag_setup(struct net_device *lag_dev, struct dsa_port *cpu_dp,
+			  struct netdev_lag_upper_info *uinfo,
+			  struct netlink_ext_ack *extack);
+void dsa_conduit_lag_teardown(struct net_device *lag_dev,
+			      struct dsa_port *cpu_dp);
+int __dsa_conduit_hwtstamp_validate(struct net_device *dev,
+				    const struct kernel_hwtstamp_config *config,
+				    struct netlink_ext_ack *extack);
+
+#endif
diff --git a/net/dsa/devlink.c b/net/dsa/devlink.c
new file mode 100644
index 000000000..ed342f345
--- /dev/null
+++ b/net/dsa/devlink.c
@@ -0,0 +1,402 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * DSA devlink handling
+ */
+
+#include <net/dsa.h>
+#include <net/devlink.h>
+
+#include "devlink.h"
+
+static int dsa_devlink_info_get(struct devlink *dl,
+				struct devlink_info_req *req,
+				struct netlink_ext_ack *extack)
+{
+	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
+
+	if (ds->ops->devlink_info_get)
+		return ds->ops->devlink_info_get(ds, req, extack);
+
+	return -EOPNOTSUPP;
+}
+
+static int dsa_devlink_sb_pool_get(struct devlink *dl,
+				   unsigned int sb_index, u16 pool_index,
+				   struct devlink_sb_pool_info *pool_info)
+{
+	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
+
+	if (!ds->ops->devlink_sb_pool_get)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_sb_pool_get(ds, sb_index, pool_index,
+					    pool_info);
+}
+
+static int dsa_devlink_sb_pool_set(struct devlink *dl, unsigned int sb_index,
+				   u16 pool_index, u32 size,
+				   enum devlink_sb_threshold_type threshold_type,
+				   struct netlink_ext_ack *extack)
+{
+	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
+
+	if (!ds->ops->devlink_sb_pool_set)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_sb_pool_set(ds, sb_index, pool_index, size,
+					    threshold_type, extack);
+}
+
+static int dsa_devlink_sb_port_pool_get(struct devlink_port *dlp,
+					unsigned int sb_index, u16 pool_index,
+					u32 *p_threshold)
+{
+	struct dsa_switch *ds = dsa_devlink_port_to_ds(dlp);
+	int port = dsa_devlink_port_to_port(dlp);
+
+	if (!ds->ops->devlink_sb_port_pool_get)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_sb_port_pool_get(ds, port, sb_index,
+						 pool_index, p_threshold);
+}
+
+static int dsa_devlink_sb_port_pool_set(struct devlink_port *dlp,
+					unsigned int sb_index, u16 pool_index,
+					u32 threshold,
+					struct netlink_ext_ack *extack)
+{
+	struct dsa_switch *ds = dsa_devlink_port_to_ds(dlp);
+	int port = dsa_devlink_port_to_port(dlp);
+
+	if (!ds->ops->devlink_sb_port_pool_set)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_sb_port_pool_set(ds, port, sb_index,
+						 pool_index, threshold, extack);
+}
+
+static int
+dsa_devlink_sb_tc_pool_bind_get(struct devlink_port *dlp,
+				unsigned int sb_index, u16 tc_index,
+				enum devlink_sb_pool_type pool_type,
+				u16 *p_pool_index, u32 *p_threshold)
+{
+	struct dsa_switch *ds = dsa_devlink_port_to_ds(dlp);
+	int port = dsa_devlink_port_to_port(dlp);
+
+	if (!ds->ops->devlink_sb_tc_pool_bind_get)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_sb_tc_pool_bind_get(ds, port, sb_index,
+						    tc_index, pool_type,
+						    p_pool_index, p_threshold);
+}
+
+static int
+dsa_devlink_sb_tc_pool_bind_set(struct devlink_port *dlp,
+				unsigned int sb_index, u16 tc_index,
+				enum devlink_sb_pool_type pool_type,
+				u16 pool_index, u32 threshold,
+				struct netlink_ext_ack *extack)
+{
+	struct dsa_switch *ds = dsa_devlink_port_to_ds(dlp);
+	int port = dsa_devlink_port_to_port(dlp);
+
+	if (!ds->ops->devlink_sb_tc_pool_bind_set)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_sb_tc_pool_bind_set(ds, port, sb_index,
+						    tc_index, pool_type,
+						    pool_index, threshold,
+						    extack);
+}
+
+static int dsa_devlink_sb_occ_snapshot(struct devlink *dl,
+				       unsigned int sb_index)
+{
+	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
+
+	if (!ds->ops->devlink_sb_occ_snapshot)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_sb_occ_snapshot(ds, sb_index);
+}
+
+static int dsa_devlink_sb_occ_max_clear(struct devlink *dl,
+					unsigned int sb_index)
+{
+	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
+
+	if (!ds->ops->devlink_sb_occ_max_clear)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_sb_occ_max_clear(ds, sb_index);
+}
+
+static int dsa_devlink_sb_occ_port_pool_get(struct devlink_port *dlp,
+					    unsigned int sb_index,
+					    u16 pool_index, u32 *p_cur,
+					    u32 *p_max)
+{
+	struct dsa_switch *ds = dsa_devlink_port_to_ds(dlp);
+	int port = dsa_devlink_port_to_port(dlp);
+
+	if (!ds->ops->devlink_sb_occ_port_pool_get)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_sb_occ_port_pool_get(ds, port, sb_index,
+						     pool_index, p_cur, p_max);
+}
+
+static int
+dsa_devlink_sb_occ_tc_port_bind_get(struct devlink_port *dlp,
+				    unsigned int sb_index, u16 tc_index,
+				    enum devlink_sb_pool_type pool_type,
+				    u32 *p_cur, u32 *p_max)
+{
+	struct dsa_switch *ds = dsa_devlink_port_to_ds(dlp);
+	int port = dsa_devlink_port_to_port(dlp);
+
+	if (!ds->ops->devlink_sb_occ_tc_port_bind_get)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_sb_occ_tc_port_bind_get(ds, port,
+							sb_index, tc_index,
+							pool_type, p_cur,
+							p_max);
+}
+
+static const struct devlink_ops dsa_devlink_ops = {
+	.info_get			= dsa_devlink_info_get,
+	.sb_pool_get			= dsa_devlink_sb_pool_get,
+	.sb_pool_set			= dsa_devlink_sb_pool_set,
+	.sb_port_pool_get		= dsa_devlink_sb_port_pool_get,
+	.sb_port_pool_set		= dsa_devlink_sb_port_pool_set,
+	.sb_tc_pool_bind_get		= dsa_devlink_sb_tc_pool_bind_get,
+	.sb_tc_pool_bind_set		= dsa_devlink_sb_tc_pool_bind_set,
+	.sb_occ_snapshot		= dsa_devlink_sb_occ_snapshot,
+	.sb_occ_max_clear		= dsa_devlink_sb_occ_max_clear,
+	.sb_occ_port_pool_get		= dsa_devlink_sb_occ_port_pool_get,
+	.sb_occ_tc_port_bind_get	= dsa_devlink_sb_occ_tc_port_bind_get,
+};
+
+int dsa_devlink_param_get(struct devlink *dl, u32 id,
+			  struct devlink_param_gset_ctx *ctx,
+			  struct netlink_ext_ack *extack)
+{
+	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
+
+	if (!ds->ops->devlink_param_get)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_param_get(ds, id, ctx);
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_param_get);
+
+int dsa_devlink_param_set(struct devlink *dl, u32 id,
+			  struct devlink_param_gset_ctx *ctx,
+			  struct netlink_ext_ack *extack)
+{
+	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
+
+	if (!ds->ops->devlink_param_set)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_param_set(ds, id, ctx);
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_param_set);
+
+int dsa_devlink_params_register(struct dsa_switch *ds,
+				const struct devlink_param *params,
+				size_t params_count)
+{
+	return devlink_params_register(ds->devlink, params, params_count);
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_params_register);
+
+void dsa_devlink_params_unregister(struct dsa_switch *ds,
+				   const struct devlink_param *params,
+				   size_t params_count)
+{
+	devlink_params_unregister(ds->devlink, params, params_count);
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_params_unregister);
+
+int dsa_devlink_resource_register(struct dsa_switch *ds,
+				  const char *resource_name,
+				  u64 resource_size,
+				  u64 resource_id,
+				  u64 parent_resource_id,
+				  const struct devlink_resource_size_params *size_params)
+{
+	int ret;
+
+	devl_lock(ds->devlink);
+	ret = devl_resource_register(ds->devlink, resource_name, resource_size,
+				     resource_id, parent_resource_id,
+				     size_params);
+	devl_unlock(ds->devlink);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_resource_register);
+
+void dsa_devlink_resources_unregister(struct dsa_switch *ds)
+{
+	devlink_resources_unregister(ds->devlink);
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_resources_unregister);
+
+void dsa_devlink_resource_occ_get_register(struct dsa_switch *ds,
+					   u64 resource_id,
+					   devlink_resource_occ_get_t *occ_get,
+					   void *occ_get_priv)
+{
+	devl_lock(ds->devlink);
+	devl_resource_occ_get_register(ds->devlink, resource_id, occ_get,
+				       occ_get_priv);
+	devl_unlock(ds->devlink);
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_register);
+
+void dsa_devlink_resource_occ_get_unregister(struct dsa_switch *ds,
+					     u64 resource_id)
+{
+	devl_lock(ds->devlink);
+	devl_resource_occ_get_unregister(ds->devlink, resource_id);
+	devl_unlock(ds->devlink);
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_unregister);
+
+struct devlink_region *
+dsa_devlink_region_create(struct dsa_switch *ds,
+			  const struct devlink_region_ops *ops,
+			  u32 region_max_snapshots, u64 region_size)
+{
+	return devlink_region_create(ds->devlink, ops, region_max_snapshots,
+				     region_size);
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_region_create);
+
+struct devlink_region *
+dsa_devlink_port_region_create(struct dsa_switch *ds,
+			       int port,
+			       const struct devlink_port_region_ops *ops,
+			       u32 region_max_snapshots, u64 region_size)
+{
+	struct dsa_port *dp = dsa_to_port(ds, port);
+
+	return devlink_port_region_create(&dp->devlink_port, ops,
+					  region_max_snapshots,
+					  region_size);
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_port_region_create);
+
+void dsa_devlink_region_destroy(struct devlink_region *region)
+{
+	devlink_region_destroy(region);
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_region_destroy);
+
+int dsa_port_devlink_setup(struct dsa_port *dp)
+{
+	struct devlink_port *dlp = &dp->devlink_port;
+	struct dsa_switch_tree *dst = dp->ds->dst;
+	struct devlink_port_attrs attrs = {};
+	struct devlink *dl = dp->ds->devlink;
+	struct dsa_switch *ds = dp->ds;
+	const unsigned char *id;
+	unsigned char len;
+	int err;
+
+	memset(dlp, 0, sizeof(*dlp));
+	devlink_port_init(dl, dlp);
+
+	if (ds->ops->port_setup) {
+		err = ds->ops->port_setup(ds, dp->index);
+		if (err)
+			return err;
+	}
+
+	id = (const unsigned char *)&dst->index;
+	len = sizeof(dst->index);
+
+	attrs.phys.port_number = dp->index;
+	memcpy(attrs.switch_id.id, id, len);
+	attrs.switch_id.id_len = len;
+
+	switch (dp->type) {
+	case DSA_PORT_TYPE_UNUSED:
+		attrs.flavour = DEVLINK_PORT_FLAVOUR_UNUSED;
+		break;
+	case DSA_PORT_TYPE_CPU:
+		attrs.flavour = DEVLINK_PORT_FLAVOUR_CPU;
+		break;
+	case DSA_PORT_TYPE_DSA:
+		attrs.flavour = DEVLINK_PORT_FLAVOUR_DSA;
+		break;
+	case DSA_PORT_TYPE_USER:
+		attrs.flavour = DEVLINK_PORT_FLAVOUR_PHYSICAL;
+		break;
+	}
+
+	devlink_port_attrs_set(dlp, &attrs);
+	err = devlink_port_register(dl, dlp, dp->index);
+	if (err) {
+		if (ds->ops->port_teardown)
+			ds->ops->port_teardown(ds, dp->index);
+		return err;
+	}
+
+	return 0;
+}
+
+void dsa_port_devlink_teardown(struct dsa_port *dp)
+{
+	struct devlink_port *dlp = &dp->devlink_port;
+	struct dsa_switch *ds = dp->ds;
+
+	devlink_port_unregister(dlp);
+
+	if (ds->ops->port_teardown)
+		ds->ops->port_teardown(ds, dp->index);
+
+	devlink_port_fini(dlp);
+}
+
+void dsa_switch_devlink_register(struct dsa_switch *ds)
+{
+	devlink_register(ds->devlink);
+}
+
+void dsa_switch_devlink_unregister(struct dsa_switch *ds)
+{
+	devlink_unregister(ds->devlink);
+}
+
+int dsa_switch_devlink_alloc(struct dsa_switch *ds)
+{
+	struct dsa_devlink_priv *dl_priv;
+	struct devlink *dl;
+
+	/* Add the switch to devlink before calling setup, so that setup can
+	 * add dpipe tables
+	 */
+	dl = devlink_alloc(&dsa_devlink_ops, sizeof(*dl_priv), ds->dev);
+	if (!dl)
+		return -ENOMEM;
+
+	ds->devlink = dl;
+
+	dl_priv = devlink_priv(ds->devlink);
+	dl_priv->ds = ds;
+
+	return 0;
+}
+
+void dsa_switch_devlink_free(struct dsa_switch *ds)
+{
+	devlink_free(ds->devlink);
+	ds->devlink = NULL;
+}
diff --git a/net/dsa/devlink.h b/net/dsa/devlink.h
new file mode 100644
index 000000000..4d9f4f237
--- /dev/null
+++ b/net/dsa/devlink.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __DSA_DEVLINK_H
+#define __DSA_DEVLINK_H
+
+struct dsa_port;
+struct dsa_switch;
+
+int dsa_port_devlink_setup(struct dsa_port *dp);
+void dsa_port_devlink_teardown(struct dsa_port *dp);
+void dsa_switch_devlink_register(struct dsa_switch *ds);
+void dsa_switch_devlink_unregister(struct dsa_switch *ds);
+int dsa_switch_devlink_alloc(struct dsa_switch *ds);
+void dsa_switch_devlink_free(struct dsa_switch *ds);
+
+#endif
diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
new file mode 100644
index 000000000..2771c34e8
--- /dev/null
+++ b/net/dsa/dsa.c
@@ -0,0 +1,1914 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * DSA topology and switch handling
+ *
+ * Copyright (c) 2008-2009 Marvell Semiconductor
+ * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
+ * Copyright (c) 2016 Andrew Lunn <andrew@lunn.ch>
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/if_hsr.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <linux/rtnetlink.h>
+#include <linux/of.h>
+#include <linux/of_net.h>
+#include <net/dsa_stubs.h>
+#include <net/netdev_lock.h>
+#include <net/sch_generic.h>
+
+#include "conduit.h"
+#include "devlink.h"
+#include "dsa.h"
+#include "netlink.h"
+#include "port.h"
+#include "switch.h"
+#include "tag.h"
+#include "user.h"
+
+#define DSA_MAX_NUM_OFFLOADING_BRIDGES		BITS_PER_LONG
+
+static DEFINE_MUTEX(dsa2_mutex);
+LIST_HEAD(dsa_tree_list);
+
+static struct workqueue_struct *dsa_owq;
+
+/* Track the bridges with forwarding offload enabled */
+static unsigned long dsa_fwd_offloading_bridges;
+
+bool dsa_schedule_work(struct work_struct *work)
+{
+	return queue_work(dsa_owq, work);
+}
+
+void dsa_flush_workqueue(void)
+{
+	flush_workqueue(dsa_owq);
+}
+EXPORT_SYMBOL_GPL(dsa_flush_workqueue);
+
+/**
+ * dsa_lag_map() - Map LAG structure to a linear LAG array
+ * @dst: Tree in which to record the mapping.
+ * @lag: LAG structure that is to be mapped to the tree's array.
+ *
+ * dsa_lag_id/dsa_lag_by_id can then be used to translate between the
+ * two spaces. The size of the mapping space is determined by the
+ * driver by setting ds->num_lag_ids. It is perfectly legal to leave
+ * it unset if it is not needed, in which case these functions become
+ * no-ops.
+ */
+void dsa_lag_map(struct dsa_switch_tree *dst, struct dsa_lag *lag)
+{
+	unsigned int id;
+
+	for (id = 1; id <= dst->lags_len; id++) {
+		if (!dsa_lag_by_id(dst, id)) {
+			dst->lags[id - 1] = lag;
+			lag->id = id;
+			return;
+		}
+	}
+
+	/* No IDs left, which is OK. Some drivers do not need it. The
+	 * ones that do, e.g. mv88e6xxx, will discover that dsa_lag_id
+	 * returns an error for this device when joining the LAG. The
+	 * driver can then return -EOPNOTSUPP back to DSA, which will
+	 * fall back to a software LAG.
+	 */
+}
+
+/**
+ * dsa_lag_unmap() - Remove a LAG ID mapping
+ * @dst: Tree in which the mapping is recorded.
+ * @lag: LAG structure that was mapped.
+ *
+ * As there may be multiple users of the mapping, it is only removed
+ * if there are no other references to it.
+ */
+void dsa_lag_unmap(struct dsa_switch_tree *dst, struct dsa_lag *lag)
+{
+	unsigned int id;
+
+	dsa_lags_foreach_id(id, dst) {
+		if (dsa_lag_by_id(dst, id) == lag) {
+			dst->lags[id - 1] = NULL;
+			lag->id = 0;
+			break;
+		}
+	}
+}
+
+struct dsa_lag *dsa_tree_lag_find(struct dsa_switch_tree *dst,
+				  const struct net_device *lag_dev)
+{
+	struct dsa_port *dp;
+
+	list_for_each_entry(dp, &dst->ports, list)
+		if (dsa_port_lag_dev_get(dp) == lag_dev)
+			return dp->lag;
+
+	return NULL;
+}
+
+struct dsa_bridge *dsa_tree_bridge_find(struct dsa_switch_tree *dst,
+					const struct net_device *br)
+{
+	struct dsa_port *dp;
+
+	list_for_each_entry(dp, &dst->ports, list)
+		if (dsa_port_bridge_dev_get(dp) == br)
+			return dp->bridge;
+
+	return NULL;
+}
+
+static int dsa_bridge_num_find(const struct net_device *bridge_dev)
+{
+	struct dsa_switch_tree *dst;
+
+	list_for_each_entry(dst, &dsa_tree_list, list) {
+		struct dsa_bridge *bridge;
+
+		bridge = dsa_tree_bridge_find(dst, bridge_dev);
+		if (bridge)
+			return bridge->num;
+	}
+
+	return 0;
+}
+
+unsigned int dsa_bridge_num_get(const struct net_device *bridge_dev, int max)
+{
+	unsigned int bridge_num = dsa_bridge_num_find(bridge_dev);
+
+	/* Switches without FDB isolation support don't get unique
+	 * bridge numbering
+	 */
+	if (!max)
+		return 0;
+
+	if (!bridge_num) {
+		/* First port that requests FDB isolation or TX forwarding
+		 * offload for this bridge
+		 */
+		bridge_num = find_next_zero_bit(&dsa_fwd_offloading_bridges,
+						DSA_MAX_NUM_OFFLOADING_BRIDGES,
+						1);
+		if (bridge_num > max)
+			return 0;
+
+		set_bit(bridge_num, &dsa_fwd_offloading_bridges);
+	}
+
+	return bridge_num;
+}
+
+void dsa_bridge_num_put(const struct net_device *bridge_dev,
+			unsigned int bridge_num)
+{
+	/* Since we refcount bridges, we know that when we call this function
+	 * it is no longer in use, so we can just go ahead and remove it from
+	 * the bit mask.
+	 */
+	clear_bit(bridge_num, &dsa_fwd_offloading_bridges);
+}
+
+struct dsa_switch *dsa_switch_find(int tree_index, int sw_index)
+{
+	struct dsa_switch_tree *dst;
+	struct dsa_port *dp;
+
+	list_for_each_entry(dst, &dsa_tree_list, list) {
+		if (dst->index != tree_index)
+			continue;
+
+		list_for_each_entry(dp, &dst->ports, list) {
+			if (dp->ds->index != sw_index)
+				continue;
+
+			return dp->ds;
+		}
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(dsa_switch_find);
+
+static struct dsa_switch_tree *dsa_tree_find(int index)
+{
+	struct dsa_switch_tree *dst;
+
+	list_for_each_entry(dst, &dsa_tree_list, list)
+		if (dst->index == index)
+			return dst;
+
+	return NULL;
+}
+
+static struct dsa_switch_tree *dsa_tree_alloc(int index)
+{
+	struct dsa_switch_tree *dst;
+
+	dst = kzalloc_obj(*dst);
+	if (!dst)
+		return NULL;
+
+	dst->index = index;
+
+	INIT_LIST_HEAD(&dst->rtable);
+
+	INIT_LIST_HEAD(&dst->ports);
+
+	INIT_LIST_HEAD(&dst->list);
+	list_add_tail(&dst->list, &dsa_tree_list);
+
+	kref_init(&dst->refcount);
+
+	return dst;
+}
+
+static void dsa_tree_free(struct dsa_switch_tree *dst)
+{
+	if (dst->tag_ops)
+		dsa_tag_driver_put(dst->tag_ops);
+	list_del(&dst->list);
+	kfree(dst);
+}
+
+static struct dsa_switch_tree *dsa_tree_get(struct dsa_switch_tree *dst)
+{
+	if (dst)
+		kref_get(&dst->refcount);
+
+	return dst;
+}
+
+static struct dsa_switch_tree *dsa_tree_touch(int index)
+{
+	struct dsa_switch_tree *dst;
+
+	dst = dsa_tree_find(index);
+	if (dst)
+		return dsa_tree_get(dst);
+	else
+		return dsa_tree_alloc(index);
+}
+
+static void dsa_tree_release(struct kref *ref)
+{
+	struct dsa_switch_tree *dst;
+
+	dst = container_of(ref, struct dsa_switch_tree, refcount);
+
+	dsa_tree_free(dst);
+}
+
+static void dsa_tree_put(struct dsa_switch_tree *dst)
+{
+	if (dst)
+		kref_put(&dst->refcount, dsa_tree_release);
+}
+
+static struct dsa_port *dsa_tree_find_port_by_node(struct dsa_switch_tree *dst,
+						   struct device_node *dn)
+{
+	struct dsa_port *dp;
+
+	list_for_each_entry(dp, &dst->ports, list)
+		if (dp->dn == dn)
+			return dp;
+
+	return NULL;
+}
+
+static struct dsa_link *dsa_link_touch(struct dsa_port *dp,
+				       struct dsa_port *link_dp)
+{
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_switch_tree *dst;
+	struct dsa_link *dl;
+
+	dst = ds->dst;
+
+	list_for_each_entry(dl, &dst->rtable, list)
+		if (dl->dp == dp && dl->link_dp == link_dp)
+			return dl;
+
+	dl = kzalloc_obj(*dl);
+	if (!dl)
+		return NULL;
+
+	dl->dp = dp;
+	dl->link_dp = link_dp;
+
+	INIT_LIST_HEAD(&dl->list);
+	list_add_tail(&dl->list, &dst->rtable);
+
+	return dl;
+}
+
+static bool dsa_port_setup_routing_table(struct dsa_port *dp)
+{
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_switch_tree *dst = ds->dst;
+	struct device_node *dn = dp->dn;
+	struct of_phandle_iterator it;
+	struct dsa_port *link_dp;
+	struct dsa_link *dl;
+	int err;
+
+	of_for_each_phandle(&it, err, dn, "link", NULL, 0) {
+		link_dp = dsa_tree_find_port_by_node(dst, it.node);
+		if (!link_dp) {
+			of_node_put(it.node);
+			return false;
+		}
+
+		dl = dsa_link_touch(dp, link_dp);
+		if (!dl) {
+			of_node_put(it.node);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static bool dsa_tree_setup_routing_table(struct dsa_switch_tree *dst)
+{
+	bool complete = true;
+	struct dsa_port *dp;
+
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (dsa_port_is_dsa(dp)) {
+			complete = dsa_port_setup_routing_table(dp);
+			if (!complete)
+				break;
+		}
+	}
+
+	return complete;
+}
+
+static struct dsa_port *dsa_tree_find_first_cpu(struct dsa_switch_tree *dst)
+{
+	struct dsa_port *dp;
+
+	list_for_each_entry(dp, &dst->ports, list)
+		if (dsa_port_is_cpu(dp))
+			return dp;
+
+	return NULL;
+}
+
+struct net_device *dsa_tree_find_first_conduit(struct dsa_switch_tree *dst)
+{
+	struct dsa_port *cpu_dp;
+
+	cpu_dp = dsa_tree_find_first_cpu(dst);
+	return cpu_dp->conduit;
+}
+
+/* Assign the default CPU port (the first one in the tree) to all ports of the
+ * fabric which don't already have one as part of their own switch.
+ */
+static int dsa_tree_setup_default_cpu(struct dsa_switch_tree *dst)
+{
+	struct dsa_port *cpu_dp, *dp;
+
+	cpu_dp = dsa_tree_find_first_cpu(dst);
+	if (!cpu_dp) {
+		pr_err("DSA: tree %d has no CPU port\n", dst->index);
+		return -EINVAL;
+	}
+
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (dp->cpu_dp)
+			continue;
+
+		if (dsa_port_is_user(dp) || dsa_port_is_dsa(dp))
+			dp->cpu_dp = cpu_dp;
+	}
+
+	return 0;
+}
+
+static struct dsa_port *
+dsa_switch_preferred_default_local_cpu_port(struct dsa_switch *ds)
+{
+	struct dsa_port *cpu_dp;
+
+	if (!ds->ops->preferred_default_local_cpu_port)
+		return NULL;
+
+	cpu_dp = ds->ops->preferred_default_local_cpu_port(ds);
+	if (!cpu_dp)
+		return NULL;
+
+	if (WARN_ON(!dsa_port_is_cpu(cpu_dp) || cpu_dp->ds != ds))
+		return NULL;
+
+	return cpu_dp;
+}
+
+/* Perform initial assignment of CPU ports to user ports and DSA links in the
+ * fabric, giving preference to CPU ports local to each switch. Default to
+ * using the first CPU port in the switch tree if the port does not have a CPU
+ * port local to this switch.
+ */
+static int dsa_tree_setup_cpu_ports(struct dsa_switch_tree *dst)
+{
+	struct dsa_port *preferred_cpu_dp, *cpu_dp, *dp;
+
+	list_for_each_entry(cpu_dp, &dst->ports, list) {
+		if (!dsa_port_is_cpu(cpu_dp))
+			continue;
+
+		preferred_cpu_dp = dsa_switch_preferred_default_local_cpu_port(cpu_dp->ds);
+		if (preferred_cpu_dp && preferred_cpu_dp != cpu_dp)
+			continue;
+
+		/* Prefer a local CPU port */
+		dsa_switch_for_each_port(dp, cpu_dp->ds) {
+			/* Prefer the first local CPU port found */
+			if (dp->cpu_dp)
+				continue;
+
+			if (dsa_port_is_user(dp) || dsa_port_is_dsa(dp))
+				dp->cpu_dp = cpu_dp;
+		}
+	}
+
+	return dsa_tree_setup_default_cpu(dst);
+}
+
+static void dsa_tree_teardown_cpu_ports(struct dsa_switch_tree *dst)
+{
+	struct dsa_port *dp;
+
+	list_for_each_entry(dp, &dst->ports, list)
+		if (dsa_port_is_user(dp) || dsa_port_is_dsa(dp))
+			dp->cpu_dp = NULL;
+}
+
+static int dsa_port_setup(struct dsa_port *dp)
+{
+	bool dsa_port_link_registered = false;
+	struct dsa_switch *ds = dp->ds;
+	bool dsa_port_enabled = false;
+	int err = 0;
+
+	if (dp->setup)
+		return 0;
+
+	err = dsa_port_devlink_setup(dp);
+	if (err)
+		return err;
+
+	switch (dp->type) {
+	case DSA_PORT_TYPE_UNUSED:
+		dsa_port_disable(dp);
+		break;
+	case DSA_PORT_TYPE_CPU:
+		if (dp->dn) {
+			err = dsa_shared_port_link_register_of(dp);
+			if (err)
+				break;
+			dsa_port_link_registered = true;
+		} else {
+			dev_warn(ds->dev,
+				 "skipping link registration for CPU port %d\n",
+				 dp->index);
+		}
+
+		err = dsa_port_enable(dp, NULL);
+		if (err)
+			break;
+		dsa_port_enabled = true;
+
+		break;
+	case DSA_PORT_TYPE_DSA:
+		if (dp->dn) {
+			err = dsa_shared_port_link_register_of(dp);
+			if (err)
+				break;
+			dsa_port_link_registered = true;
+		} else {
+			dev_warn(ds->dev,
+				 "skipping link registration for DSA port %d\n",
+				 dp->index);
+		}
+
+		err = dsa_port_enable(dp, NULL);
+		if (err)
+			break;
+		dsa_port_enabled = true;
+
+		break;
+	case DSA_PORT_TYPE_USER:
+		of_get_mac_address(dp->dn, dp->mac);
+		err = dsa_user_create(dp);
+		break;
+	}
+
+	if (err && dsa_port_enabled)
+		dsa_port_disable(dp);
+	if (err && dsa_port_link_registered)
+		dsa_shared_port_link_unregister_of(dp);
+	if (err) {
+		dsa_port_devlink_teardown(dp);
+		return err;
+	}
+
+	dp->setup = true;
+
+	return 0;
+}
+
+static void dsa_port_teardown(struct dsa_port *dp)
+{
+	if (!dp->setup)
+		return;
+
+	switch (dp->type) {
+	case DSA_PORT_TYPE_UNUSED:
+		break;
+	case DSA_PORT_TYPE_CPU:
+		dsa_port_disable(dp);
+		if (dp->dn)
+			dsa_shared_port_link_unregister_of(dp);
+		break;
+	case DSA_PORT_TYPE_DSA:
+		dsa_port_disable(dp);
+		if (dp->dn)
+			dsa_shared_port_link_unregister_of(dp);
+		break;
+	case DSA_PORT_TYPE_USER:
+		if (dp->user) {
+			dsa_user_destroy(dp->user);
+			dp->user = NULL;
+		}
+		break;
+	}
+
+	dsa_port_devlink_teardown(dp);
+
+	dp->setup = false;
+}
+
+static int dsa_port_setup_as_unused(struct dsa_port *dp)
+{
+	dp->type = DSA_PORT_TYPE_UNUSED;
+	return dsa_port_setup(dp);
+}
+
+static int dsa_switch_setup_tag_protocol(struct dsa_switch *ds)
+{
+	const struct dsa_device_ops *tag_ops = ds->dst->tag_ops;
+	struct dsa_switch_tree *dst = ds->dst;
+	int err;
+
+	if (tag_ops->proto == dst->default_proto)
+		goto connect;
+
+	rtnl_lock();
+	err = ds->ops->change_tag_protocol(ds, tag_ops->proto);
+	rtnl_unlock();
+	if (err) {
+		dev_err(ds->dev, "Unable to use tag protocol \"%s\": %pe\n",
+			tag_ops->name, ERR_PTR(err));
+		return err;
+	}
+
+connect:
+	if (tag_ops->connect) {
+		err = tag_ops->connect(ds);
+		if (err)
+			return err;
+	}
+
+	if (ds->ops->connect_tag_protocol) {
+		err = ds->ops->connect_tag_protocol(ds, tag_ops->proto);
+		if (err) {
+			dev_err(ds->dev,
+				"Unable to connect to tag protocol \"%s\": %pe\n",
+				tag_ops->name, ERR_PTR(err));
+			goto disconnect;
+		}
+	}
+
+	return 0;
+
+disconnect:
+	if (tag_ops->disconnect)
+		tag_ops->disconnect(ds);
+
+	return err;
+}
+
+static void dsa_switch_teardown_tag_protocol(struct dsa_switch *ds)
+{
+	const struct dsa_device_ops *tag_ops = ds->dst->tag_ops;
+
+	if (tag_ops->disconnect)
+		tag_ops->disconnect(ds);
+}
+
+static int dsa_switch_setup(struct dsa_switch *ds)
+{
+	int err;
+
+	if (ds->setup)
+		return 0;
+
+	/* Initialize ds->phys_mii_mask before registering the user MDIO bus
+	 * driver and before ops->setup() has run, since the switch drivers and
+	 * the user MDIO bus driver rely on these values for probing PHY
+	 * devices or not
+	 */
+	ds->phys_mii_mask |= dsa_user_ports(ds);
+
+	err = dsa_switch_devlink_alloc(ds);
+	if (err)
+		return err;
+
+	err = dsa_switch_register_notifier(ds);
+	if (err)
+		goto devlink_free;
+
+	ds->configure_vlan_while_not_filtering = true;
+
+	err = ds->ops->setup(ds);
+	if (err < 0)
+		goto unregister_notifier;
+
+	err = dsa_switch_setup_tag_protocol(ds);
+	if (err)
+		goto teardown;
+
+	if (!ds->user_mii_bus && ds->ops->phy_read) {
+		ds->user_mii_bus = mdiobus_alloc();
+		if (!ds->user_mii_bus) {
+			err = -ENOMEM;
+			goto teardown;
+		}
+
+		dsa_user_mii_bus_init(ds);
+
+		err = mdiobus_register(ds->user_mii_bus);
+		if (err < 0)
+			goto free_user_mii_bus;
+	}
+
+	dsa_switch_devlink_register(ds);
+
+	ds->setup = true;
+	return 0;
+
+free_user_mii_bus:
+	if (ds->user_mii_bus && ds->ops->phy_read)
+		mdiobus_free(ds->user_mii_bus);
+teardown:
+	if (ds->ops->teardown)
+		ds->ops->teardown(ds);
+unregister_notifier:
+	dsa_switch_unregister_notifier(ds);
+devlink_free:
+	dsa_switch_devlink_free(ds);
+	return err;
+}
+
+static void dsa_switch_teardown(struct dsa_switch *ds)
+{
+	if (!ds->setup)
+		return;
+
+	dsa_switch_devlink_unregister(ds);
+
+	if (ds->user_mii_bus && ds->ops->phy_read) {
+		mdiobus_unregister(ds->user_mii_bus);
+		mdiobus_free(ds->user_mii_bus);
+		ds->user_mii_bus = NULL;
+	}
+
+	dsa_switch_teardown_tag_protocol(ds);
+
+	if (ds->ops->teardown)
+		ds->ops->teardown(ds);
+
+	dsa_switch_unregister_notifier(ds);
+
+	dsa_switch_devlink_free(ds);
+
+	ds->setup = false;
+}
+
+/* First tear down the non-shared, then the shared ports. This ensures that
+ * all work items scheduled by our switchdev handlers for user ports have
+ * completed before we destroy the refcounting kept on the shared ports.
+ */
+static void dsa_tree_teardown_ports(struct dsa_switch_tree *dst)
+{
+	struct dsa_port *dp;
+
+	list_for_each_entry(dp, &dst->ports, list)
+		if (dsa_port_is_user(dp) || dsa_port_is_unused(dp))
+			dsa_port_teardown(dp);
+
+	dsa_flush_workqueue();
+
+	list_for_each_entry(dp, &dst->ports, list)
+		if (dsa_port_is_dsa(dp) || dsa_port_is_cpu(dp))
+			dsa_port_teardown(dp);
+}
+
+static void dsa_tree_teardown_switches(struct dsa_switch_tree *dst)
+{
+	struct dsa_port *dp;
+
+	list_for_each_entry(dp, &dst->ports, list)
+		dsa_switch_teardown(dp->ds);
+}
+
+/* Bring shared ports up first, then non-shared ports */
+static int dsa_tree_setup_ports(struct dsa_switch_tree *dst)
+{
+	struct dsa_port *dp;
+	int err = 0;
+
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (dsa_port_is_dsa(dp) || dsa_port_is_cpu(dp)) {
+			err = dsa_port_setup(dp);
+			if (err)
+				goto teardown;
+		}
+	}
+
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (dsa_port_is_user(dp) || dsa_port_is_unused(dp)) {
+			err = dsa_port_setup(dp);
+			if (err) {
+				err = dsa_port_setup_as_unused(dp);
+				if (err)
+					goto teardown;
+			}
+		}
+	}
+
+	return 0;
+
+teardown:
+	dsa_tree_teardown_ports(dst);
+
+	return err;
+}
+
+static int dsa_tree_setup_switches(struct dsa_switch_tree *dst)
+{
+	struct dsa_port *dp;
+	int err = 0;
+
+	list_for_each_entry(dp, &dst->ports, list) {
+		err = dsa_switch_setup(dp->ds);
+		if (err) {
+			dsa_tree_teardown_switches(dst);
+			break;
+		}
+	}
+
+	return err;
+}
+
+static int dsa_tree_setup_conduit(struct dsa_switch_tree *dst)
+{
+	struct dsa_port *cpu_dp;
+	int err = 0;
+
+	rtnl_lock();
+
+	dsa_tree_for_each_cpu_port(cpu_dp, dst) {
+		struct net_device *conduit = cpu_dp->conduit;
+		bool admin_up = (conduit->flags & IFF_UP) &&
+				!qdisc_tx_is_noop(conduit);
+
+		err = dsa_conduit_setup(conduit, cpu_dp);
+		if (err)
+			break;
+
+		/* Replay conduit state event */
+		dsa_tree_conduit_admin_state_change(dst, conduit, admin_up);
+		dsa_tree_conduit_oper_state_change(dst, conduit,
+						   netif_oper_up(conduit));
+	}
+
+	rtnl_unlock();
+
+	return err;
+}
+
+static void dsa_tree_teardown_conduit(struct dsa_switch_tree *dst)
+{
+	struct dsa_port *cpu_dp;
+
+	rtnl_lock();
+
+	dsa_tree_for_each_cpu_port(cpu_dp, dst) {
+		struct net_device *conduit = cpu_dp->conduit;
+
+		/* Synthesizing an "admin down" state is sufficient for
+		 * the switches to get a notification if the conduit is
+		 * currently up and running.
+		 */
+		dsa_tree_conduit_admin_state_change(dst, conduit, false);
+
+		dsa_conduit_teardown(conduit);
+	}
+
+	rtnl_unlock();
+}
+
+static int dsa_tree_setup_lags(struct dsa_switch_tree *dst)
+{
+	unsigned int len = 0;
+	struct dsa_port *dp;
+
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (dp->ds->num_lag_ids > len)
+			len = dp->ds->num_lag_ids;
+	}
+
+	if (!len)
+		return 0;
+
+	dst->lags = kzalloc_objs(*dst->lags, len);
+	if (!dst->lags)
+		return -ENOMEM;
+
+	dst->lags_len = len;
+	return 0;
+}
+
+static void dsa_tree_teardown_lags(struct dsa_switch_tree *dst)
+{
+	kfree(dst->lags);
+}
+
+static void dsa_tree_teardown_routing_table(struct dsa_switch_tree *dst)
+{
+	struct dsa_link *dl, *next;
+
+	list_for_each_entry_safe(dl, next, &dst->rtable, list) {
+		list_del(&dl->list);
+		kfree(dl);
+	}
+}
+
+static int dsa_tree_setup(struct dsa_switch_tree *dst)
+{
+	bool complete;
+	int err;
+
+	if (dst->setup) {
+		pr_err("DSA: tree %d already setup! Disjoint trees?\n",
+		       dst->index);
+		return -EEXIST;
+	}
+
+	complete = dsa_tree_setup_routing_table(dst);
+	if (!complete)
+		return 0;
+
+	err = dsa_tree_setup_cpu_ports(dst);
+	if (err)
+		goto teardown_rtable;
+
+	err = dsa_tree_setup_switches(dst);
+	if (err)
+		goto teardown_cpu_ports;
+
+	err = dsa_tree_setup_ports(dst);
+	if (err)
+		goto teardown_switches;
+
+	err = dsa_tree_setup_conduit(dst);
+	if (err)
+		goto teardown_ports;
+
+	err = dsa_tree_setup_lags(dst);
+	if (err)
+		goto teardown_conduit;
+
+	dst->setup = true;
+
+	pr_info("DSA: tree %d setup\n", dst->index);
+
+	return 0;
+
+teardown_conduit:
+	dsa_tree_teardown_conduit(dst);
+teardown_ports:
+	dsa_tree_teardown_ports(dst);
+teardown_switches:
+	dsa_tree_teardown_switches(dst);
+teardown_cpu_ports:
+	dsa_tree_teardown_cpu_ports(dst);
+teardown_rtable:
+	dsa_tree_teardown_routing_table(dst);
+
+	return err;
+}
+
+static void dsa_tree_teardown(struct dsa_switch_tree *dst)
+{
+	if (!dst->setup)
+		return;
+
+	dsa_tree_teardown_lags(dst);
+
+	dsa_tree_teardown_conduit(dst);
+
+	dsa_tree_teardown_ports(dst);
+
+	dsa_tree_teardown_switches(dst);
+
+	dsa_tree_teardown_cpu_ports(dst);
+
+	dsa_tree_teardown_routing_table(dst);
+
+	pr_info("DSA: tree %d torn down\n", dst->index);
+
+	dst->setup = false;
+}
+
+static int dsa_tree_bind_tag_proto(struct dsa_switch_tree *dst,
+				   const struct dsa_device_ops *tag_ops)
+{
+	const struct dsa_device_ops *old_tag_ops = dst->tag_ops;
+	struct dsa_notifier_tag_proto_info info;
+	int err;
+
+	dst->tag_ops = tag_ops;
+
+	/* Notify the switches from this tree about the connection
+	 * to the new tagger
+	 */
+	info.tag_ops = tag_ops;
+	err = dsa_tree_notify(dst, DSA_NOTIFIER_TAG_PROTO_CONNECT, &info);
+	if (err && err != -EOPNOTSUPP)
+		goto out_disconnect;
+
+	/* Notify the old tagger about the disconnection from this tree */
+	info.tag_ops = old_tag_ops;
+	dsa_tree_notify(dst, DSA_NOTIFIER_TAG_PROTO_DISCONNECT, &info);
+
+	return 0;
+
+out_disconnect:
+	info.tag_ops = tag_ops;
+	dsa_tree_notify(dst, DSA_NOTIFIER_TAG_PROTO_DISCONNECT, &info);
+	dst->tag_ops = old_tag_ops;
+
+	return err;
+}
+
+/* Since the dsa/tagging sysfs device attribute is per conduit, the assumption
+ * is that all DSA switches within a tree share the same tagger, otherwise
+ * they would have formed disjoint trees (different "dsa,member" values).
+ */
+int dsa_tree_change_tag_proto(struct dsa_switch_tree *dst,
+			      const struct dsa_device_ops *tag_ops,
+			      const struct dsa_device_ops *old_tag_ops)
+{
+	struct dsa_notifier_tag_proto_info info;
+	struct dsa_port *dp;
+	int err = -EBUSY;
+
+	if (!rtnl_trylock())
+		return restart_syscall();
+
+	/* At the moment we don't allow changing the tag protocol under
+	 * traffic. The rtnl_mutex also happens to serialize concurrent
+	 * attempts to change the tagging protocol. If we ever lift the IFF_UP
+	 * restriction, there needs to be another mutex which serializes this.
+	 */
+	dsa_tree_for_each_user_port(dp, dst) {
+		if (dsa_port_to_conduit(dp)->flags & IFF_UP)
+			goto out_unlock;
+
+		if (dp->user->flags & IFF_UP)
+			goto out_unlock;
+	}
+
+	/* Notify the tag protocol change */
+	info.tag_ops = tag_ops;
+	err = dsa_tree_notify(dst, DSA_NOTIFIER_TAG_PROTO, &info);
+	if (err)
+		goto out_unwind_tagger;
+
+	err = dsa_tree_bind_tag_proto(dst, tag_ops);
+	if (err)
+		goto out_unwind_tagger;
+
+	rtnl_unlock();
+
+	return 0;
+
+out_unwind_tagger:
+	info.tag_ops = old_tag_ops;
+	dsa_tree_notify(dst, DSA_NOTIFIER_TAG_PROTO, &info);
+out_unlock:
+	rtnl_unlock();
+	return err;
+}
+
+static void dsa_tree_conduit_state_change(struct dsa_switch_tree *dst,
+					  struct net_device *conduit)
+{
+	struct dsa_notifier_conduit_state_info info;
+	struct dsa_port *cpu_dp = conduit->dsa_ptr;
+
+	info.conduit = conduit;
+	info.operational = dsa_port_conduit_is_operational(cpu_dp);
+
+	dsa_tree_notify(dst, DSA_NOTIFIER_CONDUIT_STATE_CHANGE, &info);
+}
+
+void dsa_tree_conduit_admin_state_change(struct dsa_switch_tree *dst,
+					 struct net_device *conduit,
+					 bool up)
+{
+	struct dsa_port *cpu_dp = conduit->dsa_ptr;
+	bool notify = false;
+
+	/* Don't keep track of admin state on LAG DSA conduits,
+	 * but rather just of physical DSA conduits
+	 */
+	if (netif_is_lag_master(conduit))
+		return;
+
+	if ((dsa_port_conduit_is_operational(cpu_dp)) !=
+	    (up && cpu_dp->conduit_oper_up))
+		notify = true;
+
+	cpu_dp->conduit_admin_up = up;
+
+	if (notify)
+		dsa_tree_conduit_state_change(dst, conduit);
+}
+
+void dsa_tree_conduit_oper_state_change(struct dsa_switch_tree *dst,
+					struct net_device *conduit,
+					bool up)
+{
+	struct dsa_port *cpu_dp = conduit->dsa_ptr;
+	bool notify = false;
+
+	/* Don't keep track of oper state on LAG DSA conduits,
+	 * but rather just of physical DSA conduits
+	 */
+	if (netif_is_lag_master(conduit))
+		return;
+
+	if ((dsa_port_conduit_is_operational(cpu_dp)) !=
+	    (cpu_dp->conduit_admin_up && up))
+		notify = true;
+
+	cpu_dp->conduit_oper_up = up;
+
+	if (notify)
+		dsa_tree_conduit_state_change(dst, conduit);
+}
+
+static struct dsa_port *dsa_port_touch(struct dsa_switch *ds, int index)
+{
+	struct dsa_switch_tree *dst = ds->dst;
+	struct dsa_port *dp;
+
+	dsa_switch_for_each_port(dp, ds)
+		if (dp->index == index)
+			return dp;
+
+	dp = kzalloc_obj(*dp);
+	if (!dp)
+		return NULL;
+
+	dp->ds = ds;
+	dp->index = index;
+
+	mutex_init(&dp->addr_lists_lock);
+	mutex_init(&dp->vlans_lock);
+	INIT_LIST_HEAD(&dp->fdbs);
+	INIT_LIST_HEAD(&dp->mdbs);
+	INIT_LIST_HEAD(&dp->vlans); /* also initializes &dp->user_vlans */
+	INIT_LIST_HEAD(&dp->list);
+	list_add_tail(&dp->list, &dst->ports);
+
+	return dp;
+}
+
+static int dsa_port_parse_user(struct dsa_port *dp, const char *name)
+{
+	dp->type = DSA_PORT_TYPE_USER;
+	dp->name = name;
+
+	return 0;
+}
+
+static int dsa_port_parse_dsa(struct dsa_port *dp)
+{
+	dp->type = DSA_PORT_TYPE_DSA;
+
+	return 0;
+}
+
+static enum dsa_tag_protocol dsa_get_tag_protocol(struct dsa_port *dp,
+						  struct net_device *conduit)
+{
+	enum dsa_tag_protocol tag_protocol = DSA_TAG_PROTO_NONE;
+	struct dsa_switch *mds, *ds = dp->ds;
+	unsigned int mdp_upstream;
+	struct dsa_port *mdp;
+
+	/* It is possible to stack DSA switches onto one another when that
+	 * happens the switch driver may want to know if its tagging protocol
+	 * is going to work in such a configuration.
+	 */
+	if (dsa_user_dev_check(conduit)) {
+		mdp = dsa_user_to_port(conduit);
+		mds = mdp->ds;
+		mdp_upstream = dsa_upstream_port(mds, mdp->index);
+		tag_protocol = mds->ops->get_tag_protocol(mds, mdp_upstream,
+							  DSA_TAG_PROTO_NONE);
+	}
+
+	/* If the conduit device is not itself a DSA user in a disjoint DSA
+	 * tree, then return immediately.
+	 */
+	return ds->ops->get_tag_protocol(ds, dp->index, tag_protocol);
+}
+
+static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *conduit,
+			      const char *user_protocol)
+{
+	const struct dsa_device_ops *tag_ops = NULL;
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_switch_tree *dst = ds->dst;
+	enum dsa_tag_protocol default_proto;
+
+	/* Find out which protocol the switch would prefer. */
+	default_proto = dsa_get_tag_protocol(dp, conduit);
+	if (dst->default_proto) {
+		if (dst->default_proto != default_proto) {
+			dev_err(ds->dev,
+				"A DSA switch tree can have only one tagging protocol\n");
+			return -EINVAL;
+		}
+	} else {
+		dst->default_proto = default_proto;
+	}
+
+	/* See if the user wants to override that preference. */
+	if (user_protocol) {
+		if (!ds->ops->change_tag_protocol) {
+			dev_err(ds->dev, "Tag protocol cannot be modified\n");
+			return -EINVAL;
+		}
+
+		tag_ops = dsa_tag_driver_get_by_name(user_protocol);
+		if (IS_ERR(tag_ops)) {
+			dev_warn(ds->dev,
+				 "Failed to find a tagging driver for protocol %s, using default\n",
+				 user_protocol);
+			tag_ops = NULL;
+		}
+	}
+
+	if (!tag_ops)
+		tag_ops = dsa_tag_driver_get_by_id(default_proto);
+
+	if (IS_ERR(tag_ops)) {
+		if (PTR_ERR(tag_ops) == -ENOPROTOOPT)
+			return -EPROBE_DEFER;
+
+		dev_warn(ds->dev, "No tagger for this switch\n");
+		return PTR_ERR(tag_ops);
+	}
+
+	if (dst->tag_ops) {
+		if (dst->tag_ops != tag_ops) {
+			dev_err(ds->dev,
+				"A DSA switch tree can have only one tagging protocol\n");
+
+			dsa_tag_driver_put(tag_ops);
+			return -EINVAL;
+		}
+
+		/* In the case of multiple CPU ports per switch, the tagging
+		 * protocol is still reference-counted only per switch tree.
+		 */
+		dsa_tag_driver_put(tag_ops);
+	} else {
+		dst->tag_ops = tag_ops;
+	}
+
+	dp->conduit = conduit;
+	dp->type = DSA_PORT_TYPE_CPU;
+	dsa_port_set_tag_protocol(dp, dst->tag_ops);
+	dp->dst = dst;
+
+	/* At this point, the tree may be configured to use a different
+	 * tagger than the one chosen by the switch driver during
+	 * .setup, in the case when a user selects a custom protocol
+	 * through the DT.
+	 *
+	 * This is resolved by syncing the driver with the tree in
+	 * dsa_switch_setup_tag_protocol once .setup has run and the
+	 * driver is ready to accept calls to .change_tag_protocol. If
+	 * the driver does not support the custom protocol at that
+	 * point, the tree is wholly rejected, thereby ensuring that the
+	 * tree and driver are always in agreement on the protocol to
+	 * use.
+	 */
+	return 0;
+}
+
+static int dsa_port_parse_of(struct dsa_port *dp, struct device_node *dn)
+{
+	struct device_node *ethernet = of_parse_phandle(dn, "ethernet", 0);
+	const char *name = of_get_property(dn, "label", NULL);
+	bool link = of_property_read_bool(dn, "link");
+
+	dp->dn = dn;
+
+	if (ethernet) {
+		struct net_device *conduit;
+		const char *user_protocol;
+		int err;
+
+		rtnl_lock();
+		conduit = of_find_net_device_by_node(ethernet);
+		of_node_put(ethernet);
+		if (!conduit) {
+			rtnl_unlock();
+			return -EPROBE_DEFER;
+		}
+
+		netdev_hold(conduit, &dp->conduit_tracker, GFP_KERNEL);
+		put_device(&conduit->dev);
+		rtnl_unlock();
+
+		user_protocol = of_get_property(dn, "dsa-tag-protocol", NULL);
+		err = dsa_port_parse_cpu(dp, conduit, user_protocol);
+		if (err)
+			netdev_put(conduit, &dp->conduit_tracker);
+		return err;
+	}
+
+	if (link)
+		return dsa_port_parse_dsa(dp);
+
+	return dsa_port_parse_user(dp, name);
+}
+
+static int dsa_switch_parse_ports_of(struct dsa_switch *ds,
+				     struct device_node *dn)
+{
+	struct device_node *ports, *port;
+	struct dsa_port *dp;
+	int err = 0;
+	u32 reg;
+
+	ports = of_get_child_by_name(dn, "ports");
+	if (!ports) {
+		/* The second possibility is "ethernet-ports" */
+		ports = of_get_child_by_name(dn, "ethernet-ports");
+		if (!ports) {
+			dev_err(ds->dev, "no ports child node found\n");
+			return -EINVAL;
+		}
+	}
+
+	for_each_available_child_of_node(ports, port) {
+		err = of_property_read_u32(port, "reg", &reg);
+		if (err) {
+			of_node_put(port);
+			goto out_put_node;
+		}
+
+		if (reg >= ds->num_ports) {
+			dev_err(ds->dev, "port %pOF index %u exceeds num_ports (%u)\n",
+				port, reg, ds->num_ports);
+			of_node_put(port);
+			err = -EINVAL;
+			goto out_put_node;
+		}
+
+		dp = dsa_to_port(ds, reg);
+
+		err = dsa_port_parse_of(dp, port);
+		if (err) {
+			of_node_put(port);
+			goto out_put_node;
+		}
+	}
+
+out_put_node:
+	of_node_put(ports);
+	return err;
+}
+
+static int dsa_switch_parse_member_of(struct dsa_switch *ds,
+				      struct device_node *dn)
+{
+	u32 m[2] = { 0, 0 };
+	int sz;
+
+	/* Don't error out if this optional property isn't found */
+	sz = of_property_read_variable_u32_array(dn, "dsa,member", m, 2, 2);
+	if (sz < 0 && sz != -EINVAL)
+		return sz;
+
+	ds->index = m[1];
+
+	ds->dst = dsa_tree_touch(m[0]);
+	if (!ds->dst)
+		return -ENOMEM;
+
+	if (dsa_switch_find(ds->dst->index, ds->index)) {
+		dev_err(ds->dev,
+			"A DSA switch with index %d already exists in tree %d\n",
+			ds->index, ds->dst->index);
+		return -EEXIST;
+	}
+
+	if (ds->dst->last_switch < ds->index)
+		ds->dst->last_switch = ds->index;
+
+	return 0;
+}
+
+static int dsa_switch_touch_ports(struct dsa_switch *ds)
+{
+	struct dsa_port *dp;
+	int port;
+
+	for (port = 0; port < ds->num_ports; port++) {
+		dp = dsa_port_touch(ds, port);
+		if (!dp)
+			return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int dsa_switch_parse_of(struct dsa_switch *ds, struct device_node *dn)
+{
+	int err;
+
+	err = dsa_switch_parse_member_of(ds, dn);
+	if (err)
+		return err;
+
+	err = dsa_switch_touch_ports(ds);
+	if (err)
+		return err;
+
+	return dsa_switch_parse_ports_of(ds, dn);
+}
+
+static int dev_is_class(struct device *dev, const void *class)
+{
+	if (dev->class && !strcmp(dev->class->name, class))
+		return 1;
+
+	return 0;
+}
+
+static struct device *dev_find_class(struct device *parent, char *class)
+{
+	if (dev_is_class(parent, class)) {
+		get_device(parent);
+		return parent;
+	}
+
+	return device_find_child(parent, class, dev_is_class);
+}
+
+static int dsa_port_parse(struct dsa_port *dp, const char *name,
+			  struct device *dev)
+{
+	if (!strcmp(name, "cpu")) {
+		struct net_device *conduit;
+		struct device *d;
+		int err;
+
+		rtnl_lock();
+		d = dev_find_class(dev, "net");
+		if (!d) {
+			rtnl_unlock();
+			return -EPROBE_DEFER;
+		}
+
+		conduit = to_net_dev(d);
+		netdev_hold(conduit, &dp->conduit_tracker, GFP_KERNEL);
+		put_device(d);
+		rtnl_unlock();
+
+		err = dsa_port_parse_cpu(dp, conduit, NULL);
+		if (err)
+			netdev_put(conduit, &dp->conduit_tracker);
+		return err;
+	}
+
+	if (!strcmp(name, "dsa"))
+		return dsa_port_parse_dsa(dp);
+
+	return dsa_port_parse_user(dp, name);
+}
+
+static int dsa_switch_parse_ports(struct dsa_switch *ds,
+				  struct dsa_chip_data *cd)
+{
+	bool valid_name_found = false;
+	struct dsa_port *dp;
+	struct device *dev;
+	const char *name;
+	unsigned int i;
+	int err;
+
+	for (i = 0; i < DSA_MAX_PORTS; i++) {
+		name = cd->port_names[i];
+		dev = cd->netdev[i];
+		dp = dsa_to_port(ds, i);
+
+		if (!name)
+			continue;
+
+		err = dsa_port_parse(dp, name, dev);
+		if (err)
+			return err;
+
+		valid_name_found = true;
+	}
+
+	if (!valid_name_found && i == DSA_MAX_PORTS)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int dsa_switch_parse(struct dsa_switch *ds, struct dsa_chip_data *cd)
+{
+	int err;
+
+	ds->cd = cd;
+
+	/* We don't support interconnected switches nor multiple trees via
+	 * platform data, so this is the unique switch of the tree.
+	 */
+	ds->index = 0;
+	ds->dst = dsa_tree_touch(0);
+	if (!ds->dst)
+		return -ENOMEM;
+
+	err = dsa_switch_touch_ports(ds);
+	if (err)
+		return err;
+
+	return dsa_switch_parse_ports(ds, cd);
+}
+
+static void dsa_switch_release_ports(struct dsa_switch *ds)
+{
+	struct dsa_mac_addr *a, *tmp;
+	struct dsa_port *dp, *next;
+	struct dsa_vlan *v, *n;
+
+	dsa_switch_for_each_port_safe(dp, next, ds) {
+		if (dsa_port_is_cpu(dp) && dp->conduit)
+			netdev_put(dp->conduit, &dp->conduit_tracker);
+
+		/* These are either entries that upper layers lost track of
+		 * (probably due to bugs), or installed through interfaces
+		 * where one does not necessarily have to remove them, like
+		 * ndo_dflt_fdb_add().
+		 */
+		list_for_each_entry_safe(a, tmp, &dp->fdbs, list) {
+			dev_info(ds->dev,
+				 "Cleaning up unicast address %pM vid %u from port %d\n",
+				 a->addr, a->vid, dp->index);
+			list_del(&a->list);
+			kfree(a);
+		}
+
+		list_for_each_entry_safe(a, tmp, &dp->mdbs, list) {
+			dev_info(ds->dev,
+				 "Cleaning up multicast address %pM vid %u from port %d\n",
+				 a->addr, a->vid, dp->index);
+			list_del(&a->list);
+			kfree(a);
+		}
+
+		/* These are entries that upper layers have lost track of,
+		 * probably due to bugs, but also due to dsa_port_do_vlan_del()
+		 * having failed and the VLAN entry still lingering on.
+		 */
+		list_for_each_entry_safe(v, n, &dp->vlans, list) {
+			dev_info(ds->dev,
+				 "Cleaning up vid %u from port %d\n",
+				 v->vid, dp->index);
+			list_del(&v->list);
+			kfree(v);
+		}
+
+		list_del(&dp->list);
+		kfree(dp);
+	}
+}
+
+static int dsa_switch_probe(struct dsa_switch *ds)
+{
+	struct dsa_switch_tree *dst;
+	struct dsa_chip_data *pdata;
+	struct device_node *np;
+	int err;
+
+	if (!ds->dev)
+		return -ENODEV;
+
+	pdata = ds->dev->platform_data;
+	np = ds->dev->of_node;
+
+	if (!ds->num_ports)
+		return -EINVAL;
+
+	if (np) {
+		err = dsa_switch_parse_of(ds, np);
+		if (err)
+			dsa_switch_release_ports(ds);
+	} else if (pdata) {
+		err = dsa_switch_parse(ds, pdata);
+		if (err)
+			dsa_switch_release_ports(ds);
+	} else {
+		err = -ENODEV;
+	}
+
+	if (err)
+		return err;
+
+	dst = ds->dst;
+	dsa_tree_get(dst);
+	err = dsa_tree_setup(dst);
+	if (err) {
+		dsa_switch_release_ports(ds);
+		dsa_tree_put(dst);
+	}
+
+	return err;
+}
+
+int dsa_register_switch(struct dsa_switch *ds)
+{
+	int err;
+
+	mutex_lock(&dsa2_mutex);
+	err = dsa_switch_probe(ds);
+	dsa_tree_put(ds->dst);
+	mutex_unlock(&dsa2_mutex);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(dsa_register_switch);
+
+static void dsa_switch_remove(struct dsa_switch *ds)
+{
+	struct dsa_switch_tree *dst = ds->dst;
+
+	dsa_tree_teardown(dst);
+	dsa_switch_release_ports(ds);
+	dsa_tree_put(dst);
+}
+
+void dsa_unregister_switch(struct dsa_switch *ds)
+{
+	mutex_lock(&dsa2_mutex);
+	dsa_switch_remove(ds);
+	mutex_unlock(&dsa2_mutex);
+}
+EXPORT_SYMBOL_GPL(dsa_unregister_switch);
+
+/* If the DSA conduit chooses to unregister its net_device on .shutdown, DSA is
+ * blocking that operation from completion, due to the dev_hold taken inside
+ * netdev_upper_dev_link. Unlink the DSA user interfaces from being uppers of
+ * the DSA conduit, so that the system can reboot successfully.
+ */
+void dsa_switch_shutdown(struct dsa_switch *ds)
+{
+	struct net_device *conduit, *user_dev;
+	LIST_HEAD(close_list);
+	struct dsa_port *dp;
+
+	mutex_lock(&dsa2_mutex);
+
+	if (!ds->setup)
+		goto out;
+
+	rtnl_lock();
+
+	dsa_switch_for_each_cpu_port(dp, ds) {
+		if (!(dp->conduit->flags & IFF_UP))
+			continue;
+		list_add_tail(&dp->conduit->close_list, &close_list);
+		netdev_lock_ops(dp->conduit);
+	}
+
+	netif_close_many(&close_list, false);
+
+	while (!list_empty(&close_list)) {
+		struct net_device *conduit;
+
+		conduit = list_first_entry(&close_list, struct net_device,
+					   close_list);
+		netdev_unlock_ops(conduit);
+		list_del_init(&conduit->close_list);
+	}
+
+	dsa_switch_for_each_user_port(dp, ds) {
+		conduit = dsa_port_to_conduit(dp);
+		user_dev = dp->user;
+
+		netif_device_detach(user_dev);
+		netdev_upper_dev_unlink(conduit, user_dev);
+	}
+
+	/* Disconnect from further netdevice notifiers on the conduit,
+	 * since netdev_uses_dsa() will now return false.
+	 */
+	dsa_switch_for_each_cpu_port(dp, ds) {
+		dp->conduit->dsa_ptr = NULL;
+		netdev_put(dp->conduit, &dp->conduit_tracker);
+	}
+
+	rtnl_unlock();
+out:
+	mutex_unlock(&dsa2_mutex);
+}
+EXPORT_SYMBOL_GPL(dsa_switch_shutdown);
+
+#ifdef CONFIG_PM_SLEEP
+static bool dsa_port_is_initialized(const struct dsa_port *dp)
+{
+	return dp->type == DSA_PORT_TYPE_USER && dp->user;
+}
+
+int dsa_switch_suspend(struct dsa_switch *ds)
+{
+	struct dsa_port *dp;
+	int ret = 0;
+
+	/* Suspend user network devices */
+	dsa_switch_for_each_port(dp, ds) {
+		if (!dsa_port_is_initialized(dp))
+			continue;
+
+		ret = dsa_user_suspend(dp->user);
+		if (ret)
+			return ret;
+	}
+
+	if (ds->ops->suspend)
+		ret = ds->ops->suspend(ds);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dsa_switch_suspend);
+
+int dsa_switch_resume(struct dsa_switch *ds)
+{
+	struct dsa_port *dp;
+	int ret = 0;
+
+	if (ds->ops->resume)
+		ret = ds->ops->resume(ds);
+
+	if (ret)
+		return ret;
+
+	/* Resume user network devices */
+	dsa_switch_for_each_port(dp, ds) {
+		if (!dsa_port_is_initialized(dp))
+			continue;
+
+		ret = dsa_user_resume(dp->user);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dsa_switch_resume);
+#endif
+
+struct dsa_port *dsa_port_from_netdev(struct net_device *netdev)
+{
+	if (!netdev || !dsa_user_dev_check(netdev))
+		return ERR_PTR(-ENODEV);
+
+	return dsa_user_to_port(netdev);
+}
+EXPORT_SYMBOL_GPL(dsa_port_from_netdev);
+
+bool dsa_db_equal(const struct dsa_db *a, const struct dsa_db *b)
+{
+	if (a->type != b->type)
+		return false;
+
+	switch (a->type) {
+	case DSA_DB_PORT:
+		return a->dp == b->dp;
+	case DSA_DB_LAG:
+		return a->lag.dev == b->lag.dev;
+	case DSA_DB_BRIDGE:
+		return a->bridge.num == b->bridge.num;
+	default:
+		WARN_ON(1);
+		return false;
+	}
+}
+
+bool dsa_fdb_present_in_other_db(struct dsa_switch *ds, int port,
+				 const unsigned char *addr, u16 vid,
+				 struct dsa_db db)
+{
+	struct dsa_port *dp = dsa_to_port(ds, port);
+	struct dsa_mac_addr *a;
+
+	lockdep_assert_held(&dp->addr_lists_lock);
+
+	list_for_each_entry(a, &dp->fdbs, list) {
+		if (!ether_addr_equal(a->addr, addr) || a->vid != vid)
+			continue;
+
+		if (a->db.type == db.type && !dsa_db_equal(&a->db, &db))
+			return true;
+	}
+
+	return false;
+}
+EXPORT_SYMBOL_GPL(dsa_fdb_present_in_other_db);
+
+bool dsa_mdb_present_in_other_db(struct dsa_switch *ds, int port,
+				 const struct switchdev_obj_port_mdb *mdb,
+				 struct dsa_db db)
+{
+	struct dsa_port *dp = dsa_to_port(ds, port);
+	struct dsa_mac_addr *a;
+
+	lockdep_assert_held(&dp->addr_lists_lock);
+
+	list_for_each_entry(a, &dp->mdbs, list) {
+		if (!ether_addr_equal(a->addr, mdb->addr) || a->vid != mdb->vid)
+			continue;
+
+		if (a->db.type == db.type && !dsa_db_equal(&a->db, &db))
+			return true;
+	}
+
+	return false;
+}
+EXPORT_SYMBOL_GPL(dsa_mdb_present_in_other_db);
+
+/* Helpers for switches without specific HSR offloads, but which can implement
+ * NETIF_F_HW_HSR_DUP because their tagger uses dsa_xmit_port_mask()
+ */
+int dsa_port_simple_hsr_validate(struct dsa_switch *ds, int port,
+				 struct net_device *hsr,
+				 struct netlink_ext_ack *extack)
+{
+	enum hsr_port_type type;
+	int err;
+
+	err = hsr_get_port_type(hsr, dsa_to_port(ds, port)->user, &type);
+	if (err)
+		return err;
+
+	if (type != HSR_PT_SLAVE_A && type != HSR_PT_SLAVE_B) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Only HSR slave ports can be offloaded");
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dsa_port_simple_hsr_validate);
+
+int dsa_port_simple_hsr_join(struct dsa_switch *ds, int port,
+			     struct net_device *hsr,
+			     struct netlink_ext_ack *extack)
+{
+	struct dsa_port *dp = dsa_to_port(ds, port), *other_dp;
+	int err;
+
+	err = dsa_port_simple_hsr_validate(ds, port, hsr, extack);
+	if (err)
+		return err;
+
+	dsa_hsr_foreach_port(other_dp, ds, hsr) {
+		if (other_dp != dp) {
+			dp->user->features |= NETIF_F_HW_HSR_DUP;
+			other_dp->user->features |= NETIF_F_HW_HSR_DUP;
+			break;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dsa_port_simple_hsr_join);
+
+int dsa_port_simple_hsr_leave(struct dsa_switch *ds, int port,
+			      struct net_device *hsr)
+{
+	struct dsa_port *dp = dsa_to_port(ds, port), *other_dp;
+
+	dsa_hsr_foreach_port(other_dp, ds, hsr) {
+		if (other_dp != dp) {
+			dp->user->features &= ~NETIF_F_HW_HSR_DUP;
+			other_dp->user->features &= ~NETIF_F_HW_HSR_DUP;
+			break;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dsa_port_simple_hsr_leave);
+
+static const struct dsa_stubs __dsa_stubs = {
+	.conduit_hwtstamp_validate = __dsa_conduit_hwtstamp_validate,
+};
+
+static void dsa_register_stubs(void)
+{
+	dsa_stubs = &__dsa_stubs;
+}
+
+static void dsa_unregister_stubs(void)
+{
+	dsa_stubs = NULL;
+}
+
+static int __init dsa_init_module(void)
+{
+	int rc;
+
+	dsa_owq = alloc_ordered_workqueue("dsa_ordered",
+					  WQ_MEM_RECLAIM);
+	if (!dsa_owq)
+		return -ENOMEM;
+
+	rc = dsa_user_register_notifier();
+	if (rc)
+		goto register_notifier_fail;
+
+	dev_add_pack(&dsa_pack_type);
+
+	rc = rtnl_link_register(&dsa_link_ops);
+	if (rc)
+		goto netlink_register_fail;
+
+	dsa_register_stubs();
+
+	return 0;
+
+netlink_register_fail:
+	dsa_user_unregister_notifier();
+	dev_remove_pack(&dsa_pack_type);
+register_notifier_fail:
+	destroy_workqueue(dsa_owq);
+
+	return rc;
+}
+module_init(dsa_init_module);
+
+static void __exit dsa_cleanup_module(void)
+{
+	dsa_unregister_stubs();
+
+	rtnl_link_unregister(&dsa_link_ops);
+
+	dsa_user_unregister_notifier();
+	dev_remove_pack(&dsa_pack_type);
+	destroy_workqueue(dsa_owq);
+}
+module_exit(dsa_cleanup_module);
+
+MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
+MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:dsa");
+MODULE_IMPORT_NS("NETDEV_INTERNAL");
diff --git a/net/dsa/dsa.h b/net/dsa/dsa.h
new file mode 100644
index 000000000..3cc7823e9
--- /dev/null
+++ b/net/dsa/dsa.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __DSA_H
+#define __DSA_H
+
+#include <linux/list.h>
+#include <linux/types.h>
+
+struct dsa_db;
+struct dsa_device_ops;
+struct dsa_lag;
+struct dsa_switch_tree;
+struct net_device;
+struct work_struct;
+
+extern struct list_head dsa_tree_list;
+
+bool dsa_db_equal(const struct dsa_db *a, const struct dsa_db *b);
+bool dsa_schedule_work(struct work_struct *work);
+void dsa_lag_map(struct dsa_switch_tree *dst, struct dsa_lag *lag);
+void dsa_lag_unmap(struct dsa_switch_tree *dst, struct dsa_lag *lag);
+struct dsa_lag *dsa_tree_lag_find(struct dsa_switch_tree *dst,
+				  const struct net_device *lag_dev);
+struct net_device *dsa_tree_find_first_conduit(struct dsa_switch_tree *dst);
+int dsa_tree_change_tag_proto(struct dsa_switch_tree *dst,
+			      const struct dsa_device_ops *tag_ops,
+			      const struct dsa_device_ops *old_tag_ops);
+void dsa_tree_conduit_admin_state_change(struct dsa_switch_tree *dst,
+					 struct net_device *conduit,
+					 bool up);
+void dsa_tree_conduit_oper_state_change(struct dsa_switch_tree *dst,
+					struct net_device *conduit,
+					bool up);
+unsigned int dsa_bridge_num_get(const struct net_device *bridge_dev, int max);
+void dsa_bridge_num_put(const struct net_device *bridge_dev,
+			unsigned int bridge_num);
+struct dsa_bridge *dsa_tree_bridge_find(struct dsa_switch_tree *dst,
+					const struct net_device *br);
+
+#endif
diff --git a/net/dsa/netlink.c b/net/dsa/netlink.c
new file mode 100644
index 000000000..1332e5634
--- /dev/null
+++ b/net/dsa/netlink.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2022 NXP
+ */
+#include <linux/netdevice.h>
+#include <net/rtnetlink.h>
+
+#include "netlink.h"
+#include "user.h"
+
+static const struct nla_policy dsa_policy[IFLA_DSA_MAX + 1] = {
+	[IFLA_DSA_CONDUIT]	= { .type = NLA_U32 },
+};
+
+static int dsa_changelink(struct net_device *dev, struct nlattr *tb[],
+			  struct nlattr *data[],
+			  struct netlink_ext_ack *extack)
+{
+	int err;
+
+	if (!data)
+		return 0;
+
+	if (data[IFLA_DSA_CONDUIT]) {
+		u32 ifindex = nla_get_u32(data[IFLA_DSA_CONDUIT]);
+		struct net_device *conduit;
+
+		conduit = __dev_get_by_index(dev_net(dev), ifindex);
+		if (!conduit)
+			return -EINVAL;
+
+		err = dsa_user_change_conduit(dev, conduit, extack);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static size_t dsa_get_size(const struct net_device *dev)
+{
+	return nla_total_size(sizeof(u32)) +	/* IFLA_DSA_CONDUIT  */
+	       0;
+}
+
+static int dsa_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+	struct net_device *conduit = dsa_user_to_conduit(dev);
+
+	if (nla_put_u32(skb, IFLA_DSA_CONDUIT, conduit->ifindex))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+struct rtnl_link_ops dsa_link_ops __read_mostly = {
+	.kind			= "dsa",
+	.priv_size		= sizeof(struct dsa_port),
+	.maxtype		= IFLA_DSA_MAX,
+	.policy			= dsa_policy,
+	.changelink		= dsa_changelink,
+	.get_size		= dsa_get_size,
+	.fill_info		= dsa_fill_info,
+	.netns_refund		= true,
+};
diff --git a/net/dsa/netlink.h b/net/dsa/netlink.h
new file mode 100644
index 000000000..7eda2fa15
--- /dev/null
+++ b/net/dsa/netlink.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __DSA_NETLINK_H
+#define __DSA_NETLINK_H
+
+extern struct rtnl_link_ops dsa_link_ops __read_mostly;
+
+#endif
diff --git a/net/dsa/port.c b/net/dsa/port.c
new file mode 100644
index 000000000..1f5536c0d
--- /dev/null
+++ b/net/dsa/port.c
@@ -0,0 +1,1955 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Handling of a single switch port
+ *
+ * Copyright (c) 2017 Savoir-faire Linux Inc.
+ *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
+ */
+
+#include <linux/if_bridge.h>
+#include <linux/netdevice.h>
+#include <linux/notifier.h>
+#include <linux/of_mdio.h>
+#include <linux/of_net.h>
+
+#include "dsa.h"
+#include "port.h"
+#include "switch.h"
+#include "tag_8021q.h"
+#include "user.h"
+
+/**
+ * dsa_port_notify - Notify the switching fabric of changes to a port
+ * @dp: port on which change occurred
+ * @e: event, must be of type DSA_NOTIFIER_*
+ * @v: event-specific value.
+ *
+ * Notify all switches in the DSA tree that this port's switch belongs to,
+ * including this switch itself, of an event. Allows the other switches to
+ * reconfigure themselves for cross-chip operations. Can also be used to
+ * reconfigure ports without net_devices (CPU ports, DSA links) whenever
+ * a user port's state changes.
+ */
+static int dsa_port_notify(const struct dsa_port *dp, unsigned long e, void *v)
+{
+	return dsa_tree_notify(dp->ds->dst, e, v);
+}
+
+static void dsa_port_notify_bridge_fdb_flush(const struct dsa_port *dp, u16 vid)
+{
+	struct net_device *brport_dev = dsa_port_to_bridge_port(dp);
+	struct switchdev_notifier_fdb_info info = {
+		.vid = vid,
+	};
+
+	/* When the port becomes standalone it has already left the bridge.
+	 * Don't notify the bridge in that case.
+	 */
+	if (!brport_dev)
+		return;
+
+	call_switchdev_notifiers(SWITCHDEV_FDB_FLUSH_TO_BRIDGE,
+				 brport_dev, &info.info, NULL);
+}
+
+static void dsa_port_fast_age(const struct dsa_port *dp)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->port_fast_age)
+		return;
+
+	ds->ops->port_fast_age(ds, dp->index);
+
+	/* flush all VLANs */
+	dsa_port_notify_bridge_fdb_flush(dp, 0);
+}
+
+static int dsa_port_vlan_fast_age(const struct dsa_port *dp, u16 vid)
+{
+	struct dsa_switch *ds = dp->ds;
+	int err;
+
+	if (!ds->ops->port_vlan_fast_age)
+		return -EOPNOTSUPP;
+
+	err = ds->ops->port_vlan_fast_age(ds, dp->index, vid);
+
+	if (!err)
+		dsa_port_notify_bridge_fdb_flush(dp, vid);
+
+	return err;
+}
+
+static int dsa_port_msti_fast_age(const struct dsa_port *dp, u16 msti)
+{
+	DECLARE_BITMAP(vids, VLAN_N_VID) = { 0 };
+	int err, vid;
+
+	err = br_mst_get_info(dsa_port_bridge_dev_get(dp), msti, vids);
+	if (err)
+		return err;
+
+	for_each_set_bit(vid, vids, VLAN_N_VID) {
+		err = dsa_port_vlan_fast_age(dp, vid);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static bool dsa_port_can_configure_learning(struct dsa_port *dp)
+{
+	struct switchdev_brport_flags flags = {
+		.mask = BR_LEARNING,
+	};
+	struct dsa_switch *ds = dp->ds;
+	int err;
+
+	if (!ds->ops->port_bridge_flags || !ds->ops->port_pre_bridge_flags)
+		return false;
+
+	err = ds->ops->port_pre_bridge_flags(ds, dp->index, flags, NULL);
+	return !err;
+}
+
+bool dsa_port_supports_hwtstamp(struct dsa_port *dp)
+{
+	struct kernel_hwtstamp_config config = {};
+	struct dsa_switch *ds = dp->ds;
+	int err;
+
+	if (!ds->ops->port_hwtstamp_get || !ds->ops->port_hwtstamp_set)
+		return false;
+
+	/* "See through" shim implementations of the "get" method. */
+	err = ds->ops->port_hwtstamp_get(ds, dp->index, &config);
+	return err != -EOPNOTSUPP;
+}
+
+int dsa_port_set_state(struct dsa_port *dp, u8 state, bool do_fast_age)
+{
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index;
+
+	if (!ds->ops->port_stp_state_set)
+		return -EOPNOTSUPP;
+
+	ds->ops->port_stp_state_set(ds, port, state);
+
+	if (!dsa_port_can_configure_learning(dp) ||
+	    (do_fast_age && dp->learning)) {
+		/* Fast age FDB entries or flush appropriate forwarding database
+		 * for the given port, if we are moving it from Learning or
+		 * Forwarding state, to Disabled or Blocking or Listening state.
+		 * Ports that were standalone before the STP state change don't
+		 * need to fast age the FDB, since address learning is off in
+		 * standalone mode.
+		 */
+
+		if ((dp->stp_state == BR_STATE_LEARNING ||
+		     dp->stp_state == BR_STATE_FORWARDING) &&
+		    (state == BR_STATE_DISABLED ||
+		     state == BR_STATE_BLOCKING ||
+		     state == BR_STATE_LISTENING))
+			dsa_port_fast_age(dp);
+	}
+
+	dp->stp_state = state;
+
+	return 0;
+}
+
+static void dsa_port_set_state_now(struct dsa_port *dp, u8 state,
+				   bool do_fast_age)
+{
+	struct dsa_switch *ds = dp->ds;
+	int err;
+
+	err = dsa_port_set_state(dp, state, do_fast_age);
+	if (err && err != -EOPNOTSUPP) {
+		dev_err(ds->dev, "port %d failed to set STP state %u: %pe\n",
+			dp->index, state, ERR_PTR(err));
+	}
+}
+
+int dsa_port_set_mst_state(struct dsa_port *dp,
+			   const struct switchdev_mst_state *state,
+			   struct netlink_ext_ack *extack)
+{
+	struct dsa_switch *ds = dp->ds;
+	u8 prev_state;
+	int err;
+
+	if (!ds->ops->port_mst_state_set)
+		return -EOPNOTSUPP;
+
+	err = br_mst_get_state(dsa_port_to_bridge_port(dp), state->msti,
+			       &prev_state);
+	if (err)
+		return err;
+
+	err = ds->ops->port_mst_state_set(ds, dp->index, state);
+	if (err)
+		return err;
+
+	if (!(dp->learning &&
+	      (prev_state == BR_STATE_LEARNING ||
+	       prev_state == BR_STATE_FORWARDING) &&
+	      (state->state == BR_STATE_DISABLED ||
+	       state->state == BR_STATE_BLOCKING ||
+	       state->state == BR_STATE_LISTENING)))
+		return 0;
+
+	err = dsa_port_msti_fast_age(dp, state->msti);
+	if (err)
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Unable to flush associated VLANs");
+
+	return 0;
+}
+
+int dsa_port_enable_rt(struct dsa_port *dp, struct phy_device *phy)
+{
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index;
+	int err;
+
+	if (ds->ops->port_enable) {
+		err = ds->ops->port_enable(ds, port, phy);
+		if (err)
+			return err;
+	}
+
+	if (!dp->bridge)
+		dsa_port_set_state_now(dp, BR_STATE_FORWARDING, false);
+
+	if (dp->pl)
+		phylink_start(dp->pl);
+
+	return 0;
+}
+
+int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy)
+{
+	int err;
+
+	rtnl_lock();
+	err = dsa_port_enable_rt(dp, phy);
+	rtnl_unlock();
+
+	return err;
+}
+
+void dsa_port_disable_rt(struct dsa_port *dp)
+{
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index;
+
+	if (dp->pl)
+		phylink_stop(dp->pl);
+
+	if (!dp->bridge)
+		dsa_port_set_state_now(dp, BR_STATE_DISABLED, false);
+
+	if (ds->ops->port_disable)
+		ds->ops->port_disable(ds, port);
+}
+
+void dsa_port_disable(struct dsa_port *dp)
+{
+	rtnl_lock();
+	dsa_port_disable_rt(dp);
+	rtnl_unlock();
+}
+
+static void dsa_port_reset_vlan_filtering(struct dsa_port *dp,
+					  struct dsa_bridge bridge)
+{
+	struct netlink_ext_ack extack = {0};
+	bool change_vlan_filtering = false;
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_port *other_dp;
+	bool vlan_filtering;
+	int err;
+
+	if (ds->needs_standalone_vlan_filtering &&
+	    !br_vlan_enabled(bridge.dev)) {
+		change_vlan_filtering = true;
+		vlan_filtering = true;
+	} else if (!ds->needs_standalone_vlan_filtering &&
+		   br_vlan_enabled(bridge.dev)) {
+		change_vlan_filtering = true;
+		vlan_filtering = false;
+	}
+
+	/* If the bridge was vlan_filtering, the bridge core doesn't trigger an
+	 * event for changing vlan_filtering setting upon user ports leaving
+	 * it. That is a good thing, because that lets us handle it and also
+	 * handle the case where the switch's vlan_filtering setting is global
+	 * (not per port). When that happens, the correct moment to trigger the
+	 * vlan_filtering callback is only when the last port leaves the last
+	 * VLAN-aware bridge.
+	 */
+	if (change_vlan_filtering && ds->vlan_filtering_is_global) {
+		dsa_switch_for_each_port(other_dp, ds) {
+			struct net_device *br = dsa_port_bridge_dev_get(other_dp);
+
+			if (br && br_vlan_enabled(br)) {
+				change_vlan_filtering = false;
+				break;
+			}
+		}
+	}
+
+	if (!change_vlan_filtering)
+		return;
+
+	err = dsa_port_vlan_filtering(dp, vlan_filtering, &extack);
+	if (extack._msg) {
+		dev_err(ds->dev, "port %d: %s\n", dp->index,
+			extack._msg);
+	}
+	if (err && err != -EOPNOTSUPP) {
+		dev_err(ds->dev,
+			"port %d failed to reset VLAN filtering to %d: %pe\n",
+		       dp->index, vlan_filtering, ERR_PTR(err));
+	}
+}
+
+static int dsa_port_inherit_brport_flags(struct dsa_port *dp,
+					 struct netlink_ext_ack *extack)
+{
+	const unsigned long mask = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD |
+				   BR_BCAST_FLOOD | BR_PORT_LOCKED;
+	struct net_device *brport_dev = dsa_port_to_bridge_port(dp);
+	int flag, err;
+
+	for_each_set_bit(flag, &mask, 32) {
+		struct switchdev_brport_flags flags = {0};
+
+		flags.mask = BIT(flag);
+
+		if (br_port_flag_is_set(brport_dev, BIT(flag)))
+			flags.val = BIT(flag);
+
+		err = dsa_port_bridge_flags(dp, flags, extack);
+		if (err && err != -EOPNOTSUPP)
+			return err;
+	}
+
+	return 0;
+}
+
+static void dsa_port_clear_brport_flags(struct dsa_port *dp)
+{
+	const unsigned long val = BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD;
+	const unsigned long mask = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD |
+				   BR_BCAST_FLOOD | BR_PORT_LOCKED;
+	int flag, err;
+
+	for_each_set_bit(flag, &mask, 32) {
+		struct switchdev_brport_flags flags = {0};
+
+		flags.mask = BIT(flag);
+		flags.val = val & BIT(flag);
+
+		err = dsa_port_bridge_flags(dp, flags, NULL);
+		if (err && err != -EOPNOTSUPP)
+			dev_err(dp->ds->dev,
+				"failed to clear bridge port flag %lu: %pe\n",
+				flags.val, ERR_PTR(err));
+	}
+}
+
+static int dsa_port_switchdev_sync_attrs(struct dsa_port *dp,
+					 struct netlink_ext_ack *extack)
+{
+	struct net_device *brport_dev = dsa_port_to_bridge_port(dp);
+	struct net_device *br = dsa_port_bridge_dev_get(dp);
+	int err;
+
+	err = dsa_port_inherit_brport_flags(dp, extack);
+	if (err)
+		return err;
+
+	err = dsa_port_set_state(dp, br_port_get_stp_state(brport_dev), false);
+	if (err && err != -EOPNOTSUPP)
+		return err;
+
+	err = dsa_port_vlan_filtering(dp, br_vlan_enabled(br), extack);
+	if (err && err != -EOPNOTSUPP)
+		return err;
+
+	err = dsa_port_ageing_time(dp, br_get_ageing_time(br));
+	if (err && err != -EOPNOTSUPP)
+		return err;
+
+	return 0;
+}
+
+static void dsa_port_switchdev_unsync_attrs(struct dsa_port *dp,
+					    struct dsa_bridge bridge)
+{
+	/* Configure the port for standalone mode (no address learning,
+	 * flood everything).
+	 * The bridge only emits SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS events
+	 * when the user requests it through netlink or sysfs, but not
+	 * automatically at port join or leave, so we need to handle resetting
+	 * the brport flags ourselves. But we even prefer it that way, because
+	 * otherwise, some setups might never get the notification they need,
+	 * for example, when a port leaves a LAG that offloads the bridge,
+	 * it becomes standalone, but as far as the bridge is concerned, no
+	 * port ever left.
+	 */
+	dsa_port_clear_brport_flags(dp);
+
+	/* Port left the bridge, put in BR_STATE_DISABLED by the bridge layer,
+	 * so allow it to be in BR_STATE_FORWARDING to be kept functional
+	 */
+	dsa_port_set_state_now(dp, BR_STATE_FORWARDING, true);
+
+	dsa_port_reset_vlan_filtering(dp, bridge);
+
+	/* Ageing time may be global to the switch chip, so don't change it
+	 * here because we have no good reason (or value) to change it to.
+	 */
+}
+
+static int dsa_port_bridge_create(struct dsa_port *dp,
+				  struct net_device *br,
+				  struct netlink_ext_ack *extack)
+{
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_bridge *bridge;
+
+	bridge = dsa_tree_bridge_find(ds->dst, br);
+	if (bridge) {
+		refcount_inc(&bridge->refcount);
+		dp->bridge = bridge;
+		return 0;
+	}
+
+	bridge = kzalloc_obj(*bridge);
+	if (!bridge)
+		return -ENOMEM;
+
+	refcount_set(&bridge->refcount, 1);
+
+	bridge->dev = br;
+
+	bridge->num = dsa_bridge_num_get(br, ds->max_num_bridges);
+	if (ds->max_num_bridges && !bridge->num) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Range of offloadable bridges exceeded");
+		kfree(bridge);
+		return -EOPNOTSUPP;
+	}
+
+	dp->bridge = bridge;
+
+	return 0;
+}
+
+static void dsa_port_bridge_destroy(struct dsa_port *dp,
+				    const struct net_device *br)
+{
+	struct dsa_bridge *bridge = dp->bridge;
+
+	dp->bridge = NULL;
+
+	if (!refcount_dec_and_test(&bridge->refcount))
+		return;
+
+	if (bridge->num)
+		dsa_bridge_num_put(br, bridge->num);
+
+	kfree(bridge);
+}
+
+static bool dsa_port_supports_mst(struct dsa_port *dp)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	return ds->ops->vlan_msti_set &&
+		ds->ops->port_mst_state_set &&
+		ds->ops->port_vlan_fast_age &&
+		dsa_port_can_configure_learning(dp);
+}
+
+int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br,
+			 struct netlink_ext_ack *extack)
+{
+	struct dsa_notifier_bridge_info info = {
+		.dp = dp,
+		.extack = extack,
+	};
+	struct net_device *dev = dp->user;
+	struct net_device *brport_dev;
+	int err;
+
+	if (br_mst_enabled(br) && !dsa_port_supports_mst(dp))
+		return -EOPNOTSUPP;
+
+	/* Here the interface is already bridged. Reflect the current
+	 * configuration so that drivers can program their chips accordingly.
+	 */
+	err = dsa_port_bridge_create(dp, br, extack);
+	if (err)
+		return err;
+
+	brport_dev = dsa_port_to_bridge_port(dp);
+
+	info.bridge = *dp->bridge;
+	err = dsa_broadcast(DSA_NOTIFIER_BRIDGE_JOIN, &info);
+	if (err)
+		goto out_rollback;
+
+	/* Drivers which support bridge TX forwarding should set this */
+	dp->bridge->tx_fwd_offload = info.tx_fwd_offload;
+
+	err = switchdev_bridge_port_offload(brport_dev, dev, dp,
+					    &dsa_user_switchdev_notifier,
+					    &dsa_user_switchdev_blocking_notifier,
+					    dp->bridge->tx_fwd_offload, extack);
+	if (err)
+		goto out_rollback_unbridge;
+
+	err = dsa_port_switchdev_sync_attrs(dp, extack);
+	if (err)
+		goto out_rollback_unoffload;
+
+	return 0;
+
+out_rollback_unoffload:
+	switchdev_bridge_port_unoffload(brport_dev, dp,
+					&dsa_user_switchdev_notifier,
+					&dsa_user_switchdev_blocking_notifier);
+	dsa_flush_workqueue();
+out_rollback_unbridge:
+	dsa_broadcast(DSA_NOTIFIER_BRIDGE_LEAVE, &info);
+out_rollback:
+	dsa_port_bridge_destroy(dp, br);
+	return err;
+}
+
+void dsa_port_pre_bridge_leave(struct dsa_port *dp, struct net_device *br)
+{
+	struct net_device *brport_dev = dsa_port_to_bridge_port(dp);
+
+	/* Don't try to unoffload something that is not offloaded */
+	if (!brport_dev)
+		return;
+
+	switchdev_bridge_port_unoffload(brport_dev, dp,
+					&dsa_user_switchdev_notifier,
+					&dsa_user_switchdev_blocking_notifier);
+
+	dsa_flush_workqueue();
+}
+
+void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br)
+{
+	struct dsa_notifier_bridge_info info = {
+		.dp = dp,
+	};
+	int err;
+
+	/* If the port could not be offloaded to begin with, then
+	 * there is nothing to do.
+	 */
+	if (!dp->bridge)
+		return;
+
+	info.bridge = *dp->bridge;
+
+	/* Here the port is already unbridged. Reflect the current configuration
+	 * so that drivers can program their chips accordingly.
+	 */
+	dsa_port_bridge_destroy(dp, br);
+
+	err = dsa_broadcast(DSA_NOTIFIER_BRIDGE_LEAVE, &info);
+	if (err)
+		dev_err(dp->ds->dev,
+			"port %d failed to notify DSA_NOTIFIER_BRIDGE_LEAVE: %pe\n",
+			dp->index, ERR_PTR(err));
+
+	dsa_port_switchdev_unsync_attrs(dp, info.bridge);
+}
+
+int dsa_port_lag_change(struct dsa_port *dp,
+			struct netdev_lag_lower_state_info *linfo)
+{
+	struct dsa_notifier_lag_info info = {
+		.dp = dp,
+	};
+	bool tx_enabled;
+
+	if (!dp->lag)
+		return 0;
+
+	/* On statically configured aggregates (e.g. loadbalance
+	 * without LACP) ports will always be tx_enabled, even if the
+	 * link is down. Thus we require both link_up and tx_enabled
+	 * in order to include it in the tx set.
+	 */
+	tx_enabled = linfo->link_up && linfo->tx_enabled;
+
+	if (tx_enabled == dp->lag_tx_enabled)
+		return 0;
+
+	dp->lag_tx_enabled = tx_enabled;
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_LAG_CHANGE, &info);
+}
+
+static int dsa_port_lag_create(struct dsa_port *dp,
+			       struct net_device *lag_dev)
+{
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_lag *lag;
+
+	lag = dsa_tree_lag_find(ds->dst, lag_dev);
+	if (lag) {
+		refcount_inc(&lag->refcount);
+		dp->lag = lag;
+		return 0;
+	}
+
+	lag = kzalloc_obj(*lag);
+	if (!lag)
+		return -ENOMEM;
+
+	refcount_set(&lag->refcount, 1);
+	mutex_init(&lag->fdb_lock);
+	INIT_LIST_HEAD(&lag->fdbs);
+	lag->dev = lag_dev;
+	dsa_lag_map(ds->dst, lag);
+	dp->lag = lag;
+
+	return 0;
+}
+
+static void dsa_port_lag_destroy(struct dsa_port *dp)
+{
+	struct dsa_lag *lag = dp->lag;
+
+	dp->lag = NULL;
+	dp->lag_tx_enabled = false;
+
+	if (!refcount_dec_and_test(&lag->refcount))
+		return;
+
+	WARN_ON(!list_empty(&lag->fdbs));
+	dsa_lag_unmap(dp->ds->dst, lag);
+	kfree(lag);
+}
+
+int dsa_port_lag_join(struct dsa_port *dp, struct net_device *lag_dev,
+		      struct netdev_lag_upper_info *uinfo,
+		      struct netlink_ext_ack *extack)
+{
+	struct dsa_notifier_lag_info info = {
+		.dp = dp,
+		.info = uinfo,
+		.extack = extack,
+	};
+	struct net_device *bridge_dev;
+	int err;
+
+	err = dsa_port_lag_create(dp, lag_dev);
+	if (err)
+		goto err_lag_create;
+
+	info.lag = *dp->lag;
+	err = dsa_port_notify(dp, DSA_NOTIFIER_LAG_JOIN, &info);
+	if (err)
+		goto err_lag_join;
+
+	bridge_dev = netdev_master_upper_dev_get(lag_dev);
+	if (!bridge_dev || !netif_is_bridge_master(bridge_dev))
+		return 0;
+
+	err = dsa_port_bridge_join(dp, bridge_dev, extack);
+	if (err)
+		goto err_bridge_join;
+
+	return 0;
+
+err_bridge_join:
+	dsa_port_notify(dp, DSA_NOTIFIER_LAG_LEAVE, &info);
+err_lag_join:
+	dsa_port_lag_destroy(dp);
+err_lag_create:
+	return err;
+}
+
+void dsa_port_pre_lag_leave(struct dsa_port *dp, struct net_device *lag_dev)
+{
+	struct net_device *br = dsa_port_bridge_dev_get(dp);
+
+	if (br)
+		dsa_port_pre_bridge_leave(dp, br);
+}
+
+void dsa_port_lag_leave(struct dsa_port *dp, struct net_device *lag_dev)
+{
+	struct net_device *br = dsa_port_bridge_dev_get(dp);
+	struct dsa_notifier_lag_info info = {
+		.dp = dp,
+	};
+	int err;
+
+	if (!dp->lag)
+		return;
+
+	/* Port might have been part of a LAG that in turn was
+	 * attached to a bridge.
+	 */
+	if (br)
+		dsa_port_bridge_leave(dp, br);
+
+	info.lag = *dp->lag;
+
+	dsa_port_lag_destroy(dp);
+
+	err = dsa_port_notify(dp, DSA_NOTIFIER_LAG_LEAVE, &info);
+	if (err)
+		dev_err(dp->ds->dev,
+			"port %d failed to notify DSA_NOTIFIER_LAG_LEAVE: %pe\n",
+			dp->index, ERR_PTR(err));
+}
+
+/* Must be called under rcu_read_lock() */
+static bool dsa_port_can_apply_vlan_filtering(struct dsa_port *dp,
+					      bool vlan_filtering,
+					      struct netlink_ext_ack *extack)
+{
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_port *other_dp;
+	int err;
+
+	/* VLAN awareness was off, so the question is "can we turn it on".
+	 * We may have had 8021q uppers, those need to go. Make sure we don't
+	 * enter an inconsistent state: deny changing the VLAN awareness state
+	 * as long as we have 8021q uppers.
+	 */
+	if (vlan_filtering && dsa_port_is_user(dp)) {
+		struct net_device *br = dsa_port_bridge_dev_get(dp);
+		struct net_device *upper_dev, *user = dp->user;
+		struct list_head *iter;
+
+		netdev_for_each_upper_dev_rcu(user, upper_dev, iter) {
+			struct bridge_vlan_info br_info;
+			u16 vid;
+
+			if (!is_vlan_dev(upper_dev))
+				continue;
+
+			vid = vlan_dev_vlan_id(upper_dev);
+
+			/* br_vlan_get_info() returns -EINVAL or -ENOENT if the
+			 * device, respectively the VID is not found, returning
+			 * 0 means success, which is a failure for us here.
+			 */
+			err = br_vlan_get_info(br, vid, &br_info);
+			if (err == 0) {
+				NL_SET_ERR_MSG_MOD(extack,
+						   "Must first remove VLAN uppers having VIDs also present in bridge");
+				return false;
+			}
+		}
+	}
+
+	if (!ds->vlan_filtering_is_global)
+		return true;
+
+	/* For cases where enabling/disabling VLAN awareness is global to the
+	 * switch, we need to handle the case where multiple bridges span
+	 * different ports of the same switch device and one of them has a
+	 * different setting than what is being requested.
+	 */
+	dsa_switch_for_each_port(other_dp, ds) {
+		struct net_device *other_br = dsa_port_bridge_dev_get(other_dp);
+
+		/* If it's the same bridge, it also has same
+		 * vlan_filtering setting => no need to check
+		 */
+		if (!other_br || other_br == dsa_port_bridge_dev_get(dp))
+			continue;
+
+		if (br_vlan_enabled(other_br) != vlan_filtering) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "VLAN filtering is a global setting");
+			return false;
+		}
+	}
+	return true;
+}
+
+int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
+			    struct netlink_ext_ack *extack)
+{
+	bool old_vlan_filtering = dsa_port_is_vlan_filtering(dp);
+	struct dsa_switch *ds = dp->ds;
+	bool apply;
+	int err;
+
+	if (!ds->ops->port_vlan_filtering)
+		return -EOPNOTSUPP;
+
+	/* We are called from dsa_user_switchdev_blocking_event(),
+	 * which is not under rcu_read_lock(), unlike
+	 * dsa_user_switchdev_event().
+	 */
+	rcu_read_lock();
+	apply = dsa_port_can_apply_vlan_filtering(dp, vlan_filtering, extack);
+	rcu_read_unlock();
+	if (!apply)
+		return -EINVAL;
+
+	if (dsa_port_is_vlan_filtering(dp) == vlan_filtering)
+		return 0;
+
+	err = ds->ops->port_vlan_filtering(ds, dp->index, vlan_filtering,
+					   extack);
+	if (err)
+		return err;
+
+	if (ds->vlan_filtering_is_global) {
+		struct dsa_port *other_dp;
+
+		ds->vlan_filtering = vlan_filtering;
+
+		dsa_switch_for_each_user_port(other_dp, ds) {
+			struct net_device *user = other_dp->user;
+
+			/* We might be called in the unbind path, so not
+			 * all user devices might still be registered.
+			 */
+			if (!user)
+				continue;
+
+			err = dsa_user_manage_vlan_filtering(user,
+							     vlan_filtering);
+			if (err)
+				goto restore;
+		}
+	} else {
+		dp->vlan_filtering = vlan_filtering;
+
+		err = dsa_user_manage_vlan_filtering(dp->user,
+						     vlan_filtering);
+		if (err)
+			goto restore;
+	}
+
+	return 0;
+
+restore:
+	ds->ops->port_vlan_filtering(ds, dp->index, old_vlan_filtering, NULL);
+
+	if (ds->vlan_filtering_is_global)
+		ds->vlan_filtering = old_vlan_filtering;
+	else
+		dp->vlan_filtering = old_vlan_filtering;
+
+	return err;
+}
+
+/* This enforces legacy behavior for switch drivers which assume they can't
+ * receive VLAN configuration when joining a bridge with vlan_filtering=0
+ */
+bool dsa_port_skip_vlan_configuration(struct dsa_port *dp)
+{
+	struct net_device *br = dsa_port_bridge_dev_get(dp);
+	struct dsa_switch *ds = dp->ds;
+
+	if (!br)
+		return false;
+
+	return !ds->configure_vlan_while_not_filtering && !br_vlan_enabled(br);
+}
+
+int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock)
+{
+	unsigned long ageing_jiffies = clock_t_to_jiffies(ageing_clock);
+	unsigned int ageing_time = jiffies_to_msecs(ageing_jiffies);
+	struct dsa_notifier_ageing_time_info info;
+	int err;
+
+	info.ageing_time = ageing_time;
+
+	err = dsa_port_notify(dp, DSA_NOTIFIER_AGEING_TIME, &info);
+	if (err)
+		return err;
+
+	dp->ageing_time = ageing_time;
+
+	return 0;
+}
+
+int dsa_port_mst_enable(struct dsa_port *dp, bool on,
+			struct netlink_ext_ack *extack)
+{
+	if (on && !dsa_port_supports_mst(dp)) {
+		NL_SET_ERR_MSG_MOD(extack, "Hardware does not support MST");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int dsa_port_pre_bridge_flags(const struct dsa_port *dp,
+			      struct switchdev_brport_flags flags,
+			      struct netlink_ext_ack *extack)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->port_pre_bridge_flags)
+		return -EINVAL;
+
+	return ds->ops->port_pre_bridge_flags(ds, dp->index, flags, extack);
+}
+
+int dsa_port_bridge_flags(struct dsa_port *dp,
+			  struct switchdev_brport_flags flags,
+			  struct netlink_ext_ack *extack)
+{
+	struct dsa_switch *ds = dp->ds;
+	int err;
+
+	if (!ds->ops->port_bridge_flags)
+		return -EOPNOTSUPP;
+
+	err = ds->ops->port_bridge_flags(ds, dp->index, flags, extack);
+	if (err)
+		return err;
+
+	if (flags.mask & BR_LEARNING) {
+		bool learning = flags.val & BR_LEARNING;
+
+		if (learning == dp->learning)
+			return 0;
+
+		if ((dp->learning && !learning) &&
+		    (dp->stp_state == BR_STATE_LEARNING ||
+		     dp->stp_state == BR_STATE_FORWARDING))
+			dsa_port_fast_age(dp);
+
+		dp->learning = learning;
+	}
+
+	return 0;
+}
+
+void dsa_port_set_host_flood(struct dsa_port *dp, bool uc, bool mc)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->port_set_host_flood)
+		ds->ops->port_set_host_flood(ds, dp->index, uc, mc);
+}
+
+int dsa_port_vlan_msti(struct dsa_port *dp,
+		       const struct switchdev_vlan_msti *msti)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->vlan_msti_set)
+		return -EOPNOTSUPP;
+
+	return ds->ops->vlan_msti_set(ds, *dp->bridge, msti);
+}
+
+int dsa_port_mtu_change(struct dsa_port *dp, int new_mtu)
+{
+	struct dsa_notifier_mtu_info info = {
+		.dp = dp,
+		.mtu = new_mtu,
+	};
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_MTU, &info);
+}
+
+int dsa_port_fdb_add(struct dsa_port *dp, const unsigned char *addr,
+		     u16 vid)
+{
+	struct dsa_notifier_fdb_info info = {
+		.dp = dp,
+		.addr = addr,
+		.vid = vid,
+		.db = {
+			.type = DSA_DB_BRIDGE,
+			.bridge = *dp->bridge,
+		},
+	};
+
+	/* Refcounting takes bridge.num as a key, and should be global for all
+	 * bridges in the absence of FDB isolation, and per bridge otherwise.
+	 * Force the bridge.num to zero here in the absence of FDB isolation.
+	 */
+	if (!dp->ds->fdb_isolation)
+		info.db.bridge.num = 0;
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_FDB_ADD, &info);
+}
+
+int dsa_port_fdb_del(struct dsa_port *dp, const unsigned char *addr,
+		     u16 vid)
+{
+	struct dsa_notifier_fdb_info info = {
+		.dp = dp,
+		.addr = addr,
+		.vid = vid,
+		.db = {
+			.type = DSA_DB_BRIDGE,
+			.bridge = *dp->bridge,
+		},
+	};
+
+	if (!dp->ds->fdb_isolation)
+		info.db.bridge.num = 0;
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_FDB_DEL, &info);
+}
+
+static int dsa_port_host_fdb_add(struct dsa_port *dp,
+				 const unsigned char *addr, u16 vid,
+				 struct dsa_db db)
+{
+	struct dsa_notifier_fdb_info info = {
+		.dp = dp,
+		.addr = addr,
+		.vid = vid,
+		.db = db,
+	};
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_HOST_FDB_ADD, &info);
+}
+
+int dsa_port_standalone_host_fdb_add(struct dsa_port *dp,
+				     const unsigned char *addr, u16 vid)
+{
+	struct dsa_db db = {
+		.type = DSA_DB_PORT,
+		.dp = dp,
+	};
+
+	return dsa_port_host_fdb_add(dp, addr, vid, db);
+}
+
+int dsa_port_bridge_host_fdb_add(struct dsa_port *dp,
+				 const unsigned char *addr, u16 vid)
+{
+	struct net_device *conduit = dsa_port_to_conduit(dp);
+	struct dsa_db db = {
+		.type = DSA_DB_BRIDGE,
+		.bridge = *dp->bridge,
+	};
+	int err;
+
+	if (!dp->ds->fdb_isolation)
+		db.bridge.num = 0;
+
+	/* Avoid a call to __dev_set_promiscuity() on the conduit, which
+	 * requires rtnl_lock(), since we can't guarantee that is held here,
+	 * and we can't take it either.
+	 */
+	if (conduit->priv_flags & IFF_UNICAST_FLT) {
+		err = dev_uc_add(conduit, addr);
+		if (err)
+			return err;
+	}
+
+	return dsa_port_host_fdb_add(dp, addr, vid, db);
+}
+
+static int dsa_port_host_fdb_del(struct dsa_port *dp,
+				 const unsigned char *addr, u16 vid,
+				 struct dsa_db db)
+{
+	struct dsa_notifier_fdb_info info = {
+		.dp = dp,
+		.addr = addr,
+		.vid = vid,
+		.db = db,
+	};
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_HOST_FDB_DEL, &info);
+}
+
+int dsa_port_standalone_host_fdb_del(struct dsa_port *dp,
+				     const unsigned char *addr, u16 vid)
+{
+	struct dsa_db db = {
+		.type = DSA_DB_PORT,
+		.dp = dp,
+	};
+
+	return dsa_port_host_fdb_del(dp, addr, vid, db);
+}
+
+int dsa_port_bridge_host_fdb_del(struct dsa_port *dp,
+				 const unsigned char *addr, u16 vid)
+{
+	struct net_device *conduit = dsa_port_to_conduit(dp);
+	struct dsa_db db = {
+		.type = DSA_DB_BRIDGE,
+		.bridge = *dp->bridge,
+	};
+	int err;
+
+	if (!dp->ds->fdb_isolation)
+		db.bridge.num = 0;
+
+	if (conduit->priv_flags & IFF_UNICAST_FLT) {
+		err = dev_uc_del(conduit, addr);
+		if (err)
+			return err;
+	}
+
+	return dsa_port_host_fdb_del(dp, addr, vid, db);
+}
+
+int dsa_port_lag_fdb_add(struct dsa_port *dp, const unsigned char *addr,
+			 u16 vid)
+{
+	struct dsa_notifier_lag_fdb_info info = {
+		.lag = dp->lag,
+		.addr = addr,
+		.vid = vid,
+		.db = {
+			.type = DSA_DB_BRIDGE,
+			.bridge = *dp->bridge,
+		},
+	};
+
+	if (!dp->ds->fdb_isolation)
+		info.db.bridge.num = 0;
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_LAG_FDB_ADD, &info);
+}
+
+int dsa_port_lag_fdb_del(struct dsa_port *dp, const unsigned char *addr,
+			 u16 vid)
+{
+	struct dsa_notifier_lag_fdb_info info = {
+		.lag = dp->lag,
+		.addr = addr,
+		.vid = vid,
+		.db = {
+			.type = DSA_DB_BRIDGE,
+			.bridge = *dp->bridge,
+		},
+	};
+
+	if (!dp->ds->fdb_isolation)
+		info.db.bridge.num = 0;
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_LAG_FDB_DEL, &info);
+}
+
+int dsa_port_fdb_dump(struct dsa_port *dp, dsa_fdb_dump_cb_t *cb, void *data)
+{
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index;
+
+	if (!ds->ops->port_fdb_dump)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_fdb_dump(ds, port, cb, data);
+}
+
+int dsa_port_mdb_add(const struct dsa_port *dp,
+		     const struct switchdev_obj_port_mdb *mdb)
+{
+	struct dsa_notifier_mdb_info info = {
+		.dp = dp,
+		.mdb = mdb,
+		.db = {
+			.type = DSA_DB_BRIDGE,
+			.bridge = *dp->bridge,
+		},
+	};
+
+	if (!dp->ds->fdb_isolation)
+		info.db.bridge.num = 0;
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_MDB_ADD, &info);
+}
+
+int dsa_port_mdb_del(const struct dsa_port *dp,
+		     const struct switchdev_obj_port_mdb *mdb)
+{
+	struct dsa_notifier_mdb_info info = {
+		.dp = dp,
+		.mdb = mdb,
+		.db = {
+			.type = DSA_DB_BRIDGE,
+			.bridge = *dp->bridge,
+		},
+	};
+
+	if (!dp->ds->fdb_isolation)
+		info.db.bridge.num = 0;
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_MDB_DEL, &info);
+}
+
+static int dsa_port_host_mdb_add(const struct dsa_port *dp,
+				 const struct switchdev_obj_port_mdb *mdb,
+				 struct dsa_db db)
+{
+	struct dsa_notifier_mdb_info info = {
+		.dp = dp,
+		.mdb = mdb,
+		.db = db,
+	};
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_HOST_MDB_ADD, &info);
+}
+
+int dsa_port_standalone_host_mdb_add(const struct dsa_port *dp,
+				     const struct switchdev_obj_port_mdb *mdb)
+{
+	struct dsa_db db = {
+		.type = DSA_DB_PORT,
+		.dp = dp,
+	};
+
+	return dsa_port_host_mdb_add(dp, mdb, db);
+}
+
+int dsa_port_bridge_host_mdb_add(const struct dsa_port *dp,
+				 const struct switchdev_obj_port_mdb *mdb)
+{
+	struct net_device *conduit = dsa_port_to_conduit(dp);
+	struct dsa_db db = {
+		.type = DSA_DB_BRIDGE,
+		.bridge = *dp->bridge,
+	};
+	int err;
+
+	if (!dp->ds->fdb_isolation)
+		db.bridge.num = 0;
+
+	err = dev_mc_add(conduit, mdb->addr);
+	if (err)
+		return err;
+
+	return dsa_port_host_mdb_add(dp, mdb, db);
+}
+
+static int dsa_port_host_mdb_del(const struct dsa_port *dp,
+				 const struct switchdev_obj_port_mdb *mdb,
+				 struct dsa_db db)
+{
+	struct dsa_notifier_mdb_info info = {
+		.dp = dp,
+		.mdb = mdb,
+		.db = db,
+	};
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_HOST_MDB_DEL, &info);
+}
+
+int dsa_port_standalone_host_mdb_del(const struct dsa_port *dp,
+				     const struct switchdev_obj_port_mdb *mdb)
+{
+	struct dsa_db db = {
+		.type = DSA_DB_PORT,
+		.dp = dp,
+	};
+
+	return dsa_port_host_mdb_del(dp, mdb, db);
+}
+
+int dsa_port_bridge_host_mdb_del(const struct dsa_port *dp,
+				 const struct switchdev_obj_port_mdb *mdb)
+{
+	struct net_device *conduit = dsa_port_to_conduit(dp);
+	struct dsa_db db = {
+		.type = DSA_DB_BRIDGE,
+		.bridge = *dp->bridge,
+	};
+	int err;
+
+	if (!dp->ds->fdb_isolation)
+		db.bridge.num = 0;
+
+	err = dev_mc_del(conduit, mdb->addr);
+	if (err)
+		return err;
+
+	return dsa_port_host_mdb_del(dp, mdb, db);
+}
+
+int dsa_port_vlan_add(struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan,
+		      struct netlink_ext_ack *extack)
+{
+	struct dsa_notifier_vlan_info info = {
+		.dp = dp,
+		.vlan = vlan,
+		.extack = extack,
+	};
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_ADD, &info);
+}
+
+int dsa_port_vlan_del(struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan)
+{
+	struct dsa_notifier_vlan_info info = {
+		.dp = dp,
+		.vlan = vlan,
+	};
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_DEL, &info);
+}
+
+int dsa_port_host_vlan_add(struct dsa_port *dp,
+			   const struct switchdev_obj_port_vlan *vlan,
+			   struct netlink_ext_ack *extack)
+{
+	struct net_device *conduit = dsa_port_to_conduit(dp);
+	struct dsa_notifier_vlan_info info = {
+		.dp = dp,
+		.vlan = vlan,
+		.extack = extack,
+	};
+	int err;
+
+	err = dsa_port_notify(dp, DSA_NOTIFIER_HOST_VLAN_ADD, &info);
+	if (err && err != -EOPNOTSUPP)
+		return err;
+
+	vlan_vid_add(conduit, htons(ETH_P_8021Q), vlan->vid);
+
+	return err;
+}
+
+int dsa_port_host_vlan_del(struct dsa_port *dp,
+			   const struct switchdev_obj_port_vlan *vlan)
+{
+	struct net_device *conduit = dsa_port_to_conduit(dp);
+	struct dsa_notifier_vlan_info info = {
+		.dp = dp,
+		.vlan = vlan,
+	};
+	int err;
+
+	err = dsa_port_notify(dp, DSA_NOTIFIER_HOST_VLAN_DEL, &info);
+	if (err && err != -EOPNOTSUPP)
+		return err;
+
+	vlan_vid_del(conduit, htons(ETH_P_8021Q), vlan->vid);
+
+	return err;
+}
+
+int dsa_port_mrp_add(const struct dsa_port *dp,
+		     const struct switchdev_obj_mrp *mrp)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->port_mrp_add)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_mrp_add(ds, dp->index, mrp);
+}
+
+int dsa_port_mrp_del(const struct dsa_port *dp,
+		     const struct switchdev_obj_mrp *mrp)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->port_mrp_del)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_mrp_del(ds, dp->index, mrp);
+}
+
+int dsa_port_mrp_add_ring_role(const struct dsa_port *dp,
+			       const struct switchdev_obj_ring_role_mrp *mrp)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->port_mrp_add_ring_role)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_mrp_add_ring_role(ds, dp->index, mrp);
+}
+
+int dsa_port_mrp_del_ring_role(const struct dsa_port *dp,
+			       const struct switchdev_obj_ring_role_mrp *mrp)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->port_mrp_del_ring_role)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_mrp_del_ring_role(ds, dp->index, mrp);
+}
+
+static int dsa_port_assign_conduit(struct dsa_port *dp,
+				   struct net_device *conduit,
+				   struct netlink_ext_ack *extack,
+				   bool fail_on_err)
+{
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index, err;
+
+	err = ds->ops->port_change_conduit(ds, port, conduit, extack);
+	if (err && !fail_on_err)
+		dev_err(ds->dev, "port %d failed to assign conduit %s: %pe\n",
+			port, conduit->name, ERR_PTR(err));
+
+	if (err && fail_on_err)
+		return err;
+
+	dp->cpu_dp = conduit->dsa_ptr;
+	dp->cpu_port_in_lag = netif_is_lag_master(conduit);
+
+	return 0;
+}
+
+/* Change the dp->cpu_dp affinity for a user port. Note that both cross-chip
+ * notifiers and drivers have implicit assumptions about user-to-CPU-port
+ * mappings, so we unfortunately cannot delay the deletion of the objects
+ * (switchdev, standalone addresses, standalone VLANs) on the old CPU port
+ * until the new CPU port has been set up. So we need to completely tear down
+ * the old CPU port before changing it, and restore it on errors during the
+ * bringup of the new one.
+ */
+int dsa_port_change_conduit(struct dsa_port *dp, struct net_device *conduit,
+			    struct netlink_ext_ack *extack)
+{
+	struct net_device *bridge_dev = dsa_port_bridge_dev_get(dp);
+	struct net_device *old_conduit = dsa_port_to_conduit(dp);
+	struct net_device *dev = dp->user;
+	struct dsa_switch *ds = dp->ds;
+	bool vlan_filtering;
+	int err, tmp;
+
+	/* Bridges may hold host FDB, MDB and VLAN objects. These need to be
+	 * migrated, so dynamically unoffload and later reoffload the bridge
+	 * port.
+	 */
+	if (bridge_dev) {
+		dsa_port_pre_bridge_leave(dp, bridge_dev);
+		dsa_port_bridge_leave(dp, bridge_dev);
+	}
+
+	/* The port might still be VLAN filtering even if it's no longer
+	 * under a bridge, either due to ds->vlan_filtering_is_global or
+	 * ds->needs_standalone_vlan_filtering. In turn this means VLANs
+	 * on the CPU port.
+	 */
+	vlan_filtering = dsa_port_is_vlan_filtering(dp);
+	if (vlan_filtering) {
+		err = dsa_user_manage_vlan_filtering(dev, false);
+		if (err) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Failed to remove standalone VLANs");
+			goto rewind_old_bridge;
+		}
+	}
+
+	/* Standalone addresses, and addresses of upper interfaces like
+	 * VLAN, LAG, HSR need to be migrated.
+	 */
+	dsa_user_unsync_ha(dev);
+
+	/* If live-changing, we also need to uninstall the user device address
+	 * from the port FDB and the conduit interface.
+	 */
+	if (dev->flags & IFF_UP)
+		dsa_user_host_uc_uninstall(dev);
+
+	err = dsa_port_assign_conduit(dp, conduit, extack, true);
+	if (err)
+		goto rewind_old_addrs;
+
+	/* If the port doesn't have its own MAC address and relies on the DSA
+	 * conduit's one, inherit it again from the new DSA conduit.
+	 */
+	if (is_zero_ether_addr(dp->mac))
+		eth_hw_addr_inherit(dev, conduit);
+
+	/* If live-changing, we need to install the user device address to the
+	 * port FDB and the conduit interface.
+	 */
+	if (dev->flags & IFF_UP) {
+		err = dsa_user_host_uc_install(dev, dev->dev_addr);
+		if (err) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Failed to install host UC address");
+			goto rewind_addr_inherit;
+		}
+	}
+
+	dsa_user_sync_ha(dev);
+
+	if (vlan_filtering) {
+		err = dsa_user_manage_vlan_filtering(dev, true);
+		if (err) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Failed to restore standalone VLANs");
+			goto rewind_new_addrs;
+		}
+	}
+
+	if (bridge_dev) {
+		err = dsa_port_bridge_join(dp, bridge_dev, extack);
+		if (err && err == -EOPNOTSUPP) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Failed to reoffload bridge");
+			goto rewind_new_vlan;
+		}
+	}
+
+	return 0;
+
+rewind_new_vlan:
+	if (vlan_filtering)
+		dsa_user_manage_vlan_filtering(dev, false);
+
+rewind_new_addrs:
+	dsa_user_unsync_ha(dev);
+
+	if (dev->flags & IFF_UP)
+		dsa_user_host_uc_uninstall(dev);
+
+rewind_addr_inherit:
+	if (is_zero_ether_addr(dp->mac))
+		eth_hw_addr_inherit(dev, old_conduit);
+
+	dsa_port_assign_conduit(dp, old_conduit, NULL, false);
+
+/* Restore the objects on the old CPU port */
+rewind_old_addrs:
+	if (dev->flags & IFF_UP) {
+		tmp = dsa_user_host_uc_install(dev, dev->dev_addr);
+		if (tmp) {
+			dev_err(ds->dev,
+				"port %d failed to restore host UC address: %pe\n",
+				dp->index, ERR_PTR(tmp));
+		}
+	}
+
+	dsa_user_sync_ha(dev);
+
+	if (vlan_filtering) {
+		tmp = dsa_user_manage_vlan_filtering(dev, true);
+		if (tmp) {
+			dev_err(ds->dev,
+				"port %d failed to restore standalone VLANs: %pe\n",
+				dp->index, ERR_PTR(tmp));
+		}
+	}
+
+rewind_old_bridge:
+	if (bridge_dev) {
+		tmp = dsa_port_bridge_join(dp, bridge_dev, extack);
+		if (tmp) {
+			dev_err(ds->dev,
+				"port %d failed to rejoin bridge %s: %pe\n",
+				dp->index, bridge_dev->name, ERR_PTR(tmp));
+		}
+	}
+
+	return err;
+}
+
+void dsa_port_set_tag_protocol(struct dsa_port *cpu_dp,
+			       const struct dsa_device_ops *tag_ops)
+{
+	cpu_dp->rcv = tag_ops->rcv;
+	cpu_dp->tag_ops = tag_ops;
+}
+
+/* dsa_supports_eee - indicate that EEE is supported
+ * @ds: pointer to &struct dsa_switch
+ * @port: port index
+ *
+ * A default implementation for the .support_eee() DSA operations member,
+ * which drivers can use to indicate that they support EEE on all of their
+ * user ports.
+ *
+ * Returns: true
+ */
+bool dsa_supports_eee(struct dsa_switch *ds, int port)
+{
+	return true;
+}
+EXPORT_SYMBOL_GPL(dsa_supports_eee);
+
+static void dsa_port_phylink_mac_config(struct phylink_config *config,
+					unsigned int mode,
+					const struct phylink_link_state *state)
+{
+}
+
+static void dsa_port_phylink_mac_link_down(struct phylink_config *config,
+					   unsigned int mode,
+					   phy_interface_t interface)
+{
+}
+
+static void dsa_port_phylink_mac_link_up(struct phylink_config *config,
+					 struct phy_device *phydev,
+					 unsigned int mode,
+					 phy_interface_t interface,
+					 int speed, int duplex,
+					 bool tx_pause, bool rx_pause)
+{
+}
+
+static const struct phylink_mac_ops dsa_port_phylink_mac_ops = {
+	.mac_config = dsa_port_phylink_mac_config,
+	.mac_link_down = dsa_port_phylink_mac_link_down,
+	.mac_link_up = dsa_port_phylink_mac_link_up,
+};
+
+int dsa_port_phylink_create(struct dsa_port *dp)
+{
+	const struct phylink_mac_ops *mac_ops;
+	struct dsa_switch *ds = dp->ds;
+	phy_interface_t mode;
+	struct phylink *pl;
+	int err;
+
+	err = of_get_phy_mode(dp->dn, &mode);
+	if (err)
+		mode = PHY_INTERFACE_MODE_NA;
+
+	if (ds->ops->phylink_get_caps) {
+		ds->ops->phylink_get_caps(ds, dp->index, &dp->pl_config);
+	} else {
+		/* For legacy drivers */
+		if (mode != PHY_INTERFACE_MODE_NA) {
+			__set_bit(mode, dp->pl_config.supported_interfaces);
+		} else {
+			__set_bit(PHY_INTERFACE_MODE_INTERNAL,
+				  dp->pl_config.supported_interfaces);
+			__set_bit(PHY_INTERFACE_MODE_GMII,
+				  dp->pl_config.supported_interfaces);
+		}
+	}
+
+	mac_ops = &dsa_port_phylink_mac_ops;
+	if (ds->phylink_mac_ops)
+		mac_ops = ds->phylink_mac_ops;
+
+	pl = phylink_create(&dp->pl_config, of_fwnode_handle(dp->dn), mode,
+			    mac_ops);
+	if (IS_ERR(pl)) {
+		pr_err("error creating PHYLINK: %ld\n", PTR_ERR(pl));
+		return PTR_ERR(pl);
+	}
+
+	dp->pl = pl;
+
+	return 0;
+}
+
+void dsa_port_phylink_destroy(struct dsa_port *dp)
+{
+	phylink_destroy(dp->pl);
+	dp->pl = NULL;
+}
+
+static int dsa_shared_port_phylink_register(struct dsa_port *dp)
+{
+	struct dsa_switch *ds = dp->ds;
+	struct device_node *port_dn = dp->dn;
+	int err;
+
+	dp->pl_config.dev = ds->dev;
+	dp->pl_config.type = PHYLINK_DEV;
+
+	err = dsa_port_phylink_create(dp);
+	if (err)
+		return err;
+
+	err = phylink_of_phy_connect(dp->pl, port_dn, 0);
+	if (err && err != -ENODEV) {
+		pr_err("could not attach to PHY: %d\n", err);
+		goto err_phy_connect;
+	}
+
+	return 0;
+
+err_phy_connect:
+	dsa_port_phylink_destroy(dp);
+	return err;
+}
+
+/* During the initial DSA driver migration to OF, port nodes were sometimes
+ * added to device trees with no indication of how they should operate from a
+ * link management perspective (phy-handle, fixed-link, etc). Additionally, the
+ * phy-mode may be absent. The interpretation of these port OF nodes depends on
+ * their type.
+ *
+ * User ports with no phy-handle or fixed-link are expected to connect to an
+ * internal PHY located on the ds->user_mii_bus at an MDIO address equal to
+ * the port number. This description is still actively supported.
+ *
+ * Shared (CPU and DSA) ports with no phy-handle or fixed-link are expected to
+ * operate at the maximum speed that their phy-mode is capable of. If the
+ * phy-mode is absent, they are expected to operate using the phy-mode
+ * supported by the port that gives the highest link speed. It is unspecified
+ * if the port should use flow control or not, half duplex or full duplex, or
+ * if the phy-mode is a SERDES link, whether in-band autoneg is expected to be
+ * enabled or not.
+ *
+ * In the latter case of shared ports, omitting the link management description
+ * from the firmware node is deprecated and strongly discouraged. DSA uses
+ * phylink, which rejects the firmware nodes of these ports for lacking
+ * required properties.
+ *
+ * For switches in this table, DSA will skip enforcing validation and will
+ * later omit registering a phylink instance for the shared ports, if they lack
+ * a fixed-link, a phy-handle, or a managed = "in-band-status" property.
+ * It becomes the responsibility of the driver to ensure that these ports
+ * operate at the maximum speed (whatever this means) and will interoperate
+ * with the DSA conduit or other cascade port, since phylink methods will not be
+ * invoked for them.
+ *
+ * If you are considering expanding this table for newly introduced switches,
+ * think again. It is OK to remove switches from this table if there aren't DT
+ * blobs in circulation which rely on defaulting the shared ports.
+ */
+static const char * const dsa_switches_apply_workarounds[] = {
+#if IS_ENABLED(CONFIG_NET_DSA_XRS700X)
+	"arrow,xrs7003e",
+	"arrow,xrs7003f",
+	"arrow,xrs7004e",
+	"arrow,xrs7004f",
+#endif
+#if IS_ENABLED(CONFIG_B53)
+	"brcm,bcm5325",
+	"brcm,bcm53115",
+	"brcm,bcm53125",
+	"brcm,bcm53128",
+	"brcm,bcm5365",
+	"brcm,bcm5389",
+	"brcm,bcm5395",
+	"brcm,bcm5397",
+	"brcm,bcm5398",
+	"brcm,bcm53010-srab",
+	"brcm,bcm53011-srab",
+	"brcm,bcm53012-srab",
+	"brcm,bcm53018-srab",
+	"brcm,bcm53019-srab",
+	"brcm,bcm5301x-srab",
+	"brcm,bcm11360-srab",
+	"brcm,bcm58522-srab",
+	"brcm,bcm58525-srab",
+	"brcm,bcm58535-srab",
+	"brcm,bcm58622-srab",
+	"brcm,bcm58623-srab",
+	"brcm,bcm58625-srab",
+	"brcm,bcm88312-srab",
+	"brcm,cygnus-srab",
+	"brcm,nsp-srab",
+	"brcm,omega-srab",
+	"brcm,bcm3384-switch",
+	"brcm,bcm6328-switch",
+	"brcm,bcm6368-switch",
+	"brcm,bcm63xx-switch",
+#endif
+#if IS_ENABLED(CONFIG_NET_DSA_BCM_SF2)
+	"brcm,bcm7445-switch-v4.0",
+	"brcm,bcm7278-switch-v4.0",
+	"brcm,bcm7278-switch-v4.8",
+#endif
+#if IS_ENABLED(CONFIG_NET_DSA_LANTIQ_GSWIP)
+	"lantiq,xrx200-gswip",
+	"lantiq,xrx300-gswip",
+	"lantiq,xrx330-gswip",
+#endif
+#if IS_ENABLED(CONFIG_NET_DSA_MV88E6060)
+	"marvell,mv88e6060",
+#endif
+#if IS_ENABLED(CONFIG_NET_DSA_MV88E6XXX)
+	"marvell,mv88e6085",
+	"marvell,mv88e6190",
+	"marvell,mv88e6250",
+#endif
+#if IS_ENABLED(CONFIG_NET_DSA_MICROCHIP_KSZ_COMMON)
+	"microchip,ksz8765",
+	"microchip,ksz8794",
+	"microchip,ksz8795",
+	"microchip,ksz8863",
+	"microchip,ksz8873",
+	"microchip,ksz9477",
+	"microchip,ksz9897",
+	"microchip,ksz9893",
+	"microchip,ksz9563",
+	"microchip,ksz8563",
+	"microchip,ksz9567",
+#endif
+#if IS_ENABLED(CONFIG_NET_DSA_SMSC_LAN9303_MDIO)
+	"smsc,lan9303-mdio",
+#endif
+#if IS_ENABLED(CONFIG_NET_DSA_SMSC_LAN9303_I2C)
+	"smsc,lan9303-i2c",
+#endif
+	NULL,
+};
+
+static void dsa_shared_port_validate_of(struct dsa_port *dp,
+					bool *missing_phy_mode,
+					bool *missing_link_description)
+{
+	struct device_node *dn = dp->dn, *phy_np;
+	struct dsa_switch *ds = dp->ds;
+	phy_interface_t mode;
+
+	*missing_phy_mode = false;
+	*missing_link_description = false;
+
+	if (of_get_phy_mode(dn, &mode)) {
+		*missing_phy_mode = true;
+		dev_err(ds->dev,
+			"OF node %pOF of %s port %d lacks the required \"phy-mode\" property\n",
+			dn, dsa_port_is_cpu(dp) ? "CPU" : "DSA", dp->index);
+	}
+
+	/* Note: of_phy_is_fixed_link() also returns true for
+	 * managed = "in-band-status"
+	 */
+	if (of_phy_is_fixed_link(dn))
+		return;
+
+	phy_np = of_parse_phandle(dn, "phy-handle", 0);
+	if (phy_np) {
+		of_node_put(phy_np);
+		return;
+	}
+
+	*missing_link_description = true;
+
+	dev_err(ds->dev,
+		"OF node %pOF of %s port %d lacks the required \"phy-handle\", \"fixed-link\" or \"managed\" properties\n",
+		dn, dsa_port_is_cpu(dp) ? "CPU" : "DSA", dp->index);
+}
+
+static void dsa_shared_port_link_down(struct dsa_port *dp)
+{
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->phylink_mac_ops && ds->phylink_mac_ops->mac_link_down)
+		ds->phylink_mac_ops->mac_link_down(&dp->pl_config, MLO_AN_FIXED,
+						   PHY_INTERFACE_MODE_NA);
+}
+
+int dsa_shared_port_link_register_of(struct dsa_port *dp)
+{
+	struct dsa_switch *ds = dp->ds;
+	bool missing_link_description;
+	bool missing_phy_mode;
+
+	dsa_shared_port_validate_of(dp, &missing_phy_mode,
+				    &missing_link_description);
+
+	if ((missing_phy_mode || missing_link_description) &&
+	    !of_device_compatible_match(ds->dev->of_node,
+					dsa_switches_apply_workarounds))
+		return -EINVAL;
+
+	if (missing_link_description) {
+		dev_warn(ds->dev,
+			 "Skipping phylink registration for %s port %d\n",
+			 dsa_port_is_cpu(dp) ? "CPU" : "DSA", dp->index);
+	} else {
+		dsa_shared_port_link_down(dp);
+
+		return dsa_shared_port_phylink_register(dp);
+	}
+
+	return 0;
+}
+
+void dsa_shared_port_link_unregister_of(struct dsa_port *dp)
+{
+	if (dp->pl) {
+		rtnl_lock();
+		phylink_disconnect_phy(dp->pl);
+		rtnl_unlock();
+		dsa_port_phylink_destroy(dp);
+		return;
+	}
+}
+
+int dsa_port_hsr_join(struct dsa_port *dp, struct net_device *hsr,
+		      struct netlink_ext_ack *extack)
+{
+	struct dsa_switch *ds = dp->ds;
+	int err;
+
+	if (!ds->ops->port_hsr_join)
+		return -EOPNOTSUPP;
+
+	dp->hsr_dev = hsr;
+
+	err = ds->ops->port_hsr_join(ds, dp->index, hsr, extack);
+	if (err)
+		dp->hsr_dev = NULL;
+
+	return err;
+}
+
+void dsa_port_hsr_leave(struct dsa_port *dp, struct net_device *hsr)
+{
+	struct dsa_switch *ds = dp->ds;
+	int err;
+
+	if (!dp->hsr_dev)
+		return;
+
+	dp->hsr_dev = NULL;
+
+	if (ds->ops->port_hsr_leave) {
+		err = ds->ops->port_hsr_leave(ds, dp->index, hsr);
+		if (err)
+			dev_err(dp->ds->dev,
+				"port %d failed to leave HSR %s: %pe\n",
+				dp->index, hsr->name, ERR_PTR(err));
+	}
+}
+
+int dsa_port_tag_8021q_vlan_add(struct dsa_port *dp, u16 vid, bool broadcast)
+{
+	struct dsa_notifier_tag_8021q_vlan_info info = {
+		.dp = dp,
+		.vid = vid,
+	};
+
+	if (broadcast)
+		return dsa_broadcast(DSA_NOTIFIER_TAG_8021Q_VLAN_ADD, &info);
+
+	return dsa_port_notify(dp, DSA_NOTIFIER_TAG_8021Q_VLAN_ADD, &info);
+}
+
+void dsa_port_tag_8021q_vlan_del(struct dsa_port *dp, u16 vid, bool broadcast)
+{
+	struct dsa_notifier_tag_8021q_vlan_info info = {
+		.dp = dp,
+		.vid = vid,
+	};
+	int err;
+
+	if (broadcast)
+		err = dsa_broadcast(DSA_NOTIFIER_TAG_8021Q_VLAN_DEL, &info);
+	else
+		err = dsa_port_notify(dp, DSA_NOTIFIER_TAG_8021Q_VLAN_DEL, &info);
+	if (err)
+		dev_err(dp->ds->dev,
+			"port %d failed to notify tag_8021q VLAN %d deletion: %pe\n",
+			dp->index, vid, ERR_PTR(err));
+}
diff --git a/net/dsa/port.h b/net/dsa/port.h
new file mode 100644
index 000000000..6bc329157
--- /dev/null
+++ b/net/dsa/port.h
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __DSA_PORT_H
+#define __DSA_PORT_H
+
+#include <linux/types.h>
+#include <net/dsa.h>
+
+struct ifreq;
+struct netdev_lag_lower_state_info;
+struct netdev_lag_upper_info;
+struct netlink_ext_ack;
+struct switchdev_mst_state;
+struct switchdev_obj_port_mdb;
+struct switchdev_vlan_msti;
+struct phy_device;
+
+bool dsa_port_supports_hwtstamp(struct dsa_port *dp);
+void dsa_port_set_tag_protocol(struct dsa_port *cpu_dp,
+			       const struct dsa_device_ops *tag_ops);
+int dsa_port_set_state(struct dsa_port *dp, u8 state, bool do_fast_age);
+int dsa_port_set_mst_state(struct dsa_port *dp,
+			   const struct switchdev_mst_state *state,
+			   struct netlink_ext_ack *extack);
+int dsa_port_enable_rt(struct dsa_port *dp, struct phy_device *phy);
+int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy);
+void dsa_port_disable_rt(struct dsa_port *dp);
+void dsa_port_disable(struct dsa_port *dp);
+int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br,
+			 struct netlink_ext_ack *extack);
+void dsa_port_pre_bridge_leave(struct dsa_port *dp, struct net_device *br);
+void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br);
+int dsa_port_lag_change(struct dsa_port *dp,
+			struct netdev_lag_lower_state_info *linfo);
+int dsa_port_lag_join(struct dsa_port *dp, struct net_device *lag_dev,
+		      struct netdev_lag_upper_info *uinfo,
+		      struct netlink_ext_ack *extack);
+void dsa_port_pre_lag_leave(struct dsa_port *dp, struct net_device *lag_dev);
+void dsa_port_lag_leave(struct dsa_port *dp, struct net_device *lag_dev);
+int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
+			    struct netlink_ext_ack *extack);
+bool dsa_port_skip_vlan_configuration(struct dsa_port *dp);
+int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock);
+int dsa_port_mst_enable(struct dsa_port *dp, bool on,
+			struct netlink_ext_ack *extack);
+int dsa_port_vlan_msti(struct dsa_port *dp,
+		       const struct switchdev_vlan_msti *msti);
+int dsa_port_mtu_change(struct dsa_port *dp, int new_mtu);
+int dsa_port_fdb_add(struct dsa_port *dp, const unsigned char *addr,
+		     u16 vid);
+int dsa_port_fdb_del(struct dsa_port *dp, const unsigned char *addr,
+		     u16 vid);
+int dsa_port_standalone_host_fdb_add(struct dsa_port *dp,
+				     const unsigned char *addr, u16 vid);
+int dsa_port_standalone_host_fdb_del(struct dsa_port *dp,
+				     const unsigned char *addr, u16 vid);
+int dsa_port_bridge_host_fdb_add(struct dsa_port *dp, const unsigned char *addr,
+				 u16 vid);
+int dsa_port_bridge_host_fdb_del(struct dsa_port *dp, const unsigned char *addr,
+				 u16 vid);
+int dsa_port_lag_fdb_add(struct dsa_port *dp, const unsigned char *addr,
+			 u16 vid);
+int dsa_port_lag_fdb_del(struct dsa_port *dp, const unsigned char *addr,
+			 u16 vid);
+int dsa_port_fdb_dump(struct dsa_port *dp, dsa_fdb_dump_cb_t *cb, void *data);
+int dsa_port_mdb_add(const struct dsa_port *dp,
+		     const struct switchdev_obj_port_mdb *mdb);
+int dsa_port_mdb_del(const struct dsa_port *dp,
+		     const struct switchdev_obj_port_mdb *mdb);
+int dsa_port_standalone_host_mdb_add(const struct dsa_port *dp,
+				     const struct switchdev_obj_port_mdb *mdb);
+int dsa_port_standalone_host_mdb_del(const struct dsa_port *dp,
+				     const struct switchdev_obj_port_mdb *mdb);
+int dsa_port_bridge_host_mdb_add(const struct dsa_port *dp,
+				 const struct switchdev_obj_port_mdb *mdb);
+int dsa_port_bridge_host_mdb_del(const struct dsa_port *dp,
+				 const struct switchdev_obj_port_mdb *mdb);
+int dsa_port_pre_bridge_flags(const struct dsa_port *dp,
+			      struct switchdev_brport_flags flags,
+			      struct netlink_ext_ack *extack);
+int dsa_port_bridge_flags(struct dsa_port *dp,
+			  struct switchdev_brport_flags flags,
+			  struct netlink_ext_ack *extack);
+int dsa_port_vlan_add(struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan,
+		      struct netlink_ext_ack *extack);
+int dsa_port_vlan_del(struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan);
+int dsa_port_host_vlan_add(struct dsa_port *dp,
+			   const struct switchdev_obj_port_vlan *vlan,
+			   struct netlink_ext_ack *extack);
+int dsa_port_host_vlan_del(struct dsa_port *dp,
+			   const struct switchdev_obj_port_vlan *vlan);
+int dsa_port_mrp_add(const struct dsa_port *dp,
+		     const struct switchdev_obj_mrp *mrp);
+int dsa_port_mrp_del(const struct dsa_port *dp,
+		     const struct switchdev_obj_mrp *mrp);
+int dsa_port_mrp_add_ring_role(const struct dsa_port *dp,
+			       const struct switchdev_obj_ring_role_mrp *mrp);
+int dsa_port_mrp_del_ring_role(const struct dsa_port *dp,
+			       const struct switchdev_obj_ring_role_mrp *mrp);
+int dsa_port_phylink_create(struct dsa_port *dp);
+void dsa_port_phylink_destroy(struct dsa_port *dp);
+int dsa_shared_port_link_register_of(struct dsa_port *dp);
+void dsa_shared_port_link_unregister_of(struct dsa_port *dp);
+int dsa_port_hsr_join(struct dsa_port *dp, struct net_device *hsr,
+		      struct netlink_ext_ack *extack);
+void dsa_port_hsr_leave(struct dsa_port *dp, struct net_device *hsr);
+int dsa_port_tag_8021q_vlan_add(struct dsa_port *dp, u16 vid, bool broadcast);
+void dsa_port_tag_8021q_vlan_del(struct dsa_port *dp, u16 vid, bool broadcast);
+void dsa_port_set_host_flood(struct dsa_port *dp, bool uc, bool mc);
+int dsa_port_change_conduit(struct dsa_port *dp, struct net_device *conduit,
+			    struct netlink_ext_ack *extack);
+
+#endif
diff --git a/net/dsa/stubs.c b/net/dsa/stubs.c
new file mode 100644
index 000000000..2ed8a6c85
--- /dev/null
+++ b/net/dsa/stubs.c
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Stubs for DSA functionality called by the core network stack.
+ * These are necessary because CONFIG_NET_DSA can be a module, and built-in
+ * code cannot directly call symbols exported by modules.
+ */
+#include <net/dsa_stubs.h>
+
+const struct dsa_stubs *dsa_stubs;
+EXPORT_SYMBOL_GPL(dsa_stubs);
diff --git a/net/dsa/switch.c b/net/dsa/switch.c
new file mode 100644
index 000000000..a670a04ed
--- /dev/null
+++ b/net/dsa/switch.c
@@ -0,0 +1,1134 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Handling of a single switch chip, part of a switch fabric
+ *
+ * Copyright (c) 2017 Savoir-faire Linux Inc.
+ *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
+ */
+
+#include <linux/if_bridge.h>
+#include <linux/netdevice.h>
+#include <linux/notifier.h>
+#include <linux/if_vlan.h>
+#include <net/switchdev.h>
+
+#include "dsa.h"
+#include "netlink.h"
+#include "port.h"
+#include "switch.h"
+#include "tag_8021q.h"
+#include "trace.h"
+#include "user.h"
+
+static unsigned int dsa_switch_fastest_ageing_time(struct dsa_switch *ds,
+						   unsigned int ageing_time)
+{
+	struct dsa_port *dp;
+
+	dsa_switch_for_each_port(dp, ds)
+		if (dp->ageing_time && dp->ageing_time < ageing_time)
+			ageing_time = dp->ageing_time;
+
+	return ageing_time;
+}
+
+static int dsa_switch_ageing_time(struct dsa_switch *ds,
+				  struct dsa_notifier_ageing_time_info *info)
+{
+	unsigned int ageing_time = info->ageing_time;
+
+	if (ds->ageing_time_min && ageing_time < ds->ageing_time_min)
+		return -ERANGE;
+
+	if (ds->ageing_time_max && ageing_time > ds->ageing_time_max)
+		return -ERANGE;
+
+	/* Program the fastest ageing time in case of multiple bridges */
+	ageing_time = dsa_switch_fastest_ageing_time(ds, ageing_time);
+
+	if (ds->ops->set_ageing_time)
+		return ds->ops->set_ageing_time(ds, ageing_time);
+
+	return 0;
+}
+
+static bool dsa_port_mtu_match(struct dsa_port *dp,
+			       struct dsa_notifier_mtu_info *info)
+{
+	return dp == info->dp || dsa_port_is_dsa(dp) || dsa_port_is_cpu(dp);
+}
+
+static int dsa_switch_mtu(struct dsa_switch *ds,
+			  struct dsa_notifier_mtu_info *info)
+{
+	struct dsa_port *dp;
+	int ret;
+
+	if (!ds->ops->port_change_mtu)
+		return -EOPNOTSUPP;
+
+	dsa_switch_for_each_port(dp, ds) {
+		if (dsa_port_mtu_match(dp, info)) {
+			ret = ds->ops->port_change_mtu(ds, dp->index,
+						       info->mtu);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int dsa_switch_bridge_join(struct dsa_switch *ds,
+				  struct dsa_notifier_bridge_info *info)
+{
+	int err;
+
+	if (info->dp->ds == ds) {
+		if (!ds->ops->port_bridge_join)
+			return -EOPNOTSUPP;
+
+		err = ds->ops->port_bridge_join(ds, info->dp->index,
+						info->bridge,
+						&info->tx_fwd_offload,
+						info->extack);
+		if (err)
+			return err;
+	}
+
+	if (info->dp->ds != ds && ds->ops->crosschip_bridge_join) {
+		err = ds->ops->crosschip_bridge_join(ds,
+						     info->dp->ds->dst->index,
+						     info->dp->ds->index,
+						     info->dp->index,
+						     info->bridge,
+						     info->extack);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static int dsa_switch_bridge_leave(struct dsa_switch *ds,
+				   struct dsa_notifier_bridge_info *info)
+{
+	if (info->dp->ds == ds && ds->ops->port_bridge_leave)
+		ds->ops->port_bridge_leave(ds, info->dp->index, info->bridge);
+
+	if (info->dp->ds != ds && ds->ops->crosschip_bridge_leave)
+		ds->ops->crosschip_bridge_leave(ds, info->dp->ds->dst->index,
+						info->dp->ds->index,
+						info->dp->index,
+						info->bridge);
+
+	return 0;
+}
+
+/* Matches for all upstream-facing ports (the CPU port and all upstream-facing
+ * DSA links) that sit between the targeted port on which the notifier was
+ * emitted and its dedicated CPU port.
+ */
+static bool dsa_port_host_address_match(struct dsa_port *dp,
+					const struct dsa_port *targeted_dp)
+{
+	struct dsa_port *cpu_dp = targeted_dp->cpu_dp;
+
+	if (dsa_switch_is_upstream_of(dp->ds, targeted_dp->ds))
+		return dp->index == dsa_towards_port(dp->ds, cpu_dp->ds->index,
+						     cpu_dp->index);
+
+	return false;
+}
+
+static struct dsa_mac_addr *dsa_mac_addr_find(struct list_head *addr_list,
+					      const unsigned char *addr, u16 vid,
+					      struct dsa_db db)
+{
+	struct dsa_mac_addr *a;
+
+	list_for_each_entry(a, addr_list, list)
+		if (ether_addr_equal(a->addr, addr) && a->vid == vid &&
+		    dsa_db_equal(&a->db, &db))
+			return a;
+
+	return NULL;
+}
+
+static int dsa_port_do_mdb_add(struct dsa_port *dp,
+			       const struct switchdev_obj_port_mdb *mdb,
+			       struct dsa_db db)
+{
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_mac_addr *a;
+	int port = dp->index;
+	int err = 0;
+
+	/* No need to bother with refcounting for user ports */
+	if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) {
+		err = ds->ops->port_mdb_add(ds, port, mdb, db);
+		trace_dsa_mdb_add_hw(dp, mdb->addr, mdb->vid, &db, err);
+
+		return err;
+	}
+
+	mutex_lock(&dp->addr_lists_lock);
+
+	a = dsa_mac_addr_find(&dp->mdbs, mdb->addr, mdb->vid, db);
+	if (a) {
+		refcount_inc(&a->refcount);
+		trace_dsa_mdb_add_bump(dp, mdb->addr, mdb->vid, &db,
+				       &a->refcount);
+		goto out;
+	}
+
+	a = kzalloc_obj(*a);
+	if (!a) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = ds->ops->port_mdb_add(ds, port, mdb, db);
+	trace_dsa_mdb_add_hw(dp, mdb->addr, mdb->vid, &db, err);
+	if (err) {
+		kfree(a);
+		goto out;
+	}
+
+	ether_addr_copy(a->addr, mdb->addr);
+	a->vid = mdb->vid;
+	a->db = db;
+	refcount_set(&a->refcount, 1);
+	list_add_tail(&a->list, &dp->mdbs);
+
+out:
+	mutex_unlock(&dp->addr_lists_lock);
+
+	return err;
+}
+
+static int dsa_port_do_mdb_del(struct dsa_port *dp,
+			       const struct switchdev_obj_port_mdb *mdb,
+			       struct dsa_db db)
+{
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_mac_addr *a;
+	int port = dp->index;
+	int err = 0;
+
+	/* No need to bother with refcounting for user ports */
+	if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) {
+		err = ds->ops->port_mdb_del(ds, port, mdb, db);
+		trace_dsa_mdb_del_hw(dp, mdb->addr, mdb->vid, &db, err);
+
+		return err;
+	}
+
+	mutex_lock(&dp->addr_lists_lock);
+
+	a = dsa_mac_addr_find(&dp->mdbs, mdb->addr, mdb->vid, db);
+	if (!a) {
+		trace_dsa_mdb_del_not_found(dp, mdb->addr, mdb->vid, &db);
+		err = -ENOENT;
+		goto out;
+	}
+
+	if (!refcount_dec_and_test(&a->refcount)) {
+		trace_dsa_mdb_del_drop(dp, mdb->addr, mdb->vid, &db,
+				       &a->refcount);
+		goto out;
+	}
+
+	err = ds->ops->port_mdb_del(ds, port, mdb, db);
+	trace_dsa_mdb_del_hw(dp, mdb->addr, mdb->vid, &db, err);
+	if (err) {
+		refcount_set(&a->refcount, 1);
+		goto out;
+	}
+
+	list_del(&a->list);
+	kfree(a);
+
+out:
+	mutex_unlock(&dp->addr_lists_lock);
+
+	return err;
+}
+
+static int dsa_port_do_fdb_add(struct dsa_port *dp, const unsigned char *addr,
+			       u16 vid, struct dsa_db db)
+{
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_mac_addr *a;
+	int port = dp->index;
+	int err = 0;
+
+	/* No need to bother with refcounting for user ports */
+	if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) {
+		err = ds->ops->port_fdb_add(ds, port, addr, vid, db);
+		trace_dsa_fdb_add_hw(dp, addr, vid, &db, err);
+
+		return err;
+	}
+
+	mutex_lock(&dp->addr_lists_lock);
+
+	a = dsa_mac_addr_find(&dp->fdbs, addr, vid, db);
+	if (a) {
+		refcount_inc(&a->refcount);
+		trace_dsa_fdb_add_bump(dp, addr, vid, &db, &a->refcount);
+		goto out;
+	}
+
+	a = kzalloc_obj(*a);
+	if (!a) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = ds->ops->port_fdb_add(ds, port, addr, vid, db);
+	trace_dsa_fdb_add_hw(dp, addr, vid, &db, err);
+	if (err) {
+		kfree(a);
+		goto out;
+	}
+
+	ether_addr_copy(a->addr, addr);
+	a->vid = vid;
+	a->db = db;
+	refcount_set(&a->refcount, 1);
+	list_add_tail(&a->list, &dp->fdbs);
+
+out:
+	mutex_unlock(&dp->addr_lists_lock);
+
+	return err;
+}
+
+static int dsa_port_do_fdb_del(struct dsa_port *dp, const unsigned char *addr,
+			       u16 vid, struct dsa_db db)
+{
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_mac_addr *a;
+	int port = dp->index;
+	int err = 0;
+
+	/* No need to bother with refcounting for user ports */
+	if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) {
+		err = ds->ops->port_fdb_del(ds, port, addr, vid, db);
+		trace_dsa_fdb_del_hw(dp, addr, vid, &db, err);
+
+		return err;
+	}
+
+	mutex_lock(&dp->addr_lists_lock);
+
+	a = dsa_mac_addr_find(&dp->fdbs, addr, vid, db);
+	if (!a) {
+		trace_dsa_fdb_del_not_found(dp, addr, vid, &db);
+		err = -ENOENT;
+		goto out;
+	}
+
+	if (!refcount_dec_and_test(&a->refcount)) {
+		trace_dsa_fdb_del_drop(dp, addr, vid, &db, &a->refcount);
+		goto out;
+	}
+
+	err = ds->ops->port_fdb_del(ds, port, addr, vid, db);
+	trace_dsa_fdb_del_hw(dp, addr, vid, &db, err);
+	if (err) {
+		refcount_set(&a->refcount, 1);
+		goto out;
+	}
+
+	list_del(&a->list);
+	kfree(a);
+
+out:
+	mutex_unlock(&dp->addr_lists_lock);
+
+	return err;
+}
+
+static int dsa_switch_do_lag_fdb_add(struct dsa_switch *ds, struct dsa_lag *lag,
+				     const unsigned char *addr, u16 vid,
+				     struct dsa_db db)
+{
+	struct dsa_mac_addr *a;
+	int err = 0;
+
+	mutex_lock(&lag->fdb_lock);
+
+	a = dsa_mac_addr_find(&lag->fdbs, addr, vid, db);
+	if (a) {
+		refcount_inc(&a->refcount);
+		trace_dsa_lag_fdb_add_bump(lag->dev, addr, vid, &db,
+					   &a->refcount);
+		goto out;
+	}
+
+	a = kzalloc_obj(*a);
+	if (!a) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = ds->ops->lag_fdb_add(ds, *lag, addr, vid, db);
+	trace_dsa_lag_fdb_add_hw(lag->dev, addr, vid, &db, err);
+	if (err) {
+		kfree(a);
+		goto out;
+	}
+
+	ether_addr_copy(a->addr, addr);
+	a->vid = vid;
+	a->db = db;
+	refcount_set(&a->refcount, 1);
+	list_add_tail(&a->list, &lag->fdbs);
+
+out:
+	mutex_unlock(&lag->fdb_lock);
+
+	return err;
+}
+
+static int dsa_switch_do_lag_fdb_del(struct dsa_switch *ds, struct dsa_lag *lag,
+				     const unsigned char *addr, u16 vid,
+				     struct dsa_db db)
+{
+	struct dsa_mac_addr *a;
+	int err = 0;
+
+	mutex_lock(&lag->fdb_lock);
+
+	a = dsa_mac_addr_find(&lag->fdbs, addr, vid, db);
+	if (!a) {
+		trace_dsa_lag_fdb_del_not_found(lag->dev, addr, vid, &db);
+		err = -ENOENT;
+		goto out;
+	}
+
+	if (!refcount_dec_and_test(&a->refcount)) {
+		trace_dsa_lag_fdb_del_drop(lag->dev, addr, vid, &db,
+					   &a->refcount);
+		goto out;
+	}
+
+	err = ds->ops->lag_fdb_del(ds, *lag, addr, vid, db);
+	trace_dsa_lag_fdb_del_hw(lag->dev, addr, vid, &db, err);
+	if (err) {
+		refcount_set(&a->refcount, 1);
+		goto out;
+	}
+
+	list_del(&a->list);
+	kfree(a);
+
+out:
+	mutex_unlock(&lag->fdb_lock);
+
+	return err;
+}
+
+static int dsa_switch_host_fdb_add(struct dsa_switch *ds,
+				   struct dsa_notifier_fdb_info *info)
+{
+	struct dsa_port *dp;
+	int err = 0;
+
+	if (!ds->ops->port_fdb_add)
+		return -EOPNOTSUPP;
+
+	dsa_switch_for_each_port(dp, ds) {
+		if (dsa_port_host_address_match(dp, info->dp)) {
+			if (dsa_port_is_cpu(dp) && info->dp->cpu_port_in_lag) {
+				err = dsa_switch_do_lag_fdb_add(ds, dp->lag,
+								info->addr,
+								info->vid,
+								info->db);
+			} else {
+				err = dsa_port_do_fdb_add(dp, info->addr,
+							  info->vid, info->db);
+			}
+			if (err)
+				break;
+		}
+	}
+
+	return err;
+}
+
+static int dsa_switch_host_fdb_del(struct dsa_switch *ds,
+				   struct dsa_notifier_fdb_info *info)
+{
+	struct dsa_port *dp;
+	int err = 0;
+
+	if (!ds->ops->port_fdb_del)
+		return -EOPNOTSUPP;
+
+	dsa_switch_for_each_port(dp, ds) {
+		if (dsa_port_host_address_match(dp, info->dp)) {
+			if (dsa_port_is_cpu(dp) && info->dp->cpu_port_in_lag) {
+				err = dsa_switch_do_lag_fdb_del(ds, dp->lag,
+								info->addr,
+								info->vid,
+								info->db);
+			} else {
+				err = dsa_port_do_fdb_del(dp, info->addr,
+							  info->vid, info->db);
+			}
+			if (err)
+				break;
+		}
+	}
+
+	return err;
+}
+
+static int dsa_switch_fdb_add(struct dsa_switch *ds,
+			      struct dsa_notifier_fdb_info *info)
+{
+	int port = dsa_towards_port(ds, info->dp->ds->index, info->dp->index);
+	struct dsa_port *dp = dsa_to_port(ds, port);
+
+	if (!ds->ops->port_fdb_add)
+		return -EOPNOTSUPP;
+
+	return dsa_port_do_fdb_add(dp, info->addr, info->vid, info->db);
+}
+
+static int dsa_switch_fdb_del(struct dsa_switch *ds,
+			      struct dsa_notifier_fdb_info *info)
+{
+	int port = dsa_towards_port(ds, info->dp->ds->index, info->dp->index);
+	struct dsa_port *dp = dsa_to_port(ds, port);
+
+	if (!ds->ops->port_fdb_del)
+		return -EOPNOTSUPP;
+
+	return dsa_port_do_fdb_del(dp, info->addr, info->vid, info->db);
+}
+
+static int dsa_switch_lag_fdb_add(struct dsa_switch *ds,
+				  struct dsa_notifier_lag_fdb_info *info)
+{
+	struct dsa_port *dp;
+
+	if (!ds->ops->lag_fdb_add)
+		return -EOPNOTSUPP;
+
+	/* Notify switch only if it has a port in this LAG */
+	dsa_switch_for_each_port(dp, ds)
+		if (dsa_port_offloads_lag(dp, info->lag))
+			return dsa_switch_do_lag_fdb_add(ds, info->lag,
+							 info->addr, info->vid,
+							 info->db);
+
+	return 0;
+}
+
+static int dsa_switch_lag_fdb_del(struct dsa_switch *ds,
+				  struct dsa_notifier_lag_fdb_info *info)
+{
+	struct dsa_port *dp;
+
+	if (!ds->ops->lag_fdb_del)
+		return -EOPNOTSUPP;
+
+	/* Notify switch only if it has a port in this LAG */
+	dsa_switch_for_each_port(dp, ds)
+		if (dsa_port_offloads_lag(dp, info->lag))
+			return dsa_switch_do_lag_fdb_del(ds, info->lag,
+							 info->addr, info->vid,
+							 info->db);
+
+	return 0;
+}
+
+static int dsa_switch_lag_change(struct dsa_switch *ds,
+				 struct dsa_notifier_lag_info *info)
+{
+	if (info->dp->ds == ds && ds->ops->port_lag_change)
+		return ds->ops->port_lag_change(ds, info->dp->index);
+
+	if (info->dp->ds != ds && ds->ops->crosschip_lag_change)
+		return ds->ops->crosschip_lag_change(ds, info->dp->ds->index,
+						     info->dp->index);
+
+	return 0;
+}
+
+static int dsa_switch_lag_join(struct dsa_switch *ds,
+			       struct dsa_notifier_lag_info *info)
+{
+	if (info->dp->ds == ds && ds->ops->port_lag_join)
+		return ds->ops->port_lag_join(ds, info->dp->index, info->lag,
+					      info->info, info->extack);
+
+	if (info->dp->ds != ds && ds->ops->crosschip_lag_join)
+		return ds->ops->crosschip_lag_join(ds, info->dp->ds->index,
+						   info->dp->index, info->lag,
+						   info->info, info->extack);
+
+	return -EOPNOTSUPP;
+}
+
+static int dsa_switch_lag_leave(struct dsa_switch *ds,
+				struct dsa_notifier_lag_info *info)
+{
+	if (info->dp->ds == ds && ds->ops->port_lag_leave)
+		return ds->ops->port_lag_leave(ds, info->dp->index, info->lag);
+
+	if (info->dp->ds != ds && ds->ops->crosschip_lag_leave)
+		return ds->ops->crosschip_lag_leave(ds, info->dp->ds->index,
+						    info->dp->index, info->lag);
+
+	return -EOPNOTSUPP;
+}
+
+static int dsa_switch_mdb_add(struct dsa_switch *ds,
+			      struct dsa_notifier_mdb_info *info)
+{
+	int port = dsa_towards_port(ds, info->dp->ds->index, info->dp->index);
+	struct dsa_port *dp = dsa_to_port(ds, port);
+
+	if (!ds->ops->port_mdb_add)
+		return -EOPNOTSUPP;
+
+	return dsa_port_do_mdb_add(dp, info->mdb, info->db);
+}
+
+static int dsa_switch_mdb_del(struct dsa_switch *ds,
+			      struct dsa_notifier_mdb_info *info)
+{
+	int port = dsa_towards_port(ds, info->dp->ds->index, info->dp->index);
+	struct dsa_port *dp = dsa_to_port(ds, port);
+
+	if (!ds->ops->port_mdb_del)
+		return -EOPNOTSUPP;
+
+	return dsa_port_do_mdb_del(dp, info->mdb, info->db);
+}
+
+static int dsa_switch_host_mdb_add(struct dsa_switch *ds,
+				   struct dsa_notifier_mdb_info *info)
+{
+	struct dsa_port *dp;
+	int err = 0;
+
+	if (!ds->ops->port_mdb_add)
+		return -EOPNOTSUPP;
+
+	dsa_switch_for_each_port(dp, ds) {
+		if (dsa_port_host_address_match(dp, info->dp)) {
+			err = dsa_port_do_mdb_add(dp, info->mdb, info->db);
+			if (err)
+				break;
+		}
+	}
+
+	return err;
+}
+
+static int dsa_switch_host_mdb_del(struct dsa_switch *ds,
+				   struct dsa_notifier_mdb_info *info)
+{
+	struct dsa_port *dp;
+	int err = 0;
+
+	if (!ds->ops->port_mdb_del)
+		return -EOPNOTSUPP;
+
+	dsa_switch_for_each_port(dp, ds) {
+		if (dsa_port_host_address_match(dp, info->dp)) {
+			err = dsa_port_do_mdb_del(dp, info->mdb, info->db);
+			if (err)
+				break;
+		}
+	}
+
+	return err;
+}
+
+/* Port VLANs match on the targeted port and on all DSA ports */
+static bool dsa_port_vlan_match(struct dsa_port *dp,
+				struct dsa_notifier_vlan_info *info)
+{
+	return dsa_port_is_dsa(dp) || dp == info->dp;
+}
+
+/* Host VLANs match on the targeted port's CPU port, and on all DSA ports
+ * (upstream and downstream) of that switch and its upstream switches.
+ */
+static bool dsa_port_host_vlan_match(struct dsa_port *dp,
+				     const struct dsa_port *targeted_dp)
+{
+	struct dsa_port *cpu_dp = targeted_dp->cpu_dp;
+
+	if (dsa_switch_is_upstream_of(dp->ds, targeted_dp->ds))
+		return dsa_port_is_dsa(dp) || dp == cpu_dp;
+
+	return false;
+}
+
+struct dsa_vlan *dsa_vlan_find(struct list_head *vlan_list,
+			       const struct switchdev_obj_port_vlan *vlan)
+{
+	struct dsa_vlan *v;
+
+	list_for_each_entry(v, vlan_list, list)
+		if (v->vid == vlan->vid)
+			return v;
+
+	return NULL;
+}
+
+static int dsa_port_do_vlan_add(struct dsa_port *dp,
+				const struct switchdev_obj_port_vlan *vlan,
+				struct netlink_ext_ack *extack)
+{
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index;
+	struct dsa_vlan *v;
+	int err = 0;
+
+	/* No need to bother with refcounting for user ports. */
+	if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) {
+		err = ds->ops->port_vlan_add(ds, port, vlan, extack);
+		trace_dsa_vlan_add_hw(dp, vlan, err);
+
+		return err;
+	}
+
+	/* No need to propagate on shared ports the existing VLANs that were
+	 * re-notified after just the flags have changed. This would cause a
+	 * refcount bump which we need to avoid, since it unbalances the
+	 * additions with the deletions.
+	 */
+	if (vlan->changed)
+		return 0;
+
+	mutex_lock(&dp->vlans_lock);
+
+	v = dsa_vlan_find(&dp->vlans, vlan);
+	if (v) {
+		refcount_inc(&v->refcount);
+		trace_dsa_vlan_add_bump(dp, vlan, &v->refcount);
+		goto out;
+	}
+
+	v = kzalloc_obj(*v);
+	if (!v) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = ds->ops->port_vlan_add(ds, port, vlan, extack);
+	trace_dsa_vlan_add_hw(dp, vlan, err);
+	if (err) {
+		kfree(v);
+		goto out;
+	}
+
+	v->vid = vlan->vid;
+	refcount_set(&v->refcount, 1);
+	list_add_tail(&v->list, &dp->vlans);
+
+out:
+	mutex_unlock(&dp->vlans_lock);
+
+	return err;
+}
+
+static int dsa_port_do_vlan_del(struct dsa_port *dp,
+				const struct switchdev_obj_port_vlan *vlan)
+{
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index;
+	struct dsa_vlan *v;
+	int err = 0;
+
+	/* No need to bother with refcounting for user ports */
+	if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) {
+		err = ds->ops->port_vlan_del(ds, port, vlan);
+		trace_dsa_vlan_del_hw(dp, vlan, err);
+
+		return err;
+	}
+
+	mutex_lock(&dp->vlans_lock);
+
+	v = dsa_vlan_find(&dp->vlans, vlan);
+	if (!v) {
+		trace_dsa_vlan_del_not_found(dp, vlan);
+		err = -ENOENT;
+		goto out;
+	}
+
+	if (!refcount_dec_and_test(&v->refcount)) {
+		trace_dsa_vlan_del_drop(dp, vlan, &v->refcount);
+		goto out;
+	}
+
+	err = ds->ops->port_vlan_del(ds, port, vlan);
+	trace_dsa_vlan_del_hw(dp, vlan, err);
+	if (err) {
+		refcount_set(&v->refcount, 1);
+		goto out;
+	}
+
+	list_del(&v->list);
+	kfree(v);
+
+out:
+	mutex_unlock(&dp->vlans_lock);
+
+	return err;
+}
+
+static int dsa_switch_vlan_add(struct dsa_switch *ds,
+			       struct dsa_notifier_vlan_info *info)
+{
+	struct dsa_port *dp;
+	int err;
+
+	if (!ds->ops->port_vlan_add)
+		return -EOPNOTSUPP;
+
+	dsa_switch_for_each_port(dp, ds) {
+		if (dsa_port_vlan_match(dp, info)) {
+			err = dsa_port_do_vlan_add(dp, info->vlan,
+						   info->extack);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+static int dsa_switch_vlan_del(struct dsa_switch *ds,
+			       struct dsa_notifier_vlan_info *info)
+{
+	struct dsa_port *dp;
+	int err;
+
+	if (!ds->ops->port_vlan_del)
+		return -EOPNOTSUPP;
+
+	dsa_switch_for_each_port(dp, ds) {
+		if (dsa_port_vlan_match(dp, info)) {
+			err = dsa_port_do_vlan_del(dp, info->vlan);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+static int dsa_switch_host_vlan_add(struct dsa_switch *ds,
+				    struct dsa_notifier_vlan_info *info)
+{
+	struct dsa_port *dp;
+	int err;
+
+	if (!ds->ops->port_vlan_add)
+		return -EOPNOTSUPP;
+
+	dsa_switch_for_each_port(dp, ds) {
+		if (dsa_port_host_vlan_match(dp, info->dp)) {
+			err = dsa_port_do_vlan_add(dp, info->vlan,
+						   info->extack);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+static int dsa_switch_host_vlan_del(struct dsa_switch *ds,
+				    struct dsa_notifier_vlan_info *info)
+{
+	struct dsa_port *dp;
+	int err;
+
+	if (!ds->ops->port_vlan_del)
+		return -EOPNOTSUPP;
+
+	dsa_switch_for_each_port(dp, ds) {
+		if (dsa_port_host_vlan_match(dp, info->dp)) {
+			err = dsa_port_do_vlan_del(dp, info->vlan);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+static int dsa_switch_change_tag_proto(struct dsa_switch *ds,
+				       struct dsa_notifier_tag_proto_info *info)
+{
+	const struct dsa_device_ops *tag_ops = info->tag_ops;
+	struct dsa_port *dp, *cpu_dp;
+	int err;
+
+	if (!ds->ops->change_tag_protocol)
+		return -EOPNOTSUPP;
+
+	ASSERT_RTNL();
+
+	err = ds->ops->change_tag_protocol(ds, tag_ops->proto);
+	if (err)
+		return err;
+
+	dsa_switch_for_each_cpu_port(cpu_dp, ds)
+		dsa_port_set_tag_protocol(cpu_dp, tag_ops);
+
+	/* Now that changing the tag protocol can no longer fail, let's update
+	 * the remaining bits which are "duplicated for faster access", and the
+	 * bits that depend on the tagger, such as the MTU.
+	 */
+	dsa_switch_for_each_user_port(dp, ds) {
+		struct net_device *user = dp->user;
+
+		dsa_user_setup_tagger(user);
+
+		/* rtnl_mutex is held in dsa_tree_change_tag_proto */
+		dsa_user_change_mtu(user, user->mtu);
+	}
+
+	return 0;
+}
+
+/* We use the same cross-chip notifiers to inform both the tagger side, as well
+ * as the switch side, of connection and disconnection events.
+ * Since ds->tagger_data is owned by the tagger, it isn't a hard error if the
+ * switch side doesn't support connecting to this tagger, and therefore, the
+ * fact that we don't disconnect the tagger side doesn't constitute a memory
+ * leak: the tagger will still operate with persistent per-switch memory, just
+ * with the switch side unconnected to it. What does constitute a hard error is
+ * when the switch side supports connecting but fails.
+ */
+static int
+dsa_switch_connect_tag_proto(struct dsa_switch *ds,
+			     struct dsa_notifier_tag_proto_info *info)
+{
+	const struct dsa_device_ops *tag_ops = info->tag_ops;
+	int err;
+
+	/* Notify the new tagger about the connection to this switch */
+	if (tag_ops->connect) {
+		err = tag_ops->connect(ds);
+		if (err)
+			return err;
+	}
+
+	if (!ds->ops->connect_tag_protocol)
+		return -EOPNOTSUPP;
+
+	/* Notify the switch about the connection to the new tagger */
+	err = ds->ops->connect_tag_protocol(ds, tag_ops->proto);
+	if (err) {
+		/* Revert the new tagger's connection to this tree */
+		if (tag_ops->disconnect)
+			tag_ops->disconnect(ds);
+		return err;
+	}
+
+	return 0;
+}
+
+static int
+dsa_switch_disconnect_tag_proto(struct dsa_switch *ds,
+				struct dsa_notifier_tag_proto_info *info)
+{
+	const struct dsa_device_ops *tag_ops = info->tag_ops;
+
+	/* Notify the tagger about the disconnection from this switch */
+	if (tag_ops->disconnect && ds->tagger_data)
+		tag_ops->disconnect(ds);
+
+	/* No need to notify the switch, since it shouldn't have any
+	 * resources to tear down
+	 */
+	return 0;
+}
+
+static int
+dsa_switch_conduit_state_change(struct dsa_switch *ds,
+				struct dsa_notifier_conduit_state_info *info)
+{
+	if (!ds->ops->conduit_state_change)
+		return 0;
+
+	ds->ops->conduit_state_change(ds, info->conduit, info->operational);
+
+	return 0;
+}
+
+static int dsa_switch_event(struct notifier_block *nb,
+			    unsigned long event, void *info)
+{
+	struct dsa_switch *ds = container_of(nb, struct dsa_switch, nb);
+	int err;
+
+	switch (event) {
+	case DSA_NOTIFIER_AGEING_TIME:
+		err = dsa_switch_ageing_time(ds, info);
+		break;
+	case DSA_NOTIFIER_BRIDGE_JOIN:
+		err = dsa_switch_bridge_join(ds, info);
+		break;
+	case DSA_NOTIFIER_BRIDGE_LEAVE:
+		err = dsa_switch_bridge_leave(ds, info);
+		break;
+	case DSA_NOTIFIER_FDB_ADD:
+		err = dsa_switch_fdb_add(ds, info);
+		break;
+	case DSA_NOTIFIER_FDB_DEL:
+		err = dsa_switch_fdb_del(ds, info);
+		break;
+	case DSA_NOTIFIER_HOST_FDB_ADD:
+		err = dsa_switch_host_fdb_add(ds, info);
+		break;
+	case DSA_NOTIFIER_HOST_FDB_DEL:
+		err = dsa_switch_host_fdb_del(ds, info);
+		break;
+	case DSA_NOTIFIER_LAG_FDB_ADD:
+		err = dsa_switch_lag_fdb_add(ds, info);
+		break;
+	case DSA_NOTIFIER_LAG_FDB_DEL:
+		err = dsa_switch_lag_fdb_del(ds, info);
+		break;
+	case DSA_NOTIFIER_LAG_CHANGE:
+		err = dsa_switch_lag_change(ds, info);
+		break;
+	case DSA_NOTIFIER_LAG_JOIN:
+		err = dsa_switch_lag_join(ds, info);
+		break;
+	case DSA_NOTIFIER_LAG_LEAVE:
+		err = dsa_switch_lag_leave(ds, info);
+		break;
+	case DSA_NOTIFIER_MDB_ADD:
+		err = dsa_switch_mdb_add(ds, info);
+		break;
+	case DSA_NOTIFIER_MDB_DEL:
+		err = dsa_switch_mdb_del(ds, info);
+		break;
+	case DSA_NOTIFIER_HOST_MDB_ADD:
+		err = dsa_switch_host_mdb_add(ds, info);
+		break;
+	case DSA_NOTIFIER_HOST_MDB_DEL:
+		err = dsa_switch_host_mdb_del(ds, info);
+		break;
+	case DSA_NOTIFIER_VLAN_ADD:
+		err = dsa_switch_vlan_add(ds, info);
+		break;
+	case DSA_NOTIFIER_VLAN_DEL:
+		err = dsa_switch_vlan_del(ds, info);
+		break;
+	case DSA_NOTIFIER_HOST_VLAN_ADD:
+		err = dsa_switch_host_vlan_add(ds, info);
+		break;
+	case DSA_NOTIFIER_HOST_VLAN_DEL:
+		err = dsa_switch_host_vlan_del(ds, info);
+		break;
+	case DSA_NOTIFIER_MTU:
+		err = dsa_switch_mtu(ds, info);
+		break;
+	case DSA_NOTIFIER_TAG_PROTO:
+		err = dsa_switch_change_tag_proto(ds, info);
+		break;
+	case DSA_NOTIFIER_TAG_PROTO_CONNECT:
+		err = dsa_switch_connect_tag_proto(ds, info);
+		break;
+	case DSA_NOTIFIER_TAG_PROTO_DISCONNECT:
+		err = dsa_switch_disconnect_tag_proto(ds, info);
+		break;
+	case DSA_NOTIFIER_TAG_8021Q_VLAN_ADD:
+		err = dsa_switch_tag_8021q_vlan_add(ds, info);
+		break;
+	case DSA_NOTIFIER_TAG_8021Q_VLAN_DEL:
+		err = dsa_switch_tag_8021q_vlan_del(ds, info);
+		break;
+	case DSA_NOTIFIER_CONDUIT_STATE_CHANGE:
+		err = dsa_switch_conduit_state_change(ds, info);
+		break;
+	default:
+		err = -EOPNOTSUPP;
+		break;
+	}
+
+	if (err)
+		dev_dbg(ds->dev, "breaking chain for DSA event %lu (%d)\n",
+			event, err);
+
+	return notifier_from_errno(err);
+}
+
+/**
+ * dsa_tree_notify - Execute code for all switches in a DSA switch tree.
+ * @dst: collection of struct dsa_switch devices to notify.
+ * @e: event, must be of type DSA_NOTIFIER_*
+ * @v: event-specific value.
+ *
+ * Given a struct dsa_switch_tree, this can be used to run a function once for
+ * each member DSA switch. The other alternative of traversing the tree is only
+ * through its ports list, which does not uniquely list the switches.
+ */
+int dsa_tree_notify(struct dsa_switch_tree *dst, unsigned long e, void *v)
+{
+	struct raw_notifier_head *nh = &dst->nh;
+	int err;
+
+	err = raw_notifier_call_chain(nh, e, v);
+
+	return notifier_to_errno(err);
+}
+
+/**
+ * dsa_broadcast - Notify all DSA trees in the system.
+ * @e: event, must be of type DSA_NOTIFIER_*
+ * @v: event-specific value.
+ *
+ * Can be used to notify the switching fabric of events such as cross-chip
+ * bridging between disjoint trees (such as islands of tagger-compatible
+ * switches bridged by an incompatible middle switch).
+ *
+ * WARNING: this function is not reliable during probe time, because probing
+ * between trees is asynchronous and not all DSA trees might have probed.
+ */
+int dsa_broadcast(unsigned long e, void *v)
+{
+	struct dsa_switch_tree *dst;
+	int err = 0;
+
+	list_for_each_entry(dst, &dsa_tree_list, list) {
+		err = dsa_tree_notify(dst, e, v);
+		if (err)
+			break;
+	}
+
+	return err;
+}
+
+int dsa_switch_register_notifier(struct dsa_switch *ds)
+{
+	ds->nb.notifier_call = dsa_switch_event;
+
+	return raw_notifier_chain_register(&ds->dst->nh, &ds->nb);
+}
+
+void dsa_switch_unregister_notifier(struct dsa_switch *ds)
+{
+	int err;
+
+	err = raw_notifier_chain_unregister(&ds->dst->nh, &ds->nb);
+	if (err)
+		dev_err(ds->dev, "failed to unregister notifier (%d)\n", err);
+}
diff --git a/net/dsa/switch.h b/net/dsa/switch.h
new file mode 100644
index 000000000..be0a2749c
--- /dev/null
+++ b/net/dsa/switch.h
@@ -0,0 +1,123 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __DSA_SWITCH_H
+#define __DSA_SWITCH_H
+
+#include <net/dsa.h>
+
+struct netlink_ext_ack;
+
+enum {
+	DSA_NOTIFIER_AGEING_TIME,
+	DSA_NOTIFIER_BRIDGE_JOIN,
+	DSA_NOTIFIER_BRIDGE_LEAVE,
+	DSA_NOTIFIER_FDB_ADD,
+	DSA_NOTIFIER_FDB_DEL,
+	DSA_NOTIFIER_HOST_FDB_ADD,
+	DSA_NOTIFIER_HOST_FDB_DEL,
+	DSA_NOTIFIER_LAG_FDB_ADD,
+	DSA_NOTIFIER_LAG_FDB_DEL,
+	DSA_NOTIFIER_LAG_CHANGE,
+	DSA_NOTIFIER_LAG_JOIN,
+	DSA_NOTIFIER_LAG_LEAVE,
+	DSA_NOTIFIER_MDB_ADD,
+	DSA_NOTIFIER_MDB_DEL,
+	DSA_NOTIFIER_HOST_MDB_ADD,
+	DSA_NOTIFIER_HOST_MDB_DEL,
+	DSA_NOTIFIER_VLAN_ADD,
+	DSA_NOTIFIER_VLAN_DEL,
+	DSA_NOTIFIER_HOST_VLAN_ADD,
+	DSA_NOTIFIER_HOST_VLAN_DEL,
+	DSA_NOTIFIER_MTU,
+	DSA_NOTIFIER_TAG_PROTO,
+	DSA_NOTIFIER_TAG_PROTO_CONNECT,
+	DSA_NOTIFIER_TAG_PROTO_DISCONNECT,
+	DSA_NOTIFIER_TAG_8021Q_VLAN_ADD,
+	DSA_NOTIFIER_TAG_8021Q_VLAN_DEL,
+	DSA_NOTIFIER_CONDUIT_STATE_CHANGE,
+};
+
+/* DSA_NOTIFIER_AGEING_TIME */
+struct dsa_notifier_ageing_time_info {
+	unsigned int ageing_time;
+};
+
+/* DSA_NOTIFIER_BRIDGE_* */
+struct dsa_notifier_bridge_info {
+	const struct dsa_port *dp;
+	struct dsa_bridge bridge;
+	bool tx_fwd_offload;
+	struct netlink_ext_ack *extack;
+};
+
+/* DSA_NOTIFIER_FDB_* */
+struct dsa_notifier_fdb_info {
+	const struct dsa_port *dp;
+	const unsigned char *addr;
+	u16 vid;
+	struct dsa_db db;
+};
+
+/* DSA_NOTIFIER_LAG_FDB_* */
+struct dsa_notifier_lag_fdb_info {
+	struct dsa_lag *lag;
+	const unsigned char *addr;
+	u16 vid;
+	struct dsa_db db;
+};
+
+/* DSA_NOTIFIER_MDB_* */
+struct dsa_notifier_mdb_info {
+	const struct dsa_port *dp;
+	const struct switchdev_obj_port_mdb *mdb;
+	struct dsa_db db;
+};
+
+/* DSA_NOTIFIER_LAG_* */
+struct dsa_notifier_lag_info {
+	const struct dsa_port *dp;
+	struct dsa_lag lag;
+	struct netdev_lag_upper_info *info;
+	struct netlink_ext_ack *extack;
+};
+
+/* DSA_NOTIFIER_VLAN_* */
+struct dsa_notifier_vlan_info {
+	const struct dsa_port *dp;
+	const struct switchdev_obj_port_vlan *vlan;
+	struct netlink_ext_ack *extack;
+};
+
+/* DSA_NOTIFIER_MTU */
+struct dsa_notifier_mtu_info {
+	const struct dsa_port *dp;
+	int mtu;
+};
+
+/* DSA_NOTIFIER_TAG_PROTO_* */
+struct dsa_notifier_tag_proto_info {
+	const struct dsa_device_ops *tag_ops;
+};
+
+/* DSA_NOTIFIER_TAG_8021Q_VLAN_* */
+struct dsa_notifier_tag_8021q_vlan_info {
+	const struct dsa_port *dp;
+	u16 vid;
+};
+
+/* DSA_NOTIFIER_CONDUIT_STATE_CHANGE */
+struct dsa_notifier_conduit_state_info {
+	const struct net_device *conduit;
+	bool operational;
+};
+
+struct dsa_vlan *dsa_vlan_find(struct list_head *vlan_list,
+			       const struct switchdev_obj_port_vlan *vlan);
+
+int dsa_tree_notify(struct dsa_switch_tree *dst, unsigned long e, void *v);
+int dsa_broadcast(unsigned long e, void *v);
+
+int dsa_switch_register_notifier(struct dsa_switch *ds);
+void dsa_switch_unregister_notifier(struct dsa_switch *ds);
+
+#endif
diff --git a/net/dsa/tag.c b/net/dsa/tag.c
new file mode 100644
index 000000000..991732d6e
--- /dev/null
+++ b/net/dsa/tag.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * DSA tagging protocol handling
+ *
+ * Copyright (c) 2008-2009 Marvell Semiconductor
+ * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
+ * Copyright (c) 2016 Andrew Lunn <andrew@lunn.ch>
+ */
+
+#include <linux/netdevice.h>
+#include <linux/ptp_classify.h>
+#include <linux/skbuff.h>
+#include <net/dsa.h>
+#include <net/dst_metadata.h>
+
+#include "tag.h"
+#include "user.h"
+
+static LIST_HEAD(dsa_tag_drivers_list);
+static DEFINE_MUTEX(dsa_tag_drivers_lock);
+
+/* Determine if we should defer delivery of skb until we have a rx timestamp.
+ *
+ * Called from dsa_switch_rcv. For now, this will only work if tagging is
+ * enabled on the switch. Normally the MAC driver would retrieve the hardware
+ * timestamp when it reads the packet out of the hardware. However in a DSA
+ * switch, the DSA driver owning the interface to which the packet is
+ * delivered is never notified unless we do so here.
+ */
+static bool dsa_skb_defer_rx_timestamp(struct dsa_user_priv *p,
+				       struct sk_buff *skb)
+{
+	struct dsa_switch *ds = p->dp->ds;
+	unsigned int type;
+
+	if (!ds->ops->port_rxtstamp)
+		return false;
+
+	if (skb_headroom(skb) < ETH_HLEN)
+		return false;
+
+	__skb_push(skb, ETH_HLEN);
+
+	type = ptp_classify_raw(skb);
+
+	__skb_pull(skb, ETH_HLEN);
+
+	if (type == PTP_CLASS_NONE)
+		return false;
+
+	return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
+}
+
+static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
+			  struct packet_type *pt, struct net_device *unused)
+{
+	struct metadata_dst *md_dst = skb_metadata_dst(skb);
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+	struct sk_buff *nskb = NULL;
+	struct dsa_user_priv *p;
+
+	if (unlikely(!cpu_dp)) {
+		kfree_skb(skb);
+		return 0;
+	}
+
+	skb = skb_unshare(skb, GFP_ATOMIC);
+	if (!skb)
+		return 0;
+
+	if (md_dst && md_dst->type == METADATA_HW_PORT_MUX) {
+		unsigned int port = md_dst->u.port_info.port_id;
+
+		skb_dst_drop(skb);
+		if (!skb_has_extensions(skb))
+			skb->slow_gro = 0;
+
+		skb->dev = dsa_conduit_find_user(dev, 0, port);
+		if (likely(skb->dev)) {
+			dsa_default_offload_fwd_mark(skb);
+			nskb = skb;
+		} else {
+			/* Just drop the skb if we can't find the user */
+			kfree_skb(skb);
+		}
+	} else {
+		nskb = cpu_dp->rcv(skb, dev);
+	}
+
+	if (!nskb)
+		return 0;
+
+	skb = nskb;
+	skb_push(skb, ETH_HLEN);
+	skb->pkt_type = PACKET_HOST;
+	skb->protocol = eth_type_trans(skb, skb->dev);
+
+	if (unlikely(!dsa_user_dev_check(skb->dev))) {
+		/* Packet is to be injected directly on an upper
+		 * device, e.g. a team/bond, so skip all DSA-port
+		 * specific actions.
+		 */
+		netif_rx(skb);
+		return 0;
+	}
+
+	p = netdev_priv(skb->dev);
+
+	if (unlikely(cpu_dp->ds->untag_bridge_pvid ||
+		     cpu_dp->ds->untag_vlan_aware_bridge_pvid)) {
+		/* dsa_software_vlan_untag() drops skb on failure */
+		nskb = dsa_software_vlan_untag(skb);
+		if (!nskb)
+			return 0;
+		skb = nskb;
+	}
+
+	dev_sw_netstats_rx_add(skb->dev, skb->len + ETH_HLEN);
+
+	if (dsa_skb_defer_rx_timestamp(p, skb))
+		return 0;
+
+	gro_cells_receive(&p->gcells, skb);
+
+	return 0;
+}
+
+struct packet_type dsa_pack_type __read_mostly = {
+	.type	= cpu_to_be16(ETH_P_XDSA),
+	.func	= dsa_switch_rcv,
+};
+
+static void dsa_tag_driver_register(struct dsa_tag_driver *dsa_tag_driver,
+				    struct module *owner)
+{
+	dsa_tag_driver->owner = owner;
+
+	mutex_lock(&dsa_tag_drivers_lock);
+	list_add_tail(&dsa_tag_driver->list, &dsa_tag_drivers_list);
+	mutex_unlock(&dsa_tag_drivers_lock);
+}
+
+void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
+			      unsigned int count, struct module *owner)
+{
+	unsigned int i;
+
+	for (i = 0; i < count; i++)
+		dsa_tag_driver_register(dsa_tag_driver_array[i], owner);
+}
+
+static void dsa_tag_driver_unregister(struct dsa_tag_driver *dsa_tag_driver)
+{
+	mutex_lock(&dsa_tag_drivers_lock);
+	list_del(&dsa_tag_driver->list);
+	mutex_unlock(&dsa_tag_drivers_lock);
+}
+EXPORT_SYMBOL_GPL(dsa_tag_drivers_register);
+
+void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
+				unsigned int count)
+{
+	unsigned int i;
+
+	for (i = 0; i < count; i++)
+		dsa_tag_driver_unregister(dsa_tag_driver_array[i]);
+}
+EXPORT_SYMBOL_GPL(dsa_tag_drivers_unregister);
+
+const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops)
+{
+	return ops->name;
+};
+
+/* Function takes a reference on the module owning the tagger,
+ * so dsa_tag_driver_put must be called afterwards.
+ */
+const struct dsa_device_ops *dsa_tag_driver_get_by_name(const char *name)
+{
+	const struct dsa_device_ops *ops = ERR_PTR(-ENOPROTOOPT);
+	struct dsa_tag_driver *dsa_tag_driver;
+
+	request_module("%s%s", DSA_TAG_DRIVER_ALIAS, name);
+
+	mutex_lock(&dsa_tag_drivers_lock);
+	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
+		const struct dsa_device_ops *tmp = dsa_tag_driver->ops;
+
+		if (strcmp(name, tmp->name))
+			continue;
+
+		if (!try_module_get(dsa_tag_driver->owner))
+			break;
+
+		ops = tmp;
+		break;
+	}
+	mutex_unlock(&dsa_tag_drivers_lock);
+
+	return ops;
+}
+
+const struct dsa_device_ops *dsa_tag_driver_get_by_id(int tag_protocol)
+{
+	struct dsa_tag_driver *dsa_tag_driver;
+	const struct dsa_device_ops *ops;
+	bool found = false;
+
+	request_module("%sid-%d", DSA_TAG_DRIVER_ALIAS, tag_protocol);
+
+	mutex_lock(&dsa_tag_drivers_lock);
+	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
+		ops = dsa_tag_driver->ops;
+		if (ops->proto == tag_protocol) {
+			found = true;
+			break;
+		}
+	}
+
+	if (found) {
+		if (!try_module_get(dsa_tag_driver->owner))
+			ops = ERR_PTR(-ENOPROTOOPT);
+	} else {
+		ops = ERR_PTR(-ENOPROTOOPT);
+	}
+
+	mutex_unlock(&dsa_tag_drivers_lock);
+
+	return ops;
+}
+
+void dsa_tag_driver_put(const struct dsa_device_ops *ops)
+{
+	struct dsa_tag_driver *dsa_tag_driver;
+
+	mutex_lock(&dsa_tag_drivers_lock);
+	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
+		if (dsa_tag_driver->ops == ops) {
+			module_put(dsa_tag_driver->owner);
+			break;
+		}
+	}
+	mutex_unlock(&dsa_tag_drivers_lock);
+}
diff --git a/net/dsa/tag.h b/net/dsa/tag.h
new file mode 100644
index 000000000..cf52283fe
--- /dev/null
+++ b/net/dsa/tag.h
@@ -0,0 +1,409 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __DSA_TAG_H
+#define __DSA_TAG_H
+
+#include <linux/if_vlan.h>
+#include <linux/list.h>
+#include <linux/types.h>
+#include <net/dsa.h>
+
+#include "port.h"
+#include "user.h"
+
+struct dsa_tag_driver {
+	const struct dsa_device_ops *ops;
+	struct list_head list;
+	struct module *owner;
+};
+
+extern struct packet_type dsa_pack_type;
+
+const struct dsa_device_ops *dsa_tag_driver_get_by_id(int tag_protocol);
+const struct dsa_device_ops *dsa_tag_driver_get_by_name(const char *name);
+void dsa_tag_driver_put(const struct dsa_device_ops *ops);
+const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops);
+
+static inline int dsa_tag_protocol_overhead(const struct dsa_device_ops *ops)
+{
+	return ops->needed_headroom + ops->needed_tailroom;
+}
+
+static inline struct net_device *dsa_conduit_find_user(struct net_device *dev,
+						       int device, int port)
+{
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+	struct dsa_switch_tree *dst = cpu_dp->dst;
+	struct dsa_port *dp;
+
+	list_for_each_entry(dp, &dst->ports, list)
+		if (dp->ds->index == device && dp->index == port &&
+		    dp->type == DSA_PORT_TYPE_USER)
+			return dp->user;
+
+	return NULL;
+}
+
+/**
+ * dsa_software_untag_vlan_aware_bridge: Software untagging for VLAN-aware bridge
+ * @skb: Pointer to received socket buffer (packet)
+ * @br: Pointer to bridge upper interface of ingress port
+ * @vid: Parsed VID from packet
+ *
+ * The bridge can process tagged packets. Software like STP/PTP may not. The
+ * bridge can also process untagged packets, to the same effect as if they were
+ * tagged with the PVID of the ingress port. So packets tagged with the PVID of
+ * the bridge port must be software-untagged, to support both use cases.
+ */
+static inline void dsa_software_untag_vlan_aware_bridge(struct sk_buff *skb,
+							struct net_device *br,
+							u16 vid)
+{
+	u16 pvid, proto;
+	int err;
+
+	err = br_vlan_get_proto(br, &proto);
+	if (err)
+		return;
+
+	err = br_vlan_get_pvid_rcu(skb->dev, &pvid);
+	if (err)
+		return;
+
+	if (vid == pvid && skb->vlan_proto == htons(proto))
+		__vlan_hwaccel_clear_tag(skb);
+}
+
+/**
+ * dsa_software_untag_vlan_unaware_bridge: Software untagging for VLAN-unaware bridge
+ * @skb: Pointer to received socket buffer (packet)
+ * @br: Pointer to bridge upper interface of ingress port
+ * @vid: Parsed VID from packet
+ *
+ * The bridge ignores all VLAN tags. Software like STP/PTP may not (it may run
+ * on the plain port, or on a VLAN upper interface). Maybe packets are coming
+ * to software as tagged with a driver-defined VID which is NOT equal to the
+ * PVID of the bridge port (since the bridge is VLAN-unaware, its configuration
+ * should NOT be committed to hardware). DSA needs a method for this private
+ * VID to be communicated by software to it, and if packets are tagged with it,
+ * software-untag them. Note: the private VID may be different per bridge, to
+ * support the FDB isolation use case.
+ *
+ * FIXME: this is currently implemented based on the broken assumption that
+ * the "private VID" used by the driver in VLAN-unaware mode is equal to the
+ * bridge PVID. It should not be, except for a coincidence; the bridge PVID is
+ * irrelevant to the data path in the VLAN-unaware mode. Thus, the VID that
+ * this function removes is wrong.
+ *
+ * All users of ds->untag_bridge_pvid should fix their drivers, if necessary,
+ * to make the two independent. Only then, if there still remains a need to
+ * strip the private VID from packets, then a new ds->ops->get_private_vid()
+ * API shall be introduced to communicate to DSA what this VID is, which needs
+ * to be stripped here.
+ */
+static inline void dsa_software_untag_vlan_unaware_bridge(struct sk_buff *skb,
+							  struct net_device *br,
+							  u16 vid)
+{
+	struct net_device *upper_dev;
+	u16 pvid, proto;
+	int err;
+
+	err = br_vlan_get_proto(br, &proto);
+	if (err)
+		return;
+
+	err = br_vlan_get_pvid_rcu(skb->dev, &pvid);
+	if (err)
+		return;
+
+	if (vid != pvid || skb->vlan_proto != htons(proto))
+		return;
+
+	/* The sad part about attempting to untag from DSA is that we
+	 * don't know, unless we check, if the skb will end up in
+	 * the bridge's data path - br_allowed_ingress() - or not.
+	 * For example, there might be an 8021q upper for the
+	 * default_pvid of the bridge, which will steal VLAN-tagged traffic
+	 * from the bridge's data path. This is a configuration that DSA
+	 * supports because vlan_filtering is 0. In that case, we should
+	 * definitely keep the tag, to make sure it keeps working.
+	 */
+	upper_dev = __vlan_find_dev_deep_rcu(br, htons(proto), vid);
+	if (!upper_dev)
+		__vlan_hwaccel_clear_tag(skb);
+}
+
+/**
+ * dsa_software_vlan_untag: Software VLAN untagging in DSA receive path
+ * @skb: Pointer to socket buffer (packet)
+ *
+ * Receive path method for switches which send some packets as VLAN-tagged
+ * towards the CPU port (generally from VLAN-aware bridge ports) even when the
+ * packet was not tagged on the wire. Called when ds->untag_bridge_pvid
+ * (legacy) or ds->untag_vlan_aware_bridge_pvid is set to true.
+ *
+ * As a side effect of this method, any VLAN tag from the skb head is moved
+ * to hwaccel.
+ */
+static inline struct sk_buff *dsa_software_vlan_untag(struct sk_buff *skb)
+{
+	struct dsa_port *dp = dsa_user_to_port(skb->dev);
+	struct net_device *br = dsa_port_bridge_dev_get(dp);
+	u16 vid, proto;
+	int err;
+
+	/* software untagging for standalone ports not yet necessary */
+	if (!br)
+		return skb;
+
+	err = br_vlan_get_proto(br, &proto);
+	if (err)
+		return skb;
+
+	/* Move VLAN tag from data to hwaccel */
+	if (!skb_vlan_tag_present(skb) && skb->protocol == htons(proto)) {
+		skb = skb_vlan_untag(skb);
+		if (!skb)
+			return NULL;
+	}
+
+	if (!skb_vlan_tag_present(skb))
+		return skb;
+
+	vid = skb_vlan_tag_get_id(skb);
+
+	if (br_vlan_enabled(br)) {
+		if (dp->ds->untag_vlan_aware_bridge_pvid)
+			dsa_software_untag_vlan_aware_bridge(skb, br, vid);
+	} else {
+		if (dp->ds->untag_bridge_pvid)
+			dsa_software_untag_vlan_unaware_bridge(skb, br, vid);
+	}
+
+	return skb;
+}
+
+/* For switches without hardware support for DSA tagging to be able
+ * to support termination through the bridge.
+ */
+static inline struct net_device *
+dsa_find_designated_bridge_port_by_vid(struct net_device *conduit, u16 vid)
+{
+	struct dsa_port *cpu_dp = conduit->dsa_ptr;
+	struct dsa_switch_tree *dst = cpu_dp->dst;
+	struct bridge_vlan_info vinfo;
+	struct net_device *user;
+	struct dsa_port *dp;
+	int err;
+
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (dp->type != DSA_PORT_TYPE_USER)
+			continue;
+
+		if (!dp->bridge)
+			continue;
+
+		if (dp->stp_state != BR_STATE_LEARNING &&
+		    dp->stp_state != BR_STATE_FORWARDING)
+			continue;
+
+		/* Since the bridge might learn this packet, keep the CPU port
+		 * affinity with the port that will be used for the reply on
+		 * xmit.
+		 */
+		if (dp->cpu_dp != cpu_dp)
+			continue;
+
+		user = dp->user;
+
+		err = br_vlan_get_info_rcu(user, vid, &vinfo);
+		if (err)
+			continue;
+
+		return user;
+	}
+
+	return NULL;
+}
+
+/* If the ingress port offloads the bridge, we mark the frame as autonomously
+ * forwarded by hardware, so the software bridge doesn't forward in twice, back
+ * to us, because we already did. However, if we're in fallback mode and we do
+ * software bridging, we are not offloading it, therefore the dp->bridge
+ * pointer is not populated, and flooding needs to be done by software (we are
+ * effectively operating in standalone ports mode).
+ */
+static inline void dsa_default_offload_fwd_mark(struct sk_buff *skb)
+{
+	struct dsa_port *dp = dsa_user_to_port(skb->dev);
+
+	skb->offload_fwd_mark = !!(dp->bridge);
+}
+
+/* Helper for removing DSA header tags from packets in the RX path.
+ * Must not be called before skb_pull(len).
+ *                                                                 skb->data
+ *                                                                         |
+ *                                                                         v
+ * |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
+ * +-----------------------+-----------------------+---------------+-------+
+ * |    Destination MAC    |      Source MAC       |  DSA header   | EType |
+ * +-----------------------+-----------------------+---------------+-------+
+ *                                                 |               |
+ * <----- len ----->                               <----- len ----->
+ *                 |
+ *       >>>>>>>   v
+ *       >>>>>>>   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
+ *       >>>>>>>   +-----------------------+-----------------------+-------+
+ *       >>>>>>>   |    Destination MAC    |      Source MAC       | EType |
+ *                 +-----------------------+-----------------------+-------+
+ *                                                                         ^
+ *                                                                         |
+ *                                                                 skb->data
+ */
+static inline void dsa_strip_etype_header(struct sk_buff *skb, int len)
+{
+	memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - len, 2 * ETH_ALEN);
+}
+
+/* Helper for creating space for DSA header tags in TX path packets.
+ * Must not be called before skb_push(len).
+ *
+ * Before:
+ *
+ *       <<<<<<<   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
+ * ^     <<<<<<<   +-----------------------+-----------------------+-------+
+ * |     <<<<<<<   |    Destination MAC    |      Source MAC       | EType |
+ * |               +-----------------------+-----------------------+-------+
+ * <----- len ----->
+ * |
+ * |
+ * skb->data
+ *
+ * After:
+ *
+ * |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
+ * +-----------------------+-----------------------+---------------+-------+
+ * |    Destination MAC    |      Source MAC       |  DSA header   | EType |
+ * +-----------------------+-----------------------+---------------+-------+
+ * ^                                               |               |
+ * |                                               <----- len ----->
+ * skb->data
+ */
+static inline void dsa_alloc_etype_header(struct sk_buff *skb, int len)
+{
+	memmove(skb->data, skb->data + len, 2 * ETH_ALEN);
+}
+
+/* On RX, eth_type_trans() on the DSA conduit pulls ETH_HLEN bytes starting from
+ * skb_mac_header(skb), which leaves skb->data pointing at the first byte after
+ * what the DSA conduit perceives as the EtherType (the beginning of the L3
+ * protocol). Since DSA EtherType header taggers treat the EtherType as part of
+ * the DSA tag itself, and the EtherType is 2 bytes in length, the DSA header
+ * is located 2 bytes behind skb->data. Note that EtherType in this context
+ * means the first 2 bytes of the DSA header, not the encapsulated EtherType
+ * that will become visible after the DSA header is stripped.
+ */
+static inline void *dsa_etype_header_pos_rx(struct sk_buff *skb)
+{
+	return skb->data - 2;
+}
+
+/* On TX, skb->data points to the MAC header, which means that EtherType
+ * header taggers start exactly where the EtherType is (the EtherType is
+ * treated as part of the DSA header).
+ */
+static inline void *dsa_etype_header_pos_tx(struct sk_buff *skb)
+{
+	return skb->data + 2 * ETH_ALEN;
+}
+
+static inline unsigned long dsa_xmit_port_mask(const struct sk_buff *skb,
+					       const struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	unsigned long mask = BIT(dp->index);
+
+	if (IS_ENABLED(CONFIG_HSR) &&
+	    unlikely(dev->features & NETIF_F_HW_HSR_DUP)) {
+		struct net_device *hsr_dev = dp->hsr_dev;
+		struct dsa_port *other_dp;
+
+		dsa_hsr_foreach_port(other_dp, dp->ds, hsr_dev)
+			mask |= BIT(other_dp->index);
+	}
+
+	return mask;
+}
+
+/* Create 2 modaliases per tagging protocol, one to auto-load the module
+ * given the ID reported by get_tag_protocol(), and the other by name.
+ */
+#define DSA_TAG_DRIVER_ALIAS "dsa_tag:"
+#define MODULE_ALIAS_DSA_TAG_DRIVER(__proto, __name) \
+	MODULE_ALIAS(DSA_TAG_DRIVER_ALIAS __name); \
+	MODULE_ALIAS(DSA_TAG_DRIVER_ALIAS "id-" \
+		     __stringify(__proto##_VALUE))
+
+void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
+			      unsigned int count,
+			      struct module *owner);
+void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
+				unsigned int count);
+
+#define dsa_tag_driver_module_drivers(__dsa_tag_drivers_array, __count)	\
+static int __init dsa_tag_driver_module_init(void)			\
+{									\
+	dsa_tag_drivers_register(__dsa_tag_drivers_array, __count,	\
+				 THIS_MODULE);				\
+	return 0;							\
+}									\
+module_init(dsa_tag_driver_module_init);				\
+									\
+static void __exit dsa_tag_driver_module_exit(void)			\
+{									\
+	dsa_tag_drivers_unregister(__dsa_tag_drivers_array, __count);	\
+}									\
+module_exit(dsa_tag_driver_module_exit)
+
+/**
+ * module_dsa_tag_drivers() - Helper macro for registering DSA tag
+ * drivers
+ * @__ops_array: Array of tag driver structures
+ *
+ * Helper macro for DSA tag drivers which do not do anything special
+ * in module init/exit. Each module may only use this macro once, and
+ * calling it replaces module_init() and module_exit().
+ */
+#define module_dsa_tag_drivers(__ops_array)				\
+dsa_tag_driver_module_drivers(__ops_array, ARRAY_SIZE(__ops_array))
+
+#define DSA_TAG_DRIVER_NAME(__ops) dsa_tag_driver ## _ ## __ops
+
+/* Create a static structure we can build a linked list of dsa_tag
+ * drivers
+ */
+#define DSA_TAG_DRIVER(__ops)						\
+static struct dsa_tag_driver DSA_TAG_DRIVER_NAME(__ops) = {		\
+	.ops = &__ops,							\
+}
+
+/**
+ * module_dsa_tag_driver() - Helper macro for registering a single DSA tag
+ * driver
+ * @__ops: Single tag driver structures
+ *
+ * Helper macro for DSA tag drivers which do not do anything special
+ * in module init/exit. Each module may only use this macro once, and
+ * calling it replaces module_init() and module_exit().
+ */
+#define module_dsa_tag_driver(__ops)					\
+DSA_TAG_DRIVER(__ops);							\
+									\
+static struct dsa_tag_driver *dsa_tag_driver_array[] =	{		\
+	&DSA_TAG_DRIVER_NAME(__ops)					\
+};									\
+module_dsa_tag_drivers(dsa_tag_driver_array)
+
+#endif
diff --git a/net/dsa/tag_8021q.c b/net/dsa/tag_8021q.c
new file mode 100644
index 000000000..f91646e60
--- /dev/null
+++ b/net/dsa/tag_8021q.c
@@ -0,0 +1,588 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019, Vladimir Oltean <olteanv@gmail.com>
+ *
+ * This module is not a complete tagger implementation. It only provides
+ * primitives for taggers that rely on 802.1Q VLAN tags to use.
+ */
+#include <linux/if_vlan.h>
+#include <linux/dsa/8021q.h>
+
+#include "port.h"
+#include "switch.h"
+#include "tag.h"
+#include "tag_8021q.h"
+
+/* Binary structure of the fake 12-bit VID field (when the TPID is
+ * ETH_P_DSA_8021Q):
+ *
+ * | 11  | 10  |  9  |  8  |  7  |  6  |  5  |  4  |  3  |  2  |  1  |  0  |
+ * +-----------+-----+-----------------+-----------+-----------------------+
+ * |    RSV    | VBID|    SWITCH_ID    |   VBID    |          PORT         |
+ * +-----------+-----+-----------------+-----------+-----------------------+
+ *
+ * RSV - VID[11:10]:
+ *	Reserved. Must be set to 3 (0b11).
+ *
+ * SWITCH_ID - VID[8:6]:
+ *	Index of switch within DSA tree. Must be between 0 and 7.
+ *
+ * VBID - { VID[9], VID[5:4] }:
+ *	Virtual bridge ID. If between 1 and 7, packet targets the broadcast
+ *	domain of a bridge. If transmitted as zero, packet targets a single
+ *	port.
+ *
+ * PORT - VID[3:0]:
+ *	Index of switch port. Must be between 0 and 15.
+ */
+
+#define DSA_8021Q_RSV_VAL		3
+#define DSA_8021Q_RSV_SHIFT		10
+#define DSA_8021Q_RSV_MASK		GENMASK(11, 10)
+#define DSA_8021Q_RSV			((DSA_8021Q_RSV_VAL << DSA_8021Q_RSV_SHIFT) & \
+							       DSA_8021Q_RSV_MASK)
+
+#define DSA_8021Q_SWITCH_ID_SHIFT	6
+#define DSA_8021Q_SWITCH_ID_MASK	GENMASK(8, 6)
+#define DSA_8021Q_SWITCH_ID(x)		(((x) << DSA_8021Q_SWITCH_ID_SHIFT) & \
+						 DSA_8021Q_SWITCH_ID_MASK)
+
+#define DSA_8021Q_VBID_HI_SHIFT		9
+#define DSA_8021Q_VBID_HI_MASK		GENMASK(9, 9)
+#define DSA_8021Q_VBID_LO_SHIFT		4
+#define DSA_8021Q_VBID_LO_MASK		GENMASK(5, 4)
+#define DSA_8021Q_VBID_HI(x)		(((x) & GENMASK(2, 2)) >> 2)
+#define DSA_8021Q_VBID_LO(x)		((x) & GENMASK(1, 0))
+#define DSA_8021Q_VBID(x)		\
+		(((DSA_8021Q_VBID_LO(x) << DSA_8021Q_VBID_LO_SHIFT) & \
+		  DSA_8021Q_VBID_LO_MASK) | \
+		 ((DSA_8021Q_VBID_HI(x) << DSA_8021Q_VBID_HI_SHIFT) & \
+		  DSA_8021Q_VBID_HI_MASK))
+
+#define DSA_8021Q_PORT_SHIFT		0
+#define DSA_8021Q_PORT_MASK		GENMASK(3, 0)
+#define DSA_8021Q_PORT(x)		(((x) << DSA_8021Q_PORT_SHIFT) & \
+						 DSA_8021Q_PORT_MASK)
+
+struct dsa_tag_8021q_vlan {
+	struct list_head list;
+	int port;
+	u16 vid;
+	refcount_t refcount;
+};
+
+struct dsa_8021q_context {
+	struct dsa_switch *ds;
+	struct list_head vlans;
+	/* EtherType of RX VID, used for filtering on conduit interface */
+	__be16 proto;
+};
+
+u16 dsa_tag_8021q_bridge_vid(unsigned int bridge_num)
+{
+	/* The VBID value of 0 is reserved for precise TX, but it is also
+	 * reserved/invalid for the bridge_num, so all is well.
+	 */
+	return DSA_8021Q_RSV | DSA_8021Q_VBID(bridge_num);
+}
+EXPORT_SYMBOL_GPL(dsa_tag_8021q_bridge_vid);
+
+/* Returns the VID that will be installed as pvid for this switch port, sent as
+ * tagged egress towards the CPU port and decoded by the rcv function.
+ */
+u16 dsa_tag_8021q_standalone_vid(const struct dsa_port *dp)
+{
+	return DSA_8021Q_RSV | DSA_8021Q_SWITCH_ID(dp->ds->index) |
+	       DSA_8021Q_PORT(dp->index);
+}
+EXPORT_SYMBOL_GPL(dsa_tag_8021q_standalone_vid);
+
+/* Returns the decoded switch ID from the RX VID. */
+int dsa_8021q_rx_switch_id(u16 vid)
+{
+	return (vid & DSA_8021Q_SWITCH_ID_MASK) >> DSA_8021Q_SWITCH_ID_SHIFT;
+}
+EXPORT_SYMBOL_GPL(dsa_8021q_rx_switch_id);
+
+/* Returns the decoded port ID from the RX VID. */
+int dsa_8021q_rx_source_port(u16 vid)
+{
+	return (vid & DSA_8021Q_PORT_MASK) >> DSA_8021Q_PORT_SHIFT;
+}
+EXPORT_SYMBOL_GPL(dsa_8021q_rx_source_port);
+
+/* Returns the decoded VBID from the RX VID. */
+static int dsa_tag_8021q_rx_vbid(u16 vid)
+{
+	u16 vbid_hi = (vid & DSA_8021Q_VBID_HI_MASK) >> DSA_8021Q_VBID_HI_SHIFT;
+	u16 vbid_lo = (vid & DSA_8021Q_VBID_LO_MASK) >> DSA_8021Q_VBID_LO_SHIFT;
+
+	return (vbid_hi << 2) | vbid_lo;
+}
+
+bool vid_is_dsa_8021q(u16 vid)
+{
+	u16 rsv = (vid & DSA_8021Q_RSV_MASK) >> DSA_8021Q_RSV_SHIFT;
+
+	return rsv == DSA_8021Q_RSV_VAL;
+}
+EXPORT_SYMBOL_GPL(vid_is_dsa_8021q);
+
+static struct dsa_tag_8021q_vlan *
+dsa_tag_8021q_vlan_find(struct dsa_8021q_context *ctx, int port, u16 vid)
+{
+	struct dsa_tag_8021q_vlan *v;
+
+	list_for_each_entry(v, &ctx->vlans, list)
+		if (v->vid == vid && v->port == port)
+			return v;
+
+	return NULL;
+}
+
+static int dsa_port_do_tag_8021q_vlan_add(struct dsa_port *dp, u16 vid,
+					  u16 flags)
+{
+	struct dsa_8021q_context *ctx = dp->ds->tag_8021q_ctx;
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_tag_8021q_vlan *v;
+	int port = dp->index;
+	int err;
+
+	/* No need to bother with refcounting for user ports */
+	if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp)))
+		return ds->ops->tag_8021q_vlan_add(ds, port, vid, flags);
+
+	v = dsa_tag_8021q_vlan_find(ctx, port, vid);
+	if (v) {
+		refcount_inc(&v->refcount);
+		return 0;
+	}
+
+	v = kzalloc_obj(*v);
+	if (!v)
+		return -ENOMEM;
+
+	err = ds->ops->tag_8021q_vlan_add(ds, port, vid, flags);
+	if (err) {
+		kfree(v);
+		return err;
+	}
+
+	v->vid = vid;
+	v->port = port;
+	refcount_set(&v->refcount, 1);
+	list_add_tail(&v->list, &ctx->vlans);
+
+	return 0;
+}
+
+static int dsa_port_do_tag_8021q_vlan_del(struct dsa_port *dp, u16 vid)
+{
+	struct dsa_8021q_context *ctx = dp->ds->tag_8021q_ctx;
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_tag_8021q_vlan *v;
+	int port = dp->index;
+	int err;
+
+	/* No need to bother with refcounting for user ports */
+	if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp)))
+		return ds->ops->tag_8021q_vlan_del(ds, port, vid);
+
+	v = dsa_tag_8021q_vlan_find(ctx, port, vid);
+	if (!v)
+		return -ENOENT;
+
+	if (!refcount_dec_and_test(&v->refcount))
+		return 0;
+
+	err = ds->ops->tag_8021q_vlan_del(ds, port, vid);
+	if (err) {
+		refcount_set(&v->refcount, 1);
+		return err;
+	}
+
+	list_del(&v->list);
+	kfree(v);
+
+	return 0;
+}
+
+static bool
+dsa_port_tag_8021q_vlan_match(struct dsa_port *dp,
+			      struct dsa_notifier_tag_8021q_vlan_info *info)
+{
+	return dsa_port_is_dsa(dp) || dsa_port_is_cpu(dp) || dp == info->dp;
+}
+
+int dsa_switch_tag_8021q_vlan_add(struct dsa_switch *ds,
+				  struct dsa_notifier_tag_8021q_vlan_info *info)
+{
+	struct dsa_port *dp;
+	int err;
+
+	/* Since we use dsa_broadcast(), there might be other switches in other
+	 * trees which don't support tag_8021q, so don't return an error.
+	 * Or they might even support tag_8021q but have not registered yet to
+	 * use it (maybe they use another tagger currently).
+	 */
+	if (!ds->ops->tag_8021q_vlan_add || !ds->tag_8021q_ctx)
+		return 0;
+
+	dsa_switch_for_each_port(dp, ds) {
+		if (dsa_port_tag_8021q_vlan_match(dp, info)) {
+			u16 flags = 0;
+
+			if (dsa_port_is_user(dp))
+				flags |= BRIDGE_VLAN_INFO_UNTAGGED |
+					 BRIDGE_VLAN_INFO_PVID;
+
+			err = dsa_port_do_tag_8021q_vlan_add(dp, info->vid,
+							     flags);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+int dsa_switch_tag_8021q_vlan_del(struct dsa_switch *ds,
+				  struct dsa_notifier_tag_8021q_vlan_info *info)
+{
+	struct dsa_port *dp;
+	int err;
+
+	if (!ds->ops->tag_8021q_vlan_del || !ds->tag_8021q_ctx)
+		return 0;
+
+	dsa_switch_for_each_port(dp, ds) {
+		if (dsa_port_tag_8021q_vlan_match(dp, info)) {
+			err = dsa_port_do_tag_8021q_vlan_del(dp, info->vid);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+/* There are 2 ways of offloading tag_8021q VLANs.
+ *
+ * One is to use a hardware TCAM to push the port's standalone VLAN into the
+ * frame when forwarding it to the CPU, as an egress modification rule on the
+ * CPU port. This is preferable because it has no side effects for the
+ * autonomous forwarding path, and accomplishes tag_8021q's primary goal of
+ * identifying the source port of each packet based on VLAN ID.
+ *
+ * The other is to commit the tag_8021q VLAN as a PVID to the VLAN table, and
+ * to configure the port as VLAN-unaware. This is less preferable because
+ * unique source port identification can only be done for standalone ports;
+ * under a VLAN-unaware bridge, all ports share the same tag_8021q VLAN as
+ * PVID, and under a VLAN-aware bridge, packets received by software will not
+ * have tag_8021q VLANs appended, just bridge VLANs.
+ *
+ * For tag_8021q implementations of the second type, this method is used to
+ * replace the standalone tag_8021q VLAN of a port with the tag_8021q VLAN to
+ * be used for VLAN-unaware bridging.
+ */
+int dsa_tag_8021q_bridge_join(struct dsa_switch *ds, int port,
+			      struct dsa_bridge bridge, bool *tx_fwd_offload,
+			      struct netlink_ext_ack *extack)
+{
+	struct dsa_port *dp = dsa_to_port(ds, port);
+	u16 standalone_vid, bridge_vid;
+	int err;
+
+	/* Delete the standalone VLAN of the port and replace it with a
+	 * bridging VLAN
+	 */
+	standalone_vid = dsa_tag_8021q_standalone_vid(dp);
+	bridge_vid = dsa_tag_8021q_bridge_vid(bridge.num);
+
+	err = dsa_port_tag_8021q_vlan_add(dp, bridge_vid, true);
+	if (err)
+		return err;
+
+	dsa_port_tag_8021q_vlan_del(dp, standalone_vid, false);
+
+	*tx_fwd_offload = true;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dsa_tag_8021q_bridge_join);
+
+void dsa_tag_8021q_bridge_leave(struct dsa_switch *ds, int port,
+				struct dsa_bridge bridge)
+{
+	struct dsa_port *dp = dsa_to_port(ds, port);
+	u16 standalone_vid, bridge_vid;
+	int err;
+
+	/* Delete the bridging VLAN of the port and replace it with a
+	 * standalone VLAN
+	 */
+	standalone_vid = dsa_tag_8021q_standalone_vid(dp);
+	bridge_vid = dsa_tag_8021q_bridge_vid(bridge.num);
+
+	err = dsa_port_tag_8021q_vlan_add(dp, standalone_vid, false);
+	if (err) {
+		dev_err(ds->dev,
+			"Failed to delete tag_8021q standalone VLAN %d from port %d: %pe\n",
+			standalone_vid, port, ERR_PTR(err));
+	}
+
+	dsa_port_tag_8021q_vlan_del(dp, bridge_vid, true);
+}
+EXPORT_SYMBOL_GPL(dsa_tag_8021q_bridge_leave);
+
+/* Set up a port's standalone tag_8021q VLAN */
+static int dsa_tag_8021q_port_setup(struct dsa_switch *ds, int port)
+{
+	struct dsa_8021q_context *ctx = ds->tag_8021q_ctx;
+	struct dsa_port *dp = dsa_to_port(ds, port);
+	u16 vid = dsa_tag_8021q_standalone_vid(dp);
+	struct net_device *conduit;
+	int err;
+
+	/* The CPU port is implicitly configured by
+	 * configuring the front-panel ports
+	 */
+	if (!dsa_port_is_user(dp))
+		return 0;
+
+	conduit = dsa_port_to_conduit(dp);
+
+	err = dsa_port_tag_8021q_vlan_add(dp, vid, false);
+	if (err) {
+		dev_err(ds->dev,
+			"Failed to apply standalone VID %d to port %d: %pe\n",
+			vid, port, ERR_PTR(err));
+		return err;
+	}
+
+	/* Add the VLAN to the conduit's RX filter. */
+	vlan_vid_add(conduit, ctx->proto, vid);
+
+	return err;
+}
+
+static void dsa_tag_8021q_port_teardown(struct dsa_switch *ds, int port)
+{
+	struct dsa_8021q_context *ctx = ds->tag_8021q_ctx;
+	struct dsa_port *dp = dsa_to_port(ds, port);
+	u16 vid = dsa_tag_8021q_standalone_vid(dp);
+	struct net_device *conduit;
+
+	/* The CPU port is implicitly configured by
+	 * configuring the front-panel ports
+	 */
+	if (!dsa_port_is_user(dp))
+		return;
+
+	conduit = dsa_port_to_conduit(dp);
+
+	dsa_port_tag_8021q_vlan_del(dp, vid, false);
+
+	vlan_vid_del(conduit, ctx->proto, vid);
+}
+
+static int dsa_tag_8021q_setup(struct dsa_switch *ds)
+{
+	int err, port;
+
+	ASSERT_RTNL();
+
+	for (port = 0; port < ds->num_ports; port++) {
+		err = dsa_tag_8021q_port_setup(ds, port);
+		if (err < 0) {
+			dev_err(ds->dev,
+				"Failed to setup VLAN tagging for port %d: %pe\n",
+				port, ERR_PTR(err));
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+static void dsa_tag_8021q_teardown(struct dsa_switch *ds)
+{
+	int port;
+
+	ASSERT_RTNL();
+
+	for (port = 0; port < ds->num_ports; port++)
+		dsa_tag_8021q_port_teardown(ds, port);
+}
+
+int dsa_tag_8021q_register(struct dsa_switch *ds, __be16 proto)
+{
+	struct dsa_8021q_context *ctx;
+	int err;
+
+	ctx = kzalloc_obj(*ctx);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->proto = proto;
+	ctx->ds = ds;
+
+	INIT_LIST_HEAD(&ctx->vlans);
+
+	ds->tag_8021q_ctx = ctx;
+
+	err = dsa_tag_8021q_setup(ds);
+	if (err)
+		goto err_free;
+
+	return 0;
+
+err_free:
+	kfree(ctx);
+	return err;
+}
+EXPORT_SYMBOL_GPL(dsa_tag_8021q_register);
+
+void dsa_tag_8021q_unregister(struct dsa_switch *ds)
+{
+	struct dsa_8021q_context *ctx = ds->tag_8021q_ctx;
+	struct dsa_tag_8021q_vlan *v, *n;
+
+	dsa_tag_8021q_teardown(ds);
+
+	list_for_each_entry_safe(v, n, &ctx->vlans, list) {
+		list_del(&v->list);
+		kfree(v);
+	}
+
+	ds->tag_8021q_ctx = NULL;
+
+	kfree(ctx);
+}
+EXPORT_SYMBOL_GPL(dsa_tag_8021q_unregister);
+
+struct sk_buff *dsa_8021q_xmit(struct sk_buff *skb, struct net_device *netdev,
+			       u16 tpid, u16 tci)
+{
+	/* skb->data points at the MAC header, which is fine
+	 * for vlan_insert_tag().
+	 */
+	return vlan_insert_tag(skb, htons(tpid), tci);
+}
+EXPORT_SYMBOL_GPL(dsa_8021q_xmit);
+
+static struct net_device *
+dsa_tag_8021q_find_port_by_vbid(struct net_device *conduit, int vbid)
+{
+	struct dsa_port *cpu_dp = conduit->dsa_ptr;
+	struct dsa_switch_tree *dst = cpu_dp->dst;
+	struct dsa_port *dp;
+
+	if (WARN_ON(!vbid))
+		return NULL;
+
+	dsa_tree_for_each_user_port(dp, dst) {
+		if (!dp->bridge)
+			continue;
+
+		if (dp->stp_state != BR_STATE_LEARNING &&
+		    dp->stp_state != BR_STATE_FORWARDING)
+			continue;
+
+		if (dp->cpu_dp != cpu_dp)
+			continue;
+
+		if (dsa_port_bridge_num_get(dp) == vbid)
+			return dp->user;
+	}
+
+	return NULL;
+}
+
+struct net_device *dsa_tag_8021q_find_user(struct net_device *conduit,
+					   int source_port, int switch_id,
+					   int vid, int vbid)
+{
+	/* Always prefer precise source port information, if available */
+	if (source_port != -1 && switch_id != -1)
+		return dsa_conduit_find_user(conduit, switch_id, source_port);
+	else if (vbid >= 1)
+		return dsa_tag_8021q_find_port_by_vbid(conduit, vbid);
+
+	return dsa_find_designated_bridge_port_by_vid(conduit, vid);
+}
+EXPORT_SYMBOL_GPL(dsa_tag_8021q_find_user);
+
+/**
+ * dsa_8021q_rcv - Decode source information from tag_8021q header
+ * @skb: RX socket buffer
+ * @source_port: pointer to storage for precise source port information.
+ *	If this is known already from outside tag_8021q, the pre-initialized
+ *	value is preserved. If not known, pass -1.
+ * @switch_id: similar to source_port.
+ * @vbid: pointer to storage for imprecise bridge ID. Must be pre-initialized
+ *	with -1. If a positive value is returned, the source_port and switch_id
+ *	are invalid.
+ * @vid: pointer to storage for original VID, in case tag_8021q decoding failed.
+ *
+ * If the packet has a tag_8021q header, decode it and set @source_port,
+ * @switch_id and @vbid, and strip the header. Otherwise set @vid and keep the
+ * header in the hwaccel area of the packet.
+ */
+void dsa_8021q_rcv(struct sk_buff *skb, int *source_port, int *switch_id,
+		   int *vbid, int *vid)
+{
+	int tmp_source_port, tmp_switch_id, tmp_vbid;
+	__be16 vlan_proto;
+	u16 tmp_vid, tci;
+
+	if (skb_vlan_tag_present(skb)) {
+		vlan_proto = skb->vlan_proto;
+		tci = skb_vlan_tag_get(skb);
+		__vlan_hwaccel_clear_tag(skb);
+	} else {
+		struct vlan_ethhdr *hdr = vlan_eth_hdr(skb);
+
+		vlan_proto = hdr->h_vlan_proto;
+		skb_push_rcsum(skb, ETH_HLEN);
+		__skb_vlan_pop(skb, &tci);
+		skb_pull_rcsum(skb, ETH_HLEN);
+	}
+
+	tmp_vid = tci & VLAN_VID_MASK;
+	if (!vid_is_dsa_8021q(tmp_vid)) {
+		/* Not a tag_8021q frame, so return the VID to the
+		 * caller for further processing, and put the tag back
+		 */
+		if (vid)
+			*vid = tmp_vid;
+
+		__vlan_hwaccel_put_tag(skb, vlan_proto, tci);
+
+		return;
+	}
+
+	tmp_source_port = dsa_8021q_rx_source_port(tmp_vid);
+	tmp_switch_id = dsa_8021q_rx_switch_id(tmp_vid);
+	tmp_vbid = dsa_tag_8021q_rx_vbid(tmp_vid);
+
+	/* Precise source port information is unknown when receiving from a
+	 * VLAN-unaware bridging domain, and tmp_source_port and tmp_switch_id
+	 * are zeroes in this case.
+	 *
+	 * Preserve the source information from hardware-specific mechanisms,
+	 * if available. This allows us to not overwrite a valid source port
+	 * and switch ID with less precise values.
+	 */
+	if (tmp_vbid == 0 && *source_port == -1)
+		*source_port = tmp_source_port;
+	if (tmp_vbid == 0 && *switch_id == -1)
+		*switch_id = tmp_switch_id;
+
+	if (vbid)
+		*vbid = tmp_vbid;
+
+	skb->priority = (tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
+	return;
+}
+EXPORT_SYMBOL_GPL(dsa_8021q_rcv);
diff --git a/net/dsa/tag_8021q.h b/net/dsa/tag_8021q.h
new file mode 100644
index 000000000..27b8906f9
--- /dev/null
+++ b/net/dsa/tag_8021q.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __DSA_TAG_8021Q_H
+#define __DSA_TAG_8021Q_H
+
+#include <net/dsa.h>
+
+#include "switch.h"
+
+struct sk_buff;
+struct net_device;
+
+struct sk_buff *dsa_8021q_xmit(struct sk_buff *skb, struct net_device *netdev,
+			       u16 tpid, u16 tci);
+
+void dsa_8021q_rcv(struct sk_buff *skb, int *source_port, int *switch_id,
+		   int *vbid, int *vid);
+
+struct net_device *dsa_tag_8021q_find_user(struct net_device *conduit,
+					   int source_port, int switch_id,
+					   int vid, int vbid);
+
+int dsa_switch_tag_8021q_vlan_add(struct dsa_switch *ds,
+				  struct dsa_notifier_tag_8021q_vlan_info *info);
+int dsa_switch_tag_8021q_vlan_del(struct dsa_switch *ds,
+				  struct dsa_notifier_tag_8021q_vlan_info *info);
+
+#endif
diff --git a/net/dsa/tag_ar9331.c b/net/dsa/tag_ar9331.c
new file mode 100644
index 000000000..2e2388143
--- /dev/null
+++ b/net/dsa/tag_ar9331.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
+ */
+
+
+#include <linux/bitfield.h>
+#include <linux/etherdevice.h>
+
+#include "tag.h"
+
+#define AR9331_NAME			"ar9331"
+
+#define AR9331_HDR_LEN			2
+#define AR9331_HDR_VERSION		1
+
+#define AR9331_HDR_VERSION_MASK		GENMASK(15, 14)
+#define AR9331_HDR_PRIORITY_MASK	GENMASK(13, 12)
+#define AR9331_HDR_TYPE_MASK		GENMASK(10, 8)
+#define AR9331_HDR_BROADCAST		BIT(7)
+#define AR9331_HDR_FROM_CPU		BIT(6)
+/* AR9331_HDR_RESERVED - not used or may be version field.
+ * According to the AR8216 doc it should 0b10. On AR9331 it is 0b11 on RX path
+ * and should be set to 0b11 to make it work.
+ */
+#define AR9331_HDR_RESERVED_MASK	GENMASK(5, 4)
+#define AR9331_HDR_PORT_NUM_MASK	GENMASK(3, 0)
+
+static struct sk_buff *ar9331_tag_xmit(struct sk_buff *skb,
+				       struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	__le16 *phdr;
+	u16 hdr;
+
+	phdr = skb_push(skb, AR9331_HDR_LEN);
+
+	hdr = FIELD_PREP(AR9331_HDR_VERSION_MASK, AR9331_HDR_VERSION);
+	hdr |= AR9331_HDR_FROM_CPU | dp->index;
+	/* 0b10 for AR8216 and 0b11 for AR9331 */
+	hdr |= AR9331_HDR_RESERVED_MASK;
+
+	phdr[0] = cpu_to_le16(hdr);
+
+	return skb;
+}
+
+static struct sk_buff *ar9331_tag_rcv(struct sk_buff *skb,
+				      struct net_device *ndev)
+{
+	u8 ver, port;
+	u16 hdr;
+
+	if (unlikely(!pskb_may_pull(skb, AR9331_HDR_LEN))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	hdr = le16_to_cpu(*(__le16 *)skb_mac_header(skb));
+
+	ver = FIELD_GET(AR9331_HDR_VERSION_MASK, hdr);
+	if (unlikely(ver != AR9331_HDR_VERSION)) {
+		netdev_warn_once(ndev, "%s:%i wrong header version 0x%2x\n",
+				 __func__, __LINE__, hdr);
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (unlikely(hdr & AR9331_HDR_FROM_CPU)) {
+		netdev_warn_once(ndev, "%s:%i packet should not be from cpu 0x%2x\n",
+				 __func__, __LINE__, hdr);
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	skb_pull_rcsum(skb, AR9331_HDR_LEN);
+
+	/* Get source port information */
+	port = FIELD_GET(AR9331_HDR_PORT_NUM_MASK, hdr);
+
+	skb->dev = dsa_conduit_find_user(ndev, 0, port);
+	if (!skb->dev) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	return skb;
+}
+
+static const struct dsa_device_ops ar9331_netdev_ops = {
+	.name	= AR9331_NAME,
+	.proto	= DSA_TAG_PROTO_AR9331,
+	.xmit	= ar9331_tag_xmit,
+	.rcv	= ar9331_tag_rcv,
+	.needed_headroom = AR9331_HDR_LEN,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for Atheros AR9331 SoC with built-in switch");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_AR9331, AR9331_NAME);
+module_dsa_tag_driver(ar9331_netdev_ops);
diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c
new file mode 100644
index 000000000..b7c49822c
--- /dev/null
+++ b/net/dsa/tag_brcm.c
@@ -0,0 +1,428 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Broadcom tag support
+ *
+ * Copyright (C) 2014 Broadcom Corporation
+ */
+
+#include <linux/dsa/brcm.h>
+#include <linux/etherdevice.h>
+#include <linux/if_vlan.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+
+#include "tag.h"
+
+#define BRCM_NAME		"brcm"
+#define BRCM_LEGACY_NAME	"brcm-legacy"
+#define BRCM_LEGACY_FCS_NAME	"brcm-legacy-fcs"
+#define BRCM_PREPEND_NAME	"brcm-prepend"
+
+/* Legacy Broadcom tag (6 bytes) */
+#define BRCM_LEG_TAG_LEN	6
+
+/* Type fields */
+/* 1st byte in the tag */
+#define BRCM_LEG_TYPE_HI	0x88
+/* 2nd byte in the tag */
+#define BRCM_LEG_TYPE_LO	0x74
+
+/* Tag fields */
+/* 3rd byte in the tag */
+#define BRCM_LEG_UNICAST	(0 << 5)
+#define BRCM_LEG_MULTICAST	(1 << 5)
+#define BRCM_LEG_EGRESS		(2 << 5)
+#define BRCM_LEG_INGRESS	(3 << 5)
+#define BRCM_LEG_LEN_HI(x)	(((x) >> 8) & 0x7)
+
+/* 4th byte in the tag */
+#define BRCM_LEG_LEN_LO(x)	((x) & 0xff)
+
+/* 6th byte in the tag */
+#define BRCM_LEG_PORT_ID	(0xf)
+
+/* Newer Broadcom tag (4 bytes) */
+#define BRCM_TAG_LEN	4
+
+/* Tag is constructed and deconstructed using byte by byte access
+ * because the tag is placed after the MAC Source Address, which does
+ * not make it 4-bytes aligned, so this might cause unaligned accesses
+ * on most systems where this is used.
+ */
+
+/* Ingress and egress opcodes */
+#define BRCM_OPCODE_SHIFT	5
+#define BRCM_OPCODE_MASK	0x7
+
+/* Ingress fields */
+/* 1st byte in the tag */
+#define BRCM_IG_TC_SHIFT	2
+#define BRCM_IG_TC_MASK		0x7
+/* 2nd byte in the tag */
+#define BRCM_IG_TE_MASK		0x3
+#define BRCM_IG_TS_SHIFT	7
+/* 3rd byte in the tag */
+#define BRCM_IG_DSTMAP2_MASK	1
+#define BRCM_IG_DSTMAP1_MASK	0xff
+
+/* Egress fields */
+
+/* 2nd byte in the tag */
+#define BRCM_EG_CID_MASK	0xff
+
+/* 3rd byte in the tag */
+#define BRCM_EG_RC_MASK		0xff
+#define  BRCM_EG_RC_RSVD	(3 << 6)
+#define  BRCM_EG_RC_EXCEPTION	(1 << 5)
+#define  BRCM_EG_RC_PROT_SNOOP	(1 << 4)
+#define  BRCM_EG_RC_PROT_TERM	(1 << 3)
+#define  BRCM_EG_RC_SWITCH	(1 << 2)
+#define  BRCM_EG_RC_MAC_LEARN	(1 << 1)
+#define  BRCM_EG_RC_MIRROR	(1 << 0)
+#define BRCM_EG_TC_SHIFT	5
+#define BRCM_EG_TC_MASK		0x7
+#define BRCM_EG_PID_MASK	0x1f
+
+#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM) || \
+	IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND)
+
+static struct sk_buff *brcm_tag_xmit_ll(struct sk_buff *skb,
+					struct net_device *dev,
+					unsigned int offset)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	u16 queue = skb_get_queue_mapping(skb);
+	u16 port_mask;
+	u8 *brcm_tag;
+
+	/* The Ethernet switch we are interfaced with needs packets to be at
+	 * least 64 bytes (including FCS) otherwise they will be discarded when
+	 * they enter the switch port logic. When Broadcom tags are enabled, we
+	 * need to make sure that packets are at least 68 bytes
+	 * (including FCS and tag) because the length verification is done after
+	 * the Broadcom tag is stripped off the ingress packet.
+	 *
+	 * Free the SKB on error.
+	 */
+	if (skb_put_padto(skb, ETH_ZLEN + BRCM_TAG_LEN))
+		return NULL;
+
+	skb_push(skb, BRCM_TAG_LEN);
+
+	if (offset)
+		dsa_alloc_etype_header(skb, BRCM_TAG_LEN);
+
+	brcm_tag = skb->data + offset;
+
+	/* Set the ingress opcode, traffic class, tag enforcement is
+	 * deprecated
+	 */
+	brcm_tag[0] = (1 << BRCM_OPCODE_SHIFT) |
+		       ((queue & BRCM_IG_TC_MASK) << BRCM_IG_TC_SHIFT);
+	brcm_tag[1] = 0;
+	port_mask = dsa_xmit_port_mask(skb, dev);
+	brcm_tag[2] = (port_mask >> 8) & BRCM_IG_DSTMAP2_MASK;
+	brcm_tag[3] = port_mask & BRCM_IG_DSTMAP1_MASK;
+
+	/* Now tell the conduit network device about the desired output queue
+	 * as well
+	 */
+	skb_set_queue_mapping(skb, BRCM_TAG_SET_PORT_QUEUE(dp->index, queue));
+
+	return skb;
+}
+
+/* Frames with this tag have one of these two layouts:
+ * -----------------------------------
+ * | MAC DA | MAC SA | 4b tag | Type | DSA_TAG_PROTO_BRCM
+ * -----------------------------------
+ * -----------------------------------
+ * | 4b tag | MAC DA | MAC SA | Type | DSA_TAG_PROTO_BRCM_PREPEND
+ * -----------------------------------
+ * In both cases, at receive time, skb->data points 2 bytes before the actual
+ * Ethernet type field and we have an offset of 4bytes between where skb->data
+ * and where the payload starts. So the same low-level receive function can be
+ * used.
+ */
+static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb,
+				       struct net_device *dev,
+				       unsigned int offset)
+{
+	int source_port;
+	u8 *brcm_tag;
+
+	if (unlikely(!pskb_may_pull(skb, BRCM_TAG_LEN))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	brcm_tag = skb->data - offset;
+
+	/* The opcode should never be different than 0b000 */
+	if (unlikely((brcm_tag[0] >> BRCM_OPCODE_SHIFT) & BRCM_OPCODE_MASK)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* We should never see a reserved reason code without knowing how to
+	 * handle it
+	 */
+	if (unlikely(brcm_tag[2] & BRCM_EG_RC_RSVD)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Locate which port this is coming from */
+	source_port = brcm_tag[3] & BRCM_EG_PID_MASK;
+
+	skb->dev = dsa_conduit_find_user(dev, 0, source_port);
+	if (!skb->dev) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Remove Broadcom tag and update checksum */
+	skb_pull_rcsum(skb, BRCM_TAG_LEN);
+
+	if (likely(!is_link_local_ether_addr(eth_hdr(skb)->h_dest)))
+		dsa_default_offload_fwd_mark(skb);
+
+	return skb;
+}
+#endif
+
+#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM)
+static struct sk_buff *brcm_tag_xmit(struct sk_buff *skb,
+				     struct net_device *dev)
+{
+	/* Build the tag after the MAC Source Address */
+	return brcm_tag_xmit_ll(skb, dev, 2 * ETH_ALEN);
+}
+
+
+static struct sk_buff *brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+	struct sk_buff *nskb;
+
+	/* skb->data points to the EtherType, the tag is right before it */
+	nskb = brcm_tag_rcv_ll(skb, dev, 2);
+	if (!nskb)
+		return nskb;
+
+	dsa_strip_etype_header(skb, BRCM_TAG_LEN);
+
+	return nskb;
+}
+
+static const struct dsa_device_ops brcm_netdev_ops = {
+	.name	= BRCM_NAME,
+	.proto	= DSA_TAG_PROTO_BRCM,
+	.xmit	= brcm_tag_xmit,
+	.rcv	= brcm_tag_rcv,
+	.needed_headroom = BRCM_TAG_LEN,
+};
+
+DSA_TAG_DRIVER(brcm_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM, BRCM_NAME);
+#endif
+
+#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY) || \
+	IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY_FCS)
+static struct sk_buff *brcm_leg_tag_rcv(struct sk_buff *skb,
+					struct net_device *dev)
+{
+	int len = BRCM_LEG_TAG_LEN;
+	int source_port;
+	__be16 *proto;
+	u8 *brcm_tag;
+
+	if (unlikely(!pskb_may_pull(skb, BRCM_LEG_TAG_LEN + VLAN_HLEN))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	brcm_tag = dsa_etype_header_pos_rx(skb);
+	proto = (__be16 *)(brcm_tag + BRCM_LEG_TAG_LEN);
+
+	source_port = brcm_tag[5] & BRCM_LEG_PORT_ID;
+
+	skb->dev = dsa_conduit_find_user(dev, 0, source_port);
+	if (!skb->dev) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* The internal switch in BCM63XX SoCs always tags on egress on the CPU
+	 * port. We use VID 0 internally for untagged traffic, so strip the tag
+	 * if the TCI field is all 0, and keep it otherwise to also retain
+	 * e.g. 802.1p tagged packets.
+	 */
+	if (proto[0] == htons(ETH_P_8021Q) && proto[1] == 0)
+		len += VLAN_HLEN;
+
+	/* Remove Broadcom tag and update checksum */
+	skb_pull_rcsum(skb, len);
+
+	if (likely(!is_link_local_ether_addr(eth_hdr(skb)->h_dest)))
+		dsa_default_offload_fwd_mark(skb);
+
+	dsa_strip_etype_header(skb, len);
+
+	return skb;
+}
+#endif /* CONFIG_NET_DSA_TAG_BRCM_LEGACY || CONFIG_NET_DSA_TAG_BRCM_LEGACY_FCS */
+
+#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY)
+static struct sk_buff *brcm_leg_tag_xmit(struct sk_buff *skb,
+					 struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	u8 *brcm_tag;
+
+	/* The Ethernet switch we are interfaced with needs packets to be at
+	 * least 64 bytes (including FCS) otherwise they will be discarded when
+	 * they enter the switch port logic. When Broadcom tags are enabled, we
+	 * need to make sure that packets are at least 70 bytes
+	 * (including FCS and tag) because the length verification is done after
+	 * the Broadcom tag is stripped off the ingress packet.
+	 */
+	if (skb_put_padto(skb, ETH_ZLEN + BRCM_LEG_TAG_LEN))
+		return NULL;
+
+	skb_push(skb, BRCM_LEG_TAG_LEN);
+
+	dsa_alloc_etype_header(skb, BRCM_LEG_TAG_LEN);
+
+	brcm_tag = skb->data + 2 * ETH_ALEN;
+
+	/* Broadcom tag type */
+	brcm_tag[0] = BRCM_LEG_TYPE_HI;
+	brcm_tag[1] = BRCM_LEG_TYPE_LO;
+
+	/* Broadcom tag value */
+	brcm_tag[2] = BRCM_LEG_EGRESS;
+	brcm_tag[3] = 0;
+	brcm_tag[4] = 0;
+	brcm_tag[5] = dp->index & BRCM_LEG_PORT_ID;
+
+	return skb;
+}
+
+static const struct dsa_device_ops brcm_legacy_netdev_ops = {
+	.name = BRCM_LEGACY_NAME,
+	.proto = DSA_TAG_PROTO_BRCM_LEGACY,
+	.xmit = brcm_leg_tag_xmit,
+	.rcv = brcm_leg_tag_rcv,
+	.needed_headroom = BRCM_LEG_TAG_LEN,
+};
+
+DSA_TAG_DRIVER(brcm_legacy_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_LEGACY, BRCM_LEGACY_NAME);
+#endif /* CONFIG_NET_DSA_TAG_BRCM_LEGACY */
+
+#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY_FCS)
+static struct sk_buff *brcm_leg_fcs_tag_xmit(struct sk_buff *skb,
+					     struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	unsigned int fcs_len;
+	__le32 fcs_val;
+	u8 *brcm_tag;
+
+	/* The Ethernet switch we are interfaced with needs packets to be at
+	 * least 64 bytes (including FCS) otherwise they will be discarded when
+	 * they enter the switch port logic. When Broadcom tags are enabled, we
+	 * need to make sure that packets are at least 70 bytes (including FCS
+	 * and tag) because the length verification is done after the Broadcom
+	 * tag is stripped off the ingress packet.
+	 */
+	if (skb_put_padto(skb, ETH_ZLEN + BRCM_LEG_TAG_LEN))
+		return NULL;
+
+	fcs_len = skb->len;
+	fcs_val = cpu_to_le32(crc32_le(~0, skb->data, fcs_len) ^ ~0);
+
+	skb_push(skb, BRCM_LEG_TAG_LEN);
+
+	dsa_alloc_etype_header(skb, BRCM_LEG_TAG_LEN);
+
+	brcm_tag = skb->data + 2 * ETH_ALEN;
+
+	/* Broadcom tag type */
+	brcm_tag[0] = BRCM_LEG_TYPE_HI;
+	brcm_tag[1] = BRCM_LEG_TYPE_LO;
+
+	/* Broadcom tag value */
+	brcm_tag[2] = BRCM_LEG_EGRESS | BRCM_LEG_LEN_HI(fcs_len);
+	brcm_tag[3] = BRCM_LEG_LEN_LO(fcs_len);
+	brcm_tag[4] = 0;
+	brcm_tag[5] = dp->index & BRCM_LEG_PORT_ID;
+
+	/* Original FCS value */
+	if (skb_pad(skb, ETH_FCS_LEN))
+		return NULL;
+
+	skb_put_data(skb, &fcs_val, ETH_FCS_LEN);
+
+	return skb;
+}
+
+static const struct dsa_device_ops brcm_legacy_fcs_netdev_ops = {
+	.name = BRCM_LEGACY_FCS_NAME,
+	.proto = DSA_TAG_PROTO_BRCM_LEGACY_FCS,
+	.xmit = brcm_leg_fcs_tag_xmit,
+	.rcv = brcm_leg_tag_rcv,
+	.needed_headroom = BRCM_LEG_TAG_LEN,
+	.needed_tailroom = ETH_FCS_LEN,
+};
+
+DSA_TAG_DRIVER(brcm_legacy_fcs_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_LEGACY_FCS, BRCM_LEGACY_FCS_NAME);
+#endif /* CONFIG_NET_DSA_TAG_BRCM_LEGACY_FCS */
+
+#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND)
+static struct sk_buff *brcm_tag_xmit_prepend(struct sk_buff *skb,
+					     struct net_device *dev)
+{
+	/* tag is prepended to the packet */
+	return brcm_tag_xmit_ll(skb, dev, 0);
+}
+
+static struct sk_buff *brcm_tag_rcv_prepend(struct sk_buff *skb,
+					    struct net_device *dev)
+{
+	/* tag is prepended to the packet */
+	return brcm_tag_rcv_ll(skb, dev, ETH_HLEN);
+}
+
+static const struct dsa_device_ops brcm_prepend_netdev_ops = {
+	.name	= BRCM_PREPEND_NAME,
+	.proto	= DSA_TAG_PROTO_BRCM_PREPEND,
+	.xmit	= brcm_tag_xmit_prepend,
+	.rcv	= brcm_tag_rcv_prepend,
+	.needed_headroom = BRCM_TAG_LEN,
+};
+
+DSA_TAG_DRIVER(brcm_prepend_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_PREPEND, BRCM_PREPEND_NAME);
+#endif
+
+static struct dsa_tag_driver *dsa_tag_driver_array[] =	{
+#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM)
+	&DSA_TAG_DRIVER_NAME(brcm_netdev_ops),
+#endif
+#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY)
+	&DSA_TAG_DRIVER_NAME(brcm_legacy_netdev_ops),
+#endif
+#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY_FCS)
+	&DSA_TAG_DRIVER_NAME(brcm_legacy_fcs_netdev_ops),
+#endif
+#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND)
+	&DSA_TAG_DRIVER_NAME(brcm_prepend_netdev_ops),
+#endif
+};
+
+module_dsa_tag_drivers(dsa_tag_driver_array);
+
+MODULE_DESCRIPTION("DSA tag driver for Broadcom switches using in-frame headers");
+MODULE_LICENSE("GPL");
diff --git a/net/dsa/tag_dsa.c b/net/dsa/tag_dsa.c
new file mode 100644
index 000000000..d5ffee35f
--- /dev/null
+++ b/net/dsa/tag_dsa.c
@@ -0,0 +1,419 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Regular and Ethertype DSA tagging
+ * Copyright (c) 2008-2009 Marvell Semiconductor
+ *
+ * Regular DSA
+ * -----------
+
+ * For untagged (in 802.1Q terms) packets, the switch will splice in
+ * the tag between the SA and the ethertype of the original
+ * packet. Tagged frames will instead have their outermost .1Q tag
+ * converted to a DSA tag. It expects the same layout when receiving
+ * packets from the CPU.
+ *
+ * Example:
+ *
+ *     .----.----.----.---------
+ * Pu: | DA | SA | ET | Payload ...
+ *     '----'----'----'---------
+ *       6    6    2       N
+ *     .----.----.--------.-----.----.---------
+ * Pt: | DA | SA | 0x8100 | TCI | ET | Payload ...
+ *     '----'----'--------'-----'----'---------
+ *       6    6       2      2    2       N
+ *     .----.----.-----.----.---------
+ * Pd: | DA | SA | DSA | ET | Payload ...
+ *     '----'----'-----'----'---------
+ *       6    6     4    2       N
+ *
+ * No matter if a packet is received untagged (Pu) or tagged (Pt),
+ * they will both have the same layout (Pd) when they are sent to the
+ * CPU. This is done by ignoring 802.3, replacing the ethertype field
+ * with more metadata, among which is a bit to signal if the original
+ * packet was tagged or not.
+ *
+ * Ethertype DSA
+ * -------------
+ * Uses the exact same tag format as regular DSA, but also includes a
+ * proper ethertype field (which the mv88e6xxx driver sets to
+ * ETH_P_EDSA/0xdada) followed by two zero bytes:
+ *
+ * .----.----.--------.--------.-----.----.---------
+ * | DA | SA | 0xdada | 0x0000 | DSA | ET | Payload ...
+ * '----'----'--------'--------'-----'----'---------
+ *   6    6       2        2      4    2       N
+ */
+
+#include <linux/dsa/mv88e6xxx.h>
+#include <linux/etherdevice.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+
+#include "tag.h"
+
+#define DSA_NAME	"dsa"
+#define EDSA_NAME	"edsa"
+
+#define DSA_HLEN	4
+
+/**
+ * enum dsa_cmd - DSA Command
+ * @DSA_CMD_TO_CPU: Set on packets that were trapped or mirrored to
+ *     the CPU port. This is needed to implement control protocols,
+ *     e.g. STP and LLDP, that must not allow those control packets to
+ *     be switched according to the normal rules.
+ * @DSA_CMD_FROM_CPU: Used by the CPU to send a packet to a specific
+ *     port, ignoring all the barriers that the switch normally
+ *     enforces (VLANs, STP port states etc.). No source address
+ *     learning takes place. "sudo send packet"
+ * @DSA_CMD_TO_SNIFFER: Set on the copies of packets that matched some
+ *     user configured ingress or egress monitor criteria. These are
+ *     forwarded by the switch tree to the user configured ingress or
+ *     egress monitor port, which can be set to the CPU port or a
+ *     regular port. If the destination is a regular port, the tag
+ *     will be removed before egressing the port. If the destination
+ *     is the CPU port, the tag will not be removed.
+ * @DSA_CMD_FORWARD: This tag is used on all bulk traffic passing
+ *     through the switch tree, including the flows that are directed
+ *     towards the CPU. Its device/port tuple encodes the original
+ *     source port on which the packet ingressed. It can also be used
+ *     on transmit by the CPU to defer the forwarding decision to the
+ *     hardware, based on the current config of PVT/VTU/ATU
+ *     etc. Source address learning takes places if enabled on the
+ *     receiving DSA/CPU port.
+ */
+enum dsa_cmd {
+	DSA_CMD_TO_CPU     = 0,
+	DSA_CMD_FROM_CPU   = 1,
+	DSA_CMD_TO_SNIFFER = 2,
+	DSA_CMD_FORWARD    = 3
+};
+
+/**
+ * enum dsa_code - TO_CPU Code
+ *
+ * @DSA_CODE_MGMT_TRAP: DA was classified as a management
+ *     address. Typical examples include STP BPDUs and LLDP.
+ * @DSA_CODE_FRAME2REG: Response to a "remote management" request.
+ * @DSA_CODE_IGMP_MLD_TRAP: IGMP/MLD signaling.
+ * @DSA_CODE_POLICY_TRAP: Frame matched some policy configuration on
+ *     the device. Typical examples are matching on DA/SA/VID and DHCP
+ *     snooping.
+ * @DSA_CODE_ARP_MIRROR: The name says it all really.
+ * @DSA_CODE_POLICY_MIRROR: Same as @DSA_CODE_POLICY_TRAP, but the
+ *     particular policy was set to trigger a mirror instead of a
+ *     trap.
+ * @DSA_CODE_RESERVED_6: Unused on all devices up to at least 6393X.
+ * @DSA_CODE_RESERVED_7: Unused on all devices up to at least 6393X.
+ *
+ * A 3-bit code is used to relay why a particular frame was sent to
+ * the CPU. We only use this to determine if the packet was mirrored
+ * or trapped, i.e. whether the packet has been forwarded by hardware
+ * or not.
+ *
+ * This is the superset of all possible codes. Any particular device
+ * may only implement a subset.
+ */
+enum dsa_code {
+	DSA_CODE_MGMT_TRAP     = 0,
+	DSA_CODE_FRAME2REG     = 1,
+	DSA_CODE_IGMP_MLD_TRAP = 2,
+	DSA_CODE_POLICY_TRAP   = 3,
+	DSA_CODE_ARP_MIRROR    = 4,
+	DSA_CODE_POLICY_MIRROR = 5,
+	DSA_CODE_RESERVED_6    = 6,
+	DSA_CODE_RESERVED_7    = 7
+};
+
+static struct sk_buff *dsa_xmit_ll(struct sk_buff *skb, struct net_device *dev,
+				   u8 extra)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct net_device *br_dev;
+	u8 tag_dev, tag_port;
+	enum dsa_cmd cmd;
+	u8 *dsa_header;
+
+	if (skb->offload_fwd_mark) {
+		unsigned int bridge_num = dsa_port_bridge_num_get(dp);
+		struct dsa_switch_tree *dst = dp->ds->dst;
+
+		cmd = DSA_CMD_FORWARD;
+
+		/* When offloading forwarding for a bridge, inject FORWARD
+		 * packets on behalf of a virtual switch device with an index
+		 * past the physical switches.
+		 */
+		tag_dev = dst->last_switch + bridge_num;
+		tag_port = 0;
+	} else {
+		cmd = DSA_CMD_FROM_CPU;
+		tag_dev = dp->ds->index;
+		tag_port = dp->index;
+	}
+
+	br_dev = dsa_port_bridge_dev_get(dp);
+
+	/* If frame is already 802.1Q tagged, we can convert it to a DSA
+	 * tag (avoiding a memmove), but only if the port is standalone
+	 * (in which case we always send FROM_CPU) or if the port's
+	 * bridge has VLAN filtering enabled (in which case the CPU port
+	 * will be a member of the VLAN).
+	 */
+	if (skb->protocol == htons(ETH_P_8021Q) &&
+	    (!br_dev || br_vlan_enabled(br_dev))) {
+		if (extra) {
+			skb_push(skb, extra);
+			dsa_alloc_etype_header(skb, extra);
+		}
+
+		/* Construct tagged DSA tag from 802.1Q tag. */
+		dsa_header = dsa_etype_header_pos_tx(skb) + extra;
+		dsa_header[0] = (cmd << 6) | 0x20 | tag_dev;
+		dsa_header[1] = tag_port << 3;
+
+		/* Move CFI field from byte 2 to byte 1. */
+		if (dsa_header[2] & 0x10) {
+			dsa_header[1] |= 0x01;
+			dsa_header[2] &= ~0x10;
+		}
+	} else {
+		u16 vid;
+
+		vid = br_dev ? MV88E6XXX_VID_BRIDGED : MV88E6XXX_VID_STANDALONE;
+
+		skb_push(skb, DSA_HLEN + extra);
+		dsa_alloc_etype_header(skb, DSA_HLEN + extra);
+
+		/* Construct DSA header from untagged frame. */
+		dsa_header = dsa_etype_header_pos_tx(skb) + extra;
+
+		dsa_header[0] = (cmd << 6) | tag_dev;
+		dsa_header[1] = tag_port << 3;
+		dsa_header[2] = vid >> 8;
+		dsa_header[3] = vid & 0xff;
+	}
+
+	return skb;
+}
+
+static struct sk_buff *dsa_rcv_ll(struct sk_buff *skb, struct net_device *dev,
+				  u8 extra)
+{
+	bool trap = false, trunk = false;
+	int source_device, source_port;
+	enum dsa_code code;
+	enum dsa_cmd cmd;
+	u8 *dsa_header;
+
+	/* The ethertype field is part of the DSA header. */
+	dsa_header = dsa_etype_header_pos_rx(skb);
+
+	cmd = dsa_header[0] >> 6;
+	switch (cmd) {
+	case DSA_CMD_FORWARD:
+		trunk = !!(dsa_header[1] & 4);
+		break;
+
+	case DSA_CMD_TO_CPU:
+		code = (dsa_header[1] & 0x6) | ((dsa_header[2] >> 4) & 1);
+
+		switch (code) {
+		case DSA_CODE_FRAME2REG:
+			/* Remote management is not implemented yet,
+			 * drop.
+			 */
+			kfree_skb(skb);
+			return NULL;
+		case DSA_CODE_ARP_MIRROR:
+		case DSA_CODE_POLICY_MIRROR:
+			/* Mark mirrored packets to notify any upper
+			 * device (like a bridge) that forwarding has
+			 * already been done by hardware.
+			 */
+			break;
+		case DSA_CODE_MGMT_TRAP:
+		case DSA_CODE_IGMP_MLD_TRAP:
+		case DSA_CODE_POLICY_TRAP:
+			/* Traps have, by definition, not been
+			 * forwarded by hardware, so don't mark them.
+			 */
+			trap = true;
+			break;
+		default:
+			/* Reserved code, this could be anything. Drop
+			 * seems like the safest option.
+			 */
+			kfree_skb(skb);
+			return NULL;
+		}
+
+		break;
+
+	default:
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	source_device = dsa_header[0] & 0x1f;
+	source_port = (dsa_header[1] >> 3) & 0x1f;
+
+	if (trunk) {
+		struct dsa_port *cpu_dp = dev->dsa_ptr;
+		struct dsa_lag *lag;
+
+		/* The exact source port is not available in the tag,
+		 * so we inject the frame directly on the upper
+		 * team/bond.
+		 */
+		lag = dsa_lag_by_id(cpu_dp->dst, source_port + 1);
+		skb->dev = lag ? lag->dev : NULL;
+	} else {
+		skb->dev = dsa_conduit_find_user(dev, source_device,
+						 source_port);
+	}
+
+	if (!skb->dev) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* When using LAG offload, skb->dev is not a DSA user interface,
+	 * so we cannot call dsa_default_offload_fwd_mark and we need to
+	 * special-case it.
+	 */
+	if (trunk)
+		skb->offload_fwd_mark = true;
+	else if (!trap)
+		dsa_default_offload_fwd_mark(skb);
+
+	/* If the 'tagged' bit is set; convert the DSA tag to a 802.1Q
+	 * tag, and delete the ethertype (extra) if applicable. If the
+	 * 'tagged' bit is cleared; delete the DSA tag, and ethertype
+	 * if applicable.
+	 */
+	if (dsa_header[0] & 0x20) {
+		u8 new_header[4];
+
+		/* Insert 802.1Q ethertype and copy the VLAN-related
+		 * fields, but clear the bit that will hold CFI (since
+		 * DSA uses that bit location for another purpose).
+		 */
+		new_header[0] = (ETH_P_8021Q >> 8) & 0xff;
+		new_header[1] = ETH_P_8021Q & 0xff;
+		new_header[2] = dsa_header[2] & ~0x10;
+		new_header[3] = dsa_header[3];
+
+		/* Move CFI bit from its place in the DSA header to
+		 * its 802.1Q-designated place.
+		 */
+		if (dsa_header[1] & 0x01)
+			new_header[2] |= 0x10;
+
+		/* Update packet checksum if skb is CHECKSUM_COMPLETE. */
+		if (skb->ip_summed == CHECKSUM_COMPLETE) {
+			__wsum c = skb->csum;
+			c = csum_add(c, csum_partial(new_header + 2, 2, 0));
+			c = csum_sub(c, csum_partial(dsa_header + 2, 2, 0));
+			skb->csum = c;
+		}
+
+		memcpy(dsa_header, new_header, DSA_HLEN);
+
+		if (extra)
+			dsa_strip_etype_header(skb, extra);
+	} else {
+		skb_pull_rcsum(skb, DSA_HLEN);
+		dsa_strip_etype_header(skb, DSA_HLEN + extra);
+	}
+
+	return skb;
+}
+
+#if IS_ENABLED(CONFIG_NET_DSA_TAG_DSA)
+
+static struct sk_buff *dsa_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	return dsa_xmit_ll(skb, dev, 0);
+}
+
+static struct sk_buff *dsa_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+	if (unlikely(!pskb_may_pull(skb, DSA_HLEN))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	return dsa_rcv_ll(skb, dev, 0);
+}
+
+static const struct dsa_device_ops dsa_netdev_ops = {
+	.name	  = DSA_NAME,
+	.proto	  = DSA_TAG_PROTO_DSA,
+	.xmit	  = dsa_xmit,
+	.rcv	  = dsa_rcv,
+	.needed_headroom = DSA_HLEN,
+};
+
+DSA_TAG_DRIVER(dsa_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_DSA, DSA_NAME);
+#endif	/* CONFIG_NET_DSA_TAG_DSA */
+
+#if IS_ENABLED(CONFIG_NET_DSA_TAG_EDSA)
+
+#define EDSA_HLEN 8
+
+static struct sk_buff *edsa_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	u8 *edsa_header;
+
+	skb = dsa_xmit_ll(skb, dev, EDSA_HLEN - DSA_HLEN);
+	if (!skb)
+		return NULL;
+
+	edsa_header = dsa_etype_header_pos_tx(skb);
+	edsa_header[0] = (ETH_P_EDSA >> 8) & 0xff;
+	edsa_header[1] = ETH_P_EDSA & 0xff;
+	edsa_header[2] = 0x00;
+	edsa_header[3] = 0x00;
+	return skb;
+}
+
+static struct sk_buff *edsa_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+	if (unlikely(!pskb_may_pull(skb, EDSA_HLEN))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	skb_pull_rcsum(skb, EDSA_HLEN - DSA_HLEN);
+
+	return dsa_rcv_ll(skb, dev, EDSA_HLEN - DSA_HLEN);
+}
+
+static const struct dsa_device_ops edsa_netdev_ops = {
+	.name	  = EDSA_NAME,
+	.proto	  = DSA_TAG_PROTO_EDSA,
+	.xmit	  = edsa_xmit,
+	.rcv	  = edsa_rcv,
+	.needed_headroom = EDSA_HLEN,
+};
+
+DSA_TAG_DRIVER(edsa_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_EDSA, EDSA_NAME);
+#endif	/* CONFIG_NET_DSA_TAG_EDSA */
+
+static struct dsa_tag_driver *dsa_tag_drivers[] = {
+#if IS_ENABLED(CONFIG_NET_DSA_TAG_DSA)
+	&DSA_TAG_DRIVER_NAME(dsa_netdev_ops),
+#endif
+#if IS_ENABLED(CONFIG_NET_DSA_TAG_EDSA)
+	&DSA_TAG_DRIVER_NAME(edsa_netdev_ops),
+#endif
+};
+
+module_dsa_tag_drivers(dsa_tag_drivers);
+
+MODULE_DESCRIPTION("DSA tag driver for Marvell switches using DSA headers");
+MODULE_LICENSE("GPL");
diff --git a/net/dsa/tag_gswip.c b/net/dsa/tag_gswip.c
new file mode 100644
index 000000000..5c407d448
--- /dev/null
+++ b/net/dsa/tag_gswip.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel / Lantiq GSWIP V2.0 PMAC tag support
+ *
+ * Copyright (C) 2017 - 2018 Hauke Mehrtens <hauke@hauke-m.de>
+ */
+
+#include <linux/bitops.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <net/dsa.h>
+
+#include "tag.h"
+
+#define GSWIP_NAME			"gswip"
+
+#define GSWIP_TX_HEADER_LEN		4
+
+/* special tag in TX path header */
+/* Byte 0 */
+#define GSWIP_TX_SLPID_SHIFT		0	/* source port ID */
+#define  GSWIP_TX_SLPID_CPU		2
+#define  GSWIP_TX_SLPID_APP1		3
+#define  GSWIP_TX_SLPID_APP2		4
+#define  GSWIP_TX_SLPID_APP3		5
+#define  GSWIP_TX_SLPID_APP4		6
+#define  GSWIP_TX_SLPID_APP5		7
+
+/* Byte 1 */
+#define GSWIP_TX_CRCGEN_DIS		BIT(7)
+#define GSWIP_TX_DPID_SHIFT		0	/* destination group ID */
+#define  GSWIP_TX_DPID_ELAN		0
+#define  GSWIP_TX_DPID_EWAN		1
+#define  GSWIP_TX_DPID_CPU		2
+#define  GSWIP_TX_DPID_APP1		3
+#define  GSWIP_TX_DPID_APP2		4
+#define  GSWIP_TX_DPID_APP3		5
+#define  GSWIP_TX_DPID_APP4		6
+#define  GSWIP_TX_DPID_APP5		7
+
+/* Byte 2 */
+#define GSWIP_TX_PORT_MAP_EN		BIT(7)
+#define GSWIP_TX_PORT_MAP_SEL		BIT(6)
+#define GSWIP_TX_LRN_DIS		BIT(5)
+#define GSWIP_TX_CLASS_EN		BIT(4)
+#define GSWIP_TX_CLASS_SHIFT		0
+#define GSWIP_TX_CLASS_MASK		GENMASK(3, 0)
+
+/* Byte 3 */
+#define GSWIP_TX_DPID_EN		BIT(0)
+#define GSWIP_TX_PORT_MAP		GENMASK(6, 1)
+
+#define GSWIP_RX_HEADER_LEN	8
+
+/* special tag in RX path header */
+/* Byte 7 */
+#define GSWIP_RX_SPPID_SHIFT		4
+#define GSWIP_RX_SPPID_MASK		GENMASK(6, 4)
+
+static struct sk_buff *gswip_tag_xmit(struct sk_buff *skb,
+				      struct net_device *dev)
+{
+	u8 *gswip_tag;
+
+	skb_push(skb, GSWIP_TX_HEADER_LEN);
+
+	gswip_tag = skb->data;
+	gswip_tag[0] = GSWIP_TX_SLPID_CPU;
+	gswip_tag[1] = GSWIP_TX_DPID_ELAN;
+	gswip_tag[2] = GSWIP_TX_PORT_MAP_EN | GSWIP_TX_PORT_MAP_SEL;
+	gswip_tag[3] = FIELD_PREP(GSWIP_TX_PORT_MAP, dsa_xmit_port_mask(skb, dev));
+	gswip_tag[3] |= GSWIP_TX_DPID_EN;
+
+	return skb;
+}
+
+static struct sk_buff *gswip_tag_rcv(struct sk_buff *skb,
+				     struct net_device *dev)
+{
+	int port;
+	u8 *gswip_tag;
+
+	if (unlikely(!pskb_may_pull(skb, GSWIP_RX_HEADER_LEN))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	gswip_tag = skb->data - ETH_HLEN;
+
+	/* Get source port information */
+	port = (gswip_tag[7] & GSWIP_RX_SPPID_MASK) >> GSWIP_RX_SPPID_SHIFT;
+	skb->dev = dsa_conduit_find_user(dev, 0, port);
+	if (!skb->dev) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* remove GSWIP tag */
+	skb_pull_rcsum(skb, GSWIP_RX_HEADER_LEN);
+
+	return skb;
+}
+
+static const struct dsa_device_ops gswip_netdev_ops = {
+	.name = GSWIP_NAME,
+	.proto	= DSA_TAG_PROTO_GSWIP,
+	.xmit = gswip_tag_xmit,
+	.rcv = gswip_tag_rcv,
+	.needed_headroom = GSWIP_RX_HEADER_LEN,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for Lantiq / Intel GSWIP switches");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_GSWIP, GSWIP_NAME);
+
+module_dsa_tag_driver(gswip_netdev_ops);
diff --git a/net/dsa/tag_hellcreek.c b/net/dsa/tag_hellcreek.c
new file mode 100644
index 000000000..dd9f328f3
--- /dev/null
+++ b/net/dsa/tag_hellcreek.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * net/dsa/tag_hellcreek.c - Hirschmann Hellcreek switch tag format handling
+ *
+ * Copyright (C) 2019,2020 Linutronix GmbH
+ * Author Kurt Kanzenbach <kurt@linutronix.de>
+ *
+ * Based on tag_ksz.c.
+ */
+
+#include <linux/skbuff.h>
+#include <net/dsa.h>
+
+#include "tag.h"
+
+#define HELLCREEK_NAME		"hellcreek"
+
+#define HELLCREEK_TAG_LEN	1
+
+static struct sk_buff *hellcreek_xmit(struct sk_buff *skb,
+				      struct net_device *dev)
+{
+	u8 *tag;
+
+	/* Calculate checksums (if required) before adding the trailer tag to
+	 * avoid including it in calculations. That would lead to wrong
+	 * checksums after the switch strips the tag.
+	 */
+	if (skb->ip_summed == CHECKSUM_PARTIAL &&
+	    skb_checksum_help(skb)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Tag encoding */
+	tag  = skb_put(skb, HELLCREEK_TAG_LEN);
+	*tag = dsa_xmit_port_mask(skb, dev);
+
+	return skb;
+}
+
+static struct sk_buff *hellcreek_rcv(struct sk_buff *skb,
+				     struct net_device *dev)
+{
+	/* Tag decoding */
+	u8 *tag = skb_tail_pointer(skb) - HELLCREEK_TAG_LEN;
+	unsigned int port = tag[0] & 0x03;
+
+	skb->dev = dsa_conduit_find_user(dev, 0, port);
+	if (!skb->dev) {
+		netdev_warn_once(dev, "Failed to get source port: %d\n", port);
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (pskb_trim_rcsum(skb, skb->len - HELLCREEK_TAG_LEN)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	dsa_default_offload_fwd_mark(skb);
+
+	return skb;
+}
+
+static const struct dsa_device_ops hellcreek_netdev_ops = {
+	.name	  = HELLCREEK_NAME,
+	.proto	  = DSA_TAG_PROTO_HELLCREEK,
+	.xmit	  = hellcreek_xmit,
+	.rcv	  = hellcreek_rcv,
+	.needed_tailroom = HELLCREEK_TAG_LEN,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for Hirschmann Hellcreek TSN switches");
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_HELLCREEK, HELLCREEK_NAME);
+
+module_dsa_tag_driver(hellcreek_netdev_ops);
diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
new file mode 100644
index 000000000..b4d70ba93
--- /dev/null
+++ b/net/dsa/tag_ksz.c
@@ -0,0 +1,546 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * net/dsa/tag_ksz.c - Microchip KSZ Switch tag format handling
+ * Copyright (c) 2017 Microchip Technology
+ */
+
+#include <linux/dsa/ksz_common.h>
+#include <linux/etherdevice.h>
+#include <linux/list.h>
+#include <linux/ptp_classify.h>
+#include <net/dsa.h>
+
+#include "tag.h"
+
+#define KSZ8463_NAME "ksz8463"
+#define KSZ8795_NAME "ksz8795"
+#define KSZ9477_NAME "ksz9477"
+#define KSZ9893_NAME "ksz9893"
+#define LAN937X_NAME "lan937x"
+
+/* Typically only one byte is used for tail tag. */
+#define KSZ_PTP_TAG_LEN			4
+#define KSZ_EGRESS_TAG_LEN		1
+#define KSZ_INGRESS_TAG_LEN		1
+
+#define KSZ_HWTS_EN  0
+
+struct ksz_tagger_private {
+	struct ksz_tagger_data data; /* Must be first */
+	unsigned long state;
+	struct kthread_worker *xmit_worker;
+};
+
+static struct ksz_tagger_private *
+ksz_tagger_private(struct dsa_switch *ds)
+{
+	return ds->tagger_data;
+}
+
+static void ksz_hwtstamp_set_state(struct dsa_switch *ds, bool on)
+{
+	struct ksz_tagger_private *priv = ksz_tagger_private(ds);
+
+	if (on)
+		set_bit(KSZ_HWTS_EN, &priv->state);
+	else
+		clear_bit(KSZ_HWTS_EN, &priv->state);
+}
+
+static void ksz_disconnect(struct dsa_switch *ds)
+{
+	struct ksz_tagger_private *priv = ds->tagger_data;
+
+	kthread_destroy_worker(priv->xmit_worker);
+	kfree(priv);
+	ds->tagger_data = NULL;
+}
+
+static int ksz_connect(struct dsa_switch *ds)
+{
+	struct ksz_tagger_data *tagger_data;
+	struct kthread_worker *xmit_worker;
+	struct ksz_tagger_private *priv;
+	int ret;
+
+	priv = kzalloc_obj(*priv);
+	if (!priv)
+		return -ENOMEM;
+
+	xmit_worker = kthread_run_worker(0, "dsa%d:%d_xmit",
+					    ds->dst->index, ds->index);
+	if (IS_ERR(xmit_worker)) {
+		ret = PTR_ERR(xmit_worker);
+		kfree(priv);
+		return ret;
+	}
+
+	priv->xmit_worker = xmit_worker;
+	/* Export functions for switch driver use */
+	tagger_data = &priv->data;
+	tagger_data->hwtstamp_set_state = ksz_hwtstamp_set_state;
+	ds->tagger_data = priv;
+
+	return 0;
+}
+
+static struct sk_buff *ksz_common_rcv(struct sk_buff *skb,
+				      struct net_device *dev,
+				      unsigned int port, unsigned int len)
+{
+	skb->dev = dsa_conduit_find_user(dev, 0, port);
+	if (!skb->dev) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (pskb_trim_rcsum(skb, skb->len - len)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	dsa_default_offload_fwd_mark(skb);
+
+	return skb;
+}
+
+/*
+ * For Ingress (Host -> KSZ9477), 2/6 bytes are added before FCS.
+ * ---------------------------------------------------------------------------
+ * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|tag1(1byte)|
+ * FCS(4bytes)
+ * ---------------------------------------------------------------------------
+ * ts   : time stamp (Present only if PTP is enabled in the Hardware)
+ * tag0 : Prioritization (not used now)
+ * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
+ *
+ * For Egress (KSZ9477 -> Host), 1/5 bytes is added before FCS.
+ * ---------------------------------------------------------------------------
+ * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|FCS(4bytes)
+ * ---------------------------------------------------------------------------
+ * ts   : time stamp (Present only if bit 7 of tag0 is set)
+ * tag0 : zero-based value represents port
+ *	  (eg, 0x00=port1, 0x02=port3, 0x06=port7)
+ */
+
+#define KSZ9477_INGRESS_TAG_LEN		2
+#define KSZ9477_PTP_TAG_LEN		4
+#define KSZ9477_PTP_TAG_INDICATION	BIT(7)
+
+#define KSZ9477_TAIL_TAG_EG_PORT_M	GENMASK(2, 0)
+#define KSZ9477_TAIL_TAG_PRIO		GENMASK(8, 7)
+#define KSZ9477_TAIL_TAG_OVERRIDE	BIT(9)
+#define KSZ9477_TAIL_TAG_LOOKUP		BIT(10)
+
+static void ksz_rcv_timestamp(struct sk_buff *skb, u8 *tag)
+{
+	u8 *tstamp_raw = tag - KSZ_PTP_TAG_LEN;
+	ktime_t tstamp;
+
+	tstamp = ksz_decode_tstamp(get_unaligned_be32(tstamp_raw));
+	KSZ_SKB_CB(skb)->tstamp = tstamp;
+}
+
+/* Time stamp tag *needs* to be inserted if PTP is enabled in hardware.
+ * Regardless of Whether it is a PTP frame or not.
+ */
+static void ksz_xmit_timestamp(struct dsa_port *dp, struct sk_buff *skb)
+{
+	struct ksz_tagger_private *priv;
+	struct ptp_header *ptp_hdr;
+	unsigned int ptp_type;
+	u32 tstamp_raw = 0;
+	s64 correction;
+
+	priv = ksz_tagger_private(dp->ds);
+
+	if (!test_bit(KSZ_HWTS_EN, &priv->state))
+		return;
+
+	if (!KSZ_SKB_CB(skb)->update_correction)
+		goto output_tag;
+
+	ptp_type = KSZ_SKB_CB(skb)->ptp_type;
+
+	ptp_hdr = ptp_parse_header(skb, ptp_type);
+	if (!ptp_hdr)
+		goto output_tag;
+
+	correction = (s64)get_unaligned_be64(&ptp_hdr->correction);
+
+	if (correction < 0) {
+		struct timespec64 ts;
+
+		ts = ns_to_timespec64(-correction >> 16);
+		tstamp_raw = ((ts.tv_sec & 3) << 30) | ts.tv_nsec;
+
+		/* Set correction field to 0 and update UDP checksum */
+		ptp_header_update_correction(skb, ptp_type, ptp_hdr, 0);
+	}
+
+output_tag:
+	put_unaligned_be32(tstamp_raw, skb_put(skb, KSZ_PTP_TAG_LEN));
+}
+
+/* Defer transmit if waiting for egress time stamp is required.  */
+static struct sk_buff *ksz_defer_xmit(struct dsa_port *dp, struct sk_buff *skb)
+{
+	struct ksz_tagger_data *tagger_data = ksz_tagger_data(dp->ds);
+	struct ksz_tagger_private *priv = ksz_tagger_private(dp->ds);
+	void (*xmit_work_fn)(struct kthread_work *work);
+	struct sk_buff *clone = KSZ_SKB_CB(skb)->clone;
+	struct ksz_deferred_xmit_work *xmit_work;
+	struct kthread_worker *xmit_worker;
+
+	if (!clone)
+		return skb;  /* no deferred xmit for this packet */
+
+	xmit_work_fn = tagger_data->xmit_work_fn;
+	xmit_worker = priv->xmit_worker;
+
+	if (!xmit_work_fn || !xmit_worker) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	xmit_work = kzalloc_obj(*xmit_work, GFP_ATOMIC);
+	if (!xmit_work) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	kthread_init_work(&xmit_work->work, xmit_work_fn);
+	xmit_work->dp = dp;
+	xmit_work->skb = skb_get(skb);
+
+	kthread_queue_work(xmit_worker, &xmit_work->work);
+
+	kfree_skb(skb);
+	return NULL;
+}
+
+static struct sk_buff *ksz_common_xmit(struct sk_buff *skb,
+				       struct net_device *dev,
+				       bool do_tstamp,
+				       u8 prio,
+				       u8 override_mask)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct ethhdr *hdr;
+	u8 *tag;
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Tag encoding */
+	if (do_tstamp)
+		ksz_xmit_timestamp(dp, skb);
+
+	tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
+	hdr = skb_eth_hdr(skb);
+
+	*tag = dsa_xmit_port_mask(skb, dev);
+	*tag |= prio;
+
+	if (is_link_local_ether_addr(hdr->h_dest))
+		*tag |= override_mask;
+
+	return ksz_defer_xmit(dp, skb);
+}
+
+static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
+				    struct net_device *dev)
+{
+	u16 queue_mapping = skb_get_queue_mapping(skb);
+	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct ethhdr *hdr;
+	__be16 *tag;
+	u16 val;
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Tag encoding */
+	ksz_xmit_timestamp(dp, skb);
+
+	tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN);
+	hdr = skb_eth_hdr(skb);
+
+	val = dsa_xmit_port_mask(skb, dev);
+	val |= FIELD_PREP(KSZ9477_TAIL_TAG_PRIO, prio);
+
+	if (is_link_local_ether_addr(hdr->h_dest))
+		val |= KSZ9477_TAIL_TAG_OVERRIDE;
+
+	*tag = cpu_to_be16(val);
+
+	return ksz_defer_xmit(dp, skb);
+}
+
+static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+	unsigned int len = KSZ_EGRESS_TAG_LEN;
+	unsigned int port;
+	u8 *tag;
+
+	if (skb_linearize(skb)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Tag decoding */
+	tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
+	port = tag[0] & KSZ9477_TAIL_TAG_EG_PORT_M;
+
+	/* Extra 4-bytes PTP timestamp */
+	if (tag[0] & KSZ9477_PTP_TAG_INDICATION) {
+		ksz_rcv_timestamp(skb, tag);
+		len += KSZ_PTP_TAG_LEN;
+	}
+
+	return ksz_common_rcv(skb, dev, port, len);
+}
+
+static const struct dsa_device_ops ksz9477_netdev_ops = {
+	.name	= KSZ9477_NAME,
+	.proto	= DSA_TAG_PROTO_KSZ9477,
+	.xmit	= ksz9477_xmit,
+	.rcv	= ksz9477_rcv,
+	.connect = ksz_connect,
+	.disconnect = ksz_disconnect,
+	.needed_tailroom = KSZ9477_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
+};
+
+DSA_TAG_DRIVER(ksz9477_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477, KSZ9477_NAME);
+
+/*
+ * For Ingress (Host -> KSZ8795), 1 byte is added before FCS.
+ * ---------------------------------------------------------------------------
+ * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag(1byte)|FCS(4bytes)
+ * ---------------------------------------------------------------------------
+ * tag : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
+ *
+ * For Egress (KSZ8795 -> Host), 1 byte is added before FCS.
+ * ---------------------------------------------------------------------------
+ * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
+ * ---------------------------------------------------------------------------
+ * tag0 : zero-based value represents port
+ *	  (eg, 0x0=port1, 0x2=port3, 0x3=port4)
+ */
+
+#define KSZ8795_TAIL_TAG_EG_PORT_M	GENMASK(1, 0)
+#define KSZ8795_TAIL_TAG_OVERRIDE	BIT(6)
+#define KSZ8795_TAIL_TAG_LOOKUP		BIT(7)
+
+static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	return ksz_common_xmit(skb, dev, false, 0, KSZ8795_TAIL_TAG_OVERRIDE);
+}
+
+static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+	u8 *tag;
+
+	if (skb_linearize(skb)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
+
+	return ksz_common_rcv(skb, dev, tag[0] & KSZ8795_TAIL_TAG_EG_PORT_M,
+			      KSZ_EGRESS_TAG_LEN);
+}
+
+static const struct dsa_device_ops ksz8795_netdev_ops = {
+	.name	= KSZ8795_NAME,
+	.proto	= DSA_TAG_PROTO_KSZ8795,
+	.xmit	= ksz8795_xmit,
+	.rcv	= ksz8795_rcv,
+	.needed_tailroom = KSZ_INGRESS_TAG_LEN,
+};
+
+DSA_TAG_DRIVER(ksz8795_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795, KSZ8795_NAME);
+
+#define KSZ9893_TAIL_TAG_PRIO		GENMASK(4, 3)
+#define KSZ9893_TAIL_TAG_OVERRIDE	BIT(5)
+#define KSZ9893_TAIL_TAG_LOOKUP		BIT(6)
+
+static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
+				    struct net_device *dev)
+{
+	u16 queue_mapping = skb_get_queue_mapping(skb);
+	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
+
+	return ksz_common_xmit(skb, dev, true,
+			       FIELD_PREP(KSZ9893_TAIL_TAG_PRIO, prio),
+			       KSZ9893_TAIL_TAG_OVERRIDE);
+}
+
+static const struct dsa_device_ops ksz9893_netdev_ops = {
+	.name	= KSZ9893_NAME,
+	.proto	= DSA_TAG_PROTO_KSZ9893,
+	.xmit	= ksz9893_xmit,
+	.rcv	= ksz9477_rcv,
+	.connect = ksz_connect,
+	.disconnect = ksz_disconnect,
+	.needed_tailroom = KSZ_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
+};
+
+DSA_TAG_DRIVER(ksz9893_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893, KSZ9893_NAME);
+
+#define KSZ8463_TAIL_TAG_PRIO		GENMASK(4, 3)
+#define KSZ8463_TAIL_TAG_EG_PORT_M	GENMASK(2, 0)
+
+static struct sk_buff *ksz8463_xmit(struct sk_buff *skb,
+				    struct net_device *dev)
+{
+	u16 queue_mapping = skb_get_queue_mapping(skb);
+	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
+
+	return ksz_common_xmit(skb, dev, false,
+			       FIELD_PREP(KSZ8463_TAIL_TAG_PRIO, prio),
+			       0);
+}
+
+static struct sk_buff *ksz8463_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+	unsigned int len = KSZ_EGRESS_TAG_LEN;
+	struct ptp_header *ptp_hdr;
+	unsigned int ptp_class;
+	unsigned int port;
+	ktime_t ts;
+	u8 *tag;
+
+	if (skb_linearize(skb)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	KSZ_SKB_CB(skb)->tstamp = 0;
+
+	/* Tag decoding */
+	tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
+	port = tag[0] & KSZ8463_TAIL_TAG_EG_PORT_M;
+
+	__skb_push(skb, ETH_HLEN);
+	ptp_class = ptp_classify_raw(skb);
+	__skb_pull(skb, ETH_HLEN);
+	if (ptp_class == PTP_CLASS_NONE)
+		goto common_rcv;
+
+	ptp_hdr = ptp_parse_header(skb, ptp_class);
+	if (ptp_hdr) {
+		ts = ksz_decode_tstamp(get_unaligned_be32(&ptp_hdr->reserved2));
+		KSZ_SKB_CB(skb)->tstamp = ts;
+		ptp_hdr->reserved2 = 0;
+	}
+
+common_rcv:
+	return ksz_common_rcv(skb, dev, port, len);
+}
+
+static const struct dsa_device_ops ksz8463_netdev_ops = {
+	.name	= KSZ8463_NAME,
+	.proto	= DSA_TAG_PROTO_KSZ8463,
+	.xmit	= ksz8463_xmit,
+	.rcv	= ksz8463_rcv,
+	.connect = ksz_connect,
+	.disconnect = ksz_disconnect,
+	.needed_tailroom = KSZ_INGRESS_TAG_LEN,
+};
+
+DSA_TAG_DRIVER(ksz8463_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8463, KSZ8463_NAME);
+
+/* For xmit, 2/6 bytes are added before FCS.
+ * ---------------------------------------------------------------------------
+ * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|tag1(1byte)|
+ * FCS(4bytes)
+ * ---------------------------------------------------------------------------
+ * ts   : time stamp (Present only if PTP is enabled in the Hardware)
+ * tag0 : represents tag override, lookup and valid
+ * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x80=port8)
+ *
+ * For rcv, 1/5 bytes is added before FCS.
+ * ---------------------------------------------------------------------------
+ * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|FCS(4bytes)
+ * ---------------------------------------------------------------------------
+ * ts   : time stamp (Present only if bit 7 of tag0 is set)
+ * tag0 : zero-based value represents port
+ *	  (eg, 0x00=port1, 0x02=port3, 0x07=port8)
+ */
+#define LAN937X_EGRESS_TAG_LEN		2
+
+#define LAN937X_TAIL_TAG_BLOCKING_OVERRIDE	BIT(11)
+#define LAN937X_TAIL_TAG_LOOKUP			BIT(12)
+#define LAN937X_TAIL_TAG_VALID			BIT(13)
+#define LAN937X_TAIL_TAG_PRIO			GENMASK(10, 8)
+#define LAN937X_TAIL_TAG_PORT_MASK		7
+
+static struct sk_buff *lan937x_xmit(struct sk_buff *skb,
+				    struct net_device *dev)
+{
+	u16 queue_mapping = skb_get_queue_mapping(skb);
+	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	const struct ethhdr *hdr = eth_hdr(skb);
+	__be16 *tag;
+	u16 val;
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	ksz_xmit_timestamp(dp, skb);
+
+	tag = skb_put(skb, LAN937X_EGRESS_TAG_LEN);
+
+	val = dsa_xmit_port_mask(skb, dev);
+	val |= FIELD_PREP(LAN937X_TAIL_TAG_PRIO, prio);
+
+	if (is_link_local_ether_addr(hdr->h_dest))
+		val |= LAN937X_TAIL_TAG_BLOCKING_OVERRIDE;
+
+	/* Tail tag valid bit - This bit should always be set by the CPU */
+	val |= LAN937X_TAIL_TAG_VALID;
+
+	put_unaligned_be16(val, tag);
+
+	return ksz_defer_xmit(dp, skb);
+}
+
+static const struct dsa_device_ops lan937x_netdev_ops = {
+	.name	= LAN937X_NAME,
+	.proto	= DSA_TAG_PROTO_LAN937X,
+	.xmit	= lan937x_xmit,
+	.rcv	= ksz9477_rcv,
+	.connect = ksz_connect,
+	.disconnect = ksz_disconnect,
+	.needed_tailroom = LAN937X_EGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
+};
+
+DSA_TAG_DRIVER(lan937x_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_LAN937X, LAN937X_NAME);
+
+static struct dsa_tag_driver *dsa_tag_driver_array[] = {
+	&DSA_TAG_DRIVER_NAME(ksz8463_netdev_ops),
+	&DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops),
+	&DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
+	&DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
+	&DSA_TAG_DRIVER_NAME(lan937x_netdev_ops),
+};
+
+module_dsa_tag_drivers(dsa_tag_driver_array);
+
+MODULE_DESCRIPTION("DSA tag driver for Microchip 8795/937x/9477/9893 families of switches");
+MODULE_LICENSE("GPL");
diff --git a/net/dsa/tag_lan9303.c b/net/dsa/tag_lan9303.c
new file mode 100644
index 000000000..d11946964
--- /dev/null
+++ b/net/dsa/tag_lan9303.c
@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2017 Pengutronix, Juergen Borleis <jbe@pengutronix.de>
+ */
+#include <linux/dsa/lan9303.h>
+#include <linux/etherdevice.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+
+#include "tag.h"
+
+/* To define the outgoing port and to discover the incoming port a regular
+ * VLAN tag is used by the LAN9303. But its VID meaning is 'special':
+ *
+ *       Dest MAC       Src MAC        TAG    Type
+ * ...| 1 2 3 4 5 6 | 1 2 3 4 5 6 | 1 2 3 4 | 1 2 |...
+ *                                |<------->|
+ * TAG:
+ *    |<------------->|
+ *    |  1  2 | 3  4  |
+ *      TPID    VID
+ *     0x8100
+ *
+ * VID bit 3 indicates a request for an ALR lookup.
+ *
+ * If VID bit 3 is zero, then bits 0 and 1 specify the destination port
+ * (0, 1, 2) or broadcast (3) or the source port (1, 2).
+ *
+ * VID bit 4 is used to specify if the STP port state should be overridden.
+ * Required when no forwarding between the external ports should happen.
+ */
+
+#define LAN9303_NAME "lan9303"
+
+#define LAN9303_TAG_LEN 4
+# define LAN9303_TAG_TX_USE_ALR BIT(3)
+# define LAN9303_TAG_TX_STP_OVERRIDE BIT(4)
+# define LAN9303_TAG_RX_IGMP BIT(3)
+# define LAN9303_TAG_RX_STP BIT(4)
+# define LAN9303_TAG_RX_TRAPPED_TO_CPU (LAN9303_TAG_RX_IGMP | \
+					LAN9303_TAG_RX_STP)
+
+/* Decide whether to transmit using ALR lookup, or transmit directly to
+ * port using tag. ALR learning is performed only when using ALR lookup.
+ * If the two external ports are bridged and the frame is unicast,
+ * then use ALR lookup to allow ALR learning on CPU port.
+ * Otherwise transmit directly to port with STP state override.
+ * See also: lan9303_separate_ports() and lan9303.pdf 6.4.10.1
+ */
+static int lan9303_xmit_use_arl(struct dsa_port *dp, u8 *dest_addr)
+{
+	struct lan9303 *chip = dp->ds->priv;
+
+	return chip->is_bridged && !is_multicast_ether_addr(dest_addr);
+}
+
+static struct sk_buff *lan9303_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	__be16 *lan9303_tag;
+	u16 tag;
+
+	/* provide 'LAN9303_TAG_LEN' bytes additional space */
+	skb_push(skb, LAN9303_TAG_LEN);
+
+	/* make room between MACs and Ether-Type */
+	dsa_alloc_etype_header(skb, LAN9303_TAG_LEN);
+
+	lan9303_tag = dsa_etype_header_pos_tx(skb);
+
+	tag = lan9303_xmit_use_arl(dp, skb->data) ?
+		LAN9303_TAG_TX_USE_ALR :
+		dp->index | LAN9303_TAG_TX_STP_OVERRIDE;
+	lan9303_tag[0] = htons(ETH_P_8021Q);
+	lan9303_tag[1] = htons(tag);
+
+	return skb;
+}
+
+static struct sk_buff *lan9303_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+	u16 lan9303_tag1;
+	unsigned int source_port;
+
+	if (unlikely(!pskb_may_pull(skb, LAN9303_TAG_LEN))) {
+		dev_warn_ratelimited(&dev->dev,
+				     "Dropping packet, cannot pull\n");
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (skb_vlan_tag_present(skb)) {
+		lan9303_tag1 = skb_vlan_tag_get(skb);
+		__vlan_hwaccel_clear_tag(skb);
+	} else {
+		skb_push_rcsum(skb, ETH_HLEN);
+		__skb_vlan_pop(skb, &lan9303_tag1);
+		skb_pull_rcsum(skb, ETH_HLEN);
+	}
+
+	source_port = lan9303_tag1 & 0x3;
+
+	skb->dev = dsa_conduit_find_user(dev, 0, source_port);
+	if (!skb->dev) {
+		dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid source port\n");
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (!(lan9303_tag1 & LAN9303_TAG_RX_TRAPPED_TO_CPU))
+		dsa_default_offload_fwd_mark(skb);
+
+	return skb;
+}
+
+static const struct dsa_device_ops lan9303_netdev_ops = {
+	.name = LAN9303_NAME,
+	.proto	= DSA_TAG_PROTO_LAN9303,
+	.xmit = lan9303_xmit,
+	.rcv = lan9303_rcv,
+	.needed_headroom = LAN9303_TAG_LEN,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for SMSC/Microchip LAN9303 family of switches");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_LAN9303, LAN9303_NAME);
+
+module_dsa_tag_driver(lan9303_netdev_ops);
diff --git a/net/dsa/tag_mt7628.c b/net/dsa/tag_mt7628.c
new file mode 100644
index 000000000..80b50ff08
--- /dev/null
+++ b/net/dsa/tag_mt7628.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2026, Joris Vaisvila <joey@tinyisr.com>
+ * MT7628 switch tag support
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/dsa/8021q.h>
+#include <net/dsa.h>
+
+#include "tag.h"
+
+/*
+ * The MT7628 tag is encoded in the VLAN TPID field.
+ * On TX the lower 6 bits encode the destination port bitmask.
+ * On RX the lower 3 bits encode the source port number.
+ *
+ * The switch hardware will not modify the TPID of an incoming packet if it is
+ * already VLAN tagged. To work around this the switch is configured to always
+ * append a tag_8021q standalone VLAN tag for each port. That means we can
+ * safely strip the outer VLAN tag after parsing it.
+ *
+ * A VLAN tag is constructed on egress to target the standalone VLAN and
+ * destination port.
+ */
+
+#define MT7628_TAG_NAME "mt7628"
+
+#define MT7628_TAG_TX_PORT GENMASK(5, 0)
+#define MT7628_TAG_RX_PORT GENMASK(2, 0)
+#define MT7628_TAG_LEN 4
+
+static struct sk_buff *mt7628_tag_xmit(struct sk_buff *skb,
+				       struct net_device *dev)
+{
+	struct dsa_port *dp;
+	u16 xmit_vlan;
+	__be16 *tag;
+
+	dp = dsa_user_to_port(dev);
+	xmit_vlan = dsa_tag_8021q_standalone_vid(dp);
+
+	skb_push(skb, MT7628_TAG_LEN);
+	dsa_alloc_etype_header(skb, MT7628_TAG_LEN);
+
+	tag = dsa_etype_header_pos_tx(skb);
+
+	tag[0] = htons(ETH_P_8021Q |
+		       FIELD_PREP(MT7628_TAG_TX_PORT,
+				  dsa_xmit_port_mask(skb, dev)));
+	tag[1] = htons(xmit_vlan);
+
+	return skb;
+}
+
+static struct sk_buff *mt7628_tag_rcv(struct sk_buff *skb,
+				      struct net_device *dev)
+{
+	__be16 *phdr;
+
+	if (unlikely(!pskb_may_pull(skb, MT7628_TAG_LEN))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	phdr = dsa_etype_header_pos_rx(skb);
+	skb->dev =
+	    dsa_conduit_find_user(dev, 0,
+				  FIELD_GET(MT7628_TAG_RX_PORT, ntohs(*phdr)));
+	if (!skb->dev) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	skb_pull_rcsum(skb, MT7628_TAG_LEN);
+	dsa_strip_etype_header(skb, MT7628_TAG_LEN);
+	dsa_default_offload_fwd_mark(skb);
+	return skb;
+}
+
+static const struct dsa_device_ops mt7628_tag_ops = {
+	.name = MT7628_TAG_NAME,
+	.proto = DSA_TAG_PROTO_MT7628,
+	.xmit = mt7628_tag_xmit,
+	.rcv = mt7628_tag_rcv,
+	.needed_headroom = MT7628_TAG_LEN,
+};
+
+module_dsa_tag_driver(mt7628_tag_ops);
+
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_MT7628, MT7628_TAG_NAME);
+MODULE_DESCRIPTION("DSA tag driver for MT7628 switch");
+MODULE_LICENSE("GPL");
diff --git a/net/dsa/tag_mtk.c b/net/dsa/tag_mtk.c
new file mode 100644
index 000000000..c7dc77316
--- /dev/null
+++ b/net/dsa/tag_mtk.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Mediatek DSA Tag support
+ * Copyright (C) 2017 Landen Chao <landen.chao@mediatek.com>
+ *		      Sean Wang <sean.wang@mediatek.com>
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/if_vlan.h>
+
+#include "tag.h"
+
+#define MTK_NAME		"mtk"
+
+#define MTK_HDR_LEN		4
+#define MTK_HDR_XMIT_UNTAGGED		0
+#define MTK_HDR_XMIT_TAGGED_TPID_8100	1
+#define MTK_HDR_XMIT_TAGGED_TPID_88A8	2
+#define MTK_HDR_RECV_SOURCE_PORT_MASK	GENMASK(2, 0)
+#define MTK_HDR_XMIT_DP_BIT_MASK	GENMASK(5, 0)
+#define MTK_HDR_XMIT_SA_DIS		BIT(6)
+
+static struct sk_buff *mtk_tag_xmit(struct sk_buff *skb,
+				    struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	u8 xmit_tpid;
+	u8 *mtk_tag;
+
+	skb_set_queue_mapping(skb, dp->index);
+
+	/* Build the special tag after the MAC Source Address. If VLAN header
+	 * is present, it's required that VLAN header and special tag is
+	 * being combined. Only in this way we can allow the switch can parse
+	 * the both special and VLAN tag at the same time and then look up VLAN
+	 * table with VID.
+	 */
+	switch (skb->protocol) {
+	case htons(ETH_P_8021Q):
+		xmit_tpid = MTK_HDR_XMIT_TAGGED_TPID_8100;
+		break;
+	case htons(ETH_P_8021AD):
+		xmit_tpid = MTK_HDR_XMIT_TAGGED_TPID_88A8;
+		break;
+	default:
+		xmit_tpid = MTK_HDR_XMIT_UNTAGGED;
+		skb_push(skb, MTK_HDR_LEN);
+		dsa_alloc_etype_header(skb, MTK_HDR_LEN);
+	}
+
+	mtk_tag = dsa_etype_header_pos_tx(skb);
+
+	/* Mark tag attribute on special tag insertion to notify hardware
+	 * whether that's a combined special tag with 802.1Q header.
+	 */
+	mtk_tag[0] = xmit_tpid;
+	mtk_tag[1] = FIELD_PREP(MTK_HDR_XMIT_DP_BIT_MASK,
+				dsa_xmit_port_mask(skb, dev));
+
+	/* Tag control information is kept for 802.1Q */
+	if (xmit_tpid == MTK_HDR_XMIT_UNTAGGED) {
+		mtk_tag[2] = 0;
+		mtk_tag[3] = 0;
+	}
+
+	return skb;
+}
+
+static struct sk_buff *mtk_tag_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+	u16 hdr;
+	int port;
+	__be16 *phdr;
+
+	if (unlikely(!pskb_may_pull(skb, MTK_HDR_LEN))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	phdr = dsa_etype_header_pos_rx(skb);
+	hdr = ntohs(*phdr);
+
+	/* Remove MTK tag and recalculate checksum. */
+	skb_pull_rcsum(skb, MTK_HDR_LEN);
+
+	dsa_strip_etype_header(skb, MTK_HDR_LEN);
+
+	/* Get source port information */
+	port = (hdr & MTK_HDR_RECV_SOURCE_PORT_MASK);
+
+	skb->dev = dsa_conduit_find_user(dev, 0, port);
+	if (!skb->dev) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	dsa_default_offload_fwd_mark(skb);
+
+	return skb;
+}
+
+static const struct dsa_device_ops mtk_netdev_ops = {
+	.name		= MTK_NAME,
+	.proto		= DSA_TAG_PROTO_MTK,
+	.xmit		= mtk_tag_xmit,
+	.rcv		= mtk_tag_rcv,
+	.needed_headroom = MTK_HDR_LEN,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for Mediatek switches");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_MTK, MTK_NAME);
+
+module_dsa_tag_driver(mtk_netdev_ops);
diff --git a/net/dsa/tag_mxl-gsw1xx.c b/net/dsa/tag_mxl-gsw1xx.c
new file mode 100644
index 000000000..4b1b6ef94
--- /dev/null
+++ b/net/dsa/tag_mxl-gsw1xx.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * DSA driver Special Tag support for MaxLinear GSW1xx switch chips
+ *
+ * Copyright (C) 2025 Daniel Golle <daniel@makrotopia.org>
+ * Copyright (C) 2023 - 2024 MaxLinear Inc.
+ */
+
+#include <linux/bitops.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <net/dsa.h>
+
+#include "tag.h"
+
+/* To define the outgoing port and to discover the incoming port a special
+ * tag is used by the GSW1xx.
+ *
+ *       Dest MAC       Src MAC    special TAG        EtherType
+ * ...| 1 2 3 4 5 6 | 1 2 3 4 5 6 | 1 2 3 4 5 6 7 8 | 1 2 |...
+ *                                |<--------------->|
+ */
+
+#define GSW1XX_TAG_NAME		"gsw1xx"
+
+/* special tag header length (RX and TX) */
+#define GSW1XX_HEADER_LEN		8
+
+/* Word 0 = Ethertype -> 0x88C3 */
+
+/* Word 1 */
+#define GSW1XX_TX_PORT_MAP		GENMASK(7, 0)
+#define GSW1XX_TX_PORT_MAP_EN		BIT(15)
+#define GSW1XX_TX_CLASS_EN		BIT(14)
+#define GSW1XX_TX_TIME_STAMP_EN		BIT(13)
+#define GSW1XX_TX_LRN_DIS		BIT(12)
+#define GSW1XX_TX_CLASS			GENMASK(11, 8)
+
+/* special tag in RX path header */
+/* Word 2 */
+#define GSW1XX_RX_PORT_MAP		GENMASK(15, 8)
+
+static struct sk_buff *gsw1xx_tag_xmit(struct sk_buff *skb,
+				       struct net_device *dev)
+{
+	__be16 *gsw1xx_tag;
+	u16 tag;
+
+	/* provide additional space 'GSW1XX_HEADER_LEN' bytes */
+	skb_push(skb, GSW1XX_HEADER_LEN);
+
+	/* add space between MAC address and Ethertype */
+	dsa_alloc_etype_header(skb, GSW1XX_HEADER_LEN);
+
+	/* special tag ingress */
+	gsw1xx_tag = dsa_etype_header_pos_tx(skb);
+	gsw1xx_tag[0] = htons(ETH_P_MXLGSW);
+
+	tag = FIELD_PREP(GSW1XX_TX_PORT_MAP, dsa_xmit_port_mask(skb, dev)) |
+	      GSW1XX_TX_PORT_MAP_EN | GSW1XX_TX_LRN_DIS;
+	gsw1xx_tag[1] = htons(tag);
+	gsw1xx_tag[2] = 0;
+	gsw1xx_tag[3] = 0;
+
+	return skb;
+}
+
+static struct sk_buff *gsw1xx_tag_rcv(struct sk_buff *skb,
+				      struct net_device *dev)
+{
+	int port;
+	__be16 *gsw1xx_tag;
+
+	if (unlikely(!pskb_may_pull(skb, GSW1XX_HEADER_LEN))) {
+		dev_warn_ratelimited(&dev->dev, "Dropping packet, cannot pull SKB\n");
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	gsw1xx_tag = dsa_etype_header_pos_rx(skb);
+
+	if (unlikely(ntohs(gsw1xx_tag[0]) != ETH_P_MXLGSW)) {
+		dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid special tag\n");
+		dev_warn_ratelimited(&dev->dev, "Tag: %8ph\n", gsw1xx_tag);
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Get source port information */
+	port = FIELD_GET(GSW1XX_RX_PORT_MAP, ntohs(gsw1xx_tag[1]));
+	skb->dev = dsa_conduit_find_user(dev, 0, port);
+	if (!skb->dev) {
+		dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid source port\n");
+		dev_warn_ratelimited(&dev->dev, "Tag: %8ph\n", gsw1xx_tag);
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* remove the GSW1xx special tag between MAC addresses and the current
+	 * ethertype field.
+	 */
+	skb_pull_rcsum(skb, GSW1XX_HEADER_LEN);
+	dsa_strip_etype_header(skb, GSW1XX_HEADER_LEN);
+
+	return skb;
+}
+
+static const struct dsa_device_ops gsw1xx_netdev_ops = {
+	.name			= GSW1XX_TAG_NAME,
+	.proto			= DSA_TAG_PROTO_MXL_GSW1XX,
+	.xmit			= gsw1xx_tag_xmit,
+	.rcv			= gsw1xx_tag_rcv,
+	.needed_headroom	= GSW1XX_HEADER_LEN,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for MaxLinear GSW1xx 8 byte protocol");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_MXL_GSW1XX, GSW1XX_TAG_NAME);
+
+module_dsa_tag_driver(gsw1xx_netdev_ops);
diff --git a/net/dsa/tag_mxl862xx.c b/net/dsa/tag_mxl862xx.c
new file mode 100644
index 000000000..87b80ddf0
--- /dev/null
+++ b/net/dsa/tag_mxl862xx.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * DSA Special Tag for MaxLinear 862xx switch chips
+ *
+ * Copyright (C) 2025 Daniel Golle <daniel@makrotopia.org>
+ * Copyright (C) 2024 MaxLinear Inc.
+ */
+
+#include <linux/bitops.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <net/dsa.h>
+#include "tag.h"
+
+#define MXL862_NAME	"mxl862xx"
+
+#define MXL862_HEADER_LEN	8
+
+/* Word 0 -> EtherType */
+
+/* Word 2 */
+#define MXL862_SUBIF_ID		GENMASK(4, 0)
+
+/* Word 3 */
+#define MXL862_IGP_EGP		GENMASK(3, 0)
+
+static struct sk_buff *mxl862_tag_xmit(struct sk_buff *skb,
+				       struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_port *cpu_dp = dp->cpu_dp;
+	unsigned int cpu_port, sub_interface;
+	__be16 *mxl862_tag;
+
+	cpu_port = cpu_dp->index;
+
+	/* target port sub-interface ID relative to the CPU port */
+	sub_interface = dp->index + 16 - cpu_port;
+
+	/* provide additional space 'MXL862_HEADER_LEN' bytes */
+	skb_push(skb, MXL862_HEADER_LEN);
+
+	/* shift MAC address to the beginning of the enlarged buffer,
+	 * releasing the space required for DSA tag (between MAC address and
+	 * Ethertype)
+	 */
+	dsa_alloc_etype_header(skb, MXL862_HEADER_LEN);
+
+	/* special tag ingress (from the perspective of the switch) */
+	mxl862_tag = dsa_etype_header_pos_tx(skb);
+	mxl862_tag[0] = htons(ETH_P_MXLGSW);
+	mxl862_tag[1] = 0;
+	mxl862_tag[2] = htons(FIELD_PREP(MXL862_SUBIF_ID, sub_interface));
+	mxl862_tag[3] = htons(FIELD_PREP(MXL862_IGP_EGP, cpu_port));
+
+	return skb;
+}
+
+static struct sk_buff *mxl862_tag_rcv(struct sk_buff *skb,
+				      struct net_device *dev)
+{
+	__be16 *mxl862_tag;
+	int port;
+
+	if (unlikely(!pskb_may_pull(skb, MXL862_HEADER_LEN))) {
+		dev_warn_ratelimited(&dev->dev, "Cannot pull SKB, packet dropped\n");
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	mxl862_tag = dsa_etype_header_pos_rx(skb);
+
+	if (unlikely(mxl862_tag[0] != htons(ETH_P_MXLGSW))) {
+		dev_warn_ratelimited(&dev->dev,
+				     "Invalid special tag marker, packet dropped, tag: %8ph\n",
+				     mxl862_tag);
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Get source port information */
+	port = FIELD_GET(MXL862_IGP_EGP, ntohs(mxl862_tag[3]));
+	skb->dev = dsa_conduit_find_user(dev, 0, port);
+	if (unlikely(!skb->dev)) {
+		dev_warn_ratelimited(&dev->dev,
+				     "Invalid source port, packet dropped, tag: %8ph\n",
+				     mxl862_tag);
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (likely(!is_link_local_ether_addr(eth_hdr(skb)->h_dest)))
+		dsa_default_offload_fwd_mark(skb);
+
+	/* remove the MxL862xx special tag between the MAC addresses and the
+	 * current ethertype field.
+	 */
+	skb_pull_rcsum(skb, MXL862_HEADER_LEN);
+	dsa_strip_etype_header(skb, MXL862_HEADER_LEN);
+
+	return skb;
+}
+
+static const struct dsa_device_ops mxl862_netdev_ops = {
+	.name = MXL862_NAME,
+	.proto = DSA_TAG_PROTO_MXL862,
+	.xmit = mxl862_tag_xmit,
+	.rcv = mxl862_tag_rcv,
+	.needed_headroom = MXL862_HEADER_LEN,
+};
+
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_MXL862, MXL862_NAME);
+MODULE_DESCRIPTION("DSA tag driver for MaxLinear MxL862xx switches");
+MODULE_LICENSE("GPL");
+
+module_dsa_tag_driver(mxl862_netdev_ops);
diff --git a/net/dsa/tag_netc.c b/net/dsa/tag_netc.c
new file mode 100644
index 000000000..df72a6179
--- /dev/null
+++ b/net/dsa/tag_netc.c
@@ -0,0 +1,216 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2025-2026 NXP
+ */
+
+#include <linux/dsa/tag_netc.h>
+
+#include "tag.h"
+
+#define NETC_NAME			"nxp_netc"
+
+/* Forward NXP switch tag */
+#define NETC_TAG_FORWARD		0
+
+/* To_Port NXP switch tag */
+#define NETC_TAG_TO_PORT		1
+/* SubType0: No request to perform timestamping */
+#define NETC_TAG_TP_SUBTYPE0		0
+
+/* To_Host NXP switch tag */
+#define NETC_TAG_TO_HOST		2
+/* SubType0: frames redirected or copied to CPU port */
+#define NETC_TAG_TH_SUBTYPE0		0
+/* SubType1: frames redirected or copied to CPU port with timestamp */
+#define NETC_TAG_TH_SUBTYPE1		1
+/* SubType2: Transmit timestamp response (two-step timestamping) */
+#define NETC_TAG_TH_SUBTYPE2		2
+
+/* NETC switch tag lengths */
+#define NETC_TAG_FORWARD_LEN		6
+#define NETC_TAG_TP_SUBTYPE0_LEN	6
+#define NETC_TAG_TH_SUBTYPE0_LEN	6
+#define NETC_TAG_TH_SUBTYPE1_LEN	14
+#define NETC_TAG_TH_SUBTYPE2_LEN	14
+#define NETC_TAG_CMN_LEN		5
+
+#define NETC_TAG_SUBTYPE		GENMASK(3, 0)
+#define NETC_TAG_TYPE			GENMASK(7, 4)
+#define NETC_TAG_QV			BIT(0)
+#define NETC_TAG_IPV			GENMASK(4, 2)
+#define NETC_TAG_SWITCH			GENMASK(2, 0)
+#define NETC_TAG_PORT			GENMASK(7, 3)
+
+struct netc_tag_cmn {
+	__be16 tpid;
+	u8 type;
+	u8 qos;
+	u8 switch_port;
+} __packed;
+
+static void netc_fill_common_tag(struct netc_tag_cmn *tag, u8 type,
+				 u8 subtype, u8 sw_id, u8 port, u8 ipv)
+{
+	tag->tpid = htons(ETH_P_NXP_NETC);
+	tag->type = FIELD_PREP(NETC_TAG_TYPE, type) |
+		    FIELD_PREP(NETC_TAG_SUBTYPE, subtype);
+	tag->qos = NETC_TAG_QV | FIELD_PREP(NETC_TAG_IPV, ipv);
+	tag->switch_port = FIELD_PREP(NETC_TAG_SWITCH, sw_id) |
+			   FIELD_PREP(NETC_TAG_PORT, port);
+}
+
+static void *netc_fill_common_tp_tag(struct sk_buff *skb,
+				     struct net_device *ndev,
+				     u8 subtype, int tag_len)
+{
+	struct dsa_port *dp = dsa_user_to_port(ndev);
+	u16 queue = skb_get_queue_mapping(skb);
+	s8 ipv = netdev_txq_to_tc(ndev, queue);
+	void *tag;
+
+	if (unlikely(ipv < 0))
+		ipv = 0;
+
+	skb_push(skb, tag_len);
+	dsa_alloc_etype_header(skb, tag_len);
+
+	tag = dsa_etype_header_pos_tx(skb);
+	memset(tag + NETC_TAG_CMN_LEN, 0, tag_len - NETC_TAG_CMN_LEN);
+	/* As 'dsa,member' is a required property for NETC switch, the member
+	 * is used to specify the switch ID (thus the hardware switch ID and
+	 * the software switch ID are consistent), its range is 1 ~ 7. The
+	 * NETC switch driver will check this value, and if it is invalid,
+	 * the switch driver will fail the probe.
+	 * In addition, according to the nxp,netc-switch.yaml doc, the port
+	 * index will not be greater than 0xf.
+	 */
+	netc_fill_common_tag(tag, NETC_TAG_TO_PORT, subtype,
+			     dp->ds->index, dp->index, ipv);
+
+	return tag;
+}
+
+static void netc_fill_tp_tag_subtype0(struct sk_buff *skb,
+				      struct net_device *ndev)
+{
+	netc_fill_common_tp_tag(skb, ndev, NETC_TAG_TP_SUBTYPE0,
+				NETC_TAG_TP_SUBTYPE0_LEN);
+}
+
+/* Currently only support To_Port tag, subtype 0 */
+static struct sk_buff *netc_xmit(struct sk_buff *skb,
+				 struct net_device *ndev)
+{
+	netc_fill_tp_tag_subtype0(skb, ndev);
+
+	return skb;
+}
+
+static int netc_get_rx_tag_len(int type, int subtype)
+{
+	/* Only NETC_TAG_TO_HOST and NETC_TAG_FORWARD are expected in RX,
+	 * NETC_TAG_TO_PORT is a TX switch tag that does not exist in RX.
+	 */
+	if (type == NETC_TAG_TO_HOST) {
+		if (subtype == NETC_TAG_TH_SUBTYPE1)
+			return NETC_TAG_TH_SUBTYPE1_LEN;
+		else if (subtype == NETC_TAG_TH_SUBTYPE2)
+			return NETC_TAG_TH_SUBTYPE2_LEN;
+		else
+			return NETC_TAG_TH_SUBTYPE0_LEN;
+	}
+
+	return NETC_TAG_FORWARD_LEN;
+}
+
+static struct sk_buff *netc_rcv(struct sk_buff *skb,
+				struct net_device *ndev)
+{
+	struct netc_tag_cmn *tag_cmn;
+	int tag_len, sw_id, port;
+	int type, subtype;
+
+	if (unlikely(!pskb_may_pull(skb, NETC_TAG_MAX_LEN)))
+		goto err_free_skb;
+
+	tag_cmn = dsa_etype_header_pos_rx(skb);
+	if (ntohs(tag_cmn->tpid) != ETH_P_NXP_NETC) {
+		dev_warn_ratelimited(&ndev->dev, "Unknown TPID 0x%04x\n",
+				     ntohs(tag_cmn->tpid));
+		goto err_free_skb;
+	}
+
+	if (tag_cmn->qos & NETC_TAG_QV)
+		skb->priority = FIELD_GET(NETC_TAG_IPV, tag_cmn->qos);
+
+	sw_id = FIELD_GET(NETC_TAG_SWITCH, tag_cmn->switch_port);
+	/* ENETC VEPA switch ID (0) is not supported yet */
+	if (!sw_id) {
+		dev_warn_ratelimited(&ndev->dev,
+				     "VEPA switch ID is not supported yet\n");
+		goto err_free_skb;
+	}
+
+	port = FIELD_GET(NETC_TAG_PORT, tag_cmn->switch_port);
+	skb->dev = dsa_conduit_find_user(ndev, sw_id, port);
+	if (!skb->dev)
+		goto err_free_skb;
+
+	type = FIELD_GET(NETC_TAG_TYPE, tag_cmn->type);
+	subtype = FIELD_GET(NETC_TAG_SUBTYPE, tag_cmn->type);
+	if (type == NETC_TAG_FORWARD) {
+		dsa_default_offload_fwd_mark(skb);
+	} else if (type == NETC_TAG_TO_HOST) {
+		/* Currently only subtype0 supported */
+		if (subtype != NETC_TAG_TH_SUBTYPE0)
+			goto err_free_skb;
+	} else {
+		dev_warn_ratelimited(&ndev->dev,
+				     "Unexpected  tag type %d\n", type);
+		goto err_free_skb;
+	}
+
+	/* Remove Switch tag from the frame */
+	tag_len = netc_get_rx_tag_len(type, subtype);
+	skb_pull_rcsum(skb, tag_len);
+	dsa_strip_etype_header(skb, tag_len);
+
+	return skb;
+
+err_free_skb:
+	kfree_skb(skb);
+	return NULL;
+}
+
+static void netc_flow_dissect(const struct sk_buff *skb, __be16 *proto,
+			      int *offset)
+{
+	struct netc_tag_cmn *tag_cmn = (struct netc_tag_cmn *)(skb->data - 2);
+	int subtype = FIELD_GET(NETC_TAG_SUBTYPE, tag_cmn->type);
+	int type = FIELD_GET(NETC_TAG_TYPE, tag_cmn->type);
+	int tag_len = netc_get_rx_tag_len(type, subtype);
+
+	/* The RX minimum frame length of the NETC switch port is 64 bytes,
+	 * and the frame is received by the ENETC driver. From the hardware
+	 * perspective, the receive buffer of RX BD is at least 128 bytes,
+	 * so the switch tag header is guaranteed to be in the linear region
+	 * of the skb.
+	 */
+	*offset = tag_len;
+	*proto = ((__be16 *)skb->data)[(tag_len / 2) - 1];
+}
+
+static const struct dsa_device_ops netc_netdev_ops = {
+	.name			= NETC_NAME,
+	.proto			= DSA_TAG_PROTO_NETC,
+	.xmit			= netc_xmit,
+	.rcv			= netc_rcv,
+	.needed_headroom	= NETC_TAG_MAX_LEN,
+	.flow_dissect		= netc_flow_dissect,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for NXP NETC switch family");
+MODULE_LICENSE("GPL");
+
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_NETC, NETC_NAME);
+module_dsa_tag_driver(netc_netdev_ops);
diff --git a/net/dsa/tag_none.c b/net/dsa/tag_none.c
new file mode 100644
index 000000000..e9c9670a9
--- /dev/null
+++ b/net/dsa/tag_none.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * net/dsa/tag_none.c - Traffic handling for switches with no tag
+ * Copyright (c) 2008-2009 Marvell Semiconductor
+ * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
+ *
+ * WARNING: do not use this for new switches. In case of no hardware
+ * tagging support, look at tag_8021q.c instead.
+ */
+
+#include "tag.h"
+
+#define NONE_NAME	"none"
+
+static struct sk_buff *dsa_user_notag_xmit(struct sk_buff *skb,
+					   struct net_device *dev)
+{
+	/* Just return the original SKB */
+	return skb;
+}
+
+static const struct dsa_device_ops none_ops = {
+	.name	= NONE_NAME,
+	.proto	= DSA_TAG_PROTO_NONE,
+	.xmit	= dsa_user_notag_xmit,
+};
+
+module_dsa_tag_driver(none_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_NONE, NONE_NAME);
+MODULE_DESCRIPTION("DSA no-op tag driver");
+MODULE_LICENSE("GPL");
diff --git a/net/dsa/tag_ocelot.c b/net/dsa/tag_ocelot.c
new file mode 100644
index 000000000..d208c7322
--- /dev/null
+++ b/net/dsa/tag_ocelot.c
@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2019 NXP
+ */
+#include <linux/dsa/ocelot.h>
+
+#include "tag.h"
+
+#define OCELOT_NAME	"ocelot"
+#define SEVILLE_NAME	"seville"
+
+static void ocelot_xmit_common(struct sk_buff *skb, struct net_device *netdev,
+			       __be32 ifh_prefix, void **ifh)
+{
+	struct dsa_port *dp = dsa_user_to_port(netdev);
+	struct dsa_switch *ds = dp->ds;
+	u64 vlan_tci, tag_type;
+	void *injection;
+	__be32 *prefix;
+	u32 rew_op = 0;
+	u64 qos_class;
+
+	ocelot_xmit_get_vlan_info(skb, dsa_port_bridge_dev_get(dp), &vlan_tci,
+				  &tag_type);
+
+	qos_class = netdev_get_num_tc(netdev) ?
+		    netdev_get_prio_tc_map(netdev, skb->priority) : skb->priority;
+
+	injection = skb_push(skb, OCELOT_TAG_LEN);
+	prefix = skb_push(skb, OCELOT_SHORT_PREFIX_LEN);
+
+	*prefix = ifh_prefix;
+	memset(injection, 0, OCELOT_TAG_LEN);
+	ocelot_ifh_set_bypass(injection, 1);
+	ocelot_ifh_set_src(injection, ds->num_ports);
+	ocelot_ifh_set_qos_class(injection, qos_class);
+	ocelot_ifh_set_vlan_tci(injection, vlan_tci);
+	ocelot_ifh_set_tag_type(injection, tag_type);
+
+	rew_op = ocelot_ptp_rew_op(skb);
+	if (rew_op)
+		ocelot_ifh_set_rew_op(injection, rew_op);
+
+	*ifh = injection;
+}
+
+static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
+				   struct net_device *netdev)
+{
+	void *injection;
+
+	ocelot_xmit_common(skb, netdev, cpu_to_be32(0x8880000a), &injection);
+	ocelot_ifh_set_dest(injection, dsa_xmit_port_mask(skb, netdev));
+
+	return skb;
+}
+
+static struct sk_buff *seville_xmit(struct sk_buff *skb,
+				    struct net_device *netdev)
+{
+	void *injection;
+
+	ocelot_xmit_common(skb, netdev, cpu_to_be32(0x88800005), &injection);
+	seville_ifh_set_dest(injection, dsa_xmit_port_mask(skb, netdev));
+
+	return skb;
+}
+
+static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
+				  struct net_device *netdev)
+{
+	u64 src_port, qos_class;
+	u64 vlan_tci, tag_type;
+	u8 *start = skb->data;
+	struct dsa_port *dp;
+	u8 *extraction;
+	u16 vlan_tpid;
+	u64 rew_val;
+
+	/* Revert skb->data by the amount consumed by the DSA conduit,
+	 * so it points to the beginning of the frame.
+	 */
+	skb_push(skb, ETH_HLEN);
+	/* We don't care about the short prefix, it is just for easy entrance
+	 * into the DSA conduit's RX filter. Discard it now by moving it into
+	 * the headroom.
+	 */
+	skb_pull(skb, OCELOT_SHORT_PREFIX_LEN);
+	/* And skb->data now points to the extraction frame header.
+	 * Keep a pointer to it.
+	 */
+	extraction = skb->data;
+	/* Now the EFH is part of the headroom as well */
+	skb_pull(skb, OCELOT_TAG_LEN);
+	/* Reset the pointer to the real MAC header */
+	skb_reset_mac_header(skb);
+	skb_reset_mac_len(skb);
+	/* And move skb->data to the correct location again */
+	skb_pull(skb, ETH_HLEN);
+
+	/* Remove from inet csum the extraction header */
+	skb_postpull_rcsum(skb, start, OCELOT_TOTAL_TAG_LEN);
+
+	ocelot_xfh_get_src_port(extraction, &src_port);
+	ocelot_xfh_get_qos_class(extraction, &qos_class);
+	ocelot_xfh_get_tag_type(extraction, &tag_type);
+	ocelot_xfh_get_vlan_tci(extraction, &vlan_tci);
+	ocelot_xfh_get_rew_val(extraction, &rew_val);
+
+	skb->dev = dsa_conduit_find_user(netdev, 0, src_port);
+	if (!skb->dev) {
+		/* The switch will reflect back some frames sent through
+		 * sockets opened on the bare DSA conduit. These will come back
+		 * with src_port equal to the index of the CPU port, for which
+		 * there is no user registered. So don't print any error
+		 * message here (ignore and drop those frames).
+		 */
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	dsa_default_offload_fwd_mark(skb);
+	skb->priority = qos_class;
+	OCELOT_SKB_CB(skb)->tstamp_lo = rew_val;
+
+	/* Ocelot switches copy frames unmodified to the CPU. However, it is
+	 * possible for the user to request a VLAN modification through
+	 * VCAP_IS1_ACT_VID_REPLACE_ENA. In this case, what will happen is that
+	 * the VLAN ID field from the Extraction Header gets updated, but the
+	 * 802.1Q header does not (the classified VLAN only becomes visible on
+	 * egress through the "port tag" of front-panel ports).
+	 * So, for traffic extracted by the CPU, we want to pick up the
+	 * classified VLAN and manually replace the existing 802.1Q header from
+	 * the packet with it, so that the operating system is always up to
+	 * date with the result of tc-vlan actions.
+	 * NOTE: In VLAN-unaware mode, we don't want to do that, we want the
+	 * frame to remain unmodified, because the classified VLAN is always
+	 * equal to the pvid of the ingress port and should not be used for
+	 * processing.
+	 */
+	dp = dsa_user_to_port(skb->dev);
+	vlan_tpid = tag_type ? ETH_P_8021AD : ETH_P_8021Q;
+
+	if (dsa_port_is_vlan_filtering(dp) &&
+	    eth_hdr(skb)->h_proto == htons(vlan_tpid)) {
+		u16 dummy_vlan_tci;
+
+		skb_push_rcsum(skb, ETH_HLEN);
+		__skb_vlan_pop(skb, &dummy_vlan_tci);
+		skb_pull_rcsum(skb, ETH_HLEN);
+		__vlan_hwaccel_put_tag(skb, htons(vlan_tpid), vlan_tci);
+	}
+
+	return skb;
+}
+
+static const struct dsa_device_ops ocelot_netdev_ops = {
+	.name			= OCELOT_NAME,
+	.proto			= DSA_TAG_PROTO_OCELOT,
+	.xmit			= ocelot_xmit,
+	.rcv			= ocelot_rcv,
+	.needed_headroom	= OCELOT_TOTAL_TAG_LEN,
+	.promisc_on_conduit	= true,
+};
+
+DSA_TAG_DRIVER(ocelot_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_OCELOT, OCELOT_NAME);
+
+static const struct dsa_device_ops seville_netdev_ops = {
+	.name			= SEVILLE_NAME,
+	.proto			= DSA_TAG_PROTO_SEVILLE,
+	.xmit			= seville_xmit,
+	.rcv			= ocelot_rcv,
+	.needed_headroom	= OCELOT_TOTAL_TAG_LEN,
+	.promisc_on_conduit	= true,
+};
+
+DSA_TAG_DRIVER(seville_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SEVILLE, SEVILLE_NAME);
+
+static struct dsa_tag_driver *ocelot_tag_driver_array[] = {
+	&DSA_TAG_DRIVER_NAME(ocelot_netdev_ops),
+	&DSA_TAG_DRIVER_NAME(seville_netdev_ops),
+};
+
+module_dsa_tag_drivers(ocelot_tag_driver_array);
+
+MODULE_DESCRIPTION("DSA tag driver for Ocelot family of switches, using NPI port");
+MODULE_LICENSE("GPL v2");
diff --git a/net/dsa/tag_ocelot_8021q.c b/net/dsa/tag_ocelot_8021q.c
new file mode 100644
index 000000000..f50f1cd83
--- /dev/null
+++ b/net/dsa/tag_ocelot_8021q.c
@@ -0,0 +1,146 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2020-2021 NXP
+ *
+ * An implementation of the software-defined tag_8021q.c tagger format, which
+ * also preserves full functionality under a vlan_filtering bridge. It does
+ * this by using the TCAM engines for:
+ * - pushing the RX VLAN as a second, outer tag, on egress towards the CPU port
+ * - redirecting towards the correct front port based on TX VLAN and popping
+ *   that on egress
+ */
+#include <linux/dsa/8021q.h>
+#include <linux/dsa/ocelot.h>
+
+#include "tag.h"
+#include "tag_8021q.h"
+
+#define OCELOT_8021Q_NAME "ocelot-8021q"
+
+struct ocelot_8021q_tagger_private {
+	struct ocelot_8021q_tagger_data data; /* Must be first */
+	struct kthread_worker *xmit_worker;
+};
+
+static struct sk_buff *ocelot_defer_xmit(struct dsa_port *dp,
+					 struct sk_buff *skb)
+{
+	struct ocelot_8021q_tagger_private *priv = dp->ds->tagger_data;
+	struct ocelot_8021q_tagger_data *data = &priv->data;
+	void (*xmit_work_fn)(struct kthread_work *work);
+	struct felix_deferred_xmit_work *xmit_work;
+	struct kthread_worker *xmit_worker;
+
+	xmit_work_fn = data->xmit_work_fn;
+	xmit_worker = priv->xmit_worker;
+
+	if (!xmit_work_fn || !xmit_worker) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* PTP over IP packets need UDP checksumming. We may have inherited
+	 * NETIF_F_HW_CSUM from the DSA conduit, but these packets are not sent
+	 * through the DSA conduit, so calculate the checksum here.
+	 */
+	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	xmit_work = kzalloc_obj(*xmit_work, GFP_ATOMIC);
+	if (!xmit_work) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Calls felix_port_deferred_xmit in felix.c */
+	kthread_init_work(&xmit_work->work, xmit_work_fn);
+	xmit_work->dp = dp;
+	xmit_work->skb = skb_get(skb);
+
+	kthread_queue_work(xmit_worker, &xmit_work->work);
+
+	kfree_skb(skb);
+	return NULL;
+}
+
+static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
+				   struct net_device *netdev)
+{
+	struct dsa_port *dp = dsa_user_to_port(netdev);
+	u16 queue_mapping = skb_get_queue_mapping(skb);
+	u8 pcp = netdev_txq_to_tc(netdev, queue_mapping);
+	u16 tx_vid = dsa_tag_8021q_standalone_vid(dp);
+	struct ethhdr *hdr = eth_hdr(skb);
+
+	if (ocelot_ptp_rew_op(skb) || is_link_local_ether_addr(hdr->h_dest))
+		return ocelot_defer_xmit(dp, skb);
+
+	return dsa_8021q_xmit(skb, netdev, ETH_P_8021Q,
+			      ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
+}
+
+static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
+				  struct net_device *netdev)
+{
+	int src_port = -1, switch_id = -1;
+
+	dsa_8021q_rcv(skb, &src_port, &switch_id, NULL, NULL);
+
+	skb->dev = dsa_conduit_find_user(netdev, switch_id, src_port);
+	if (!skb->dev) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	dsa_default_offload_fwd_mark(skb);
+
+	return skb;
+}
+
+static void ocelot_disconnect(struct dsa_switch *ds)
+{
+	struct ocelot_8021q_tagger_private *priv = ds->tagger_data;
+
+	kthread_destroy_worker(priv->xmit_worker);
+	kfree(priv);
+	ds->tagger_data = NULL;
+}
+
+static int ocelot_connect(struct dsa_switch *ds)
+{
+	struct ocelot_8021q_tagger_private *priv;
+	int err;
+
+	priv = kzalloc_obj(*priv);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->xmit_worker = kthread_run_worker(0, "felix_xmit");
+	if (IS_ERR(priv->xmit_worker)) {
+		err = PTR_ERR(priv->xmit_worker);
+		kfree(priv);
+		return err;
+	}
+
+	ds->tagger_data = priv;
+
+	return 0;
+}
+
+static const struct dsa_device_ops ocelot_8021q_netdev_ops = {
+	.name			= OCELOT_8021Q_NAME,
+	.proto			= DSA_TAG_PROTO_OCELOT_8021Q,
+	.xmit			= ocelot_xmit,
+	.rcv			= ocelot_rcv,
+	.connect		= ocelot_connect,
+	.disconnect		= ocelot_disconnect,
+	.needed_headroom	= VLAN_HLEN,
+	.promisc_on_conduit	= true,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for Ocelot family of switches, using VLAN");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_OCELOT_8021Q, OCELOT_8021Q_NAME);
+
+module_dsa_tag_driver(ocelot_8021q_netdev_ops);
diff --git a/net/dsa/tag_qca.c b/net/dsa/tag_qca.c
new file mode 100644
index 000000000..510792fbf
--- /dev/null
+++ b/net/dsa/tag_qca.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2015, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/bitfield.h>
+#include <net/dsa.h>
+#include <linux/dsa/tag_qca.h>
+
+#include "tag.h"
+
+#define QCA_NAME "qca"
+
+static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	__be16 *phdr;
+	u16 hdr;
+
+	skb_push(skb, QCA_HDR_LEN);
+
+	dsa_alloc_etype_header(skb, QCA_HDR_LEN);
+	phdr = dsa_etype_header_pos_tx(skb);
+
+	/* Set the version field, and set destination port information */
+	hdr = FIELD_PREP(QCA_HDR_XMIT_VERSION, QCA_HDR_VERSION);
+	hdr |= QCA_HDR_XMIT_FROM_CPU;
+	hdr |= FIELD_PREP(QCA_HDR_XMIT_DP_BIT, dsa_xmit_port_mask(skb, dev));
+
+	*phdr = htons(hdr);
+
+	return skb;
+}
+
+static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+	struct qca_tagger_data *tagger_data;
+	struct dsa_port *dp = dev->dsa_ptr;
+	struct dsa_switch *ds = dp->ds;
+	u8 ver, pk_type;
+	__be16 *phdr;
+	int port;
+	u16 hdr;
+
+	BUILD_BUG_ON(sizeof(struct qca_mgmt_ethhdr) != QCA_HDR_MGMT_HEADER_LEN + QCA_HDR_LEN);
+
+	tagger_data = ds->tagger_data;
+
+	if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	phdr = dsa_etype_header_pos_rx(skb);
+	hdr = ntohs(*phdr);
+
+	/* Make sure the version is correct */
+	ver = FIELD_GET(QCA_HDR_RECV_VERSION, hdr);
+	if (unlikely(ver != QCA_HDR_VERSION)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Get pk type */
+	pk_type = FIELD_GET(QCA_HDR_RECV_TYPE, hdr);
+
+	/* Ethernet mgmt read/write packet */
+	if (pk_type == QCA_HDR_RECV_TYPE_RW_REG_ACK) {
+		if (likely(tagger_data->rw_reg_ack_handler))
+			tagger_data->rw_reg_ack_handler(ds, skb);
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Ethernet MIB counter packet */
+	if (pk_type == QCA_HDR_RECV_TYPE_MIB) {
+		if (likely(tagger_data->mib_autocast_handler))
+			tagger_data->mib_autocast_handler(ds, skb);
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Get source port information */
+	port = FIELD_GET(QCA_HDR_RECV_SOURCE_PORT, hdr);
+
+	skb->dev = dsa_conduit_find_user(dev, 0, port);
+	if (!skb->dev) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Remove QCA tag and recalculate checksum */
+	skb_pull_rcsum(skb, QCA_HDR_LEN);
+	dsa_strip_etype_header(skb, QCA_HDR_LEN);
+
+	return skb;
+}
+
+static int qca_tag_connect(struct dsa_switch *ds)
+{
+	struct qca_tagger_data *tagger_data;
+
+	tagger_data = kzalloc_obj(*tagger_data);
+	if (!tagger_data)
+		return -ENOMEM;
+
+	ds->tagger_data = tagger_data;
+
+	return 0;
+}
+
+static void qca_tag_disconnect(struct dsa_switch *ds)
+{
+	kfree(ds->tagger_data);
+	ds->tagger_data = NULL;
+}
+
+static const struct dsa_device_ops qca_netdev_ops = {
+	.name	= QCA_NAME,
+	.proto	= DSA_TAG_PROTO_QCA,
+	.connect = qca_tag_connect,
+	.disconnect = qca_tag_disconnect,
+	.xmit	= qca_tag_xmit,
+	.rcv	= qca_tag_rcv,
+	.needed_headroom = QCA_HDR_LEN,
+	.promisc_on_conduit = true,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for Qualcomm Atheros QCA8K switches");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_QCA, QCA_NAME);
+
+module_dsa_tag_driver(qca_netdev_ops);
diff --git a/net/dsa/tag_rtl4_a.c b/net/dsa/tag_rtl4_a.c
new file mode 100644
index 000000000..590ea3b92
--- /dev/null
+++ b/net/dsa/tag_rtl4_a.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Handler for Realtek 4 byte DSA switch tags
+ * Currently only supports protocol "A" found in RTL8366RB
+ * Copyright (c) 2020 Linus Walleij <linus.walleij@linaro.org>
+ *
+ * This "proprietary tag" header looks like so:
+ *
+ * -------------------------------------------------
+ * | MAC DA | MAC SA | 0x8899 | 2 bytes tag | Type |
+ * -------------------------------------------------
+ *
+ * The 2 bytes tag form a 16 bit big endian word. The exact
+ * meaning has been guessed from packet dumps from ingress
+ * frames.
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/bits.h>
+
+#include "tag.h"
+
+#define RTL4_A_NAME		"rtl4a"
+
+#define RTL4_A_HDR_LEN		4
+#define RTL4_A_PROTOCOL_SHIFT	12
+/*
+ * 0x1 = Realtek Remote Control protocol (RRCP)
+ * 0x2/0x3 seems to be used for loopback testing
+ * 0x9 = RTL8306 DSA protocol
+ * 0xa = RTL8366RB DSA protocol
+ */
+#define RTL4_A_PROTOCOL_RTL8366RB	0xa
+
+static struct sk_buff *rtl4a_tag_xmit(struct sk_buff *skb,
+				      struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	__be16 *p;
+	u8 *tag;
+	u16 out;
+
+	/* Pad out to at least 60 bytes */
+	if (unlikely(eth_skb_pad(skb)))
+		return NULL;
+
+	netdev_dbg(dev, "add realtek tag to package to port %d\n",
+		   dp->index);
+	skb_push(skb, RTL4_A_HDR_LEN);
+
+	dsa_alloc_etype_header(skb, RTL4_A_HDR_LEN);
+	tag = dsa_etype_header_pos_tx(skb);
+
+	/* Set Ethertype */
+	p = (__be16 *)tag;
+	*p = htons(ETH_P_REALTEK);
+
+	out = (RTL4_A_PROTOCOL_RTL8366RB << RTL4_A_PROTOCOL_SHIFT);
+	/* The lower bits indicate the port number */
+	out |= dsa_xmit_port_mask(skb, dev);
+
+	p = (__be16 *)(tag + 2);
+	*p = htons(out);
+
+	return skb;
+}
+
+static struct sk_buff *rtl4a_tag_rcv(struct sk_buff *skb,
+				     struct net_device *dev)
+{
+	u16 protport;
+	__be16 *p;
+	u16 etype;
+	u8 *tag;
+	u8 prot;
+	u8 port;
+
+	if (unlikely(!pskb_may_pull(skb, RTL4_A_HDR_LEN))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	tag = dsa_etype_header_pos_rx(skb);
+	p = (__be16 *)tag;
+	etype = ntohs(*p);
+	if (etype != ETH_P_REALTEK) {
+		/* Not custom, just pass through */
+		netdev_dbg(dev, "non-realtek ethertype 0x%04x\n", etype);
+		return skb;
+	}
+	p = (__be16 *)(tag + 2);
+	protport = ntohs(*p);
+	/* The 4 upper bits are the protocol */
+	prot = (protport >> RTL4_A_PROTOCOL_SHIFT) & 0x0f;
+	if (prot != RTL4_A_PROTOCOL_RTL8366RB) {
+		netdev_err(dev, "unknown realtek protocol 0x%01x\n", prot);
+		kfree_skb(skb);
+		return NULL;
+	}
+	port = protport & 0xff;
+
+	skb->dev = dsa_conduit_find_user(dev, 0, port);
+	if (!skb->dev) {
+		netdev_dbg(dev, "could not find user for port %d\n", port);
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Remove RTL4 tag and recalculate checksum */
+	skb_pull_rcsum(skb, RTL4_A_HDR_LEN);
+
+	dsa_strip_etype_header(skb, RTL4_A_HDR_LEN);
+
+	dsa_default_offload_fwd_mark(skb);
+
+	return skb;
+}
+
+static const struct dsa_device_ops rtl4a_netdev_ops = {
+	.name	= RTL4_A_NAME,
+	.proto	= DSA_TAG_PROTO_RTL4_A,
+	.xmit	= rtl4a_tag_xmit,
+	.rcv	= rtl4a_tag_rcv,
+	.needed_headroom = RTL4_A_HDR_LEN,
+};
+module_dsa_tag_driver(rtl4a_netdev_ops);
+
+MODULE_DESCRIPTION("DSA tag driver for Realtek 4 byte protocol A tags");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_RTL4_A, RTL4_A_NAME);
diff --git a/net/dsa/tag_rtl8_4.c b/net/dsa/tag_rtl8_4.c
new file mode 100644
index 000000000..4da3beebe
--- /dev/null
+++ b/net/dsa/tag_rtl8_4.c
@@ -0,0 +1,278 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Handler for Realtek 8 byte switch tags
+ *
+ * Copyright (C) 2021 Alvin Šipraga <alsi@bang-olufsen.dk>
+ *
+ * NOTE: Currently only supports protocol "4" found in the RTL8365MB, hence
+ * named tag_rtl8_4.
+ *
+ * This tag has the following format:
+ *
+ *  0                                  7|8                                 15
+ *  |-----------------------------------+-----------------------------------|---
+ *  |                               (16-bit)                                | ^
+ *  |                       Realtek EtherType [0x8899]                      | |
+ *  |-----------------------------------+-----------------------------------| 8
+ *  |              (8-bit)              |              (8-bit)              |
+ *  |          Protocol [0x04]          |              REASON               | b
+ *  |-----------------------------------+-----------------------------------| y
+ *  |   (1)   |   (3)  |   (1)  |  (3)  | (1)  | (1)  |    (1)     |  (5)   | t
+ *  | EFID_EN |  EFID  | PRI_EN |  PRI  | KEEP | VSEL | LEARN_DIS  |  VIDX  | e
+ *  |-----------------------------------+-----------------------------------| s
+ *  |   (1)  |                       (15-bit)                               | |
+ *  |  ALLOW |                        TX/RX                                 | v
+ *  |-----------------------------------+-----------------------------------|---
+ *
+ * With the following field descriptions:
+ *
+ *    field      | description
+ *   ------------+-------------
+ *    Realtek    | 0x8899: indicates that this is a proprietary Realtek tag;
+ *     EtherType |         note that Realtek uses the same EtherType for
+ *               |         other incompatible tag formats (e.g. tag_rtl4_a.c)
+ *    Protocol   | 0x04: indicates that this tag conforms to this format
+ *   ------------+-------------
+ *    REASON     | reason for forwarding packet to CPU
+ *               | 0: packet was forwarded or flooded to CPU
+ *               | 80: packet was trapped to CPU
+ *    EFID_EN    | 1: packet has an EFID
+ *               | 0: no EFID
+ *    EFID       | Extended filter ID (EFID) of packet (if EFID_EN=1)
+ *    PRI_EN     | 1: force priority of packet
+ *               | 0: don't force priority
+ *    PRI        | priority of packet (if PRI_EN=1)
+ *    KEEP       | preserve packet VLAN tag format
+ *    VSEL       | 0: switch should classify packet according to VLAN tag
+ *               | 1: switch should classify packet according to VLAN membership
+ *               |    configuration with index VIDX
+ *    LEARN_DIS  | don't learn the source MAC address of the packet
+ *    VIDX       | index of a VLAN membership configuration to use with VSEL
+ *    ALLOW      | 1: treat TX/RX field as an allowance port mask, meaning the
+ *               |    packet may only be forwarded to ports specified in the
+ *               |    mask
+ *               | 0: no allowance port mask, TX/RX field is the forwarding
+ *               |    port mask
+ *    TX/RX      | TX (switch->CPU): port number the packet was received on
+ *               | RX (CPU->switch): forwarding port mask (if ALLOW=0)
+ *               |                   allowance port mask (if ALLOW=1)
+ *
+ * The tag can be positioned before Ethertype, using tag "rtl8_4":
+ *
+ *  +--------+--------+------------+------+-----
+ *  | MAC DA | MAC SA | 8 byte tag | Type | ...
+ *  +--------+--------+------------+------+-----
+ *
+ * The tag can also appear between the end of the payload and before the CRC,
+ * using tag "rtl8_4t":
+ *
+ * +--------+--------+------+-----+---------+------------+-----+
+ * | MAC DA | MAC SA | TYPE | ... | payload | 8-byte tag | CRC |
+ * +--------+--------+------+-----+---------+------------+-----+
+ *
+ * The added bytes after the payload will break most checksums, either in
+ * software or hardware. To avoid this issue, if the checksum is still pending,
+ * this tagger checksums the packet in software before adding the tag.
+ *
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/etherdevice.h>
+
+#include "tag.h"
+
+/* Protocols supported:
+ *
+ * 0x04 = RTL8365MB DSA protocol
+ */
+
+#define RTL8_4_NAME			"rtl8_4"
+#define RTL8_4T_NAME			"rtl8_4t"
+
+#define RTL8_4_TAG_LEN			8
+
+#define RTL8_4_PROTOCOL			GENMASK(15, 8)
+#define   RTL8_4_PROTOCOL_RTL8365MB	0x04
+#define RTL8_4_REASON			GENMASK(7, 0)
+#define   RTL8_4_REASON_FORWARD		0
+#define   RTL8_4_REASON_TRAP		80
+
+#define RTL8_4_LEARN_DIS		BIT(5)
+#define RTL8_4_KEEP			BIT(7)
+
+#define RTL8_4_TX			GENMASK(3, 0)
+#define RTL8_4_RX			GENMASK(10, 0)
+
+static void rtl8_4_write_tag(struct sk_buff *skb, struct net_device *dev,
+			     void *tag)
+{
+	__be16 tag16[RTL8_4_TAG_LEN / 2];
+
+	/* Set Realtek EtherType */
+	tag16[0] = htons(ETH_P_REALTEK);
+
+	/* Set Protocol; zero REASON */
+	tag16[1] = htons(FIELD_PREP(RTL8_4_PROTOCOL, RTL8_4_PROTOCOL_RTL8365MB));
+
+	/* Zero EFID_EN, EFID, PRI_EN, PRI, VSEL, VIDX; set KEEP, LEARN_DIS */
+	tag16[2] = htons(FIELD_PREP(RTL8_4_LEARN_DIS, 1) |
+			 FIELD_PREP(RTL8_4_KEEP, 1));
+
+	/* Zero ALLOW; set RX (CPU->switch) forwarding port mask */
+	tag16[3] = htons(FIELD_PREP(RTL8_4_RX, dsa_xmit_port_mask(skb, dev)));
+
+	memcpy(tag, tag16, RTL8_4_TAG_LEN);
+}
+
+static struct sk_buff *rtl8_4_tag_xmit(struct sk_buff *skb,
+				       struct net_device *dev)
+{
+	skb_push(skb, RTL8_4_TAG_LEN);
+
+	dsa_alloc_etype_header(skb, RTL8_4_TAG_LEN);
+
+	rtl8_4_write_tag(skb, dev, dsa_etype_header_pos_tx(skb));
+
+	return skb;
+}
+
+static struct sk_buff *rtl8_4t_tag_xmit(struct sk_buff *skb,
+					struct net_device *dev)
+{
+	/* Calculate the checksum here if not done yet as trailing tags will
+	 * break either software or hardware based checksum
+	 */
+	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	rtl8_4_write_tag(skb, dev, skb_put(skb, RTL8_4_TAG_LEN));
+
+	return skb;
+}
+
+static int rtl8_4_read_tag(struct sk_buff *skb, struct net_device *dev,
+			   void *tag)
+{
+	__be16 tag16[RTL8_4_TAG_LEN / 2];
+	u16 etype;
+	u8 reason;
+	u8 proto;
+	u8 port;
+
+	memcpy(tag16, tag, RTL8_4_TAG_LEN);
+
+	/* Parse Realtek EtherType */
+	etype = ntohs(tag16[0]);
+	if (unlikely(etype != ETH_P_REALTEK)) {
+		dev_warn_ratelimited(&dev->dev,
+				     "non-realtek ethertype 0x%04x\n", etype);
+		return -EPROTO;
+	}
+
+	/* Parse Protocol */
+	proto = FIELD_GET(RTL8_4_PROTOCOL, ntohs(tag16[1]));
+	if (unlikely(proto != RTL8_4_PROTOCOL_RTL8365MB)) {
+		dev_warn_ratelimited(&dev->dev,
+				     "unknown realtek protocol 0x%02x\n",
+				     proto);
+		return -EPROTO;
+	}
+
+	/* Parse REASON */
+	reason = FIELD_GET(RTL8_4_REASON, ntohs(tag16[1]));
+
+	/* Parse TX (switch->CPU) */
+	port = FIELD_GET(RTL8_4_TX, ntohs(tag16[3]));
+	skb->dev = dsa_conduit_find_user(dev, 0, port);
+	if (!skb->dev) {
+		dev_warn_ratelimited(&dev->dev,
+				     "could not find user for port %d\n",
+				     port);
+		return -ENOENT;
+	}
+
+	if (reason != RTL8_4_REASON_TRAP)
+		dsa_default_offload_fwd_mark(skb);
+
+	return 0;
+}
+
+static struct sk_buff *rtl8_4_tag_rcv(struct sk_buff *skb,
+				      struct net_device *dev)
+{
+	if (unlikely(!pskb_may_pull(skb, RTL8_4_TAG_LEN))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (unlikely(rtl8_4_read_tag(skb, dev, dsa_etype_header_pos_rx(skb)))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Remove tag and recalculate checksum */
+	skb_pull_rcsum(skb, RTL8_4_TAG_LEN);
+
+	dsa_strip_etype_header(skb, RTL8_4_TAG_LEN);
+
+	return skb;
+}
+
+static struct sk_buff *rtl8_4t_tag_rcv(struct sk_buff *skb,
+				       struct net_device *dev)
+{
+	if (skb_linearize(skb)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (unlikely(rtl8_4_read_tag(skb, dev, skb_tail_pointer(skb) - RTL8_4_TAG_LEN))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (pskb_trim_rcsum(skb, skb->len - RTL8_4_TAG_LEN)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	return skb;
+}
+
+/* Ethertype version */
+static const struct dsa_device_ops rtl8_4_netdev_ops = {
+	.name = "rtl8_4",
+	.proto = DSA_TAG_PROTO_RTL8_4,
+	.xmit = rtl8_4_tag_xmit,
+	.rcv = rtl8_4_tag_rcv,
+	.needed_headroom = RTL8_4_TAG_LEN,
+};
+
+DSA_TAG_DRIVER(rtl8_4_netdev_ops);
+
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_RTL8_4, RTL8_4_NAME);
+
+/* Tail version */
+static const struct dsa_device_ops rtl8_4t_netdev_ops = {
+	.name = "rtl8_4t",
+	.proto = DSA_TAG_PROTO_RTL8_4T,
+	.xmit = rtl8_4t_tag_xmit,
+	.rcv = rtl8_4t_tag_rcv,
+	.needed_tailroom = RTL8_4_TAG_LEN,
+};
+
+DSA_TAG_DRIVER(rtl8_4t_netdev_ops);
+
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_RTL8_4T, RTL8_4T_NAME);
+
+static struct dsa_tag_driver *dsa_tag_drivers[] = {
+	&DSA_TAG_DRIVER_NAME(rtl8_4_netdev_ops),
+	&DSA_TAG_DRIVER_NAME(rtl8_4t_netdev_ops),
+};
+module_dsa_tag_drivers(dsa_tag_drivers);
+
+MODULE_DESCRIPTION("DSA tag driver for Realtek 8 byte protocol 4 tags");
+MODULE_LICENSE("GPL");
diff --git a/net/dsa/tag_rzn1_a5psw.c b/net/dsa/tag_rzn1_a5psw.c
new file mode 100644
index 000000000..734910156
--- /dev/null
+++ b/net/dsa/tag_rzn1_a5psw.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2022 Schneider Electric
+ *
+ * Clément Léger <clement.leger@bootlin.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/etherdevice.h>
+#include <linux/if_ether.h>
+#include <net/dsa.h>
+
+#include "tag.h"
+
+/* To define the outgoing port and to discover the incoming port a TAG is
+ * inserted after Src MAC :
+ *
+ *       Dest MAC       Src MAC           TAG         Type
+ * ...| 1 2 3 4 5 6 | 1 2 3 4 5 6 | 1 2 3 4 5 6 7 8 | 1 2 |...
+ *                                |<--------------->|
+ *
+ * See struct a5psw_tag for layout
+ */
+
+#define A5PSW_NAME			"a5psw"
+
+#define ETH_P_DSA_A5PSW			0xE001
+#define A5PSW_TAG_LEN			8
+#define A5PSW_CTRL_DATA_FORCE_FORWARD	BIT(0)
+/* This is both used for xmit tag and rcv tagging */
+#define A5PSW_CTRL_DATA_PORT		GENMASK(3, 0)
+
+struct a5psw_tag {
+	__be16 ctrl_tag;
+	__be16 ctrl_data;
+	__be16 ctrl_data2_hi;
+	__be16 ctrl_data2_lo;
+};
+
+static struct sk_buff *a5psw_tag_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct a5psw_tag *ptag;
+	u32 data2_val;
+
+	BUILD_BUG_ON(sizeof(*ptag) != A5PSW_TAG_LEN);
+
+	/* The Ethernet switch we are interfaced with needs packets to be at
+	 * least 60 bytes otherwise they will be discarded when they enter the
+	 * switch port logic.
+	 */
+	if (eth_skb_pad(skb))
+		return NULL;
+
+	/* provide 'A5PSW_TAG_LEN' bytes additional space */
+	skb_push(skb, A5PSW_TAG_LEN);
+
+	/* make room between MACs and Ether-Type to insert tag */
+	dsa_alloc_etype_header(skb, A5PSW_TAG_LEN);
+
+	ptag = dsa_etype_header_pos_tx(skb);
+
+	data2_val = FIELD_PREP(A5PSW_CTRL_DATA_PORT, dsa_xmit_port_mask(skb, dev));
+	ptag->ctrl_tag = htons(ETH_P_DSA_A5PSW);
+	ptag->ctrl_data = htons(A5PSW_CTRL_DATA_FORCE_FORWARD);
+	ptag->ctrl_data2_lo = htons(data2_val);
+	ptag->ctrl_data2_hi = 0;
+
+	return skb;
+}
+
+static struct sk_buff *a5psw_tag_rcv(struct sk_buff *skb,
+				     struct net_device *dev)
+{
+	struct a5psw_tag *tag;
+	int port;
+
+	if (unlikely(!pskb_may_pull(skb, A5PSW_TAG_LEN))) {
+		dev_warn_ratelimited(&dev->dev,
+				     "Dropping packet, cannot pull\n");
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	tag = dsa_etype_header_pos_rx(skb);
+
+	if (tag->ctrl_tag != htons(ETH_P_DSA_A5PSW)) {
+		dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid TAG marker\n");
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	port = FIELD_GET(A5PSW_CTRL_DATA_PORT, ntohs(tag->ctrl_data));
+
+	skb->dev = dsa_conduit_find_user(dev, 0, port);
+	if (!skb->dev) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	skb_pull_rcsum(skb, A5PSW_TAG_LEN);
+	dsa_strip_etype_header(skb, A5PSW_TAG_LEN);
+
+	dsa_default_offload_fwd_mark(skb);
+
+	return skb;
+}
+
+static const struct dsa_device_ops a5psw_netdev_ops = {
+	.name	= A5PSW_NAME,
+	.proto	= DSA_TAG_PROTO_RZN1_A5PSW,
+	.xmit	= a5psw_tag_xmit,
+	.rcv	= a5psw_tag_rcv,
+	.needed_headroom = A5PSW_TAG_LEN,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for Renesas RZ/N1 A5PSW switch");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_A5PSW, A5PSW_NAME);
+module_dsa_tag_driver(a5psw_netdev_ops);
diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c
new file mode 100644
index 000000000..bfe1f746f
--- /dev/null
+++ b/net/dsa/tag_sja1105.c
@@ -0,0 +1,774 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019, Vladimir Oltean <olteanv@gmail.com>
+ */
+#include <linux/if_vlan.h>
+#include <linux/dsa/sja1105.h>
+#include <linux/dsa/8021q.h>
+#include <linux/packing.h>
+
+#include "tag.h"
+#include "tag_8021q.h"
+
+#define SJA1105_NAME				"sja1105"
+#define SJA1110_NAME				"sja1110"
+
+/* Is this a TX or an RX header? */
+#define SJA1110_HEADER_HOST_TO_SWITCH		BIT(15)
+
+/* RX header */
+#define SJA1110_RX_HEADER_IS_METADATA		BIT(14)
+#define SJA1110_RX_HEADER_HOST_ONLY		BIT(13)
+#define SJA1110_RX_HEADER_HAS_TRAILER		BIT(12)
+
+/* Trap-to-host format (no trailer present) */
+#define SJA1110_RX_HEADER_SRC_PORT(x)		(((x) & GENMASK(7, 4)) >> 4)
+#define SJA1110_RX_HEADER_SWITCH_ID(x)		((x) & GENMASK(3, 0))
+
+/* Timestamp format (trailer present) */
+#define SJA1110_RX_HEADER_TRAILER_POS(x)	((x) & GENMASK(11, 0))
+
+#define SJA1110_RX_TRAILER_SWITCH_ID(x)		(((x) & GENMASK(7, 4)) >> 4)
+#define SJA1110_RX_TRAILER_SRC_PORT(x)		((x) & GENMASK(3, 0))
+
+/* Meta frame format (for 2-step TX timestamps) */
+#define SJA1110_RX_HEADER_N_TS(x)		(((x) & GENMASK(8, 4)) >> 4)
+
+/* TX header */
+#define SJA1110_TX_HEADER_UPDATE_TC		BIT(14)
+#define SJA1110_TX_HEADER_TAKE_TS		BIT(13)
+#define SJA1110_TX_HEADER_TAKE_TS_CASC		BIT(12)
+#define SJA1110_TX_HEADER_HAS_TRAILER		BIT(11)
+
+/* Only valid if SJA1110_TX_HEADER_HAS_TRAILER is false */
+#define SJA1110_TX_HEADER_PRIO(x)		(((x) << 7) & GENMASK(10, 7))
+#define SJA1110_TX_HEADER_TSTAMP_ID(x)		((x) & GENMASK(7, 0))
+
+/* Only valid if SJA1110_TX_HEADER_HAS_TRAILER is true */
+#define SJA1110_TX_HEADER_TRAILER_POS(x)	((x) & GENMASK(10, 0))
+
+#define SJA1110_TX_TRAILER_TSTAMP_ID(x)		(((x) << 24) & GENMASK(31, 24))
+#define SJA1110_TX_TRAILER_PRIO(x)		(((x) << 21) & GENMASK(23, 21))
+#define SJA1110_TX_TRAILER_SWITCHID(x)		(((x) << 12) & GENMASK(15, 12))
+#define SJA1110_TX_TRAILER_DESTPORTS(x)		(((x) << 1) & GENMASK(11, 1))
+
+#define SJA1110_META_TSTAMP_SIZE		10
+
+#define SJA1110_HEADER_LEN			4
+#define SJA1110_RX_TRAILER_LEN			13
+#define SJA1110_TX_TRAILER_LEN			4
+#define SJA1110_MAX_PADDING_LEN			15
+
+struct sja1105_tagger_private {
+	struct sja1105_tagger_data data; /* Must be first */
+	/* Protects concurrent access to the meta state machine
+	 * from taggers running on multiple ports on SMP systems
+	 */
+	spinlock_t meta_lock;
+	struct sk_buff *stampable_skb;
+	struct kthread_worker *xmit_worker;
+};
+
+static struct sja1105_tagger_private *
+sja1105_tagger_private(struct dsa_switch *ds)
+{
+	return ds->tagger_data;
+}
+
+/* Similar to is_link_local_ether_addr(hdr->h_dest) but also covers PTP */
+static bool sja1105_is_link_local(const struct sk_buff *skb)
+{
+	const struct ethhdr *hdr = eth_hdr(skb);
+	u64 dmac = ether_addr_to_u64(hdr->h_dest);
+
+	if (ntohs(hdr->h_proto) == ETH_P_SJA1105_META)
+		return false;
+	if ((dmac & SJA1105_LINKLOCAL_FILTER_A_MASK) ==
+		    SJA1105_LINKLOCAL_FILTER_A)
+		return true;
+	if ((dmac & SJA1105_LINKLOCAL_FILTER_B_MASK) ==
+		    SJA1105_LINKLOCAL_FILTER_B)
+		return true;
+	return false;
+}
+
+struct sja1105_meta {
+	u64 tstamp;
+	u64 dmac_byte_4;
+	u64 dmac_byte_3;
+	u64 source_port;
+	u64 switch_id;
+};
+
+static void sja1105_meta_unpack(const struct sk_buff *skb,
+				struct sja1105_meta *meta)
+{
+	u8 *buf = skb_mac_header(skb) + ETH_HLEN;
+
+	/* UM10944.pdf section 4.2.17 AVB Parameters:
+	 * Structure of the meta-data follow-up frame.
+	 * It is in network byte order, so there are no quirks
+	 * while unpacking the meta frame.
+	 *
+	 * Also SJA1105 E/T only populates bits 23:0 of the timestamp
+	 * whereas P/Q/R/S does 32 bits. Since the structure is the
+	 * same and the E/T puts zeroes in the high-order byte, use
+	 * a unified unpacking command for both device series.
+	 */
+	packing(buf,     &meta->tstamp,     31, 0, 4, UNPACK, 0);
+	packing(buf + 4, &meta->dmac_byte_3, 7, 0, 1, UNPACK, 0);
+	packing(buf + 5, &meta->dmac_byte_4, 7, 0, 1, UNPACK, 0);
+	packing(buf + 6, &meta->source_port, 7, 0, 1, UNPACK, 0);
+	packing(buf + 7, &meta->switch_id,   7, 0, 1, UNPACK, 0);
+}
+
+static bool sja1105_is_meta_frame(const struct sk_buff *skb)
+{
+	const struct ethhdr *hdr = eth_hdr(skb);
+	u64 smac = ether_addr_to_u64(hdr->h_source);
+	u64 dmac = ether_addr_to_u64(hdr->h_dest);
+
+	if (smac != SJA1105_META_SMAC)
+		return false;
+	if (dmac != SJA1105_META_DMAC)
+		return false;
+	if (ntohs(hdr->h_proto) != ETH_P_SJA1105_META)
+		return false;
+	return true;
+}
+
+/* Calls sja1105_port_deferred_xmit in sja1105_main.c */
+static struct sk_buff *sja1105_defer_xmit(struct dsa_port *dp,
+					  struct sk_buff *skb)
+{
+	struct sja1105_tagger_data *tagger_data = sja1105_tagger_data(dp->ds);
+	struct sja1105_tagger_private *priv = sja1105_tagger_private(dp->ds);
+	void (*xmit_work_fn)(struct kthread_work *work);
+	struct sja1105_deferred_xmit_work *xmit_work;
+	struct kthread_worker *xmit_worker;
+
+	xmit_work_fn = tagger_data->xmit_work_fn;
+	xmit_worker = priv->xmit_worker;
+
+	if (!xmit_work_fn || !xmit_worker) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	xmit_work = kzalloc_obj(*xmit_work, GFP_ATOMIC);
+	if (!xmit_work) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	kthread_init_work(&xmit_work->work, xmit_work_fn);
+	xmit_work->dp = dp;
+	xmit_work->skb = skb;
+
+	kthread_queue_work(xmit_worker, &xmit_work->work);
+
+	return NULL;
+}
+
+/* Send VLAN tags with a TPID that blends in with whatever VLAN protocol a
+ * bridge spanning ports of this switch might have.
+ */
+static u16 sja1105_xmit_tpid(struct dsa_port *dp)
+{
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_port *other_dp;
+	u16 proto;
+
+	/* Since VLAN awareness is global, then if this port is VLAN-unaware,
+	 * all ports are. Use the VLAN-unaware TPID used for tag_8021q.
+	 */
+	if (!dsa_port_is_vlan_filtering(dp))
+		return ETH_P_SJA1105;
+
+	/* Port is VLAN-aware, so there is a bridge somewhere (a single one,
+	 * we're sure about that). It may not be on this port though, so we
+	 * need to find it.
+	 */
+	dsa_switch_for_each_port(other_dp, ds) {
+		struct net_device *br = dsa_port_bridge_dev_get(other_dp);
+
+		if (!br)
+			continue;
+
+		/* Error is returned only if CONFIG_BRIDGE_VLAN_FILTERING,
+		 * which seems pointless to handle, as our port cannot become
+		 * VLAN-aware in that case.
+		 */
+		br_vlan_get_proto(br, &proto);
+
+		return proto;
+	}
+
+	WARN_ONCE(1, "Port is VLAN-aware but cannot find associated bridge!\n");
+
+	return ETH_P_SJA1105;
+}
+
+static struct sk_buff *sja1105_imprecise_xmit(struct sk_buff *skb,
+					      struct net_device *netdev)
+{
+	struct dsa_port *dp = dsa_user_to_port(netdev);
+	unsigned int bridge_num = dsa_port_bridge_num_get(dp);
+	struct net_device *br = dsa_port_bridge_dev_get(dp);
+	u16 tx_vid;
+
+	/* If the port is under a VLAN-aware bridge, just slide the
+	 * VLAN-tagged packet into the FDB and hope for the best.
+	 * This works because we support a single VLAN-aware bridge
+	 * across the entire dst, and its VLANs cannot be shared with
+	 * any standalone port.
+	 */
+	if (br_vlan_enabled(br))
+		return skb;
+
+	/* If the port is under a VLAN-unaware bridge, use an imprecise
+	 * TX VLAN that targets the bridge's entire broadcast domain,
+	 * instead of just the specific port.
+	 */
+	tx_vid = dsa_tag_8021q_bridge_vid(bridge_num);
+
+	return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp), tx_vid);
+}
+
+/* Transform untagged control packets into pvid-tagged control packets so that
+ * all packets sent by this tagger are VLAN-tagged and we can configure the
+ * switch to drop untagged packets coming from the DSA conduit.
+ */
+static struct sk_buff *sja1105_pvid_tag_control_pkt(struct dsa_port *dp,
+						    struct sk_buff *skb, u8 pcp)
+{
+	__be16 xmit_tpid = htons(sja1105_xmit_tpid(dp));
+	struct vlan_ethhdr *hdr;
+
+	/* If VLAN tag is in hwaccel area, move it to the payload
+	 * to deal with both cases uniformly and to ensure that
+	 * the VLANs are added in the right order.
+	 */
+	if (unlikely(skb_vlan_tag_present(skb))) {
+		skb = __vlan_hwaccel_push_inside(skb);
+		if (!skb)
+			return NULL;
+	}
+
+	hdr = skb_vlan_eth_hdr(skb);
+
+	/* If skb is already VLAN-tagged, leave that VLAN ID in place */
+	if (hdr->h_vlan_proto == xmit_tpid)
+		return skb;
+
+	return vlan_insert_tag(skb, xmit_tpid, (pcp << VLAN_PRIO_SHIFT) |
+			       SJA1105_DEFAULT_VLAN);
+}
+
+static struct sk_buff *sja1105_xmit(struct sk_buff *skb,
+				    struct net_device *netdev)
+{
+	struct dsa_port *dp = dsa_user_to_port(netdev);
+	u16 queue_mapping = skb_get_queue_mapping(skb);
+	u8 pcp = netdev_txq_to_tc(netdev, queue_mapping);
+	u16 tx_vid = dsa_tag_8021q_standalone_vid(dp);
+
+	if (skb->offload_fwd_mark)
+		return sja1105_imprecise_xmit(skb, netdev);
+
+	/* Transmitting management traffic does not rely upon switch tagging,
+	 * but instead SPI-installed management routes. Part 2 of this
+	 * is the .port_deferred_xmit driver callback.
+	 */
+	if (unlikely(sja1105_is_link_local(skb))) {
+		skb = sja1105_pvid_tag_control_pkt(dp, skb, pcp);
+		if (!skb)
+			return NULL;
+
+		return sja1105_defer_xmit(dp, skb);
+	}
+
+	return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp),
+			     ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
+}
+
+static struct sk_buff *sja1110_xmit(struct sk_buff *skb,
+				    struct net_device *netdev)
+{
+	struct sk_buff *clone = SJA1105_SKB_CB(skb)->clone;
+	struct dsa_port *dp = dsa_user_to_port(netdev);
+	u16 queue_mapping = skb_get_queue_mapping(skb);
+	u8 pcp = netdev_txq_to_tc(netdev, queue_mapping);
+	u16 tx_vid = dsa_tag_8021q_standalone_vid(dp);
+	__be32 *tx_trailer;
+	__be16 *tx_header;
+	int trailer_pos;
+
+	if (skb->offload_fwd_mark)
+		return sja1105_imprecise_xmit(skb, netdev);
+
+	/* Transmitting control packets is done using in-band control
+	 * extensions, while data packets are transmitted using
+	 * tag_8021q TX VLANs.
+	 */
+	if (likely(!sja1105_is_link_local(skb)))
+		return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp),
+				     ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
+
+	skb = sja1105_pvid_tag_control_pkt(dp, skb, pcp);
+	if (!skb)
+		return NULL;
+
+	skb_push(skb, SJA1110_HEADER_LEN);
+
+	dsa_alloc_etype_header(skb, SJA1110_HEADER_LEN);
+
+	trailer_pos = skb->len;
+
+	tx_header = dsa_etype_header_pos_tx(skb);
+	tx_trailer = skb_put(skb, SJA1110_TX_TRAILER_LEN);
+
+	tx_header[0] = htons(ETH_P_SJA1110);
+	tx_header[1] = htons(SJA1110_HEADER_HOST_TO_SWITCH |
+			     SJA1110_TX_HEADER_HAS_TRAILER |
+			     SJA1110_TX_HEADER_TRAILER_POS(trailer_pos));
+	*tx_trailer = cpu_to_be32(SJA1110_TX_TRAILER_PRIO(pcp) |
+				  SJA1110_TX_TRAILER_SWITCHID(dp->ds->index) |
+				  SJA1110_TX_TRAILER_DESTPORTS(BIT(dp->index)));
+	if (clone) {
+		u8 ts_id = SJA1105_SKB_CB(clone)->ts_id;
+
+		tx_header[1] |= htons(SJA1110_TX_HEADER_TAKE_TS);
+		*tx_trailer |= cpu_to_be32(SJA1110_TX_TRAILER_TSTAMP_ID(ts_id));
+	}
+
+	return skb;
+}
+
+static void sja1105_transfer_meta(struct sk_buff *skb,
+				  const struct sja1105_meta *meta)
+{
+	struct ethhdr *hdr = eth_hdr(skb);
+
+	hdr->h_dest[3] = meta->dmac_byte_3;
+	hdr->h_dest[4] = meta->dmac_byte_4;
+	SJA1105_SKB_CB(skb)->tstamp = meta->tstamp;
+}
+
+/* This is a simple state machine which follows the hardware mechanism of
+ * generating RX timestamps:
+ *
+ * After each timestampable skb (all traffic for which send_meta1 and
+ * send_meta0 is true, aka all MAC-filtered link-local traffic) a meta frame
+ * containing a partial timestamp is immediately generated by the switch and
+ * sent as a follow-up to the link-local frame on the CPU port.
+ *
+ * The meta frames have no unique identifier (such as sequence number) by which
+ * one may pair them to the correct timestampable frame.
+ * Instead, the switch has internal logic that ensures no frames are sent on
+ * the CPU port between a link-local timestampable frame and its corresponding
+ * meta follow-up. It also ensures strict ordering between ports (lower ports
+ * have higher priority towards the CPU port). For this reason, a per-port
+ * data structure is not needed/desirable.
+ *
+ * This function pairs the link-local frame with its partial timestamp from the
+ * meta follow-up frame. The full timestamp will be reconstructed later in a
+ * work queue.
+ */
+static struct sk_buff
+*sja1105_rcv_meta_state_machine(struct sk_buff *skb,
+				struct sja1105_meta *meta,
+				bool is_link_local,
+				bool is_meta)
+{
+	/* Step 1: A timestampable frame was received.
+	 * Buffer it until we get its meta frame.
+	 */
+	if (is_link_local) {
+		struct dsa_port *dp = dsa_user_to_port(skb->dev);
+		struct sja1105_tagger_private *priv;
+		struct dsa_switch *ds = dp->ds;
+
+		priv = sja1105_tagger_private(ds);
+
+		spin_lock(&priv->meta_lock);
+		/* Was this a link-local frame instead of the meta
+		 * that we were expecting?
+		 */
+		if (priv->stampable_skb) {
+			dev_err_ratelimited(ds->dev,
+					    "Expected meta frame, is %12llx "
+					    "in the DSA conduit multicast filter?\n",
+					    SJA1105_META_DMAC);
+			kfree_skb(priv->stampable_skb);
+		}
+
+		priv->stampable_skb = skb;
+		spin_unlock(&priv->meta_lock);
+
+		/* Tell DSA we got nothing */
+		return NULL;
+
+	/* Step 2: The meta frame arrived.
+	 * Time to take the stampable skb out of the closet, annotate it
+	 * with the partial timestamp, and pretend that we received it
+	 * just now (basically masquerade the buffered frame as the meta
+	 * frame, which serves no further purpose).
+	 */
+	} else if (is_meta) {
+		struct dsa_port *dp = dsa_user_to_port(skb->dev);
+		struct sja1105_tagger_private *priv;
+		struct dsa_switch *ds = dp->ds;
+		struct sk_buff *stampable_skb;
+
+		priv = sja1105_tagger_private(ds);
+
+		spin_lock(&priv->meta_lock);
+
+		stampable_skb = priv->stampable_skb;
+		priv->stampable_skb = NULL;
+
+		/* Was this a meta frame instead of the link-local
+		 * that we were expecting?
+		 */
+		if (!stampable_skb) {
+			dev_err_ratelimited(ds->dev,
+					    "Unexpected meta frame\n");
+			spin_unlock(&priv->meta_lock);
+			kfree_skb(skb);
+			return NULL;
+		}
+
+		if (stampable_skb->dev != skb->dev) {
+			dev_err_ratelimited(ds->dev,
+					    "Meta frame on wrong port\n");
+			spin_unlock(&priv->meta_lock);
+			kfree_skb(skb);
+			return NULL;
+		}
+
+		/* Free the meta frame and give DSA the buffered stampable_skb
+		 * for further processing up the network stack.
+		 */
+		kfree_skb(skb);
+		skb = stampable_skb;
+		sja1105_transfer_meta(skb, meta);
+
+		spin_unlock(&priv->meta_lock);
+	}
+
+	return skb;
+}
+
+static bool sja1105_skb_has_tag_8021q(const struct sk_buff *skb)
+{
+	u16 tpid = ntohs(eth_hdr(skb)->h_proto);
+
+	return tpid == ETH_P_SJA1105 || tpid == ETH_P_8021Q ||
+	       skb_vlan_tag_present(skb);
+}
+
+static bool sja1110_skb_has_inband_control_extension(const struct sk_buff *skb)
+{
+	return ntohs(eth_hdr(skb)->h_proto) == ETH_P_SJA1110;
+}
+
+static struct sk_buff *sja1105_rcv(struct sk_buff *skb,
+				   struct net_device *netdev)
+{
+	int source_port = -1, switch_id = -1, vbid = -1, vid = -1;
+	struct sja1105_meta meta = {0};
+	struct ethhdr *hdr;
+	bool is_link_local;
+	bool is_meta;
+
+	hdr = eth_hdr(skb);
+	is_link_local = sja1105_is_link_local(skb);
+	is_meta = sja1105_is_meta_frame(skb);
+
+	if (is_link_local) {
+		/* Management traffic path. Switch embeds the switch ID and
+		 * port ID into bytes of the destination MAC, courtesy of
+		 * the incl_srcpt options.
+		 */
+		source_port = hdr->h_dest[3];
+		switch_id = hdr->h_dest[4];
+	} else if (is_meta) {
+		sja1105_meta_unpack(skb, &meta);
+		source_port = meta.source_port;
+		switch_id = meta.switch_id;
+	}
+
+	/* Normal data plane traffic and link-local frames are tagged with
+	 * a tag_8021q VLAN which we have to strip
+	 */
+	if (sja1105_skb_has_tag_8021q(skb)) {
+		dsa_8021q_rcv(skb, &source_port, &switch_id, &vbid, &vid);
+	} else if (source_port == -1 && switch_id == -1) {
+		/* Packets with no source information have no chance of
+		 * getting accepted, drop them straight away.
+		 */
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	skb->dev = dsa_tag_8021q_find_user(netdev, source_port, switch_id,
+					   vid, vbid);
+	if (!skb->dev) {
+		netdev_warn(netdev, "Couldn't decode source port\n");
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (!is_link_local)
+		dsa_default_offload_fwd_mark(skb);
+
+	return sja1105_rcv_meta_state_machine(skb, &meta, is_link_local,
+					      is_meta);
+}
+
+static struct sk_buff *sja1110_rcv_meta(struct sk_buff *skb, u16 rx_header)
+{
+	u8 *buf = dsa_etype_header_pos_rx(skb) + SJA1110_HEADER_LEN;
+	int switch_id = SJA1110_RX_HEADER_SWITCH_ID(rx_header);
+	int n_ts = SJA1110_RX_HEADER_N_TS(rx_header);
+	struct sja1105_tagger_data *tagger_data;
+	struct net_device *conduit = skb->dev;
+	struct dsa_port *cpu_dp;
+	struct dsa_switch *ds;
+	int i;
+
+	cpu_dp = conduit->dsa_ptr;
+	ds = dsa_switch_find(cpu_dp->dst->index, switch_id);
+	if (!ds) {
+		net_err_ratelimited("%s: cannot find switch id %d\n",
+				    conduit->name, switch_id);
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	tagger_data = sja1105_tagger_data(ds);
+	if (!tagger_data->meta_tstamp_handler) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	for (i = 0; i <= n_ts; i++) {
+		u8 ts_id, source_port, dir;
+		u64 tstamp;
+
+		ts_id = buf[0];
+		source_port = (buf[1] & GENMASK(7, 4)) >> 4;
+		dir = (buf[1] & BIT(3)) >> 3;
+		tstamp = be64_to_cpu(*(__be64 *)(buf + 2));
+
+		tagger_data->meta_tstamp_handler(ds, source_port, ts_id, dir,
+						 tstamp);
+
+		buf += SJA1110_META_TSTAMP_SIZE;
+	}
+
+	/* Discard the meta frame, we've consumed the timestamps it contained */
+	kfree_skb(skb);
+	return NULL;
+}
+
+static struct sk_buff *sja1110_rcv_inband_control_extension(struct sk_buff *skb,
+							    int *source_port,
+							    int *switch_id,
+							    bool *host_only)
+{
+	u16 rx_header;
+
+	if (unlikely(!pskb_may_pull(skb, SJA1110_HEADER_LEN))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* skb->data points to skb_mac_header(skb) + ETH_HLEN, which is exactly
+	 * what we need because the caller has checked the EtherType (which is
+	 * located 2 bytes back) and we just need a pointer to the header that
+	 * comes afterwards.
+	 */
+	rx_header = ntohs(*(__be16 *)skb->data);
+
+	if (rx_header & SJA1110_RX_HEADER_HOST_ONLY)
+		*host_only = true;
+
+	if (rx_header & SJA1110_RX_HEADER_IS_METADATA)
+		return sja1110_rcv_meta(skb, rx_header);
+
+	/* Timestamp frame, we have a trailer */
+	if (rx_header & SJA1110_RX_HEADER_HAS_TRAILER) {
+		int start_of_padding = SJA1110_RX_HEADER_TRAILER_POS(rx_header);
+		u8 *rx_trailer = skb_tail_pointer(skb) - SJA1110_RX_TRAILER_LEN;
+		u64 *tstamp = &SJA1105_SKB_CB(skb)->tstamp;
+		u8 last_byte = rx_trailer[12];
+
+		/* The timestamp is unaligned, so we need to use packing()
+		 * to get it
+		 */
+		packing(rx_trailer, tstamp, 63, 0, 8, UNPACK, 0);
+
+		*source_port = SJA1110_RX_TRAILER_SRC_PORT(last_byte);
+		*switch_id = SJA1110_RX_TRAILER_SWITCH_ID(last_byte);
+
+		/* skb->len counts from skb->data, while start_of_padding
+		 * counts from the destination MAC address. Right now skb->data
+		 * is still as set by the DSA conduit, so to trim away the
+		 * padding and trailer we need to account for the fact that
+		 * skb->data points to skb_mac_header(skb) + ETH_HLEN.
+		 */
+		if (pskb_trim_rcsum(skb, start_of_padding - ETH_HLEN)) {
+			kfree_skb(skb);
+			return NULL;
+		}
+	/* Trap-to-host frame, no timestamp trailer */
+	} else {
+		*source_port = SJA1110_RX_HEADER_SRC_PORT(rx_header);
+		*switch_id = SJA1110_RX_HEADER_SWITCH_ID(rx_header);
+	}
+
+	/* Advance skb->data past the DSA header */
+	skb_pull_rcsum(skb, SJA1110_HEADER_LEN);
+
+	dsa_strip_etype_header(skb, SJA1110_HEADER_LEN);
+
+	/* With skb->data in its final place, update the MAC header
+	 * so that eth_hdr() continues to works properly.
+	 */
+	skb_set_mac_header(skb, -ETH_HLEN);
+
+	return skb;
+}
+
+static struct sk_buff *sja1110_rcv(struct sk_buff *skb,
+				   struct net_device *netdev)
+{
+	int source_port = -1, switch_id = -1, vbid = -1, vid = -1;
+	bool host_only = false;
+
+	if (sja1110_skb_has_inband_control_extension(skb)) {
+		skb = sja1110_rcv_inband_control_extension(skb, &source_port,
+							   &switch_id,
+							   &host_only);
+		if (!skb)
+			return NULL;
+	}
+
+	/* Packets with in-band control extensions might still have RX VLANs */
+	if (likely(sja1105_skb_has_tag_8021q(skb)))
+		dsa_8021q_rcv(skb, &source_port, &switch_id, &vbid, &vid);
+
+	skb->dev = dsa_tag_8021q_find_user(netdev, source_port, switch_id,
+					   vid, vbid);
+
+	if (!skb->dev) {
+		netdev_warn(netdev, "Couldn't decode source port\n");
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (!host_only)
+		dsa_default_offload_fwd_mark(skb);
+
+	return skb;
+}
+
+static void sja1105_flow_dissect(const struct sk_buff *skb, __be16 *proto,
+				 int *offset)
+{
+	/* No tag added for management frames, all ok */
+	if (unlikely(sja1105_is_link_local(skb)))
+		return;
+
+	dsa_tag_generic_flow_dissect(skb, proto, offset);
+}
+
+static void sja1110_flow_dissect(const struct sk_buff *skb, __be16 *proto,
+				 int *offset)
+{
+	/* Management frames have 2 DSA tags on RX, so the needed_headroom we
+	 * declared is fine for the generic dissector adjustment procedure.
+	 */
+	if (unlikely(sja1105_is_link_local(skb)))
+		return dsa_tag_generic_flow_dissect(skb, proto, offset);
+
+	/* For the rest, there is a single DSA tag, the tag_8021q one */
+	*offset = VLAN_HLEN;
+	*proto = ((__be16 *)skb->data)[(VLAN_HLEN / 2) - 1];
+}
+
+static void sja1105_disconnect(struct dsa_switch *ds)
+{
+	struct sja1105_tagger_private *priv = ds->tagger_data;
+
+	kthread_destroy_worker(priv->xmit_worker);
+	kfree(priv);
+	ds->tagger_data = NULL;
+}
+
+static int sja1105_connect(struct dsa_switch *ds)
+{
+	struct sja1105_tagger_private *priv;
+	struct kthread_worker *xmit_worker;
+	int err;
+
+	priv = kzalloc_obj(*priv);
+	if (!priv)
+		return -ENOMEM;
+
+	spin_lock_init(&priv->meta_lock);
+
+	xmit_worker = kthread_run_worker(0, "dsa%d:%d_xmit",
+					    ds->dst->index, ds->index);
+	if (IS_ERR(xmit_worker)) {
+		err = PTR_ERR(xmit_worker);
+		kfree(priv);
+		return err;
+	}
+
+	priv->xmit_worker = xmit_worker;
+	ds->tagger_data = priv;
+
+	return 0;
+}
+
+static const struct dsa_device_ops sja1105_netdev_ops = {
+	.name = SJA1105_NAME,
+	.proto = DSA_TAG_PROTO_SJA1105,
+	.xmit = sja1105_xmit,
+	.rcv = sja1105_rcv,
+	.connect = sja1105_connect,
+	.disconnect = sja1105_disconnect,
+	.needed_headroom = VLAN_HLEN,
+	.flow_dissect = sja1105_flow_dissect,
+	.promisc_on_conduit = true,
+};
+
+DSA_TAG_DRIVER(sja1105_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SJA1105, SJA1105_NAME);
+
+static const struct dsa_device_ops sja1110_netdev_ops = {
+	.name = SJA1110_NAME,
+	.proto = DSA_TAG_PROTO_SJA1110,
+	.xmit = sja1110_xmit,
+	.rcv = sja1110_rcv,
+	.connect = sja1105_connect,
+	.disconnect = sja1105_disconnect,
+	.flow_dissect = sja1110_flow_dissect,
+	.needed_headroom = SJA1110_HEADER_LEN + VLAN_HLEN,
+	.needed_tailroom = SJA1110_RX_TRAILER_LEN + SJA1110_MAX_PADDING_LEN,
+};
+
+DSA_TAG_DRIVER(sja1110_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SJA1110, SJA1110_NAME);
+
+static struct dsa_tag_driver *sja1105_tag_driver_array[] = {
+	&DSA_TAG_DRIVER_NAME(sja1105_netdev_ops),
+	&DSA_TAG_DRIVER_NAME(sja1110_netdev_ops),
+};
+
+module_dsa_tag_drivers(sja1105_tag_driver_array);
+
+MODULE_DESCRIPTION("DSA tag driver for NXP SJA1105 switches");
+MODULE_LICENSE("GPL v2");
diff --git a/net/dsa/tag_trailer.c b/net/dsa/tag_trailer.c
new file mode 100644
index 000000000..49c802c10
--- /dev/null
+++ b/net/dsa/tag_trailer.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * net/dsa/tag_trailer.c - Trailer tag format handling
+ * Copyright (c) 2008-2009 Marvell Semiconductor
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+
+#include "tag.h"
+
+#define TRAILER_NAME "trailer"
+
+static struct sk_buff *trailer_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	u8 *trailer;
+
+	trailer = skb_put(skb, 4);
+	trailer[0] = 0x80;
+	trailer[1] = dsa_xmit_port_mask(skb, dev);
+	trailer[2] = 0x10;
+	trailer[3] = 0x00;
+
+	return skb;
+}
+
+static struct sk_buff *trailer_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+	u8 *trailer;
+	int source_port;
+
+	if (skb_linearize(skb)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	trailer = skb_tail_pointer(skb) - 4;
+	if (trailer[0] != 0x80 || (trailer[1] & 0xf8) != 0x00 ||
+	    (trailer[2] & 0xef) != 0x00 || trailer[3] != 0x00) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	source_port = trailer[1] & 7;
+
+	skb->dev = dsa_conduit_find_user(dev, 0, source_port);
+	if (!skb->dev) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (pskb_trim_rcsum(skb, skb->len - 4)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	return skb;
+}
+
+static const struct dsa_device_ops trailer_netdev_ops = {
+	.name	= TRAILER_NAME,
+	.proto	= DSA_TAG_PROTO_TRAILER,
+	.xmit	= trailer_xmit,
+	.rcv	= trailer_rcv,
+	.needed_tailroom = 4,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for switches using a trailer tag");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_TRAILER, TRAILER_NAME);
+
+module_dsa_tag_driver(trailer_netdev_ops);
diff --git a/net/dsa/tag_vsc73xx_8021q.c b/net/dsa/tag_vsc73xx_8021q.c
new file mode 100644
index 000000000..f4736a1a7
--- /dev/null
+++ b/net/dsa/tag_vsc73xx_8021q.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/* Copyright (C) 2024 Pawel Dembicki <paweldembicki@gmail.com>
+ */
+#include <linux/dsa/8021q.h>
+
+#include "tag.h"
+#include "tag_8021q.h"
+
+#define VSC73XX_8021Q_NAME "vsc73xx-8021q"
+
+static struct sk_buff *
+vsc73xx_xmit(struct sk_buff *skb, struct net_device *netdev)
+{
+	struct dsa_port *dp = dsa_user_to_port(netdev);
+	u16 queue_mapping = skb_get_queue_mapping(skb);
+	u16 tx_vid = dsa_tag_8021q_standalone_vid(dp);
+	u8 pcp;
+
+	if (skb->offload_fwd_mark) {
+		unsigned int bridge_num = dsa_port_bridge_num_get(dp);
+		struct net_device *br = dsa_port_bridge_dev_get(dp);
+
+		if (br_vlan_enabled(br))
+			return skb;
+
+		tx_vid = dsa_tag_8021q_bridge_vid(bridge_num);
+	}
+
+	pcp = netdev_txq_to_tc(netdev, queue_mapping);
+
+	return dsa_8021q_xmit(skb, netdev, ETH_P_8021Q,
+			      ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
+}
+
+static struct sk_buff *
+vsc73xx_rcv(struct sk_buff *skb, struct net_device *netdev)
+{
+	int src_port = -1, switch_id = -1, vbid = -1, vid = -1;
+
+	dsa_8021q_rcv(skb, &src_port, &switch_id, &vbid, &vid);
+
+	skb->dev = dsa_tag_8021q_find_user(netdev, src_port, switch_id,
+					   vid, vbid);
+	if (!skb->dev) {
+		dev_warn_ratelimited(&netdev->dev,
+				     "Couldn't decode source port\n");
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	dsa_default_offload_fwd_mark(skb);
+
+	return skb;
+}
+
+static const struct dsa_device_ops vsc73xx_8021q_netdev_ops = {
+	.name			= VSC73XX_8021Q_NAME,
+	.proto			= DSA_TAG_PROTO_VSC73XX_8021Q,
+	.xmit			= vsc73xx_xmit,
+	.rcv			= vsc73xx_rcv,
+	.needed_headroom	= VLAN_HLEN,
+	.promisc_on_conduit	= true,
+};
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("DSA tag driver for VSC73XX family of switches, using VLAN");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_VSC73XX_8021Q, VSC73XX_8021Q_NAME);
+
+module_dsa_tag_driver(vsc73xx_8021q_netdev_ops);
diff --git a/net/dsa/tag_xrs700x.c b/net/dsa/tag_xrs700x.c
new file mode 100644
index 000000000..bb268020e
--- /dev/null
+++ b/net/dsa/tag_xrs700x.c
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * XRS700x tag format handling
+ * Copyright (c) 2008-2009 Marvell Semiconductor
+ * Copyright (c) 2020 NovaTech LLC
+ */
+
+#include <linux/bitops.h>
+
+#include "tag.h"
+
+#define XRS700X_NAME "xrs700x"
+
+static struct sk_buff *xrs700x_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	u8 *trailer;
+
+	trailer = skb_put(skb, 1);
+	trailer[0] = dsa_xmit_port_mask(skb, dev);
+
+	return skb;
+}
+
+static struct sk_buff *xrs700x_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+	int source_port;
+	u8 *trailer;
+
+	trailer = skb_tail_pointer(skb) - 1;
+
+	source_port = ffs((int)trailer[0]) - 1;
+
+	if (source_port < 0) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	skb->dev = dsa_conduit_find_user(dev, 0, source_port);
+	if (!skb->dev) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (pskb_trim_rcsum(skb, skb->len - 1)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Frame is forwarded by hardware, don't forward in software. */
+	dsa_default_offload_fwd_mark(skb);
+
+	return skb;
+}
+
+static const struct dsa_device_ops xrs700x_netdev_ops = {
+	.name	= XRS700X_NAME,
+	.proto	= DSA_TAG_PROTO_XRS700X,
+	.xmit	= xrs700x_xmit,
+	.rcv	= xrs700x_rcv,
+	.needed_tailroom = 1,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for XRS700x switches");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_XRS700X, XRS700X_NAME);
+
+module_dsa_tag_driver(xrs700x_netdev_ops);
diff --git a/net/dsa/tag_yt921x.c b/net/dsa/tag_yt921x.c
new file mode 100644
index 000000000..294784ab6
--- /dev/null
+++ b/net/dsa/tag_yt921x.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Motorcomm YT921x Switch Extended CPU Port Tagging
+ *
+ * Copyright (c) 2025 David Yang <mmyangfl@gmail.com>
+ *
+ * +----+----+-------+-----+----+---------
+ * | DA | SA | TagET | Tag | ET | Payload ...
+ * +----+----+-------+-----+----+---------
+ *   6    6      2      6    2       N
+ *
+ * Tag Ethertype: CPU_TAG_TPID_TPID (default: ETH_P_YT921X = 0x9988)
+ *   * Hardcoded for the moment, but still configurable. Discuss it if there
+ *     are conflicts somewhere and/or you want to change it for some reason.
+ * Tag:
+ *   2: VLAN Tag
+ *   2:
+ *     15b: Rx Port Valid
+ *     14b-11b: Rx Port
+ *     10b-8b: Tx/Rx Priority
+ *     7b: Tx/Rx Code Valid
+ *     6b-1b: Tx/Rx Code
+ *     0b: ? (unset)
+ *   2:
+ *     15b: Tx Port(s) Valid
+ *     10b-0b: Tx Port(s) Mask
+ */
+
+#include <linux/etherdevice.h>
+
+#include "tag.h"
+
+#define YT921X_TAG_NAME	"yt921x"
+
+#define YT921X_TAG_LEN	8
+
+#define YT921X_TAG_PORT_EN		BIT(15)
+#define YT921X_TAG_RX_PORT_M		GENMASK(14, 11)
+#define YT921X_TAG_PRIO_M		GENMASK(10, 8)
+#define  YT921X_TAG_PRIO(x)			FIELD_PREP(YT921X_TAG_PRIO_M, (x))
+#define YT921X_TAG_CODE_EN		BIT(7)
+#define YT921X_TAG_CODE_M		GENMASK(6, 1)
+#define  YT921X_TAG_CODE(x)			FIELD_PREP(YT921X_TAG_CODE_M, (x))
+#define YT921X_TAG_TX_PORTS_M		GENMASK(10, 0)
+#define  YT921X_TAG_TX_PORTS(x)			FIELD_PREP(YT921X_TAG_TX_PORTS_M, (x))
+
+/* Incomplete. Some are configurable via RMA_CTRL_CPU_CODE, the meaning of
+ * others remains unknown.
+ */
+enum yt921x_tag_code {
+	YT921X_TAG_CODE_FORWARD = 0,
+	YT921X_TAG_CODE_ACL = 0x17,
+	YT921X_TAG_CODE_UNK_UCAST = 0x19,
+	YT921X_TAG_CODE_UNK_MCAST = 0x1a,
+	YT921X_TAG_CODE_PORT_COPY = 0x1b,
+	YT921X_TAG_CODE_FDB_COPY = 0x1c,
+};
+
+static struct sk_buff *
+yt921x_tag_xmit(struct sk_buff *skb, struct net_device *netdev)
+{
+	__be16 *tag;
+	u16 ctrl;
+
+	skb_push(skb, YT921X_TAG_LEN);
+	dsa_alloc_etype_header(skb, YT921X_TAG_LEN);
+
+	tag = dsa_etype_header_pos_tx(skb);
+
+	tag[0] = htons(ETH_P_YT921X);
+	/* VLAN tag unrelated when TX */
+	tag[1] = 0;
+	ctrl = YT921X_TAG_CODE(YT921X_TAG_CODE_FORWARD) | YT921X_TAG_CODE_EN |
+	       YT921X_TAG_PRIO(skb->priority);
+	tag[2] = htons(ctrl);
+	ctrl = YT921X_TAG_TX_PORTS(dsa_xmit_port_mask(skb, netdev)) |
+	       YT921X_TAG_PORT_EN;
+	tag[3] = htons(ctrl);
+
+	return skb;
+}
+
+static struct sk_buff *
+yt921x_tag_rcv(struct sk_buff *skb, struct net_device *netdev)
+{
+	unsigned int port;
+	__be16 *tag;
+	u16 rx;
+
+	if (unlikely(!pskb_may_pull(skb, YT921X_TAG_LEN))) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	tag = dsa_etype_header_pos_rx(skb);
+
+	if (unlikely(tag[0] != htons(ETH_P_YT921X))) {
+		dev_warn_ratelimited(&netdev->dev,
+				     "Unexpected EtherType 0x%04x\n",
+				     ntohs(tag[0]));
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Locate which port this is coming from */
+	rx = ntohs(tag[2]);
+	if (unlikely((rx & YT921X_TAG_PORT_EN) == 0)) {
+		dev_warn_ratelimited(&netdev->dev,
+				     "Unexpected rx tag 0x%04x\n", rx);
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	port = FIELD_GET(YT921X_TAG_RX_PORT_M, rx);
+	skb->dev = dsa_conduit_find_user(netdev, 0, port);
+	if (unlikely(!skb->dev)) {
+		dev_warn_ratelimited(&netdev->dev,
+				     "Couldn't decode source port %u\n", port);
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	skb->priority = FIELD_GET(YT921X_TAG_PRIO_M, rx);
+
+	if (!(rx & YT921X_TAG_CODE_EN)) {
+		dev_warn_ratelimited(&netdev->dev,
+				     "Tag code not enabled in rx packet\n");
+	} else {
+		u16 code = FIELD_GET(YT921X_TAG_CODE_M, rx);
+
+		switch (code) {
+		case YT921X_TAG_CODE_FORWARD:
+		case YT921X_TAG_CODE_PORT_COPY:
+		case YT921X_TAG_CODE_FDB_COPY:
+			/* Already forwarded by hardware */
+			dsa_default_offload_fwd_mark(skb);
+			break;
+		case YT921X_TAG_CODE_ACL:
+		case YT921X_TAG_CODE_UNK_UCAST:
+		case YT921X_TAG_CODE_UNK_MCAST:
+			/* NOTE: hardware doesn't distinguish between TRAP (copy
+			 * to CPU only) and COPY (forward and copy to CPU). In
+			 * order to perform a soft switch, NEVER use COPY action
+			 * in the switch driver.
+			 */
+			break;
+		default:
+			dev_warn_ratelimited(&netdev->dev,
+					     "Unknown code 0x%02x\n", code);
+			break;
+		}
+	}
+
+	/* Remove YT921x tag and update checksum */
+	skb_pull_rcsum(skb, YT921X_TAG_LEN);
+	dsa_strip_etype_header(skb, YT921X_TAG_LEN);
+
+	return skb;
+}
+
+static const struct dsa_device_ops yt921x_netdev_ops = {
+	.name	= YT921X_TAG_NAME,
+	.proto	= DSA_TAG_PROTO_YT921X,
+	.xmit	= yt921x_tag_xmit,
+	.rcv	= yt921x_tag_rcv,
+	.needed_headroom = YT921X_TAG_LEN,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for Motorcomm YT921x switches");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_YT921X, YT921X_TAG_NAME);
+
+module_dsa_tag_driver(yt921x_netdev_ops);
diff --git a/net/dsa/trace.c b/net/dsa/trace.c
new file mode 100644
index 000000000..1b107165d
--- /dev/null
+++ b/net/dsa/trace.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Copyright 2022-2023 NXP
+ */
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"
+
+void dsa_db_print(const struct dsa_db *db, char buf[DSA_DB_BUFSIZ])
+{
+	switch (db->type) {
+	case DSA_DB_PORT:
+		sprintf(buf, "port %s", db->dp->name);
+		break;
+	case DSA_DB_LAG:
+		sprintf(buf, "lag %s id %d", db->lag.dev->name, db->lag.id);
+		break;
+	case DSA_DB_BRIDGE:
+		sprintf(buf, "bridge %s num %d", db->bridge.dev->name,
+			db->bridge.num);
+		break;
+	default:
+		sprintf(buf, "unknown");
+		break;
+	}
+}
+
+const char *dsa_port_kind(const struct dsa_port *dp)
+{
+	switch (dp->type) {
+	case DSA_PORT_TYPE_USER:
+		return "user";
+	case DSA_PORT_TYPE_CPU:
+		return "cpu";
+	case DSA_PORT_TYPE_DSA:
+		return "dsa";
+	default:
+		return "unused";
+	}
+}
diff --git a/net/dsa/trace.h b/net/dsa/trace.h
new file mode 100644
index 000000000..83f3e5f78
--- /dev/null
+++ b/net/dsa/trace.h
@@ -0,0 +1,447 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * Copyright 2022-2023 NXP
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM	dsa
+
+#if !defined(_NET_DSA_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _NET_DSA_TRACE_H
+
+#include <net/dsa.h>
+#include <net/switchdev.h>
+#include <linux/etherdevice.h>
+#include <linux/if_bridge.h>
+#include <linux/refcount.h>
+#include <linux/tracepoint.h>
+
+/* Enough to fit "bridge %s num %d" where num has 3 digits */
+#define DSA_DB_BUFSIZ	(IFNAMSIZ + 16)
+
+void dsa_db_print(const struct dsa_db *db, char buf[DSA_DB_BUFSIZ]);
+const char *dsa_port_kind(const struct dsa_port *dp);
+
+DECLARE_EVENT_CLASS(dsa_port_addr_op_hw,
+
+	TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, u16 vid,
+		 const struct dsa_db *db, int err),
+
+	TP_ARGS(dp, addr, vid, db, err),
+
+	TP_STRUCT__entry(
+		__string(dev, dev_name(dp->ds->dev))
+		__string(kind, dsa_port_kind(dp))
+		__field(int, port)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		__assign_str(kind);
+		__entry->port = dp->index;
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+		__entry->err = err;
+	),
+
+	TP_printk("%s %s port %d addr %pM vid %u db \"%s\" err %d",
+		  __get_str(dev), __get_str(kind), __entry->port, __entry->addr,
+		  __entry->vid, __entry->db_buf, __entry->err)
+);
+
+/* Add unicast/multicast address to hardware, either on user ports
+ * (where no refcounting is kept), or on shared ports when the entry
+ * is first seen and its refcount is 1.
+ */
+DEFINE_EVENT(dsa_port_addr_op_hw, dsa_fdb_add_hw,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db, int err),
+	     TP_ARGS(dp, addr, vid, db, err));
+
+DEFINE_EVENT(dsa_port_addr_op_hw, dsa_mdb_add_hw,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db, int err),
+	     TP_ARGS(dp, addr, vid, db, err));
+
+/* Delete unicast/multicast address from hardware, either on user ports or
+ * when the refcount on shared ports reaches 0
+ */
+DEFINE_EVENT(dsa_port_addr_op_hw, dsa_fdb_del_hw,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db, int err),
+	     TP_ARGS(dp, addr, vid, db, err));
+
+DEFINE_EVENT(dsa_port_addr_op_hw, dsa_mdb_del_hw,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db, int err),
+	     TP_ARGS(dp, addr, vid, db, err));
+
+DECLARE_EVENT_CLASS(dsa_port_addr_op_refcount,
+
+	TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, u16 vid,
+		 const struct dsa_db *db, const refcount_t *refcount),
+
+	TP_ARGS(dp, addr, vid, db, refcount),
+
+	TP_STRUCT__entry(
+		__string(dev, dev_name(dp->ds->dev))
+		__string(kind, dsa_port_kind(dp))
+		__field(int, port)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+		__field(unsigned int, refcount)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		__assign_str(kind);
+		__entry->port = dp->index;
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+		__entry->refcount = refcount_read(refcount);
+	),
+
+	TP_printk("%s %s port %d addr %pM vid %u db \"%s\" refcount %u",
+		  __get_str(dev), __get_str(kind), __entry->port, __entry->addr,
+		  __entry->vid, __entry->db_buf, __entry->refcount)
+);
+
+/* Bump the refcount of an existing unicast/multicast address on shared ports */
+DEFINE_EVENT(dsa_port_addr_op_refcount, dsa_fdb_add_bump,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db,
+		      const refcount_t *refcount),
+	     TP_ARGS(dp, addr, vid, db, refcount));
+
+DEFINE_EVENT(dsa_port_addr_op_refcount, dsa_mdb_add_bump,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db,
+		      const refcount_t *refcount),
+	     TP_ARGS(dp, addr, vid, db, refcount));
+
+/* Drop the refcount of a multicast address that we still keep on
+ * shared ports
+ */
+DEFINE_EVENT(dsa_port_addr_op_refcount, dsa_fdb_del_drop,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db,
+		      const refcount_t *refcount),
+	     TP_ARGS(dp, addr, vid, db, refcount));
+
+DEFINE_EVENT(dsa_port_addr_op_refcount, dsa_mdb_del_drop,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db,
+		      const refcount_t *refcount),
+	     TP_ARGS(dp, addr, vid, db, refcount));
+
+DECLARE_EVENT_CLASS(dsa_port_addr_del_not_found,
+
+	TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, u16 vid,
+		 const struct dsa_db *db),
+
+	TP_ARGS(dp, addr, vid, db),
+
+	TP_STRUCT__entry(
+		__string(dev, dev_name(dp->ds->dev))
+		__string(kind, dsa_port_kind(dp))
+		__field(int, port)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		__assign_str(kind);
+		__entry->port = dp->index;
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+	),
+
+	TP_printk("%s %s port %d addr %pM vid %u db \"%s\"",
+		  __get_str(dev), __get_str(kind), __entry->port,
+		  __entry->addr, __entry->vid, __entry->db_buf)
+);
+
+/* Attempt to delete a unicast/multicast address on shared ports for which
+ * the delete operation was called more times than the addition
+ */
+DEFINE_EVENT(dsa_port_addr_del_not_found, dsa_fdb_del_not_found,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db),
+	     TP_ARGS(dp, addr, vid, db));
+
+DEFINE_EVENT(dsa_port_addr_del_not_found, dsa_mdb_del_not_found,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db),
+	     TP_ARGS(dp, addr, vid, db));
+
+TRACE_EVENT(dsa_lag_fdb_add_hw,
+
+	TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr,
+		 u16 vid, const struct dsa_db *db, int err),
+
+	TP_ARGS(lag_dev, addr, vid, db, err),
+
+	TP_STRUCT__entry(
+		__string(dev, lag_dev->name)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+		__entry->err = err;
+	),
+
+	TP_printk("%s addr %pM vid %u db \"%s\" err %d",
+		  __get_str(dev), __entry->addr, __entry->vid,
+		  __entry->db_buf, __entry->err)
+);
+
+TRACE_EVENT(dsa_lag_fdb_add_bump,
+
+	TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr,
+		 u16 vid, const struct dsa_db *db, const refcount_t *refcount),
+
+	TP_ARGS(lag_dev, addr, vid, db, refcount),
+
+	TP_STRUCT__entry(
+		__string(dev, lag_dev->name)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+		__field(unsigned int, refcount)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+		__entry->refcount = refcount_read(refcount);
+	),
+
+	TP_printk("%s addr %pM vid %u db \"%s\" refcount %u",
+		  __get_str(dev), __entry->addr, __entry->vid,
+		  __entry->db_buf, __entry->refcount)
+);
+
+TRACE_EVENT(dsa_lag_fdb_del_hw,
+
+	TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr,
+		 u16 vid, const struct dsa_db *db, int err),
+
+	TP_ARGS(lag_dev, addr, vid, db, err),
+
+	TP_STRUCT__entry(
+		__string(dev, lag_dev->name)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+		__entry->err = err;
+	),
+
+	TP_printk("%s addr %pM vid %u db \"%s\" err %d",
+		  __get_str(dev), __entry->addr, __entry->vid,
+		  __entry->db_buf, __entry->err)
+);
+
+TRACE_EVENT(dsa_lag_fdb_del_drop,
+
+	TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr,
+		 u16 vid, const struct dsa_db *db, const refcount_t *refcount),
+
+	TP_ARGS(lag_dev, addr, vid, db, refcount),
+
+	TP_STRUCT__entry(
+		__string(dev, lag_dev->name)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+		__field(unsigned int, refcount)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+		__entry->refcount = refcount_read(refcount);
+	),
+
+	TP_printk("%s addr %pM vid %u db \"%s\" refcount %u",
+		  __get_str(dev), __entry->addr, __entry->vid,
+		  __entry->db_buf, __entry->refcount)
+);
+
+TRACE_EVENT(dsa_lag_fdb_del_not_found,
+
+	TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr,
+		 u16 vid, const struct dsa_db *db),
+
+	TP_ARGS(lag_dev, addr, vid, db),
+
+	TP_STRUCT__entry(
+		__string(dev, lag_dev->name)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+	),
+
+	TP_printk("%s addr %pM vid %u db \"%s\"",
+		  __get_str(dev), __entry->addr, __entry->vid, __entry->db_buf)
+);
+
+DECLARE_EVENT_CLASS(dsa_vlan_op_hw,
+
+	TP_PROTO(const struct dsa_port *dp,
+		 const struct switchdev_obj_port_vlan *vlan, int err),
+
+	TP_ARGS(dp, vlan, err),
+
+	TP_STRUCT__entry(
+		__string(dev, dev_name(dp->ds->dev))
+		__string(kind, dsa_port_kind(dp))
+		__field(int, port)
+		__field(u16, vid)
+		__field(u16, flags)
+		__field(bool, changed)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		__assign_str(kind);
+		__entry->port = dp->index;
+		__entry->vid = vlan->vid;
+		__entry->flags = vlan->flags;
+		__entry->changed = vlan->changed;
+		__entry->err = err;
+	),
+
+	TP_printk("%s %s port %d vid %u%s%s%s",
+		  __get_str(dev), __get_str(kind), __entry->port, __entry->vid,
+		  __entry->flags & BRIDGE_VLAN_INFO_PVID ? " pvid" : "",
+		  __entry->flags & BRIDGE_VLAN_INFO_UNTAGGED ? " untagged" : "",
+		  __entry->changed ? " (changed)" : "")
+);
+
+DEFINE_EVENT(dsa_vlan_op_hw, dsa_vlan_add_hw,
+	     TP_PROTO(const struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan, int err),
+	     TP_ARGS(dp, vlan, err));
+
+DEFINE_EVENT(dsa_vlan_op_hw, dsa_vlan_del_hw,
+	     TP_PROTO(const struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan, int err),
+	     TP_ARGS(dp, vlan, err));
+
+DECLARE_EVENT_CLASS(dsa_vlan_op_refcount,
+
+	TP_PROTO(const struct dsa_port *dp,
+		 const struct switchdev_obj_port_vlan *vlan,
+		 const refcount_t *refcount),
+
+	TP_ARGS(dp, vlan, refcount),
+
+	TP_STRUCT__entry(
+		__string(dev, dev_name(dp->ds->dev))
+		__string(kind, dsa_port_kind(dp))
+		__field(int, port)
+		__field(u16, vid)
+		__field(u16, flags)
+		__field(bool, changed)
+		__field(unsigned int, refcount)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		__assign_str(kind);
+		__entry->port = dp->index;
+		__entry->vid = vlan->vid;
+		__entry->flags = vlan->flags;
+		__entry->changed = vlan->changed;
+		__entry->refcount = refcount_read(refcount);
+	),
+
+	TP_printk("%s %s port %d vid %u%s%s%s refcount %u",
+		  __get_str(dev), __get_str(kind), __entry->port, __entry->vid,
+		  __entry->flags & BRIDGE_VLAN_INFO_PVID ? " pvid" : "",
+		  __entry->flags & BRIDGE_VLAN_INFO_UNTAGGED ? " untagged" : "",
+		  __entry->changed ? " (changed)" : "", __entry->refcount)
+);
+
+DEFINE_EVENT(dsa_vlan_op_refcount, dsa_vlan_add_bump,
+	     TP_PROTO(const struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan,
+		      const refcount_t *refcount),
+	     TP_ARGS(dp, vlan, refcount));
+
+DEFINE_EVENT(dsa_vlan_op_refcount, dsa_vlan_del_drop,
+	     TP_PROTO(const struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan,
+		      const refcount_t *refcount),
+	     TP_ARGS(dp, vlan, refcount));
+
+TRACE_EVENT(dsa_vlan_del_not_found,
+
+	TP_PROTO(const struct dsa_port *dp,
+		 const struct switchdev_obj_port_vlan *vlan),
+
+	TP_ARGS(dp, vlan),
+
+	TP_STRUCT__entry(
+		__string(dev, dev_name(dp->ds->dev))
+		__string(kind, dsa_port_kind(dp))
+		__field(int, port)
+		__field(u16, vid)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		__assign_str(kind);
+		__entry->port = dp->index;
+		__entry->vid = vlan->vid;
+	),
+
+	TP_printk("%s %s port %d vid %u",
+		  __get_str(dev), __get_str(kind), __entry->port, __entry->vid)
+);
+
+#endif /* _NET_DSA_TRACE_H */
+
+/* We don't want to use include/trace/events */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE	trace
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/net/dsa/user.c b/net/dsa/user.c
new file mode 100644
index 000000000..041f9060c
--- /dev/null
+++ b/net/dsa/user.c
@@ -0,0 +1,3889 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * net/dsa/user.c - user device handling
+ * Copyright (c) 2008-2009 Marvell Semiconductor
+ */
+
+#include <linux/list.h>
+#include <linux/etherdevice.h>
+#include <linux/netdevice.h>
+#include <linux/phy.h>
+#include <linux/phy_fixed.h>
+#include <linux/phylink.h>
+#include <linux/of_net.h>
+#include <linux/of_mdio.h>
+#include <linux/mdio.h>
+#include <net/netdev_lock.h>
+#include <net/rtnetlink.h>
+#include <net/pkt_cls.h>
+#include <net/selftests.h>
+#include <net/tc_act/tc_mirred.h>
+#include <linux/if_bridge.h>
+#include <linux/if_hsr.h>
+#include <net/dcbnl.h>
+#include <linux/netpoll.h>
+#include <linux/string.h>
+
+#include "conduit.h"
+#include "dsa.h"
+#include "netlink.h"
+#include "port.h"
+#include "switch.h"
+#include "tag.h"
+#include "user.h"
+
+struct dsa_switchdev_event_work {
+	struct net_device *dev;
+	struct net_device *orig_dev;
+	struct work_struct work;
+	unsigned long event;
+	/* Specific for SWITCHDEV_FDB_ADD_TO_DEVICE and
+	 * SWITCHDEV_FDB_DEL_TO_DEVICE
+	 */
+	unsigned char addr[ETH_ALEN];
+	u16 vid;
+	bool host_addr;
+};
+
+enum dsa_standalone_event {
+	DSA_UC_ADD,
+	DSA_UC_DEL,
+	DSA_MC_ADD,
+	DSA_MC_DEL,
+};
+
+struct dsa_standalone_event_work {
+	struct work_struct work;
+	struct net_device *dev;
+	enum dsa_standalone_event event;
+	unsigned char addr[ETH_ALEN];
+	u16 vid;
+};
+
+struct dsa_host_vlan_rx_filtering_ctx {
+	struct net_device *dev;
+	const unsigned char *addr;
+	enum dsa_standalone_event event;
+};
+
+static bool dsa_switch_supports_uc_filtering(struct dsa_switch *ds)
+{
+	return ds->ops->port_fdb_add && ds->ops->port_fdb_del &&
+	       ds->fdb_isolation && !ds->vlan_filtering_is_global &&
+	       !ds->needs_standalone_vlan_filtering;
+}
+
+static bool dsa_switch_supports_mc_filtering(struct dsa_switch *ds)
+{
+	return ds->ops->port_mdb_add && ds->ops->port_mdb_del &&
+	       ds->fdb_isolation && !ds->vlan_filtering_is_global &&
+	       !ds->needs_standalone_vlan_filtering;
+}
+
+static void dsa_user_standalone_event_work(struct work_struct *work)
+{
+	struct dsa_standalone_event_work *standalone_work =
+		container_of(work, struct dsa_standalone_event_work, work);
+	const unsigned char *addr = standalone_work->addr;
+	struct net_device *dev = standalone_work->dev;
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct switchdev_obj_port_mdb mdb;
+	struct dsa_switch *ds = dp->ds;
+	u16 vid = standalone_work->vid;
+	int err;
+
+	switch (standalone_work->event) {
+	case DSA_UC_ADD:
+		err = dsa_port_standalone_host_fdb_add(dp, addr, vid);
+		if (err) {
+			dev_err(ds->dev,
+				"port %d failed to add %pM vid %d to fdb: %d\n",
+				dp->index, addr, vid, err);
+			break;
+		}
+		break;
+
+	case DSA_UC_DEL:
+		err = dsa_port_standalone_host_fdb_del(dp, addr, vid);
+		if (err) {
+			dev_err(ds->dev,
+				"port %d failed to delete %pM vid %d from fdb: %d\n",
+				dp->index, addr, vid, err);
+		}
+
+		break;
+	case DSA_MC_ADD:
+		ether_addr_copy(mdb.addr, addr);
+		mdb.vid = vid;
+
+		err = dsa_port_standalone_host_mdb_add(dp, &mdb);
+		if (err) {
+			dev_err(ds->dev,
+				"port %d failed to add %pM vid %d to mdb: %d\n",
+				dp->index, addr, vid, err);
+			break;
+		}
+		break;
+	case DSA_MC_DEL:
+		ether_addr_copy(mdb.addr, addr);
+		mdb.vid = vid;
+
+		err = dsa_port_standalone_host_mdb_del(dp, &mdb);
+		if (err) {
+			dev_err(ds->dev,
+				"port %d failed to delete %pM vid %d from mdb: %d\n",
+				dp->index, addr, vid, err);
+		}
+
+		break;
+	}
+
+	kfree(standalone_work);
+}
+
+static int dsa_user_schedule_standalone_work(struct net_device *dev,
+					     enum dsa_standalone_event event,
+					     const unsigned char *addr,
+					     u16 vid)
+{
+	struct dsa_standalone_event_work *standalone_work;
+
+	standalone_work = kzalloc_obj(*standalone_work, GFP_ATOMIC);
+	if (!standalone_work)
+		return -ENOMEM;
+
+	INIT_WORK(&standalone_work->work, dsa_user_standalone_event_work);
+	standalone_work->event = event;
+	standalone_work->dev = dev;
+
+	ether_addr_copy(standalone_work->addr, addr);
+	standalone_work->vid = vid;
+
+	dsa_schedule_work(&standalone_work->work);
+
+	return 0;
+}
+
+static int dsa_user_host_vlan_rx_filtering(void *arg, int vid)
+{
+	struct dsa_host_vlan_rx_filtering_ctx *ctx = arg;
+
+	return dsa_user_schedule_standalone_work(ctx->dev, ctx->event,
+						  ctx->addr, vid);
+}
+
+static int dsa_user_vlan_for_each(struct net_device *dev,
+				  int (*cb)(void *arg, int vid), void *arg)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_vlan *v;
+	int err;
+
+	lockdep_assert_held(&dev->addr_list_lock);
+
+	err = cb(arg, 0);
+	if (err)
+		return err;
+
+	list_for_each_entry(v, &dp->user_vlans, list) {
+		err = cb(arg, v->vid);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static int dsa_user_sync_uc(struct net_device *dev,
+			    const unsigned char *addr)
+{
+	struct net_device *conduit = dsa_user_to_conduit(dev);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_host_vlan_rx_filtering_ctx ctx = {
+		.dev = dev,
+		.addr = addr,
+		.event = DSA_UC_ADD,
+	};
+
+	dev_uc_add(conduit, addr);
+
+	if (!dsa_switch_supports_uc_filtering(dp->ds))
+		return 0;
+
+	return dsa_user_vlan_for_each(dev, dsa_user_host_vlan_rx_filtering,
+				      &ctx);
+}
+
+static int dsa_user_unsync_uc(struct net_device *dev,
+			      const unsigned char *addr)
+{
+	struct net_device *conduit = dsa_user_to_conduit(dev);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_host_vlan_rx_filtering_ctx ctx = {
+		.dev = dev,
+		.addr = addr,
+		.event = DSA_UC_DEL,
+	};
+
+	dev_uc_del(conduit, addr);
+
+	if (!dsa_switch_supports_uc_filtering(dp->ds))
+		return 0;
+
+	return dsa_user_vlan_for_each(dev, dsa_user_host_vlan_rx_filtering,
+				      &ctx);
+}
+
+static int dsa_user_sync_mc(struct net_device *dev,
+			    const unsigned char *addr)
+{
+	struct net_device *conduit = dsa_user_to_conduit(dev);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_host_vlan_rx_filtering_ctx ctx = {
+		.dev = dev,
+		.addr = addr,
+		.event = DSA_MC_ADD,
+	};
+
+	dev_mc_add(conduit, addr);
+
+	if (!dsa_switch_supports_mc_filtering(dp->ds))
+		return 0;
+
+	return dsa_user_vlan_for_each(dev, dsa_user_host_vlan_rx_filtering,
+				      &ctx);
+}
+
+static int dsa_user_unsync_mc(struct net_device *dev,
+			      const unsigned char *addr)
+{
+	struct net_device *conduit = dsa_user_to_conduit(dev);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_host_vlan_rx_filtering_ctx ctx = {
+		.dev = dev,
+		.addr = addr,
+		.event = DSA_MC_DEL,
+	};
+
+	dev_mc_del(conduit, addr);
+
+	if (!dsa_switch_supports_mc_filtering(dp->ds))
+		return 0;
+
+	return dsa_user_vlan_for_each(dev, dsa_user_host_vlan_rx_filtering,
+				      &ctx);
+}
+
+void dsa_user_sync_ha(struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	struct netdev_hw_addr *ha;
+
+	netif_addr_lock_bh(dev);
+
+	netdev_for_each_synced_mc_addr(ha, dev)
+		dsa_user_sync_mc(dev, ha->addr);
+
+	netdev_for_each_synced_uc_addr(ha, dev)
+		dsa_user_sync_uc(dev, ha->addr);
+
+	netif_addr_unlock_bh(dev);
+
+	if (dsa_switch_supports_uc_filtering(ds) ||
+	    dsa_switch_supports_mc_filtering(ds))
+		dsa_flush_workqueue();
+}
+
+void dsa_user_unsync_ha(struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	struct netdev_hw_addr *ha;
+
+	netif_addr_lock_bh(dev);
+
+	netdev_for_each_synced_uc_addr(ha, dev)
+		dsa_user_unsync_uc(dev, ha->addr);
+
+	netdev_for_each_synced_mc_addr(ha, dev)
+		dsa_user_unsync_mc(dev, ha->addr);
+
+	netif_addr_unlock_bh(dev);
+
+	if (dsa_switch_supports_uc_filtering(ds) ||
+	    dsa_switch_supports_mc_filtering(ds))
+		dsa_flush_workqueue();
+}
+
+/* user mii_bus handling ***************************************************/
+static int dsa_user_phy_read(struct mii_bus *bus, int addr, int reg)
+{
+	struct dsa_switch *ds = bus->priv;
+
+	if (ds->phys_mii_mask & (1 << addr))
+		return ds->ops->phy_read(ds, addr, reg);
+
+	return 0xffff;
+}
+
+static int dsa_user_phy_write(struct mii_bus *bus, int addr, int reg, u16 val)
+{
+	struct dsa_switch *ds = bus->priv;
+
+	if (ds->phys_mii_mask & (1 << addr))
+		return ds->ops->phy_write(ds, addr, reg, val);
+
+	return 0;
+}
+
+void dsa_user_mii_bus_init(struct dsa_switch *ds)
+{
+	ds->user_mii_bus->priv = (void *)ds;
+	ds->user_mii_bus->name = "dsa user smi";
+	ds->user_mii_bus->read = dsa_user_phy_read;
+	ds->user_mii_bus->write = dsa_user_phy_write;
+	snprintf(ds->user_mii_bus->id, MII_BUS_ID_SIZE, "dsa-%d.%d",
+		 ds->dst->index, ds->index);
+	ds->user_mii_bus->parent = ds->dev;
+	ds->user_mii_bus->phy_mask = ~ds->phys_mii_mask;
+}
+
+
+/* user device handling ****************************************************/
+static int dsa_user_get_iflink(const struct net_device *dev)
+{
+	return READ_ONCE(dsa_user_to_conduit(dev)->ifindex);
+}
+
+int dsa_user_host_uc_install(struct net_device *dev, const u8 *addr)
+{
+	struct net_device *conduit = dsa_user_to_conduit(dev);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	int err;
+
+	if (dsa_switch_supports_uc_filtering(ds)) {
+		err = dsa_port_standalone_host_fdb_add(dp, addr, 0);
+		if (err)
+			goto out;
+	}
+
+	if (!ether_addr_equal(addr, conduit->dev_addr)) {
+		err = dev_uc_add(conduit, addr);
+		if (err < 0)
+			goto del_host_addr;
+	}
+
+	return 0;
+
+del_host_addr:
+	if (dsa_switch_supports_uc_filtering(ds))
+		dsa_port_standalone_host_fdb_del(dp, addr, 0);
+out:
+	return err;
+}
+
+void dsa_user_host_uc_uninstall(struct net_device *dev)
+{
+	struct net_device *conduit = dsa_user_to_conduit(dev);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ether_addr_equal(dev->dev_addr, conduit->dev_addr))
+		dev_uc_del(conduit, dev->dev_addr);
+
+	if (dsa_switch_supports_uc_filtering(ds))
+		dsa_port_standalone_host_fdb_del(dp, dev->dev_addr, 0);
+}
+
+static int dsa_user_open(struct net_device *dev)
+{
+	struct net_device *conduit = dsa_user_to_conduit(dev);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	int err;
+
+	err = dev_open(conduit, NULL);
+	if (err < 0) {
+		netdev_err(dev, "failed to open conduit %s\n", conduit->name);
+		goto out;
+	}
+
+	err = dsa_user_host_uc_install(dev, dev->dev_addr);
+	if (err)
+		goto out;
+
+	err = dsa_port_enable_rt(dp, dev->phydev);
+	if (err)
+		goto out_del_host_uc;
+
+	return 0;
+
+out_del_host_uc:
+	dsa_user_host_uc_uninstall(dev);
+out:
+	return err;
+}
+
+static int dsa_user_close(struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+
+	dsa_port_disable_rt(dp);
+
+	dsa_user_host_uc_uninstall(dev);
+
+	return 0;
+}
+
+static void dsa_user_manage_host_flood(struct net_device *dev)
+{
+	bool mc = dev->flags & (IFF_PROMISC | IFF_ALLMULTI);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	bool uc = dev->flags & IFF_PROMISC;
+
+	dsa_port_set_host_flood(dp, uc, mc);
+}
+
+static void dsa_user_change_rx_flags(struct net_device *dev, int change)
+{
+	struct net_device *conduit = dsa_user_to_conduit(dev);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (change & IFF_ALLMULTI)
+		dev_set_allmulti(conduit,
+				 dev->flags & IFF_ALLMULTI ? 1 : -1);
+	if (change & IFF_PROMISC)
+		dev_set_promiscuity(conduit,
+				    dev->flags & IFF_PROMISC ? 1 : -1);
+
+	if (dsa_switch_supports_uc_filtering(ds) &&
+	    dsa_switch_supports_mc_filtering(ds))
+		dsa_user_manage_host_flood(dev);
+}
+
+static void dsa_user_set_rx_mode(struct net_device *dev)
+{
+	__dev_mc_sync(dev, dsa_user_sync_mc, dsa_user_unsync_mc);
+	__dev_uc_sync(dev, dsa_user_sync_uc, dsa_user_unsync_uc);
+}
+
+static int dsa_user_set_mac_address(struct net_device *dev, void *a)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	struct sockaddr *addr = a;
+	int err;
+
+	if (!is_valid_ether_addr(addr->sa_data))
+		return -EADDRNOTAVAIL;
+
+	if (ds->ops->port_set_mac_address) {
+		err = ds->ops->port_set_mac_address(ds, dp->index,
+						    addr->sa_data);
+		if (err)
+			return err;
+	}
+
+	/* If the port is down, the address isn't synced yet to hardware or
+	 * to the DSA conduit, so there is nothing to change.
+	 */
+	if (!(dev->flags & IFF_UP))
+		goto out_change_dev_addr;
+
+	err = dsa_user_host_uc_install(dev, addr->sa_data);
+	if (err)
+		return err;
+
+	dsa_user_host_uc_uninstall(dev);
+
+out_change_dev_addr:
+	eth_hw_addr_set(dev, addr->sa_data);
+
+	return 0;
+}
+
+struct dsa_user_dump_ctx {
+	struct net_device *dev;
+	struct sk_buff *skb;
+	struct netlink_callback *cb;
+	int idx;
+};
+
+static int
+dsa_user_port_fdb_do_dump(const unsigned char *addr, u16 vid,
+			  bool is_static, void *data)
+{
+	struct dsa_user_dump_ctx *dump = data;
+	struct ndo_fdb_dump_context *ctx = (void *)dump->cb->ctx;
+	u32 portid = NETLINK_CB(dump->cb->skb).portid;
+	u32 seq = dump->cb->nlh->nlmsg_seq;
+	struct nlmsghdr *nlh;
+	struct ndmsg *ndm;
+
+	if (dump->idx < ctx->fdb_idx)
+		goto skip;
+
+	nlh = nlmsg_put(dump->skb, portid, seq, RTM_NEWNEIGH,
+			sizeof(*ndm), NLM_F_MULTI);
+	if (!nlh)
+		return -EMSGSIZE;
+
+	ndm = nlmsg_data(nlh);
+	ndm->ndm_family  = AF_BRIDGE;
+	ndm->ndm_pad1    = 0;
+	ndm->ndm_pad2    = 0;
+	ndm->ndm_flags   = NTF_SELF;
+	ndm->ndm_type    = 0;
+	ndm->ndm_ifindex = dump->dev->ifindex;
+	ndm->ndm_state   = is_static ? NUD_NOARP : NUD_REACHABLE;
+
+	if (nla_put(dump->skb, NDA_LLADDR, ETH_ALEN, addr))
+		goto nla_put_failure;
+
+	if (vid && nla_put_u16(dump->skb, NDA_VLAN, vid))
+		goto nla_put_failure;
+
+	nlmsg_end(dump->skb, nlh);
+
+skip:
+	dump->idx++;
+	return 0;
+
+nla_put_failure:
+	nlmsg_cancel(dump->skb, nlh);
+	return -EMSGSIZE;
+}
+
+static int
+dsa_user_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb,
+		  struct net_device *dev, struct net_device *filter_dev,
+		  int *idx)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_user_dump_ctx dump = {
+		.dev = dev,
+		.skb = skb,
+		.cb = cb,
+		.idx = *idx,
+	};
+	int err;
+
+	err = dsa_port_fdb_dump(dp, dsa_user_port_fdb_do_dump, &dump);
+	*idx = dump.idx;
+
+	return err;
+}
+
+static int dsa_user_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+	struct dsa_user_priv *p = netdev_priv(dev);
+
+	return phylink_mii_ioctl(p->dp->pl, ifr, cmd);
+}
+
+static int dsa_user_port_attr_set(struct net_device *dev, const void *ctx,
+				  const struct switchdev_attr *attr,
+				  struct netlink_ext_ack *extack)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	int ret;
+
+	if (ctx && ctx != dp)
+		return 0;
+
+	switch (attr->id) {
+	case SWITCHDEV_ATTR_ID_PORT_STP_STATE:
+		if (!dsa_port_offloads_bridge_port(dp, attr->orig_dev))
+			return -EOPNOTSUPP;
+
+		ret = dsa_port_set_state(dp, attr->u.stp_state, true);
+		break;
+	case SWITCHDEV_ATTR_ID_PORT_MST_STATE:
+		if (!dsa_port_offloads_bridge_port(dp, attr->orig_dev))
+			return -EOPNOTSUPP;
+
+		ret = dsa_port_set_mst_state(dp, &attr->u.mst_state, extack);
+		break;
+	case SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING:
+		if (!dsa_port_offloads_bridge_dev(dp, attr->orig_dev))
+			return -EOPNOTSUPP;
+
+		ret = dsa_port_vlan_filtering(dp, attr->u.vlan_filtering,
+					      extack);
+		break;
+	case SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME:
+		if (!dsa_port_offloads_bridge_dev(dp, attr->orig_dev))
+			return -EOPNOTSUPP;
+
+		ret = dsa_port_ageing_time(dp, attr->u.ageing_time);
+		break;
+	case SWITCHDEV_ATTR_ID_BRIDGE_MST:
+		if (!dsa_port_offloads_bridge_dev(dp, attr->orig_dev))
+			return -EOPNOTSUPP;
+
+		ret = dsa_port_mst_enable(dp, attr->u.mst, extack);
+		break;
+	case SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS:
+		if (!dsa_port_offloads_bridge_port(dp, attr->orig_dev))
+			return -EOPNOTSUPP;
+
+		ret = dsa_port_pre_bridge_flags(dp, attr->u.brport_flags,
+						extack);
+		break;
+	case SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS:
+		if (!dsa_port_offloads_bridge_port(dp, attr->orig_dev))
+			return -EOPNOTSUPP;
+
+		ret = dsa_port_bridge_flags(dp, attr->u.brport_flags, extack);
+		break;
+	case SWITCHDEV_ATTR_ID_VLAN_MSTI:
+		if (!dsa_port_offloads_bridge_dev(dp, attr->orig_dev))
+			return -EOPNOTSUPP;
+
+		ret = dsa_port_vlan_msti(dp, &attr->u.vlan_msti);
+		break;
+	default:
+		ret = -EOPNOTSUPP;
+		break;
+	}
+
+	return ret;
+}
+
+/* Must be called under rcu_read_lock() */
+static int
+dsa_user_vlan_check_for_8021q_uppers(struct net_device *user,
+				     const struct switchdev_obj_port_vlan *vlan)
+{
+	struct net_device *upper_dev;
+	struct list_head *iter;
+
+	netdev_for_each_upper_dev_rcu(user, upper_dev, iter) {
+		u16 vid;
+
+		if (!is_vlan_dev(upper_dev))
+			continue;
+
+		vid = vlan_dev_vlan_id(upper_dev);
+		if (vid == vlan->vid)
+			return -EBUSY;
+	}
+
+	return 0;
+}
+
+static int dsa_user_vlan_add(struct net_device *dev,
+			     const struct switchdev_obj *obj,
+			     struct netlink_ext_ack *extack)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct switchdev_obj_port_vlan *vlan;
+	int err;
+
+	if (dsa_port_skip_vlan_configuration(dp)) {
+		NL_SET_ERR_MSG_MOD(extack, "skipping configuration of VLAN");
+		return 0;
+	}
+
+	vlan = SWITCHDEV_OBJ_PORT_VLAN(obj);
+
+	/* Deny adding a bridge VLAN when there is already an 802.1Q upper with
+	 * the same VID.
+	 */
+	if (br_vlan_enabled(dsa_port_bridge_dev_get(dp))) {
+		rcu_read_lock();
+		err = dsa_user_vlan_check_for_8021q_uppers(dev, vlan);
+		rcu_read_unlock();
+		if (err) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Port already has a VLAN upper with this VID");
+			return err;
+		}
+	}
+
+	return dsa_port_vlan_add(dp, vlan, extack);
+}
+
+/* Offload a VLAN installed on the bridge or on a foreign interface by
+ * installing it as a VLAN towards the CPU port.
+ */
+static int dsa_user_host_vlan_add(struct net_device *dev,
+				  const struct switchdev_obj *obj,
+				  struct netlink_ext_ack *extack)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct switchdev_obj_port_vlan vlan;
+
+	/* Do nothing if this is a software bridge */
+	if (!dp->bridge)
+		return -EOPNOTSUPP;
+
+	if (dsa_port_skip_vlan_configuration(dp)) {
+		NL_SET_ERR_MSG_MOD(extack, "skipping configuration of VLAN");
+		return 0;
+	}
+
+	vlan = *SWITCHDEV_OBJ_PORT_VLAN(obj);
+
+	/* Even though drivers often handle CPU membership in special ways,
+	 * it doesn't make sense to program a PVID, so clear this flag.
+	 */
+	vlan.flags &= ~BRIDGE_VLAN_INFO_PVID;
+
+	return dsa_port_host_vlan_add(dp, &vlan, extack);
+}
+
+static int dsa_user_port_obj_add(struct net_device *dev, const void *ctx,
+				 const struct switchdev_obj *obj,
+				 struct netlink_ext_ack *extack)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	int err;
+
+	if (ctx && ctx != dp)
+		return 0;
+
+	switch (obj->id) {
+	case SWITCHDEV_OBJ_ID_PORT_MDB:
+		if (!dsa_port_offloads_bridge_port(dp, obj->orig_dev))
+			return -EOPNOTSUPP;
+
+		err = dsa_port_mdb_add(dp, SWITCHDEV_OBJ_PORT_MDB(obj));
+		break;
+	case SWITCHDEV_OBJ_ID_HOST_MDB:
+		if (!dsa_port_offloads_bridge_dev(dp, obj->orig_dev))
+			return -EOPNOTSUPP;
+
+		err = dsa_port_bridge_host_mdb_add(dp, SWITCHDEV_OBJ_PORT_MDB(obj));
+		break;
+	case SWITCHDEV_OBJ_ID_PORT_VLAN:
+		if (dsa_port_offloads_bridge_port(dp, obj->orig_dev))
+			err = dsa_user_vlan_add(dev, obj, extack);
+		else
+			err = dsa_user_host_vlan_add(dev, obj, extack);
+		break;
+	case SWITCHDEV_OBJ_ID_MRP:
+		if (!dsa_port_offloads_bridge_dev(dp, obj->orig_dev))
+			return -EOPNOTSUPP;
+
+		err = dsa_port_mrp_add(dp, SWITCHDEV_OBJ_MRP(obj));
+		break;
+	case SWITCHDEV_OBJ_ID_RING_ROLE_MRP:
+		if (!dsa_port_offloads_bridge_dev(dp, obj->orig_dev))
+			return -EOPNOTSUPP;
+
+		err = dsa_port_mrp_add_ring_role(dp,
+						 SWITCHDEV_OBJ_RING_ROLE_MRP(obj));
+		break;
+	default:
+		err = -EOPNOTSUPP;
+		break;
+	}
+
+	return err;
+}
+
+static int dsa_user_vlan_del(struct net_device *dev,
+			     const struct switchdev_obj *obj)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct switchdev_obj_port_vlan *vlan;
+
+	if (dsa_port_skip_vlan_configuration(dp))
+		return 0;
+
+	vlan = SWITCHDEV_OBJ_PORT_VLAN(obj);
+
+	return dsa_port_vlan_del(dp, vlan);
+}
+
+static int dsa_user_host_vlan_del(struct net_device *dev,
+				  const struct switchdev_obj *obj)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct switchdev_obj_port_vlan *vlan;
+
+	/* Do nothing if this is a software bridge */
+	if (!dp->bridge)
+		return -EOPNOTSUPP;
+
+	if (dsa_port_skip_vlan_configuration(dp))
+		return 0;
+
+	vlan = SWITCHDEV_OBJ_PORT_VLAN(obj);
+
+	return dsa_port_host_vlan_del(dp, vlan);
+}
+
+static int dsa_user_port_obj_del(struct net_device *dev, const void *ctx,
+				 const struct switchdev_obj *obj)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	int err;
+
+	if (ctx && ctx != dp)
+		return 0;
+
+	switch (obj->id) {
+	case SWITCHDEV_OBJ_ID_PORT_MDB:
+		if (!dsa_port_offloads_bridge_port(dp, obj->orig_dev))
+			return -EOPNOTSUPP;
+
+		err = dsa_port_mdb_del(dp, SWITCHDEV_OBJ_PORT_MDB(obj));
+		break;
+	case SWITCHDEV_OBJ_ID_HOST_MDB:
+		if (!dsa_port_offloads_bridge_dev(dp, obj->orig_dev))
+			return -EOPNOTSUPP;
+
+		err = dsa_port_bridge_host_mdb_del(dp, SWITCHDEV_OBJ_PORT_MDB(obj));
+		break;
+	case SWITCHDEV_OBJ_ID_PORT_VLAN:
+		if (dsa_port_offloads_bridge_port(dp, obj->orig_dev))
+			err = dsa_user_vlan_del(dev, obj);
+		else
+			err = dsa_user_host_vlan_del(dev, obj);
+		break;
+	case SWITCHDEV_OBJ_ID_MRP:
+		if (!dsa_port_offloads_bridge_dev(dp, obj->orig_dev))
+			return -EOPNOTSUPP;
+
+		err = dsa_port_mrp_del(dp, SWITCHDEV_OBJ_MRP(obj));
+		break;
+	case SWITCHDEV_OBJ_ID_RING_ROLE_MRP:
+		if (!dsa_port_offloads_bridge_dev(dp, obj->orig_dev))
+			return -EOPNOTSUPP;
+
+		err = dsa_port_mrp_del_ring_role(dp,
+						 SWITCHDEV_OBJ_RING_ROLE_MRP(obj));
+		break;
+	default:
+		err = -EOPNOTSUPP;
+		break;
+	}
+
+	return err;
+}
+
+static netdev_tx_t dsa_user_netpoll_send_skb(struct net_device *dev,
+					     struct sk_buff *skb)
+{
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	struct dsa_user_priv *p = netdev_priv(dev);
+
+	return netpoll_send_skb(p->netpoll, skb);
+#else
+	BUG();
+	return NETDEV_TX_OK;
+#endif
+}
+
+static void dsa_skb_tx_timestamp(struct dsa_user_priv *p,
+				 struct sk_buff *skb)
+{
+	struct dsa_switch *ds = p->dp->ds;
+
+	if (!(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NOBPF))
+		return;
+
+	if (!ds->ops->port_txtstamp)
+		return;
+
+	ds->ops->port_txtstamp(ds, p->dp->index, skb);
+}
+
+netdev_tx_t dsa_enqueue_skb(struct sk_buff *skb, struct net_device *dev)
+{
+	/* SKB for netpoll still need to be mangled with the protocol-specific
+	 * tag to be successfully transmitted
+	 */
+	if (unlikely(netpoll_tx_running(dev)))
+		return dsa_user_netpoll_send_skb(dev, skb);
+
+	/* Queue the SKB for transmission on the parent interface, but
+	 * do not modify its EtherType
+	 */
+	skb->dev = dsa_user_to_conduit(dev);
+	dev_queue_xmit(skb);
+
+	return NETDEV_TX_OK;
+}
+EXPORT_SYMBOL_GPL(dsa_enqueue_skb);
+
+static netdev_tx_t dsa_user_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct dsa_user_priv *p = netdev_priv(dev);
+	struct sk_buff *nskb;
+
+	dev_sw_netstats_tx_add(dev, 1, skb->len);
+
+	memset(skb->cb, 0, sizeof(skb->cb));
+
+	/* Handle tx timestamp if any */
+	dsa_skb_tx_timestamp(p, skb);
+
+	if (skb_ensure_writable_head_tail(skb, dev)) {
+		dev_kfree_skb_any(skb);
+		return NETDEV_TX_OK;
+	}
+
+	/* needed_tailroom should still be 'warm' in the cache line from
+	 * skb_ensure_writable_head_tail(), which has also ensured that
+	 * padding is safe.
+	 */
+	if (dev->needed_tailroom)
+		eth_skb_pad(skb);
+
+	/* Transmit function may have to reallocate the original SKB,
+	 * in which case it must have freed it. Taggers will drop the
+	 * passed skb on error.
+	 */
+	nskb = p->xmit(skb, dev);
+	if (!nskb)
+		return NETDEV_TX_OK;
+
+	return dsa_enqueue_skb(nskb, dev);
+}
+
+/* ethtool operations *******************************************************/
+
+static void dsa_user_get_drvinfo(struct net_device *dev,
+				 struct ethtool_drvinfo *drvinfo)
+{
+	strscpy(drvinfo->driver, "dsa", sizeof(drvinfo->driver));
+	strscpy(drvinfo->fw_version, "N/A", sizeof(drvinfo->fw_version));
+	strscpy(drvinfo->bus_info, "platform", sizeof(drvinfo->bus_info));
+}
+
+static int dsa_user_get_regs_len(struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->get_regs_len)
+		return ds->ops->get_regs_len(ds, dp->index);
+
+	return -EOPNOTSUPP;
+}
+
+static void
+dsa_user_get_regs(struct net_device *dev, struct ethtool_regs *regs, void *_p)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->get_regs)
+		ds->ops->get_regs(ds, dp->index, regs, _p);
+}
+
+static int dsa_user_nway_reset(struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+
+	return phylink_ethtool_nway_reset(dp->pl);
+}
+
+static int dsa_user_get_eeprom_len(struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->cd && ds->cd->eeprom_len)
+		return ds->cd->eeprom_len;
+
+	if (ds->ops->get_eeprom_len)
+		return ds->ops->get_eeprom_len(ds);
+
+	return 0;
+}
+
+static int dsa_user_get_eeprom(struct net_device *dev,
+			       struct ethtool_eeprom *eeprom, u8 *data)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->get_eeprom)
+		return ds->ops->get_eeprom(ds, eeprom, data);
+
+	return -EOPNOTSUPP;
+}
+
+static int dsa_user_set_eeprom(struct net_device *dev,
+			       struct ethtool_eeprom *eeprom, u8 *data)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->set_eeprom)
+		return ds->ops->set_eeprom(ds, eeprom, data);
+
+	return -EOPNOTSUPP;
+}
+
+static void dsa_user_get_strings(struct net_device *dev,
+				 uint32_t stringset, uint8_t *data)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (stringset == ETH_SS_STATS) {
+		ethtool_puts(&data, "tx_packets");
+		ethtool_puts(&data, "tx_bytes");
+		ethtool_puts(&data, "rx_packets");
+		ethtool_puts(&data, "rx_bytes");
+		if (ds->ops->get_strings)
+			ds->ops->get_strings(ds, dp->index, stringset, data);
+	} else if (stringset ==  ETH_SS_TEST) {
+		net_selftest_get_strings(data);
+	}
+
+}
+
+static void dsa_user_get_ethtool_stats(struct net_device *dev,
+				       struct ethtool_stats *stats,
+				       uint64_t *data)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	struct pcpu_sw_netstats *s;
+	unsigned int start;
+	int i;
+
+	for_each_possible_cpu(i) {
+		u64 tx_packets, tx_bytes, rx_packets, rx_bytes;
+
+		s = per_cpu_ptr(dev->tstats, i);
+		do {
+			start = u64_stats_fetch_begin(&s->syncp);
+			tx_packets = u64_stats_read(&s->tx_packets);
+			tx_bytes = u64_stats_read(&s->tx_bytes);
+			rx_packets = u64_stats_read(&s->rx_packets);
+			rx_bytes = u64_stats_read(&s->rx_bytes);
+		} while (u64_stats_fetch_retry(&s->syncp, start));
+		data[0] += tx_packets;
+		data[1] += tx_bytes;
+		data[2] += rx_packets;
+		data[3] += rx_bytes;
+	}
+	if (ds->ops->get_ethtool_stats)
+		ds->ops->get_ethtool_stats(ds, dp->index, data + 4);
+}
+
+static int dsa_user_get_sset_count(struct net_device *dev, int sset)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (sset == ETH_SS_STATS) {
+		int count = 0;
+
+		if (ds->ops->get_sset_count) {
+			count = ds->ops->get_sset_count(ds, dp->index, sset);
+			if (count < 0)
+				return count;
+		}
+
+		return count + 4;
+	} else if (sset ==  ETH_SS_TEST) {
+		return net_selftest_get_count();
+	}
+
+	return -EOPNOTSUPP;
+}
+
+static void dsa_user_get_eth_phy_stats(struct net_device *dev,
+				       struct ethtool_eth_phy_stats *phy_stats)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->get_eth_phy_stats)
+		ds->ops->get_eth_phy_stats(ds, dp->index, phy_stats);
+}
+
+static void dsa_user_get_eth_mac_stats(struct net_device *dev,
+				       struct ethtool_eth_mac_stats *mac_stats)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->get_eth_mac_stats)
+		ds->ops->get_eth_mac_stats(ds, dp->index, mac_stats);
+}
+
+static void
+dsa_user_get_eth_ctrl_stats(struct net_device *dev,
+			    struct ethtool_eth_ctrl_stats *ctrl_stats)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->get_eth_ctrl_stats)
+		ds->ops->get_eth_ctrl_stats(ds, dp->index, ctrl_stats);
+}
+
+static void
+dsa_user_get_rmon_stats(struct net_device *dev,
+			struct ethtool_rmon_stats *rmon_stats,
+			const struct ethtool_rmon_hist_range **ranges)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->get_rmon_stats)
+		ds->ops->get_rmon_stats(ds, dp->index, rmon_stats, ranges);
+}
+
+static void dsa_user_get_ts_stats(struct net_device *dev,
+				  struct ethtool_ts_stats *ts_stats)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->get_ts_stats)
+		ds->ops->get_ts_stats(ds, dp->index, ts_stats);
+}
+
+static void dsa_user_net_selftest(struct net_device *ndev,
+				  struct ethtool_test *etest, u64 *buf)
+{
+	struct dsa_port *dp = dsa_user_to_port(ndev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->self_test) {
+		ds->ops->self_test(ds, dp->index, etest, buf);
+		return;
+	}
+
+	net_selftest(ndev, etest, buf);
+}
+
+static int dsa_user_get_mm(struct net_device *dev,
+			   struct ethtool_mm_state *state)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->get_mm)
+		return -EOPNOTSUPP;
+
+	return ds->ops->get_mm(ds, dp->index, state);
+}
+
+static int dsa_user_set_mm(struct net_device *dev, struct ethtool_mm_cfg *cfg,
+			   struct netlink_ext_ack *extack)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->set_mm)
+		return -EOPNOTSUPP;
+
+	return ds->ops->set_mm(ds, dp->index, cfg, extack);
+}
+
+static void dsa_user_get_mm_stats(struct net_device *dev,
+				  struct ethtool_mm_stats *stats)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->get_mm_stats)
+		ds->ops->get_mm_stats(ds, dp->index, stats);
+}
+
+static void dsa_user_get_wol(struct net_device *dev, struct ethtool_wolinfo *w)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	phylink_ethtool_get_wol(dp->pl, w);
+
+	if (ds->ops->get_wol)
+		ds->ops->get_wol(ds, dp->index, w);
+}
+
+static int dsa_user_set_wol(struct net_device *dev, struct ethtool_wolinfo *w)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	int ret = -EOPNOTSUPP;
+
+	phylink_ethtool_set_wol(dp->pl, w);
+
+	if (ds->ops->set_wol)
+		ret = ds->ops->set_wol(ds, dp->index, w);
+
+	return ret;
+}
+
+static int dsa_user_set_eee(struct net_device *dev, struct ethtool_keee *e)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	int ret;
+
+	/* Check whether the switch supports EEE */
+	if (!ds->ops->support_eee || !ds->ops->support_eee(ds, dp->index))
+		return -EOPNOTSUPP;
+
+	/* If the port is using phylink managed EEE, then an unimplemented
+	 * set_mac_eee() is permissible.
+	 */
+	if (!phylink_mac_implements_lpi(ds->phylink_mac_ops)) {
+		/* Port's PHY and MAC both need to be EEE capable */
+		if (!dev->phydev)
+			return -ENODEV;
+
+		if (!ds->ops->set_mac_eee)
+			return -EOPNOTSUPP;
+
+		ret = ds->ops->set_mac_eee(ds, dp->index, e);
+		if (ret)
+			return ret;
+	} else if (ds->ops->set_mac_eee) {
+		ret = ds->ops->set_mac_eee(ds, dp->index, e);
+		if (ret)
+			return ret;
+	}
+
+	return phylink_ethtool_set_eee(dp->pl, e);
+}
+
+static int dsa_user_get_eee(struct net_device *dev, struct ethtool_keee *e)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	/* Check whether the switch supports EEE */
+	if (!ds->ops->support_eee || !ds->ops->support_eee(ds, dp->index))
+		return -EOPNOTSUPP;
+
+	/* Port's PHY and MAC both need to be EEE capable */
+	if (!dev->phydev)
+		return -ENODEV;
+
+	return phylink_ethtool_get_eee(dp->pl, e);
+}
+
+static int dsa_user_get_link_ksettings(struct net_device *dev,
+				       struct ethtool_link_ksettings *cmd)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+
+	return phylink_ethtool_ksettings_get(dp->pl, cmd);
+}
+
+static int dsa_user_set_link_ksettings(struct net_device *dev,
+				       const struct ethtool_link_ksettings *cmd)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+
+	return phylink_ethtool_ksettings_set(dp->pl, cmd);
+}
+
+static void dsa_user_get_pause_stats(struct net_device *dev,
+				     struct ethtool_pause_stats *pause_stats)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->get_pause_stats)
+		ds->ops->get_pause_stats(ds, dp->index, pause_stats);
+}
+
+static void dsa_user_get_pauseparam(struct net_device *dev,
+				    struct ethtool_pauseparam *pause)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+
+	phylink_ethtool_get_pauseparam(dp->pl, pause);
+}
+
+static int dsa_user_set_pauseparam(struct net_device *dev,
+				   struct ethtool_pauseparam *pause)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+
+	return phylink_ethtool_set_pauseparam(dp->pl, pause);
+}
+
+#ifdef CONFIG_NET_POLL_CONTROLLER
+static int dsa_user_netpoll_setup(struct net_device *dev)
+{
+	struct net_device *conduit = dsa_user_to_conduit(dev);
+	struct dsa_user_priv *p = netdev_priv(dev);
+	struct netpoll *netpoll;
+	int err = 0;
+
+	netpoll = kzalloc_obj(*netpoll);
+	if (!netpoll)
+		return -ENOMEM;
+
+	err = __netpoll_setup(netpoll, conduit);
+	if (err) {
+		kfree(netpoll);
+		goto out;
+	}
+
+	p->netpoll = netpoll;
+out:
+	return err;
+}
+
+static void dsa_user_netpoll_cleanup(struct net_device *dev)
+{
+	struct dsa_user_priv *p = netdev_priv(dev);
+	struct netpoll *netpoll = p->netpoll;
+
+	if (!netpoll)
+		return;
+
+	p->netpoll = NULL;
+
+	__netpoll_free(netpoll);
+}
+
+static void dsa_user_poll_controller(struct net_device *dev)
+{
+}
+#endif
+
+static struct dsa_mall_tc_entry *
+dsa_user_mall_tc_entry_find(struct net_device *dev, unsigned long cookie)
+{
+	struct dsa_user_priv *p = netdev_priv(dev);
+	struct dsa_mall_tc_entry *mall_tc_entry;
+
+	list_for_each_entry(mall_tc_entry, &p->mall_tc_list, list)
+		if (mall_tc_entry->cookie == cookie)
+			return mall_tc_entry;
+
+	return NULL;
+}
+
+static int
+dsa_user_add_cls_matchall_mirred(struct net_device *dev,
+				 struct tc_cls_matchall_offload *cls,
+				 bool ingress, bool ingress_target)
+{
+	struct netlink_ext_ack *extack = cls->common.extack;
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_user_priv *p = netdev_priv(dev);
+	struct dsa_mall_mirror_tc_entry *mirror;
+	struct dsa_mall_tc_entry *mall_tc_entry;
+	struct dsa_switch *ds = dp->ds;
+	struct flow_action_entry *act;
+	struct dsa_port *to_dp;
+	int err;
+
+	if (cls->common.protocol != htons(ETH_P_ALL)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Can only offload \"protocol all\" matchall filter");
+		return -EOPNOTSUPP;
+	}
+
+	if (!ds->ops->port_mirror_add) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Switch does not support mirroring operation");
+		return -EOPNOTSUPP;
+	}
+
+	if (!flow_action_basic_hw_stats_check(&cls->rule->action, extack))
+		return -EOPNOTSUPP;
+
+	act = &cls->rule->action.entries[0];
+
+	if (!act->dev)
+		return -EINVAL;
+
+	if (dsa_user_dev_check(act->dev)) {
+		if (ingress_target) {
+			/* We can only fulfill this using software assist */
+			if (cls->common.skip_sw) {
+				NL_SET_ERR_MSG_MOD(extack,
+						   "Can only mirred to ingress of DSA user port if filter also runs in software");
+				return -EOPNOTSUPP;
+			}
+			to_dp = dp->cpu_dp;
+		} else {
+			to_dp = dsa_user_to_port(act->dev);
+		}
+	} else {
+		/* Handle mirroring to foreign target ports as a mirror towards
+		 * the CPU. The software tc rule will take the packets from
+		 * there.
+		 */
+		if (cls->common.skip_sw) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Can only mirred to CPU if filter also runs in software");
+			return -EOPNOTSUPP;
+		}
+		to_dp = dp->cpu_dp;
+	}
+
+	if (dp->ds != to_dp->ds) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Cross-chip mirroring not implemented");
+		return -EOPNOTSUPP;
+	}
+
+	mall_tc_entry = kzalloc_obj(*mall_tc_entry);
+	if (!mall_tc_entry)
+		return -ENOMEM;
+
+	mall_tc_entry->cookie = cls->cookie;
+	mall_tc_entry->type = DSA_PORT_MALL_MIRROR;
+	mirror = &mall_tc_entry->mirror;
+	mirror->to_local_port = to_dp->index;
+	mirror->ingress = ingress;
+
+	err = ds->ops->port_mirror_add(ds, dp->index, mirror, ingress, extack);
+	if (err) {
+		kfree(mall_tc_entry);
+		return err;
+	}
+
+	list_add_tail(&mall_tc_entry->list, &p->mall_tc_list);
+
+	return err;
+}
+
+static int
+dsa_user_add_cls_matchall_police(struct net_device *dev,
+				 struct tc_cls_matchall_offload *cls,
+				 bool ingress)
+{
+	struct netlink_ext_ack *extack = cls->common.extack;
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_user_priv *p = netdev_priv(dev);
+	struct dsa_mall_tc_entry *mall_tc_entry;
+	struct flow_action_police *policer;
+	struct dsa_switch *ds = dp->ds;
+	struct flow_action_entry *act;
+	int err;
+
+	if (!ds->ops->port_policer_add) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Policing offload not implemented");
+		return -EOPNOTSUPP;
+	}
+
+	if (!ingress) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Only supported on ingress qdisc");
+		return -EOPNOTSUPP;
+	}
+
+	if (!flow_action_basic_hw_stats_check(&cls->rule->action, extack))
+		return -EOPNOTSUPP;
+
+	list_for_each_entry(mall_tc_entry, &p->mall_tc_list, list) {
+		if (mall_tc_entry->type == DSA_PORT_MALL_POLICER) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Only one port policer allowed");
+			return -EEXIST;
+		}
+	}
+
+	act = &cls->rule->action.entries[0];
+
+	mall_tc_entry = kzalloc_obj(*mall_tc_entry);
+	if (!mall_tc_entry)
+		return -ENOMEM;
+
+	mall_tc_entry->cookie = cls->cookie;
+	mall_tc_entry->type = DSA_PORT_MALL_POLICER;
+	policer = &mall_tc_entry->policer;
+	*policer = act->police;
+
+	err = ds->ops->port_policer_add(ds, dp->index, policer, extack);
+	if (err) {
+		kfree(mall_tc_entry);
+		return err;
+	}
+
+	list_add_tail(&mall_tc_entry->list, &p->mall_tc_list);
+
+	return err;
+}
+
+static int dsa_user_add_cls_matchall(struct net_device *dev,
+				     struct tc_cls_matchall_offload *cls,
+				     bool ingress)
+{
+	const struct flow_action *action = &cls->rule->action;
+	struct netlink_ext_ack *extack = cls->common.extack;
+
+	if (!flow_offload_has_one_action(action)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Cannot offload matchall filter with more than one action");
+		return -EOPNOTSUPP;
+	}
+
+	switch (action->entries[0].id) {
+	case FLOW_ACTION_MIRRED:
+		return dsa_user_add_cls_matchall_mirred(dev, cls, ingress,
+							false);
+	case FLOW_ACTION_MIRRED_INGRESS:
+		return dsa_user_add_cls_matchall_mirred(dev, cls, ingress,
+							true);
+	case FLOW_ACTION_POLICE:
+		return dsa_user_add_cls_matchall_police(dev, cls, ingress);
+	default:
+		NL_SET_ERR_MSG_MOD(extack, "Unknown action");
+		break;
+	}
+
+	return -EOPNOTSUPP;
+}
+
+static void dsa_user_del_cls_matchall(struct net_device *dev,
+				      struct tc_cls_matchall_offload *cls)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_mall_tc_entry *mall_tc_entry;
+	struct dsa_switch *ds = dp->ds;
+
+	mall_tc_entry = dsa_user_mall_tc_entry_find(dev, cls->cookie);
+	if (!mall_tc_entry)
+		return;
+
+	list_del(&mall_tc_entry->list);
+
+	switch (mall_tc_entry->type) {
+	case DSA_PORT_MALL_MIRROR:
+		if (ds->ops->port_mirror_del)
+			ds->ops->port_mirror_del(ds, dp->index,
+						 &mall_tc_entry->mirror);
+		break;
+	case DSA_PORT_MALL_POLICER:
+		if (ds->ops->port_policer_del)
+			ds->ops->port_policer_del(ds, dp->index);
+		break;
+	default:
+		WARN_ON(1);
+	}
+
+	kfree(mall_tc_entry);
+}
+
+static int dsa_user_setup_tc_cls_matchall(struct net_device *dev,
+					  struct tc_cls_matchall_offload *cls,
+					  bool ingress)
+{
+	if (cls->common.chain_index)
+		return -EOPNOTSUPP;
+
+	switch (cls->command) {
+	case TC_CLSMATCHALL_REPLACE:
+		return dsa_user_add_cls_matchall(dev, cls, ingress);
+	case TC_CLSMATCHALL_DESTROY:
+		dsa_user_del_cls_matchall(dev, cls);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int dsa_user_add_cls_flower(struct net_device *dev,
+				   struct flow_cls_offload *cls,
+				   bool ingress)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index;
+
+	if (!ds->ops->cls_flower_add)
+		return -EOPNOTSUPP;
+
+	return ds->ops->cls_flower_add(ds, port, cls, ingress);
+}
+
+static int dsa_user_del_cls_flower(struct net_device *dev,
+				   struct flow_cls_offload *cls,
+				   bool ingress)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index;
+
+	if (!ds->ops->cls_flower_del)
+		return -EOPNOTSUPP;
+
+	return ds->ops->cls_flower_del(ds, port, cls, ingress);
+}
+
+static int dsa_user_stats_cls_flower(struct net_device *dev,
+				     struct flow_cls_offload *cls,
+				     bool ingress)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index;
+
+	if (!ds->ops->cls_flower_stats)
+		return -EOPNOTSUPP;
+
+	return ds->ops->cls_flower_stats(ds, port, cls, ingress);
+}
+
+static int dsa_user_setup_tc_cls_flower(struct net_device *dev,
+					struct flow_cls_offload *cls,
+					bool ingress)
+{
+	switch (cls->command) {
+	case FLOW_CLS_REPLACE:
+		return dsa_user_add_cls_flower(dev, cls, ingress);
+	case FLOW_CLS_DESTROY:
+		return dsa_user_del_cls_flower(dev, cls, ingress);
+	case FLOW_CLS_STATS:
+		return dsa_user_stats_cls_flower(dev, cls, ingress);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int dsa_user_setup_tc_block_cb(enum tc_setup_type type, void *type_data,
+				      void *cb_priv, bool ingress)
+{
+	struct net_device *dev = cb_priv;
+
+	if (!tc_can_offload(dev))
+		return -EOPNOTSUPP;
+
+	switch (type) {
+	case TC_SETUP_CLSMATCHALL:
+		return dsa_user_setup_tc_cls_matchall(dev, type_data, ingress);
+	case TC_SETUP_CLSFLOWER:
+		return dsa_user_setup_tc_cls_flower(dev, type_data, ingress);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int dsa_user_setup_tc_block_cb_ig(enum tc_setup_type type,
+					 void *type_data, void *cb_priv)
+{
+	return dsa_user_setup_tc_block_cb(type, type_data, cb_priv, true);
+}
+
+static int dsa_user_setup_tc_block_cb_eg(enum tc_setup_type type,
+					 void *type_data, void *cb_priv)
+{
+	return dsa_user_setup_tc_block_cb(type, type_data, cb_priv, false);
+}
+
+static LIST_HEAD(dsa_user_block_cb_list);
+
+static int dsa_user_setup_tc_block(struct net_device *dev,
+				   struct flow_block_offload *f)
+{
+	struct flow_block_cb *block_cb;
+	flow_setup_cb_t *cb;
+
+	if (f->binder_type == FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS)
+		cb = dsa_user_setup_tc_block_cb_ig;
+	else if (f->binder_type == FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS)
+		cb = dsa_user_setup_tc_block_cb_eg;
+	else
+		return -EOPNOTSUPP;
+
+	f->driver_block_list = &dsa_user_block_cb_list;
+
+	switch (f->command) {
+	case FLOW_BLOCK_BIND:
+		if (flow_block_cb_is_busy(cb, dev, &dsa_user_block_cb_list))
+			return -EBUSY;
+
+		block_cb = flow_block_cb_alloc(cb, dev, dev, NULL);
+		if (IS_ERR(block_cb))
+			return PTR_ERR(block_cb);
+
+		flow_block_cb_add(block_cb, f);
+		list_add_tail(&block_cb->driver_list, &dsa_user_block_cb_list);
+		return 0;
+	case FLOW_BLOCK_UNBIND:
+		block_cb = flow_block_cb_lookup(f->block, cb, dev);
+		if (!block_cb)
+			return -ENOENT;
+
+		flow_block_cb_remove(block_cb, f);
+		list_del(&block_cb->driver_list);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int dsa_user_setup_ft_block(struct dsa_switch *ds, int port,
+				   void *type_data)
+{
+	struct net_device *conduit = dsa_port_to_conduit(dsa_to_port(ds, port));
+
+	if (!conduit->netdev_ops->ndo_setup_tc)
+		return -EOPNOTSUPP;
+
+	return conduit->netdev_ops->ndo_setup_tc(conduit, TC_SETUP_FT, type_data);
+}
+
+static int dsa_user_setup_tc(struct net_device *dev, enum tc_setup_type type,
+			     void *type_data)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	switch (type) {
+	case TC_SETUP_BLOCK:
+		return dsa_user_setup_tc_block(dev, type_data);
+	case TC_SETUP_FT:
+		return dsa_user_setup_ft_block(ds, dp->index, type_data);
+	default:
+		break;
+	}
+
+	if (!ds->ops->port_setup_tc)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_setup_tc(ds, dp->index, type, type_data);
+}
+
+static int dsa_user_get_rxnfc(struct net_device *dev,
+			      struct ethtool_rxnfc *nfc, u32 *rule_locs)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->get_rxnfc)
+		return -EOPNOTSUPP;
+
+	return ds->ops->get_rxnfc(ds, dp->index, nfc, rule_locs);
+}
+
+static int dsa_user_set_rxnfc(struct net_device *dev,
+			      struct ethtool_rxnfc *nfc)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->set_rxnfc)
+		return -EOPNOTSUPP;
+
+	return ds->ops->set_rxnfc(ds, dp->index, nfc);
+}
+
+static int dsa_user_get_ts_info(struct net_device *dev,
+				struct kernel_ethtool_ts_info *ts)
+{
+	struct dsa_user_priv *p = netdev_priv(dev);
+	struct dsa_switch *ds = p->dp->ds;
+
+	if (!ds->ops->get_ts_info)
+		return -EOPNOTSUPP;
+
+	return ds->ops->get_ts_info(ds, p->dp->index, ts);
+}
+
+static int dsa_user_vlan_rx_add_vid(struct net_device *dev, __be16 proto,
+				    u16 vid)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct switchdev_obj_port_vlan vlan = {
+		.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
+		.vid = vid,
+		/* This API only allows programming tagged, non-PVID VIDs */
+		.flags = 0,
+	};
+	struct netlink_ext_ack extack = {0};
+	struct dsa_switch *ds = dp->ds;
+	struct netdev_hw_addr *ha;
+	struct dsa_vlan *v;
+	int ret;
+
+	/* User port... */
+	ret = dsa_port_vlan_add(dp, &vlan, &extack);
+	if (ret) {
+		if (extack._msg)
+			netdev_err(dev, "%s\n", extack._msg);
+		return ret;
+	}
+
+	/* And CPU port... */
+	ret = dsa_port_host_vlan_add(dp, &vlan, &extack);
+	if (ret) {
+		if (extack._msg)
+			netdev_err(dev, "CPU port %d: %s\n", dp->cpu_dp->index,
+				   extack._msg);
+		return ret;
+	}
+
+	if (!dsa_switch_supports_uc_filtering(ds) &&
+	    !dsa_switch_supports_mc_filtering(ds))
+		return 0;
+
+	v = kzalloc_obj(*v);
+	if (!v) {
+		ret = -ENOMEM;
+		goto rollback;
+	}
+
+	netif_addr_lock_bh(dev);
+
+	v->vid = vid;
+	list_add_tail(&v->list, &dp->user_vlans);
+
+	if (dsa_switch_supports_mc_filtering(ds)) {
+		netdev_for_each_synced_mc_addr(ha, dev) {
+			dsa_user_schedule_standalone_work(dev, DSA_MC_ADD,
+							  ha->addr, vid);
+		}
+	}
+
+	if (dsa_switch_supports_uc_filtering(ds)) {
+		netdev_for_each_synced_uc_addr(ha, dev) {
+			dsa_user_schedule_standalone_work(dev, DSA_UC_ADD,
+							  ha->addr, vid);
+		}
+	}
+
+	netif_addr_unlock_bh(dev);
+
+	dsa_flush_workqueue();
+
+	return 0;
+
+rollback:
+	dsa_port_host_vlan_del(dp, &vlan);
+	dsa_port_vlan_del(dp, &vlan);
+
+	return ret;
+}
+
+static int dsa_user_vlan_rx_kill_vid(struct net_device *dev, __be16 proto,
+				     u16 vid)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct switchdev_obj_port_vlan vlan = {
+		.vid = vid,
+		/* This API only allows programming tagged, non-PVID VIDs */
+		.flags = 0,
+	};
+	struct dsa_switch *ds = dp->ds;
+	struct netdev_hw_addr *ha;
+	struct dsa_vlan *v;
+	int err;
+
+	err = dsa_port_vlan_del(dp, &vlan);
+	if (err)
+		return err;
+
+	err = dsa_port_host_vlan_del(dp, &vlan);
+	if (err)
+		return err;
+
+	if (!dsa_switch_supports_uc_filtering(ds) &&
+	    !dsa_switch_supports_mc_filtering(ds))
+		return 0;
+
+	netif_addr_lock_bh(dev);
+
+	v = dsa_vlan_find(&dp->user_vlans, &vlan);
+	if (!v) {
+		netif_addr_unlock_bh(dev);
+		return -ENOENT;
+	}
+
+	list_del(&v->list);
+	kfree(v);
+
+	if (dsa_switch_supports_mc_filtering(ds)) {
+		netdev_for_each_synced_mc_addr(ha, dev) {
+			dsa_user_schedule_standalone_work(dev, DSA_MC_DEL,
+							  ha->addr, vid);
+		}
+	}
+
+	if (dsa_switch_supports_uc_filtering(ds)) {
+		netdev_for_each_synced_uc_addr(ha, dev) {
+			dsa_user_schedule_standalone_work(dev, DSA_UC_DEL,
+							  ha->addr, vid);
+		}
+	}
+
+	netif_addr_unlock_bh(dev);
+
+	dsa_flush_workqueue();
+
+	return 0;
+}
+
+static int dsa_user_restore_vlan(struct net_device *vdev, int vid, void *arg)
+{
+	__be16 proto = vdev ? vlan_dev_vlan_proto(vdev) : htons(ETH_P_8021Q);
+
+	return dsa_user_vlan_rx_add_vid(arg, proto, vid);
+}
+
+static int dsa_user_clear_vlan(struct net_device *vdev, int vid, void *arg)
+{
+	__be16 proto = vdev ? vlan_dev_vlan_proto(vdev) : htons(ETH_P_8021Q);
+
+	return dsa_user_vlan_rx_kill_vid(arg, proto, vid);
+}
+
+/* Keep the VLAN RX filtering list in sync with the hardware only if VLAN
+ * filtering is enabled. The baseline is that only ports that offload a
+ * VLAN-aware bridge are VLAN-aware, and standalone ports are VLAN-unaware,
+ * but there are exceptions for quirky hardware.
+ *
+ * If ds->vlan_filtering_is_global = true, then standalone ports which share
+ * the same switch with other ports that offload a VLAN-aware bridge are also
+ * inevitably VLAN-aware.
+ *
+ * To summarize, a DSA switch port offloads:
+ *
+ * - If standalone (this includes software bridge, software LAG):
+ *     - if ds->needs_standalone_vlan_filtering = true, OR if
+ *       (ds->vlan_filtering_is_global = true AND there are bridges spanning
+ *       this switch chip which have vlan_filtering=1)
+ *         - the 8021q upper VLANs
+ *     - else (standalone VLAN filtering is not needed, VLAN filtering is not
+ *       global, or it is, but no port is under a VLAN-aware bridge):
+ *         - no VLAN (any 8021q upper is a software VLAN)
+ *
+ * - If under a vlan_filtering=0 bridge which it offload:
+ *     - if ds->configure_vlan_while_not_filtering = true (default):
+ *         - the bridge VLANs. These VLANs are committed to hardware but inactive.
+ *     - else (deprecated):
+ *         - no VLAN. The bridge VLANs are not restored when VLAN awareness is
+ *           enabled, so this behavior is broken and discouraged.
+ *
+ * - If under a vlan_filtering=1 bridge which it offload:
+ *     - the bridge VLANs
+ *     - the 8021q upper VLANs
+ */
+int dsa_user_manage_vlan_filtering(struct net_device *user,
+				   bool vlan_filtering)
+{
+	int err;
+
+	if (vlan_filtering) {
+		user->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
+
+		err = vlan_for_each(user, dsa_user_restore_vlan, user);
+		if (err) {
+			vlan_for_each(user, dsa_user_clear_vlan, user);
+			user->features &= ~NETIF_F_HW_VLAN_CTAG_FILTER;
+			return err;
+		}
+	} else {
+		err = vlan_for_each(user, dsa_user_clear_vlan, user);
+		if (err)
+			return err;
+
+		user->features &= ~NETIF_F_HW_VLAN_CTAG_FILTER;
+	}
+
+	return 0;
+}
+
+struct dsa_hw_port {
+	struct list_head list;
+	struct net_device *dev;
+	int old_mtu;
+};
+
+static int dsa_hw_port_list_set_mtu(struct list_head *hw_port_list, int mtu)
+{
+	const struct dsa_hw_port *p;
+	int err;
+
+	list_for_each_entry(p, hw_port_list, list) {
+		if (p->dev->mtu == mtu)
+			continue;
+
+		err = dev_set_mtu(p->dev, mtu);
+		if (err)
+			goto rollback;
+	}
+
+	return 0;
+
+rollback:
+	list_for_each_entry_continue_reverse(p, hw_port_list, list) {
+		if (p->dev->mtu == p->old_mtu)
+			continue;
+
+		if (dev_set_mtu(p->dev, p->old_mtu))
+			netdev_err(p->dev, "Failed to restore MTU\n");
+	}
+
+	return err;
+}
+
+static void dsa_hw_port_list_free(struct list_head *hw_port_list)
+{
+	struct dsa_hw_port *p, *n;
+
+	list_for_each_entry_safe(p, n, hw_port_list, list)
+		kfree(p);
+}
+
+/* Make the hardware datapath to/from @dev limited to a common MTU */
+static void dsa_bridge_mtu_normalization(struct dsa_port *dp)
+{
+	struct list_head hw_port_list;
+	struct dsa_switch_tree *dst;
+	int min_mtu = ETH_MAX_MTU;
+	struct dsa_port *other_dp;
+	int err;
+
+	if (!dp->ds->mtu_enforcement_ingress)
+		return;
+
+	if (!dp->bridge)
+		return;
+
+	INIT_LIST_HEAD(&hw_port_list);
+
+	/* Populate the list of ports that are part of the same bridge
+	 * as the newly added/modified port
+	 */
+	list_for_each_entry(dst, &dsa_tree_list, list) {
+		list_for_each_entry(other_dp, &dst->ports, list) {
+			struct dsa_hw_port *hw_port;
+			struct net_device *user;
+
+			if (other_dp->type != DSA_PORT_TYPE_USER)
+				continue;
+
+			if (!dsa_port_bridge_same(dp, other_dp))
+				continue;
+
+			if (!other_dp->ds->mtu_enforcement_ingress)
+				continue;
+
+			user = other_dp->user;
+
+			if (min_mtu > user->mtu)
+				min_mtu = user->mtu;
+
+			hw_port = kzalloc_obj(*hw_port);
+			if (!hw_port)
+				goto out;
+
+			hw_port->dev = user;
+			hw_port->old_mtu = user->mtu;
+
+			list_add(&hw_port->list, &hw_port_list);
+		}
+	}
+
+	/* Attempt to configure the entire hardware bridge to the newly added
+	 * interface's MTU first, regardless of whether the intention of the
+	 * user was to raise or lower it.
+	 */
+	err = dsa_hw_port_list_set_mtu(&hw_port_list, dp->user->mtu);
+	if (!err)
+		goto out;
+
+	/* Clearly that didn't work out so well, so just set the minimum MTU on
+	 * all hardware bridge ports now. If this fails too, then all ports will
+	 * still have their old MTU rolled back anyway.
+	 */
+	dsa_hw_port_list_set_mtu(&hw_port_list, min_mtu);
+
+out:
+	dsa_hw_port_list_free(&hw_port_list);
+}
+
+int dsa_user_change_mtu(struct net_device *dev, int new_mtu)
+{
+	struct net_device *conduit = dsa_user_to_conduit(dev);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_port *cpu_dp = dp->cpu_dp;
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_port *other_dp;
+	int largest_mtu = 0;
+	int new_conduit_mtu;
+	int old_conduit_mtu;
+	int mtu_limit;
+	int overhead;
+	int cpu_mtu;
+	int err;
+
+	if (!ds->ops->port_change_mtu)
+		return -EOPNOTSUPP;
+
+	dsa_tree_for_each_user_port(other_dp, ds->dst) {
+		int user_mtu;
+
+		/* During probe, this function will be called for each user
+		 * device, while not all of them have been allocated. That's
+		 * ok, it doesn't change what the maximum is, so ignore it.
+		 */
+		if (!other_dp->user)
+			continue;
+
+		/* Pretend that we already applied the setting, which we
+		 * actually haven't (still haven't done all integrity checks)
+		 */
+		if (dp == other_dp)
+			user_mtu = new_mtu;
+		else
+			user_mtu = other_dp->user->mtu;
+
+		if (largest_mtu < user_mtu)
+			largest_mtu = user_mtu;
+	}
+
+	overhead = dsa_tag_protocol_overhead(cpu_dp->tag_ops);
+	mtu_limit = min_t(int, conduit->max_mtu, dev->max_mtu + overhead);
+	old_conduit_mtu = conduit->mtu;
+	new_conduit_mtu = largest_mtu + overhead;
+	if (new_conduit_mtu > mtu_limit)
+		return -ERANGE;
+
+	/* If the conduit MTU isn't over limit, there's no need to check the CPU
+	 * MTU, since that surely isn't either.
+	 */
+	cpu_mtu = largest_mtu;
+
+	/* Start applying stuff */
+	if (new_conduit_mtu != old_conduit_mtu) {
+		err = dev_set_mtu(conduit, new_conduit_mtu);
+		if (err < 0)
+			goto out_conduit_failed;
+
+		/* We only need to propagate the MTU of the CPU port to
+		 * upstream switches, so emit a notifier which updates them.
+		 */
+		err = dsa_port_mtu_change(cpu_dp, cpu_mtu);
+		if (err)
+			goto out_cpu_failed;
+	}
+
+	err = ds->ops->port_change_mtu(ds, dp->index, new_mtu);
+	if (err)
+		goto out_port_failed;
+
+	WRITE_ONCE(dev->mtu, new_mtu);
+
+	dsa_bridge_mtu_normalization(dp);
+
+	return 0;
+
+out_port_failed:
+	if (new_conduit_mtu != old_conduit_mtu)
+		dsa_port_mtu_change(cpu_dp, old_conduit_mtu - overhead);
+out_cpu_failed:
+	if (new_conduit_mtu != old_conduit_mtu)
+		dev_set_mtu(conduit, old_conduit_mtu);
+out_conduit_failed:
+	return err;
+}
+
+static int __maybe_unused
+dsa_user_dcbnl_set_apptrust(struct net_device *dev, u8 *sel, int nsel)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index;
+
+	if (!ds->ops->port_set_apptrust)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_set_apptrust(ds, port, sel, nsel);
+}
+
+static int __maybe_unused
+dsa_user_dcbnl_get_apptrust(struct net_device *dev, u8 *sel, int *nsel)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index;
+
+	if (!ds->ops->port_get_apptrust)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_get_apptrust(ds, port, sel, nsel);
+}
+
+static int __maybe_unused
+dsa_user_dcbnl_set_default_prio(struct net_device *dev, struct dcb_app *app)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	unsigned long mask, new_prio;
+	int err, port = dp->index;
+
+	if (!ds->ops->port_set_default_prio)
+		return -EOPNOTSUPP;
+
+	err = dcb_ieee_setapp(dev, app);
+	if (err)
+		return err;
+
+	mask = dcb_ieee_getapp_mask(dev, app);
+	new_prio = __fls(mask);
+
+	err = ds->ops->port_set_default_prio(ds, port, new_prio);
+	if (err) {
+		dcb_ieee_delapp(dev, app);
+		return err;
+	}
+
+	return 0;
+}
+
+/* Update the DSCP prio entries on all user ports of the switch in case
+ * the switch supports global DSCP prio instead of per port DSCP prios.
+ */
+static int dsa_user_dcbnl_ieee_global_dscp_setdel(struct net_device *dev,
+						  struct dcb_app *app, bool del)
+{
+	int (*setdel)(struct net_device *dev, struct dcb_app *app);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_port *other_dp;
+	int err, restore_err;
+
+	if (del)
+		setdel = dcb_ieee_delapp;
+	else
+		setdel = dcb_ieee_setapp;
+
+	dsa_switch_for_each_user_port(other_dp, ds) {
+		struct net_device *user = other_dp->user;
+
+		if (!user || user == dev)
+			continue;
+
+		err = setdel(user, app);
+		if (err)
+			goto err_try_to_restore;
+	}
+
+	return 0;
+
+err_try_to_restore:
+
+	/* Revert logic to restore previous state of app entries */
+	if (!del)
+		setdel = dcb_ieee_delapp;
+	else
+		setdel = dcb_ieee_setapp;
+
+	dsa_switch_for_each_user_port_continue_reverse(other_dp, ds) {
+		struct net_device *user = other_dp->user;
+
+		if (!user || user == dev)
+			continue;
+
+		restore_err = setdel(user, app);
+		if (restore_err)
+			netdev_err(user, "Failed to restore DSCP prio entry configuration\n");
+	}
+
+	return err;
+}
+
+static int __maybe_unused
+dsa_user_dcbnl_add_dscp_prio(struct net_device *dev, struct dcb_app *app)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	unsigned long mask, new_prio;
+	int err, port = dp->index;
+	u8 dscp = app->protocol;
+
+	if (!ds->ops->port_add_dscp_prio)
+		return -EOPNOTSUPP;
+
+	if (dscp >= 64) {
+		netdev_err(dev, "DSCP APP entry with protocol value %u is invalid\n",
+			   dscp);
+		return -EINVAL;
+	}
+
+	err = dcb_ieee_setapp(dev, app);
+	if (err)
+		return err;
+
+	mask = dcb_ieee_getapp_mask(dev, app);
+	new_prio = __fls(mask);
+
+	err = ds->ops->port_add_dscp_prio(ds, port, dscp, new_prio);
+	if (err) {
+		dcb_ieee_delapp(dev, app);
+		return err;
+	}
+
+	if (!ds->dscp_prio_mapping_is_global)
+		return 0;
+
+	err = dsa_user_dcbnl_ieee_global_dscp_setdel(dev, app, false);
+	if (err) {
+		if (ds->ops->port_del_dscp_prio)
+			ds->ops->port_del_dscp_prio(ds, port, dscp, new_prio);
+		dcb_ieee_delapp(dev, app);
+		return err;
+	}
+
+	return 0;
+}
+
+static int __maybe_unused dsa_user_dcbnl_ieee_setapp(struct net_device *dev,
+						     struct dcb_app *app)
+{
+	switch (app->selector) {
+	case IEEE_8021QAZ_APP_SEL_ETHERTYPE:
+		switch (app->protocol) {
+		case 0:
+			return dsa_user_dcbnl_set_default_prio(dev, app);
+		default:
+			return -EOPNOTSUPP;
+		}
+		break;
+	case IEEE_8021QAZ_APP_SEL_DSCP:
+		return dsa_user_dcbnl_add_dscp_prio(dev, app);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int __maybe_unused
+dsa_user_dcbnl_del_default_prio(struct net_device *dev, struct dcb_app *app)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	unsigned long mask, new_prio;
+	int err, port = dp->index;
+
+	if (!ds->ops->port_set_default_prio)
+		return -EOPNOTSUPP;
+
+	err = dcb_ieee_delapp(dev, app);
+	if (err)
+		return err;
+
+	mask = dcb_ieee_getapp_mask(dev, app);
+	new_prio = mask ? __fls(mask) : 0;
+
+	err = ds->ops->port_set_default_prio(ds, port, new_prio);
+	if (err) {
+		dcb_ieee_setapp(dev, app);
+		return err;
+	}
+
+	return 0;
+}
+
+static int __maybe_unused
+dsa_user_dcbnl_del_dscp_prio(struct net_device *dev, struct dcb_app *app)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	int err, port = dp->index;
+	u8 dscp = app->protocol;
+
+	if (!ds->ops->port_del_dscp_prio)
+		return -EOPNOTSUPP;
+
+	err = dcb_ieee_delapp(dev, app);
+	if (err)
+		return err;
+
+	err = ds->ops->port_del_dscp_prio(ds, port, dscp, app->priority);
+	if (err) {
+		dcb_ieee_setapp(dev, app);
+		return err;
+	}
+
+	if (!ds->dscp_prio_mapping_is_global)
+		return 0;
+
+	err = dsa_user_dcbnl_ieee_global_dscp_setdel(dev, app, true);
+	if (err) {
+		if (ds->ops->port_add_dscp_prio)
+			ds->ops->port_add_dscp_prio(ds, port, dscp,
+						    app->priority);
+		dcb_ieee_setapp(dev, app);
+		return err;
+	}
+
+	return 0;
+}
+
+static int __maybe_unused dsa_user_dcbnl_ieee_delapp(struct net_device *dev,
+						     struct dcb_app *app)
+{
+	switch (app->selector) {
+	case IEEE_8021QAZ_APP_SEL_ETHERTYPE:
+		switch (app->protocol) {
+		case 0:
+			return dsa_user_dcbnl_del_default_prio(dev, app);
+		default:
+			return -EOPNOTSUPP;
+		}
+		break;
+	case IEEE_8021QAZ_APP_SEL_DSCP:
+		return dsa_user_dcbnl_del_dscp_prio(dev, app);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+/* Pre-populate the DCB application priority table with the priorities
+ * configured during switch setup, which we read from hardware here.
+ */
+static int dsa_user_dcbnl_init(struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index;
+	int err;
+
+	if (ds->ops->port_get_default_prio) {
+		int prio = ds->ops->port_get_default_prio(ds, port);
+		struct dcb_app app = {
+			.selector = IEEE_8021QAZ_APP_SEL_ETHERTYPE,
+			.protocol = 0,
+			.priority = prio,
+		};
+
+		if (prio < 0)
+			return prio;
+
+		err = dcb_ieee_setapp(dev, &app);
+		if (err)
+			return err;
+	}
+
+	if (ds->ops->port_get_dscp_prio) {
+		int protocol;
+
+		for (protocol = 0; protocol < 64; protocol++) {
+			struct dcb_app app = {
+				.selector = IEEE_8021QAZ_APP_SEL_DSCP,
+				.protocol = protocol,
+			};
+			int prio;
+
+			prio = ds->ops->port_get_dscp_prio(ds, port, protocol);
+			if (prio == -EOPNOTSUPP)
+				continue;
+			if (prio < 0)
+				return prio;
+
+			app.priority = prio;
+
+			err = dcb_ieee_setapp(dev, &app);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+static const struct ethtool_ops dsa_user_ethtool_ops = {
+	.get_drvinfo		= dsa_user_get_drvinfo,
+	.get_regs_len		= dsa_user_get_regs_len,
+	.get_regs		= dsa_user_get_regs,
+	.nway_reset		= dsa_user_nway_reset,
+	.get_link		= ethtool_op_get_link,
+	.get_eeprom_len		= dsa_user_get_eeprom_len,
+	.get_eeprom		= dsa_user_get_eeprom,
+	.set_eeprom		= dsa_user_set_eeprom,
+	.get_strings		= dsa_user_get_strings,
+	.get_ethtool_stats	= dsa_user_get_ethtool_stats,
+	.get_sset_count		= dsa_user_get_sset_count,
+	.get_eth_phy_stats	= dsa_user_get_eth_phy_stats,
+	.get_eth_mac_stats	= dsa_user_get_eth_mac_stats,
+	.get_eth_ctrl_stats	= dsa_user_get_eth_ctrl_stats,
+	.get_rmon_stats		= dsa_user_get_rmon_stats,
+	.get_ts_stats		= dsa_user_get_ts_stats,
+	.set_wol		= dsa_user_set_wol,
+	.get_wol		= dsa_user_get_wol,
+	.set_eee		= dsa_user_set_eee,
+	.get_eee		= dsa_user_get_eee,
+	.get_link_ksettings	= dsa_user_get_link_ksettings,
+	.set_link_ksettings	= dsa_user_set_link_ksettings,
+	.get_pause_stats	= dsa_user_get_pause_stats,
+	.get_pauseparam		= dsa_user_get_pauseparam,
+	.set_pauseparam		= dsa_user_set_pauseparam,
+	.get_rxnfc		= dsa_user_get_rxnfc,
+	.set_rxnfc		= dsa_user_set_rxnfc,
+	.get_ts_info		= dsa_user_get_ts_info,
+	.self_test		= dsa_user_net_selftest,
+	.get_mm			= dsa_user_get_mm,
+	.set_mm			= dsa_user_set_mm,
+	.get_mm_stats		= dsa_user_get_mm_stats,
+};
+
+static const struct dcbnl_rtnl_ops __maybe_unused dsa_user_dcbnl_ops = {
+	.ieee_setapp		= dsa_user_dcbnl_ieee_setapp,
+	.ieee_delapp		= dsa_user_dcbnl_ieee_delapp,
+	.dcbnl_setapptrust	= dsa_user_dcbnl_set_apptrust,
+	.dcbnl_getapptrust	= dsa_user_dcbnl_get_apptrust,
+};
+
+static void dsa_user_get_stats64(struct net_device *dev,
+				 struct rtnl_link_stats64 *s)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->get_stats64)
+		ds->ops->get_stats64(ds, dp->index, s);
+	else
+		dev_get_tstats64(dev, s);
+}
+
+static int dsa_user_fill_forward_path(struct net_device_path_ctx *ctx,
+				      struct net_device_path *path)
+{
+	struct dsa_port *dp = dsa_user_to_port(ctx->dev);
+	struct dsa_port *cpu_dp = dp->cpu_dp;
+
+	path->dev = ctx->dev;
+	path->type = DEV_PATH_DSA;
+	path->dsa.proto = cpu_dp->tag_ops->proto;
+	path->dsa.port = dp->index;
+	ctx->dev = NULL;
+
+	return 0;
+}
+
+static int dsa_user_hwtstamp_get(struct net_device *dev,
+				 struct kernel_hwtstamp_config *cfg)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->port_hwtstamp_get)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_hwtstamp_get(ds, dp->index, cfg);
+}
+
+static int dsa_user_hwtstamp_set(struct net_device *dev,
+				 struct kernel_hwtstamp_config *cfg,
+				 struct netlink_ext_ack *extack)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ds->ops->port_hwtstamp_set)
+		return -EOPNOTSUPP;
+
+	return ds->ops->port_hwtstamp_set(ds, dp->index, cfg, extack);
+}
+
+static const struct net_device_ops dsa_user_netdev_ops = {
+	.ndo_open		= dsa_user_open,
+	.ndo_stop		= dsa_user_close,
+	.ndo_start_xmit		= dsa_user_xmit,
+	.ndo_change_rx_flags	= dsa_user_change_rx_flags,
+	.ndo_set_rx_mode	= dsa_user_set_rx_mode,
+	.ndo_set_mac_address	= dsa_user_set_mac_address,
+	.ndo_fdb_dump		= dsa_user_fdb_dump,
+	.ndo_eth_ioctl		= dsa_user_ioctl,
+	.ndo_get_iflink		= dsa_user_get_iflink,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	.ndo_netpoll_setup	= dsa_user_netpoll_setup,
+	.ndo_netpoll_cleanup	= dsa_user_netpoll_cleanup,
+	.ndo_poll_controller	= dsa_user_poll_controller,
+#endif
+	.ndo_setup_tc		= dsa_user_setup_tc,
+	.ndo_get_stats64	= dsa_user_get_stats64,
+	.ndo_vlan_rx_add_vid	= dsa_user_vlan_rx_add_vid,
+	.ndo_vlan_rx_kill_vid	= dsa_user_vlan_rx_kill_vid,
+	.ndo_change_mtu		= dsa_user_change_mtu,
+	.ndo_fill_forward_path	= dsa_user_fill_forward_path,
+	.ndo_hwtstamp_get	= dsa_user_hwtstamp_get,
+	.ndo_hwtstamp_set	= dsa_user_hwtstamp_set,
+};
+
+static const struct device_type dsa_type = {
+	.name	= "dsa",
+};
+
+void dsa_port_phylink_mac_change(struct dsa_switch *ds, int port, bool up)
+{
+	const struct dsa_port *dp = dsa_to_port(ds, port);
+
+	if (dp->pl)
+		phylink_mac_change(dp->pl, up);
+}
+EXPORT_SYMBOL_GPL(dsa_port_phylink_mac_change);
+
+static void dsa_user_phylink_fixed_state(struct phylink_config *config,
+					 struct phylink_link_state *state)
+{
+	struct dsa_port *dp = dsa_phylink_to_port(config);
+	struct dsa_switch *ds = dp->ds;
+
+	/* No need to check that this operation is valid, the callback would
+	 * not be called if it was not.
+	 */
+	ds->ops->phylink_fixed_state(ds, dp->index, state);
+}
+
+/* user device setup *******************************************************/
+static int dsa_user_phy_connect(struct net_device *user_dev, int addr,
+				u32 flags)
+{
+	struct dsa_port *dp = dsa_user_to_port(user_dev);
+	struct dsa_switch *ds = dp->ds;
+
+	user_dev->phydev = mdiobus_get_phy(ds->user_mii_bus, addr);
+	if (!user_dev->phydev) {
+		netdev_err(user_dev, "no phy at %d\n", addr);
+		return -ENODEV;
+	}
+
+	user_dev->phydev->dev_flags |= flags;
+
+	return phylink_connect_phy(dp->pl, user_dev->phydev);
+}
+
+static int dsa_user_phy_setup(struct net_device *user_dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(user_dev);
+	struct device_node *port_dn = dp->dn;
+	struct dsa_switch *ds = dp->ds;
+	u32 phy_flags = 0;
+	int ret;
+
+	dp->pl_config.dev = &user_dev->dev;
+	dp->pl_config.type = PHYLINK_NETDEV;
+
+	/* The get_fixed_state callback takes precedence over polling the
+	 * link GPIO in PHYLINK (see phylink_get_fixed_state).  Only set
+	 * this if the switch provides such a callback.
+	 */
+	if (ds->ops->phylink_fixed_state) {
+		dp->pl_config.get_fixed_state = dsa_user_phylink_fixed_state;
+		dp->pl_config.poll_fixed_state = true;
+	}
+
+	ret = dsa_port_phylink_create(dp);
+	if (ret)
+		return ret;
+
+	if (ds->ops->get_phy_flags)
+		phy_flags = ds->ops->get_phy_flags(ds, dp->index);
+
+	ret = phylink_of_phy_connect(dp->pl, port_dn, phy_flags);
+	if (ret == -ENODEV && ds->user_mii_bus) {
+		/* We could not connect to a designated PHY or SFP, so try to
+		 * use the switch internal MDIO bus instead
+		 */
+		ret = dsa_user_phy_connect(user_dev, dp->index, phy_flags);
+	}
+	if (ret) {
+		netdev_err(user_dev, "failed to connect to PHY: %pe\n",
+			   ERR_PTR(ret));
+		dsa_port_phylink_destroy(dp);
+	}
+
+	return ret;
+}
+
+void dsa_user_setup_tagger(struct net_device *user)
+{
+	struct dsa_port *dp = dsa_user_to_port(user);
+	struct net_device *conduit = dsa_port_to_conduit(dp);
+	struct dsa_user_priv *p = netdev_priv(user);
+	const struct dsa_port *cpu_dp = dp->cpu_dp;
+	const struct dsa_switch *ds = dp->ds;
+
+	user->needed_headroom = cpu_dp->tag_ops->needed_headroom;
+	user->needed_tailroom = cpu_dp->tag_ops->needed_tailroom;
+	/* Try to save one extra realloc later in the TX path (in the conduit)
+	 * by also inheriting the conduit's needed headroom and tailroom.
+	 * The 8021q driver also does this.
+	 */
+	user->needed_headroom += conduit->needed_headroom;
+	user->needed_tailroom += conduit->needed_tailroom;
+
+	p->xmit = cpu_dp->tag_ops->xmit;
+
+	user->features = conduit->vlan_features | NETIF_F_HW_TC;
+	user->hw_features |= NETIF_F_HW_TC;
+	if (user->needed_tailroom)
+		user->features &= ~(NETIF_F_SG | NETIF_F_FRAGLIST);
+	if (ds->needs_standalone_vlan_filtering)
+		user->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
+
+	user->lltx = true;
+}
+
+int dsa_user_suspend(struct net_device *user_dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(user_dev);
+
+	if (!netif_running(user_dev))
+		return 0;
+
+	netif_device_detach(user_dev);
+
+	rtnl_lock();
+	phylink_stop(dp->pl);
+	rtnl_unlock();
+
+	return 0;
+}
+
+int dsa_user_resume(struct net_device *user_dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(user_dev);
+
+	if (!netif_running(user_dev))
+		return 0;
+
+	netif_device_attach(user_dev);
+
+	rtnl_lock();
+	phylink_start(dp->pl);
+	rtnl_unlock();
+
+	return 0;
+}
+
+int dsa_user_create(struct dsa_port *port)
+{
+	struct net_device *conduit = dsa_port_to_conduit(port);
+	struct dsa_switch *ds = port->ds;
+	struct net_device *user_dev;
+	struct dsa_user_priv *p;
+	const char *name;
+	int assign_type;
+	int ret;
+
+	if (!ds->num_tx_queues)
+		ds->num_tx_queues = 1;
+
+	if (port->name) {
+		name = port->name;
+		assign_type = NET_NAME_PREDICTABLE;
+	} else {
+		name = "eth%d";
+		assign_type = NET_NAME_ENUM;
+	}
+
+	user_dev = alloc_netdev_mqs(sizeof(struct dsa_user_priv), name,
+				    assign_type, ether_setup,
+				    ds->num_tx_queues, 1);
+	if (!user_dev)
+		return -ENOMEM;
+
+	user_dev->rtnl_link_ops = &dsa_link_ops;
+	user_dev->ethtool_ops = &dsa_user_ethtool_ops;
+#if IS_ENABLED(CONFIG_DCB)
+	user_dev->dcbnl_ops = &dsa_user_dcbnl_ops;
+#endif
+	if (!is_zero_ether_addr(port->mac))
+		eth_hw_addr_set(user_dev, port->mac);
+	else
+		eth_hw_addr_inherit(user_dev, conduit);
+	user_dev->priv_flags |= IFF_NO_QUEUE;
+	if (dsa_switch_supports_uc_filtering(ds))
+		user_dev->priv_flags |= IFF_UNICAST_FLT;
+	user_dev->netdev_ops = &dsa_user_netdev_ops;
+	if (ds->ops->port_max_mtu)
+		user_dev->max_mtu = ds->ops->port_max_mtu(ds, port->index);
+	SET_NETDEV_DEVTYPE(user_dev, &dsa_type);
+
+	SET_NETDEV_DEV(user_dev, port->ds->dev);
+	SET_NETDEV_DEVLINK_PORT(user_dev, &port->devlink_port);
+	user_dev->dev.of_node = port->dn;
+	user_dev->vlan_features = conduit->vlan_features;
+
+	p = netdev_priv(user_dev);
+	user_dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
+
+	ret = gro_cells_init(&p->gcells, user_dev);
+	if (ret)
+		goto out_free;
+
+	p->dp = port;
+	INIT_LIST_HEAD(&p->mall_tc_list);
+	port->user = user_dev;
+	dsa_user_setup_tagger(user_dev);
+
+	netif_carrier_off(user_dev);
+
+	ret = dsa_user_phy_setup(user_dev);
+	if (ret) {
+		netdev_err(user_dev,
+			   "error %d setting up PHY for tree %d, switch %d, port %d\n",
+			   ret, ds->dst->index, ds->index, port->index);
+		goto out_gcells;
+	}
+
+	rtnl_lock();
+
+	ret = dsa_user_change_mtu(user_dev, ETH_DATA_LEN);
+	if (ret && ret != -EOPNOTSUPP)
+		dev_warn(ds->dev, "nonfatal error %d setting MTU to %d on port %d\n",
+			 ret, ETH_DATA_LEN, port->index);
+
+	ret = register_netdevice(user_dev);
+	if (ret) {
+		netdev_err(conduit, "error %d registering interface %s\n",
+			   ret, user_dev->name);
+		rtnl_unlock();
+		goto out_phy;
+	}
+
+	if (IS_ENABLED(CONFIG_DCB)) {
+		ret = dsa_user_dcbnl_init(user_dev);
+		if (ret) {
+			netdev_err(user_dev,
+				   "failed to initialize DCB: %pe\n",
+				   ERR_PTR(ret));
+			rtnl_unlock();
+			goto out_unregister;
+		}
+	}
+
+	ret = netdev_upper_dev_link(conduit, user_dev, NULL);
+
+	rtnl_unlock();
+
+	if (ret)
+		goto out_unregister;
+
+	return 0;
+
+out_unregister:
+	unregister_netdev(user_dev);
+out_phy:
+	rtnl_lock();
+	phylink_disconnect_phy(p->dp->pl);
+	rtnl_unlock();
+	dsa_port_phylink_destroy(p->dp);
+out_gcells:
+	gro_cells_destroy(&p->gcells);
+out_free:
+	free_netdev(user_dev);
+	port->user = NULL;
+	return ret;
+}
+
+void dsa_user_destroy(struct net_device *user_dev)
+{
+	struct net_device *conduit = dsa_user_to_conduit(user_dev);
+	struct dsa_port *dp = dsa_user_to_port(user_dev);
+	struct dsa_user_priv *p = netdev_priv(user_dev);
+
+	netif_carrier_off(user_dev);
+	rtnl_lock();
+	netdev_upper_dev_unlink(conduit, user_dev);
+	unregister_netdevice(user_dev);
+	phylink_disconnect_phy(dp->pl);
+	rtnl_unlock();
+
+	dsa_port_phylink_destroy(dp);
+	gro_cells_destroy(&p->gcells);
+	free_netdev(user_dev);
+}
+
+int dsa_user_change_conduit(struct net_device *dev, struct net_device *conduit,
+			    struct netlink_ext_ack *extack)
+{
+	struct net_device *old_conduit = dsa_user_to_conduit(dev);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+	struct net_device *upper;
+	struct list_head *iter;
+	int err;
+
+	if (conduit == old_conduit)
+		return 0;
+
+	if (!ds->ops->port_change_conduit) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Driver does not support changing DSA conduit");
+		return -EOPNOTSUPP;
+	}
+
+	if (!netdev_uses_dsa(conduit)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Interface not eligible as DSA conduit");
+		return -EOPNOTSUPP;
+	}
+
+	netdev_for_each_upper_dev_rcu(conduit, upper, iter) {
+		if (dsa_user_dev_check(upper))
+			continue;
+		if (netif_is_bridge_master(upper))
+			continue;
+		NL_SET_ERR_MSG_MOD(extack, "Cannot join conduit with unknown uppers");
+		return -EOPNOTSUPP;
+	}
+
+	/* Since we allow live-changing the DSA conduit, plus we auto-open the
+	 * DSA conduit when the user port opens => we need to ensure that the
+	 * new DSA conduit is open too.
+	 */
+	if (dev->flags & IFF_UP) {
+		err = dev_open(conduit, extack);
+		if (err)
+			return err;
+	}
+
+	netdev_upper_dev_unlink(old_conduit, dev);
+
+	err = netdev_upper_dev_link(conduit, dev, extack);
+	if (err)
+		goto out_revert_old_conduit_unlink;
+
+	err = dsa_port_change_conduit(dp, conduit, extack);
+	if (err)
+		goto out_revert_conduit_link;
+
+	/* Update the MTU of the new CPU port through cross-chip notifiers */
+	err = dsa_user_change_mtu(dev, dev->mtu);
+	if (err && err != -EOPNOTSUPP) {
+		netdev_warn(dev,
+			    "nonfatal error updating MTU with new conduit: %pe\n",
+			    ERR_PTR(err));
+	}
+
+	return 0;
+
+out_revert_conduit_link:
+	netdev_upper_dev_unlink(conduit, dev);
+out_revert_old_conduit_unlink:
+	netdev_upper_dev_link(old_conduit, dev, NULL);
+	return err;
+}
+
+bool dsa_user_dev_check(const struct net_device *dev)
+{
+	return dev->netdev_ops == &dsa_user_netdev_ops;
+}
+EXPORT_SYMBOL_GPL(dsa_user_dev_check);
+
+static int dsa_user_changeupper(struct net_device *dev,
+				struct netdev_notifier_changeupper_info *info)
+{
+	struct netlink_ext_ack *extack;
+	int err = NOTIFY_DONE;
+	struct dsa_port *dp;
+
+	if (!dsa_user_dev_check(dev))
+		return err;
+
+	dp = dsa_user_to_port(dev);
+	extack = netdev_notifier_info_to_extack(&info->info);
+
+	if (netif_is_bridge_master(info->upper_dev)) {
+		if (info->linking) {
+			err = dsa_port_bridge_join(dp, info->upper_dev, extack);
+			if (!err)
+				dsa_bridge_mtu_normalization(dp);
+			if (err == -EOPNOTSUPP) {
+				NL_SET_ERR_MSG_WEAK_MOD(extack,
+							"Offloading not supported");
+				err = 0;
+			}
+			err = notifier_from_errno(err);
+		} else {
+			dsa_port_bridge_leave(dp, info->upper_dev);
+			err = NOTIFY_OK;
+		}
+	} else if (netif_is_lag_master(info->upper_dev)) {
+		if (info->linking) {
+			err = dsa_port_lag_join(dp, info->upper_dev,
+						info->upper_info, extack);
+			if (err == -EOPNOTSUPP) {
+				NL_SET_ERR_MSG_WEAK_MOD(extack,
+							"Offloading not supported");
+				err = 0;
+			}
+			err = notifier_from_errno(err);
+		} else {
+			dsa_port_lag_leave(dp, info->upper_dev);
+			err = NOTIFY_OK;
+		}
+	} else if (is_hsr_master(info->upper_dev)) {
+		if (info->linking) {
+			err = dsa_port_hsr_join(dp, info->upper_dev, extack);
+			if (err == -EOPNOTSUPP) {
+				NL_SET_ERR_MSG_WEAK_MOD(extack,
+							"Offloading not supported");
+				err = 0;
+			}
+			err = notifier_from_errno(err);
+		} else {
+			dsa_port_hsr_leave(dp, info->upper_dev);
+			err = NOTIFY_OK;
+		}
+	}
+
+	return err;
+}
+
+static int dsa_user_prechangeupper(struct net_device *dev,
+				   struct netdev_notifier_changeupper_info *info)
+{
+	struct dsa_port *dp;
+
+	if (!dsa_user_dev_check(dev))
+		return NOTIFY_DONE;
+
+	dp = dsa_user_to_port(dev);
+
+	if (netif_is_bridge_master(info->upper_dev) && !info->linking)
+		dsa_port_pre_bridge_leave(dp, info->upper_dev);
+	else if (netif_is_lag_master(info->upper_dev) && !info->linking)
+		dsa_port_pre_lag_leave(dp, info->upper_dev);
+	/* dsa_port_pre_hsr_leave is not yet necessary since hsr devices cannot
+	 * meaningfully placed under a bridge yet
+	 */
+
+	return NOTIFY_DONE;
+}
+
+static int
+dsa_user_lag_changeupper(struct net_device *dev,
+			 struct netdev_notifier_changeupper_info *info)
+{
+	struct net_device *lower;
+	struct list_head *iter;
+	int err = NOTIFY_DONE;
+	struct dsa_port *dp;
+
+	if (!netif_is_lag_master(dev))
+		return err;
+
+	netdev_for_each_lower_dev(dev, lower, iter) {
+		if (!dsa_user_dev_check(lower))
+			continue;
+
+		dp = dsa_user_to_port(lower);
+		if (!dp->lag)
+			/* Software LAG */
+			continue;
+
+		err = dsa_user_changeupper(lower, info);
+		if (notifier_to_errno(err))
+			break;
+	}
+
+	return err;
+}
+
+/* Same as dsa_user_lag_changeupper() except that it calls
+ * dsa_user_prechangeupper()
+ */
+static int
+dsa_user_lag_prechangeupper(struct net_device *dev,
+			    struct netdev_notifier_changeupper_info *info)
+{
+	struct net_device *lower;
+	struct list_head *iter;
+	int err = NOTIFY_DONE;
+	struct dsa_port *dp;
+
+	if (!netif_is_lag_master(dev))
+		return err;
+
+	netdev_for_each_lower_dev(dev, lower, iter) {
+		if (!dsa_user_dev_check(lower))
+			continue;
+
+		dp = dsa_user_to_port(lower);
+		if (!dp->lag)
+			/* Software LAG */
+			continue;
+
+		err = dsa_user_prechangeupper(lower, info);
+		if (notifier_to_errno(err))
+			break;
+	}
+
+	return err;
+}
+
+static int
+dsa_prevent_bridging_8021q_upper(struct net_device *dev,
+				 struct netdev_notifier_changeupper_info *info)
+{
+	struct netlink_ext_ack *ext_ack;
+	struct net_device *user, *br;
+	struct dsa_port *dp;
+
+	ext_ack = netdev_notifier_info_to_extack(&info->info);
+
+	if (!is_vlan_dev(dev))
+		return NOTIFY_DONE;
+
+	user = vlan_dev_real_dev(dev);
+	if (!dsa_user_dev_check(user))
+		return NOTIFY_DONE;
+
+	dp = dsa_user_to_port(user);
+	br = dsa_port_bridge_dev_get(dp);
+	if (!br)
+		return NOTIFY_DONE;
+
+	/* Deny enslaving a VLAN device into a VLAN-aware bridge */
+	if (br_vlan_enabled(br) &&
+	    netif_is_bridge_master(info->upper_dev) && info->linking) {
+		NL_SET_ERR_MSG_MOD(ext_ack,
+				   "Cannot make VLAN device join VLAN-aware bridge");
+		return notifier_from_errno(-EINVAL);
+	}
+
+	return NOTIFY_DONE;
+}
+
+static int
+dsa_user_check_8021q_upper(struct net_device *dev,
+			   struct netdev_notifier_changeupper_info *info)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct net_device *br = dsa_port_bridge_dev_get(dp);
+	struct bridge_vlan_info br_info;
+	struct netlink_ext_ack *extack;
+	int err = NOTIFY_DONE;
+	u16 vid;
+
+	if (!br || !br_vlan_enabled(br))
+		return NOTIFY_DONE;
+
+	extack = netdev_notifier_info_to_extack(&info->info);
+	vid = vlan_dev_vlan_id(info->upper_dev);
+
+	/* br_vlan_get_info() returns -EINVAL or -ENOENT if the
+	 * device, respectively the VID is not found, returning
+	 * 0 means success, which is a failure for us here.
+	 */
+	err = br_vlan_get_info(br, vid, &br_info);
+	if (err == 0) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "This VLAN is already configured by the bridge");
+		return notifier_from_errno(-EBUSY);
+	}
+
+	return NOTIFY_DONE;
+}
+
+static int
+dsa_user_prechangeupper_sanity_check(struct net_device *dev,
+				     struct netdev_notifier_changeupper_info *info)
+{
+	struct dsa_switch *ds;
+	struct dsa_port *dp;
+	int err;
+
+	if (!dsa_user_dev_check(dev))
+		return dsa_prevent_bridging_8021q_upper(dev, info);
+
+	dp = dsa_user_to_port(dev);
+	ds = dp->ds;
+
+	if (ds->ops->port_prechangeupper) {
+		err = ds->ops->port_prechangeupper(ds, dp->index, info);
+		if (err)
+			return notifier_from_errno(err);
+	}
+
+	if (is_vlan_dev(info->upper_dev))
+		return dsa_user_check_8021q_upper(dev, info);
+
+	return NOTIFY_DONE;
+}
+
+/* To be eligible as a DSA conduit, a LAG must have all lower interfaces be
+ * eligible DSA conduits. Additionally, all LAG slaves must be DSA conduits of
+ * switches in the same switch tree.
+ */
+static int dsa_lag_conduit_validate(struct net_device *lag_dev,
+				    struct netlink_ext_ack *extack)
+{
+	struct net_device *lower1, *lower2;
+	struct list_head *iter1, *iter2;
+
+	netdev_for_each_lower_dev(lag_dev, lower1, iter1) {
+		netdev_for_each_lower_dev(lag_dev, lower2, iter2) {
+			if (!netdev_uses_dsa(lower1) ||
+			    !netdev_uses_dsa(lower2)) {
+				NL_SET_ERR_MSG_MOD(extack,
+						   "All LAG ports must be eligible as DSA conduits");
+				return notifier_from_errno(-EINVAL);
+			}
+
+			if (lower1 == lower2)
+				continue;
+
+			if (!dsa_port_tree_same(lower1->dsa_ptr,
+						lower2->dsa_ptr)) {
+				NL_SET_ERR_MSG_MOD(extack,
+						   "LAG contains DSA conduits of disjoint switch trees");
+				return notifier_from_errno(-EINVAL);
+			}
+		}
+	}
+
+	return NOTIFY_DONE;
+}
+
+static int
+dsa_conduit_prechangeupper_sanity_check(struct net_device *conduit,
+					struct netdev_notifier_changeupper_info *info)
+{
+	struct netlink_ext_ack *extack = netdev_notifier_info_to_extack(&info->info);
+
+	if (!netdev_uses_dsa(conduit))
+		return NOTIFY_DONE;
+
+	if (!info->linking)
+		return NOTIFY_DONE;
+
+	/* Allow DSA switch uppers */
+	if (dsa_user_dev_check(info->upper_dev))
+		return NOTIFY_DONE;
+
+	/* Allow bridge uppers of DSA conduits, subject to further
+	 * restrictions in dsa_bridge_prechangelower_sanity_check()
+	 */
+	if (netif_is_bridge_master(info->upper_dev))
+		return NOTIFY_DONE;
+
+	/* Allow LAG uppers, subject to further restrictions in
+	 * dsa_lag_conduit_prechangelower_sanity_check()
+	 */
+	if (netif_is_lag_master(info->upper_dev))
+		return dsa_lag_conduit_validate(info->upper_dev, extack);
+
+	NL_SET_ERR_MSG_MOD(extack,
+			   "DSA conduit cannot join unknown upper interfaces");
+	return notifier_from_errno(-EBUSY);
+}
+
+static int
+dsa_lag_conduit_prechangelower_sanity_check(struct net_device *dev,
+					    struct netdev_notifier_changeupper_info *info)
+{
+	struct netlink_ext_ack *extack = netdev_notifier_info_to_extack(&info->info);
+	struct net_device *lag_dev = info->upper_dev;
+	struct net_device *lower;
+	struct list_head *iter;
+
+	if (!netdev_uses_dsa(lag_dev) || !netif_is_lag_master(lag_dev))
+		return NOTIFY_DONE;
+
+	if (!info->linking)
+		return NOTIFY_DONE;
+
+	if (!netdev_uses_dsa(dev)) {
+		NL_SET_ERR_MSG(extack,
+			       "Only DSA conduits can join a LAG DSA conduit");
+		return notifier_from_errno(-EINVAL);
+	}
+
+	netdev_for_each_lower_dev(lag_dev, lower, iter) {
+		if (!dsa_port_tree_same(dev->dsa_ptr, lower->dsa_ptr)) {
+			NL_SET_ERR_MSG(extack,
+				       "Interface is DSA conduit for a different switch tree than this LAG");
+			return notifier_from_errno(-EINVAL);
+		}
+
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+/* Don't allow bridging of DSA conduits, since the bridge layer rx_handler
+ * prevents the DSA fake ethertype handler to be invoked, so we don't get the
+ * chance to strip off and parse the DSA switch tag protocol header (the bridge
+ * layer just returns RX_HANDLER_CONSUMED, stopping RX processing for these
+ * frames).
+ * The only case where that would not be an issue is when bridging can already
+ * be offloaded, such as when the DSA conduit is itself a DSA or plain switchdev
+ * port, and is bridged only with other ports from the same hardware device.
+ */
+static int
+dsa_bridge_prechangelower_sanity_check(struct net_device *new_lower,
+				       struct netdev_notifier_changeupper_info *info)
+{
+	struct net_device *br = info->upper_dev;
+	struct netlink_ext_ack *extack;
+	struct net_device *lower;
+	struct list_head *iter;
+
+	if (!netif_is_bridge_master(br))
+		return NOTIFY_DONE;
+
+	if (!info->linking)
+		return NOTIFY_DONE;
+
+	extack = netdev_notifier_info_to_extack(&info->info);
+
+	netdev_for_each_lower_dev(br, lower, iter) {
+		if (!netdev_uses_dsa(new_lower) && !netdev_uses_dsa(lower))
+			continue;
+
+		if (!netdev_port_same_parent_id(lower, new_lower)) {
+			NL_SET_ERR_MSG(extack,
+				       "Cannot do software bridging with a DSA conduit");
+			return notifier_from_errno(-EINVAL);
+		}
+	}
+
+	return NOTIFY_DONE;
+}
+
+static void dsa_tree_migrate_ports_from_lag_conduit(struct dsa_switch_tree *dst,
+						    struct net_device *lag_dev)
+{
+	struct net_device *new_conduit = dsa_tree_find_first_conduit(dst);
+	struct dsa_port *dp;
+	int err;
+
+	dsa_tree_for_each_user_port(dp, dst) {
+		if (dsa_port_to_conduit(dp) != lag_dev)
+			continue;
+
+		err = dsa_user_change_conduit(dp->user, new_conduit, NULL);
+		if (err) {
+			netdev_err(dp->user,
+				   "failed to restore conduit to %s: %pe\n",
+				   new_conduit->name, ERR_PTR(err));
+		}
+	}
+}
+
+static int dsa_conduit_lag_join(struct net_device *conduit,
+				struct net_device *lag_dev,
+				struct netdev_lag_upper_info *uinfo,
+				struct netlink_ext_ack *extack)
+{
+	struct dsa_port *cpu_dp = conduit->dsa_ptr;
+	struct dsa_switch_tree *dst = cpu_dp->dst;
+	struct dsa_port *dp;
+	int err;
+
+	err = dsa_conduit_lag_setup(lag_dev, cpu_dp, uinfo, extack);
+	if (err)
+		return err;
+
+	dsa_tree_for_each_user_port(dp, dst) {
+		if (dsa_port_to_conduit(dp) != conduit)
+			continue;
+
+		err = dsa_user_change_conduit(dp->user, lag_dev, extack);
+		if (err)
+			goto restore;
+	}
+
+	return 0;
+
+restore:
+	dsa_tree_for_each_user_port_continue_reverse(dp, dst) {
+		if (dsa_port_to_conduit(dp) != lag_dev)
+			continue;
+
+		err = dsa_user_change_conduit(dp->user, conduit, NULL);
+		if (err) {
+			netdev_err(dp->user,
+				   "failed to restore conduit to %s: %pe\n",
+				   conduit->name, ERR_PTR(err));
+		}
+	}
+
+	dsa_conduit_lag_teardown(lag_dev, conduit->dsa_ptr);
+
+	return err;
+}
+
+static void dsa_conduit_lag_leave(struct net_device *conduit,
+				  struct net_device *lag_dev)
+{
+	struct dsa_port *dp, *cpu_dp = lag_dev->dsa_ptr;
+	struct dsa_switch_tree *dst = cpu_dp->dst;
+	struct dsa_port *new_cpu_dp = NULL;
+	struct net_device *lower;
+	struct list_head *iter;
+
+	netdev_for_each_lower_dev(lag_dev, lower, iter) {
+		if (netdev_uses_dsa(lower)) {
+			new_cpu_dp = lower->dsa_ptr;
+			break;
+		}
+	}
+
+	if (new_cpu_dp) {
+		/* Update the CPU port of the user ports still under the LAG
+		 * so that dsa_port_to_conduit() continues to work properly
+		 */
+		dsa_tree_for_each_user_port(dp, dst)
+			if (dsa_port_to_conduit(dp) == lag_dev)
+				dp->cpu_dp = new_cpu_dp;
+
+		/* Update the index of the virtual CPU port to match the lowest
+		 * physical CPU port
+		 */
+		lag_dev->dsa_ptr = new_cpu_dp;
+		wmb();
+	} else {
+		/* If the LAG DSA conduit has no ports left, migrate back all
+		 * user ports to the first physical CPU port
+		 */
+		dsa_tree_migrate_ports_from_lag_conduit(dst, lag_dev);
+	}
+
+	/* This DSA conduit has left its LAG in any case, so let
+	 * the CPU port leave the hardware LAG as well
+	 */
+	dsa_conduit_lag_teardown(lag_dev, conduit->dsa_ptr);
+}
+
+static int dsa_conduit_changeupper(struct net_device *dev,
+				   struct netdev_notifier_changeupper_info *info)
+{
+	struct netlink_ext_ack *extack;
+	int err = NOTIFY_DONE;
+
+	if (!netdev_uses_dsa(dev))
+		return err;
+
+	extack = netdev_notifier_info_to_extack(&info->info);
+
+	if (netif_is_lag_master(info->upper_dev)) {
+		if (info->linking) {
+			err = dsa_conduit_lag_join(dev, info->upper_dev,
+						   info->upper_info, extack);
+			err = notifier_from_errno(err);
+		} else {
+			dsa_conduit_lag_leave(dev, info->upper_dev);
+			err = NOTIFY_OK;
+		}
+	}
+
+	return err;
+}
+
+static int dsa_user_netdevice_event(struct notifier_block *nb,
+				    unsigned long event, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+	switch (event) {
+	case NETDEV_PRECHANGEUPPER: {
+		struct netdev_notifier_changeupper_info *info = ptr;
+		int err;
+
+		err = dsa_user_prechangeupper_sanity_check(dev, info);
+		if (notifier_to_errno(err))
+			return err;
+
+		err = dsa_conduit_prechangeupper_sanity_check(dev, info);
+		if (notifier_to_errno(err))
+			return err;
+
+		err = dsa_lag_conduit_prechangelower_sanity_check(dev, info);
+		if (notifier_to_errno(err))
+			return err;
+
+		err = dsa_bridge_prechangelower_sanity_check(dev, info);
+		if (notifier_to_errno(err))
+			return err;
+
+		err = dsa_user_prechangeupper(dev, ptr);
+		if (notifier_to_errno(err))
+			return err;
+
+		err = dsa_user_lag_prechangeupper(dev, ptr);
+		if (notifier_to_errno(err))
+			return err;
+
+		break;
+	}
+	case NETDEV_CHANGEUPPER: {
+		int err;
+
+		err = dsa_user_changeupper(dev, ptr);
+		if (notifier_to_errno(err))
+			return err;
+
+		err = dsa_user_lag_changeupper(dev, ptr);
+		if (notifier_to_errno(err))
+			return err;
+
+		err = dsa_conduit_changeupper(dev, ptr);
+		if (notifier_to_errno(err))
+			return err;
+
+		break;
+	}
+	case NETDEV_CHANGELOWERSTATE: {
+		struct netdev_notifier_changelowerstate_info *info = ptr;
+		struct dsa_port *dp;
+		int err = 0;
+
+		if (dsa_user_dev_check(dev)) {
+			dp = dsa_user_to_port(dev);
+
+			err = dsa_port_lag_change(dp, info->lower_state_info);
+		}
+
+		/* Mirror LAG port events on DSA conduits that are in
+		 * a LAG towards their respective switch CPU ports
+		 */
+		if (netdev_uses_dsa(dev)) {
+			dp = dev->dsa_ptr;
+
+			err = dsa_port_lag_change(dp, info->lower_state_info);
+		}
+
+		return notifier_from_errno(err);
+	}
+	case NETDEV_CHANGE:
+	case NETDEV_UP: {
+		/* Track state of conduit port.
+		 * DSA driver may require the conduit port (and indirectly
+		 * the tagger) to be available for some special operation.
+		 */
+		if (netdev_uses_dsa(dev)) {
+			struct dsa_port *cpu_dp = dev->dsa_ptr;
+			struct dsa_switch_tree *dst = cpu_dp->ds->dst;
+
+			/* Track when the conduit port is UP */
+			dsa_tree_conduit_oper_state_change(dst, dev,
+							   netif_oper_up(dev));
+
+			/* Track when the conduit port is ready and can accept
+			 * packet.
+			 * NETDEV_UP event is not enough to flag a port as ready.
+			 * We also have to wait for linkwatch_do_dev to dev_activate
+			 * and emit a NETDEV_CHANGE event.
+			 * We check if a conduit port is ready by checking if the dev
+			 * have a qdisc assigned and is not noop.
+			 */
+			dsa_tree_conduit_admin_state_change(dst, dev,
+							    !qdisc_tx_is_noop(dev));
+
+			return NOTIFY_OK;
+		}
+
+		return NOTIFY_DONE;
+	}
+	case NETDEV_GOING_DOWN: {
+		struct dsa_port *dp, *cpu_dp;
+		struct dsa_switch_tree *dst;
+		LIST_HEAD(close_list);
+
+		if (!netdev_uses_dsa(dev))
+			return NOTIFY_DONE;
+
+		cpu_dp = dev->dsa_ptr;
+		dst = cpu_dp->ds->dst;
+
+		dsa_tree_conduit_admin_state_change(dst, dev, false);
+
+		list_for_each_entry(dp, &dst->ports, list) {
+			if (!dsa_port_is_user(dp))
+				continue;
+
+			if (dp->cpu_dp != cpu_dp)
+				continue;
+
+			if (!(dp->user->flags & IFF_UP))
+				continue;
+
+			list_add_tail(&dp->user->close_list, &close_list);
+			netdev_lock_ops(dp->user);
+		}
+
+		netif_close_many(&close_list, false);
+
+		while (!list_empty(&close_list)) {
+			struct net_device *user_dev;
+
+			user_dev = list_first_entry(&close_list,
+						    struct net_device,
+						    close_list);
+			netdev_unlock_ops(user_dev);
+			list_del_init(&user_dev->close_list);
+		}
+
+		return NOTIFY_OK;
+	}
+	default:
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static void
+dsa_fdb_offload_notify(struct dsa_switchdev_event_work *switchdev_work)
+{
+	struct switchdev_notifier_fdb_info info = {};
+
+	info.addr = switchdev_work->addr;
+	info.vid = switchdev_work->vid;
+	info.offloaded = true;
+	call_switchdev_notifiers(SWITCHDEV_FDB_OFFLOADED,
+				 switchdev_work->orig_dev, &info.info, NULL);
+}
+
+static void dsa_user_switchdev_event_work(struct work_struct *work)
+{
+	struct dsa_switchdev_event_work *switchdev_work =
+		container_of(work, struct dsa_switchdev_event_work, work);
+	const unsigned char *addr = switchdev_work->addr;
+	struct net_device *dev = switchdev_work->dev;
+	u16 vid = switchdev_work->vid;
+	struct dsa_switch *ds;
+	struct dsa_port *dp;
+	int err;
+
+	dp = dsa_user_to_port(dev);
+	ds = dp->ds;
+
+	switch (switchdev_work->event) {
+	case SWITCHDEV_FDB_ADD_TO_DEVICE:
+		if (switchdev_work->host_addr)
+			err = dsa_port_bridge_host_fdb_add(dp, addr, vid);
+		else if (dp->lag)
+			err = dsa_port_lag_fdb_add(dp, addr, vid);
+		else
+			err = dsa_port_fdb_add(dp, addr, vid);
+		if (err) {
+			dev_err(ds->dev,
+				"port %d failed to add %pM vid %d to fdb: %d\n",
+				dp->index, addr, vid, err);
+			break;
+		}
+		dsa_fdb_offload_notify(switchdev_work);
+		break;
+
+	case SWITCHDEV_FDB_DEL_TO_DEVICE:
+		if (switchdev_work->host_addr)
+			err = dsa_port_bridge_host_fdb_del(dp, addr, vid);
+		else if (dp->lag)
+			err = dsa_port_lag_fdb_del(dp, addr, vid);
+		else
+			err = dsa_port_fdb_del(dp, addr, vid);
+		if (err) {
+			dev_err(ds->dev,
+				"port %d failed to delete %pM vid %d from fdb: %d\n",
+				dp->index, addr, vid, err);
+		}
+
+		break;
+	}
+
+	kfree(switchdev_work);
+}
+
+static bool dsa_foreign_dev_check(const struct net_device *dev,
+				  const struct net_device *foreign_dev)
+{
+	const struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch_tree *dst = dp->ds->dst;
+
+	if (netif_is_bridge_master(foreign_dev))
+		return !dsa_tree_offloads_bridge_dev(dst, foreign_dev);
+
+	if (netif_is_bridge_port(foreign_dev))
+		return !dsa_tree_offloads_bridge_port(dst, foreign_dev);
+
+	/* Everything else is foreign */
+	return true;
+}
+
+static int dsa_user_fdb_event(struct net_device *dev,
+			      struct net_device *orig_dev,
+			      unsigned long event, const void *ctx,
+			      const struct switchdev_notifier_fdb_info *fdb_info)
+{
+	struct dsa_switchdev_event_work *switchdev_work;
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	bool host_addr = fdb_info->is_local;
+	struct dsa_switch *ds = dp->ds;
+
+	if (ctx && ctx != dp)
+		return 0;
+
+	if (!dp->bridge)
+		return 0;
+
+	if (switchdev_fdb_is_dynamically_learned(fdb_info)) {
+		if (dsa_port_offloads_bridge_port(dp, orig_dev))
+			return 0;
+
+		/* FDB entries learned by the software bridge or by foreign
+		 * bridge ports should be installed as host addresses only if
+		 * the driver requests assisted learning.
+		 */
+		if (!ds->assisted_learning_on_cpu_port)
+			return 0;
+	}
+
+	/* Also treat FDB entries on foreign interfaces bridged with us as host
+	 * addresses.
+	 */
+	if (dsa_foreign_dev_check(dev, orig_dev))
+		host_addr = true;
+
+	/* Check early that we're not doing work in vain.
+	 * Host addresses on LAG ports still require regular FDB ops,
+	 * since the CPU port isn't in a LAG.
+	 */
+	if (dp->lag && !host_addr) {
+		if (!ds->ops->lag_fdb_add || !ds->ops->lag_fdb_del)
+			return -EOPNOTSUPP;
+	} else {
+		if (!ds->ops->port_fdb_add || !ds->ops->port_fdb_del)
+			return -EOPNOTSUPP;
+	}
+
+	switchdev_work = kzalloc_obj(*switchdev_work, GFP_ATOMIC);
+	if (!switchdev_work)
+		return -ENOMEM;
+
+	netdev_dbg(dev, "%s FDB entry towards %s, addr %pM vid %d%s\n",
+		   event == SWITCHDEV_FDB_ADD_TO_DEVICE ? "Adding" : "Deleting",
+		   orig_dev->name, fdb_info->addr, fdb_info->vid,
+		   host_addr ? " as host address" : "");
+
+	INIT_WORK(&switchdev_work->work, dsa_user_switchdev_event_work);
+	switchdev_work->event = event;
+	switchdev_work->dev = dev;
+	switchdev_work->orig_dev = orig_dev;
+
+	ether_addr_copy(switchdev_work->addr, fdb_info->addr);
+	switchdev_work->vid = fdb_info->vid;
+	switchdev_work->host_addr = host_addr;
+
+	dsa_schedule_work(&switchdev_work->work);
+
+	return 0;
+}
+
+/* Called under rcu_read_lock() */
+static int dsa_user_switchdev_event(struct notifier_block *unused,
+				    unsigned long event, void *ptr)
+{
+	struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
+	int err;
+
+	switch (event) {
+	case SWITCHDEV_PORT_ATTR_SET:
+		err = switchdev_handle_port_attr_set(dev, ptr,
+						     dsa_user_dev_check,
+						     dsa_user_port_attr_set);
+		return notifier_from_errno(err);
+	case SWITCHDEV_FDB_ADD_TO_DEVICE:
+	case SWITCHDEV_FDB_DEL_TO_DEVICE:
+		err = switchdev_handle_fdb_event_to_device(dev, event, ptr,
+							   dsa_user_dev_check,
+							   dsa_foreign_dev_check,
+							   dsa_user_fdb_event);
+		return notifier_from_errno(err);
+	default:
+		return NOTIFY_DONE;
+	}
+
+	return NOTIFY_OK;
+}
+
+static int dsa_user_switchdev_blocking_event(struct notifier_block *unused,
+					     unsigned long event, void *ptr)
+{
+	struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
+	int err;
+
+	switch (event) {
+	case SWITCHDEV_PORT_OBJ_ADD:
+		err = switchdev_handle_port_obj_add_foreign(dev, ptr,
+							    dsa_user_dev_check,
+							    dsa_foreign_dev_check,
+							    dsa_user_port_obj_add);
+		return notifier_from_errno(err);
+	case SWITCHDEV_PORT_OBJ_DEL:
+		err = switchdev_handle_port_obj_del_foreign(dev, ptr,
+							    dsa_user_dev_check,
+							    dsa_foreign_dev_check,
+							    dsa_user_port_obj_del);
+		return notifier_from_errno(err);
+	case SWITCHDEV_PORT_ATTR_SET:
+		err = switchdev_handle_port_attr_set(dev, ptr,
+						     dsa_user_dev_check,
+						     dsa_user_port_attr_set);
+		return notifier_from_errno(err);
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block dsa_user_nb __read_mostly = {
+	.notifier_call  = dsa_user_netdevice_event,
+};
+
+struct notifier_block dsa_user_switchdev_notifier = {
+	.notifier_call = dsa_user_switchdev_event,
+};
+
+struct notifier_block dsa_user_switchdev_blocking_notifier = {
+	.notifier_call = dsa_user_switchdev_blocking_event,
+};
+
+int dsa_user_register_notifier(void)
+{
+	struct notifier_block *nb;
+	int err;
+
+	err = register_netdevice_notifier(&dsa_user_nb);
+	if (err)
+		return err;
+
+	err = register_switchdev_notifier(&dsa_user_switchdev_notifier);
+	if (err)
+		goto err_switchdev_nb;
+
+	nb = &dsa_user_switchdev_blocking_notifier;
+	err = register_switchdev_blocking_notifier(nb);
+	if (err)
+		goto err_switchdev_blocking_nb;
+
+	return 0;
+
+err_switchdev_blocking_nb:
+	unregister_switchdev_notifier(&dsa_user_switchdev_notifier);
+err_switchdev_nb:
+	unregister_netdevice_notifier(&dsa_user_nb);
+	return err;
+}
+
+void dsa_user_unregister_notifier(void)
+{
+	struct notifier_block *nb;
+	int err;
+
+	nb = &dsa_user_switchdev_blocking_notifier;
+	err = unregister_switchdev_blocking_notifier(nb);
+	if (err)
+		pr_err("DSA: failed to unregister switchdev blocking notifier (%d)\n", err);
+
+	err = unregister_switchdev_notifier(&dsa_user_switchdev_notifier);
+	if (err)
+		pr_err("DSA: failed to unregister switchdev notifier (%d)\n", err);
+
+	err = unregister_netdevice_notifier(&dsa_user_nb);
+	if (err)
+		pr_err("DSA: failed to unregister user notifier (%d)\n", err);
+}
diff --git a/net/dsa/user.h b/net/dsa/user.h
new file mode 100644
index 000000000..016884bea
--- /dev/null
+++ b/net/dsa/user.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __DSA_USER_H
+#define __DSA_USER_H
+
+#include <linux/if_bridge.h>
+#include <linux/if_vlan.h>
+#include <linux/list.h>
+#include <linux/netpoll.h>
+#include <linux/types.h>
+#include <net/dsa.h>
+#include <net/gro_cells.h>
+
+struct net_device;
+struct netlink_ext_ack;
+
+extern struct notifier_block dsa_user_switchdev_notifier;
+extern struct notifier_block dsa_user_switchdev_blocking_notifier;
+
+struct dsa_user_priv {
+	/* Copy of CPU port xmit for faster access in user transmit hot path */
+	struct sk_buff *	(*xmit)(struct sk_buff *skb,
+					struct net_device *dev);
+
+	struct gro_cells	gcells;
+
+	/* DSA port data, such as switch, port index, etc. */
+	struct dsa_port		*dp;
+
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	struct netpoll		*netpoll;
+#endif
+
+	/* TC context */
+	struct list_head	mall_tc_list;
+};
+
+void dsa_user_mii_bus_init(struct dsa_switch *ds);
+int dsa_user_create(struct dsa_port *dp);
+void dsa_user_destroy(struct net_device *user_dev);
+int dsa_user_suspend(struct net_device *user_dev);
+int dsa_user_resume(struct net_device *user_dev);
+int dsa_user_register_notifier(void);
+void dsa_user_unregister_notifier(void);
+int dsa_user_host_uc_install(struct net_device *dev, const u8 *addr);
+void dsa_user_host_uc_uninstall(struct net_device *dev);
+void dsa_user_sync_ha(struct net_device *dev);
+void dsa_user_unsync_ha(struct net_device *dev);
+void dsa_user_setup_tagger(struct net_device *user);
+int dsa_user_change_mtu(struct net_device *dev, int new_mtu);
+int dsa_user_change_conduit(struct net_device *dev, struct net_device *conduit,
+			    struct netlink_ext_ack *extack);
+int dsa_user_manage_vlan_filtering(struct net_device *dev,
+				   bool vlan_filtering);
+
+static inline struct dsa_port *dsa_user_to_port(const struct net_device *dev)
+{
+	struct dsa_user_priv *p = netdev_priv(dev);
+
+	return p->dp;
+}
+
+static inline struct net_device *
+dsa_user_to_conduit(const struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_user_to_port(dev);
+
+	return dsa_port_to_conduit(dp);
+}
+
+#endif