bmips: backport b53 legacy tags support
authorÁlvaro Fernández Rojas <noltari@gmail.com>
Fri, 19 Mar 2021 09:53:51 +0000 (10:53 +0100)
committerÁlvaro Fernández Rojas <noltari@gmail.com>
Fri, 19 Mar 2021 10:00:19 +0000 (11:00 +0100)
These patches have been accepted upstream for linux 5.13.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
target/linux/bmips/patches-5.10/010-v5.11-net-dsa-implement-a-central-TX-reallocation-procedur.patch [new file with mode: 0644]
target/linux/bmips/patches-5.10/049-v5.13-net-dsa-tag_brcm-add-support-for-legacy-tags.patch [new file with mode: 0644]
target/linux/bmips/patches-5.10/050-v5.13-net-dsa-b53-support-legacy-tags.patch [new file with mode: 0644]
target/linux/bmips/patches-5.10/502-net-dsa-b53-support-tags-for-legacy-switches.patch [deleted file]

diff --git a/target/linux/bmips/patches-5.10/010-v5.11-net-dsa-implement-a-central-TX-reallocation-procedur.patch b/target/linux/bmips/patches-5.10/010-v5.11-net-dsa-implement-a-central-TX-reallocation-procedur.patch
new file mode 100644 (file)
index 0000000..4171a69
--- /dev/null
@@ -0,0 +1,104 @@
+From a3b0b6479700a5b0af2c631cb2ec0fb7a0d978f2 Mon Sep 17 00:00:00 2001
+From: Vladimir Oltean <vladimir.oltean@nxp.com>
+Date: Sun, 1 Nov 2020 21:16:09 +0200
+Subject: [PATCH] net: dsa: implement a central TX reallocation procedure
+
+At the moment, taggers are left with the task of ensuring that the skb
+headers are writable (which they aren't, if the frames were cloned for
+TX timestamping, for flooding by the bridge, etc), and that there is
+enough space in the skb data area for the DSA tag to be pushed.
+
+Moreover, the life of tail taggers is even harder, because they need to
+ensure that short frames have enough padding, a problem that normal
+taggers don't have.
+
+The principle of the DSA framework is that everything except for the
+most intimate hardware specifics (like in this case, the actual packing
+of the DSA tag bits) should be done inside the core, to avoid having
+code paths that are very rarely tested.
+
+So provide a TX reallocation procedure that should cover the known needs
+of DSA today.
+
+Note that this patch also gives the network stack a good hint about the
+headroom/tailroom it's going to need. Up till now it wasn't doing that.
+So the reallocation procedure should really be there only for the
+exceptional cases, and for cloned packets which need to be unshared.
+
+Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
+Tested-by: Christian Eggers <ceggers@arri.de> # For tail taggers only
+Tested-by: Kurt Kanzenbach <kurt@linutronix.de>
+Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+---
+ net/dsa/slave.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 45 insertions(+)
+
+--- a/net/dsa/slave.c
++++ b/net/dsa/slave.c
+@@ -548,6 +548,30 @@ netdev_tx_t dsa_enqueue_skb(struct sk_bu
+ }
+ EXPORT_SYMBOL_GPL(dsa_enqueue_skb);
++static int dsa_realloc_skb(struct sk_buff *skb, struct net_device *dev)
++{
++      int needed_headroom = dev->needed_headroom;
++      int needed_tailroom = dev->needed_tailroom;
++
++      /* For tail taggers, we need to pad short frames ourselves, to ensure
++       * that the tail tag does not fail at its role of being at the end of
++       * the packet, once the master interface pads the frame. Account for
++       * that pad length here, and pad later.
++       */
++      if (unlikely(needed_tailroom && skb->len < ETH_ZLEN))
++              needed_tailroom += ETH_ZLEN - skb->len;
++      /* skb_headroom() returns unsigned int... */
++      needed_headroom = max_t(int, needed_headroom - skb_headroom(skb), 0);
++      needed_tailroom = max_t(int, needed_tailroom - skb_tailroom(skb), 0);
++
++      if (likely(!needed_headroom && !needed_tailroom && !skb_cloned(skb)))
++              /* No reallocation needed, yay! */
++              return 0;
++
++      return pskb_expand_head(skb, needed_headroom, needed_tailroom,
++                              GFP_ATOMIC);
++}
++
+ static netdev_tx_t dsa_slave_xmit(struct sk_buff *skb, struct net_device *dev)
+ {
+       struct dsa_slave_priv *p = netdev_priv(dev);
+@@ -567,6 +591,17 @@ static netdev_tx_t dsa_slave_xmit(struct
+        */
+       dsa_skb_tx_timestamp(p, skb);
++      if (dsa_realloc_skb(skb, dev)) {
++              dev_kfree_skb_any(skb);
++              return NETDEV_TX_OK;
++      }
++
++      /* needed_tailroom should still be 'warm' in the cache line from
++       * dsa_realloc_skb(), 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. Only free it here on error.
+        */
+@@ -1825,6 +1860,16 @@ int dsa_slave_create(struct dsa_port *po
+       slave_dev->netdev_ops = &dsa_slave_netdev_ops;
+       if (ds->ops->port_max_mtu)
+               slave_dev->max_mtu = ds->ops->port_max_mtu(ds, port->index);
++      if (cpu_dp->tag_ops->tail_tag)
++              slave_dev->needed_tailroom = cpu_dp->tag_ops->overhead;
++      else
++              slave_dev->needed_headroom = cpu_dp->tag_ops->overhead;
++      /* Try to save one extra realloc later in the TX path (in the master)
++       * by also inheriting the master's needed headroom and tailroom.
++       * The 8021q driver also does this.
++       */
++      slave_dev->needed_headroom += master->needed_headroom;
++      slave_dev->needed_tailroom += master->needed_tailroom;
+       SET_NETDEV_DEVTYPE(slave_dev, &dsa_type);
+       netdev_for_each_tx_queue(slave_dev, dsa_slave_set_lockdep_class_one,
diff --git a/target/linux/bmips/patches-5.10/049-v5.13-net-dsa-tag_brcm-add-support-for-legacy-tags.patch b/target/linux/bmips/patches-5.10/049-v5.13-net-dsa-tag_brcm-add-support-for-legacy-tags.patch
new file mode 100644 (file)
index 0000000..a9b689c
--- /dev/null
@@ -0,0 +1,180 @@
+From 964dbf186eaa84d409c359ddf09c827a3fbe8228 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?=C3=81lvaro=20Fern=C3=A1ndez=20Rojas?= <noltari@gmail.com>
+Date: Wed, 17 Mar 2021 11:29:26 +0100
+Subject: [PATCH 1/2] net: dsa: tag_brcm: add support for legacy tags
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Add support for legacy Broadcom tags, which are similar to DSA_TAG_PROTO_BRCM.
+These tags are used on BCM5325, BCM5365 and BCM63xx switches.
+
+Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ include/net/dsa.h  |   2 +
+ net/dsa/Kconfig    |   7 +++
+ net/dsa/tag_brcm.c | 107 +++++++++++++++++++++++++++++++++++++++++++--
+ 3 files changed, 113 insertions(+), 3 deletions(-)
+
+--- a/include/net/dsa.h
++++ b/include/net/dsa.h
+@@ -45,10 +45,12 @@ struct phylink_link_state;
+ #define DSA_TAG_PROTO_OCELOT_VALUE            15
+ #define DSA_TAG_PROTO_AR9331_VALUE            16
+ #define DSA_TAG_PROTO_RTL4_A_VALUE            17
++#define DSA_TAG_PROTO_BRCM_LEGACY_VALUE               22
+ enum dsa_tag_protocol {
+       DSA_TAG_PROTO_NONE              = DSA_TAG_PROTO_NONE_VALUE,
+       DSA_TAG_PROTO_BRCM              = DSA_TAG_PROTO_BRCM_VALUE,
++      DSA_TAG_PROTO_BRCM_LEGACY       = DSA_TAG_PROTO_BRCM_LEGACY_VALUE,
+       DSA_TAG_PROTO_BRCM_PREPEND      = DSA_TAG_PROTO_BRCM_PREPEND_VALUE,
+       DSA_TAG_PROTO_DSA               = DSA_TAG_PROTO_DSA_VALUE,
+       DSA_TAG_PROTO_EDSA              = DSA_TAG_PROTO_EDSA_VALUE,
+--- a/net/dsa/Kconfig
++++ b/net/dsa/Kconfig
+@@ -47,6 +47,13 @@ config NET_DSA_TAG_BRCM
+         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 Broadcom 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
++        Broadcom legacy switches which place the tag after the MAC source
++        address.
+ config NET_DSA_TAG_BRCM_PREPEND
+       tristate "Tag driver for Broadcom switches using prepended headers"
+--- a/net/dsa/tag_brcm.c
++++ b/net/dsa/tag_brcm.c
+@@ -11,9 +11,26 @@
+ #include "dsa_priv.h"
+-/* This tag length is 4 bytes, older ones were 6 bytes, we do not
+- * handle them
+- */
++/* 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)
++
++/* 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 desconstructed using byte by byte access
+@@ -197,6 +214,87 @@ DSA_TAG_DRIVER(brcm_netdev_ops);
+ MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM);
+ #endif
++#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_slave_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.
++       *
++       * Let dsa_slave_xmit() free the SKB
++       */
++      if (__skb_put_padto(skb, ETH_ZLEN + BRCM_LEG_TAG_LEN, false))
++              return NULL;
++
++      skb_push(skb, BRCM_LEG_TAG_LEN);
++
++      memmove(skb->data, skb->data + BRCM_LEG_TAG_LEN, 2 * ETH_ALEN);
++
++      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 struct sk_buff *brcm_leg_tag_rcv(struct sk_buff *skb,
++                                      struct net_device *dev,
++                                      struct packet_type *pt)
++{
++      int source_port;
++      u8 *brcm_tag;
++
++      if (unlikely(!pskb_may_pull(skb, BRCM_LEG_PORT_ID)))
++              return NULL;
++
++      brcm_tag = skb->data - 2;
++
++      source_port = brcm_tag[5] & BRCM_LEG_PORT_ID;
++
++      skb->dev = dsa_master_find_slave(dev, 0, source_port);
++      if (!skb->dev)
++              return NULL;
++
++      /* Remove Broadcom tag and update checksum */
++      skb_pull_rcsum(skb, BRCM_LEG_TAG_LEN);
++
++      skb->offload_fwd_mark = 1;
++
++      /* Move the Ethernet DA and SA */
++      memmove(skb->data - ETH_HLEN,
++              skb->data - ETH_HLEN - BRCM_LEG_TAG_LEN,
++              2 * ETH_ALEN);
++
++      return skb;
++}
++
++static const struct dsa_device_ops brcm_legacy_netdev_ops = {
++      .name = "brcm-legacy",
++      .proto = DSA_TAG_PROTO_BRCM_LEGACY,
++      .xmit = brcm_leg_tag_xmit,
++      .rcv = brcm_leg_tag_rcv,
++      .overhead = BRCM_LEG_TAG_LEN,
++};
++
++DSA_TAG_DRIVER(brcm_legacy_netdev_ops);
++MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_LEGACY);
++#endif /* CONFIG_NET_DSA_TAG_BRCM_LEGACY */
++
+ #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)
+@@ -229,6 +327,9 @@ static struct dsa_tag_driver *dsa_tag_dr
+ #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_PREPEND)
+       &DSA_TAG_DRIVER_NAME(brcm_prepend_netdev_ops),
+ #endif
diff --git a/target/linux/bmips/patches-5.10/050-v5.13-net-dsa-b53-support-legacy-tags.patch b/target/linux/bmips/patches-5.10/050-v5.13-net-dsa-b53-support-legacy-tags.patch
new file mode 100644 (file)
index 0000000..59a7217
--- /dev/null
@@ -0,0 +1,53 @@
+From 46c5176c586c81306bf9e7024c13b95da775490f Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?=C3=81lvaro=20Fern=C3=A1ndez=20Rojas?= <noltari@gmail.com>
+Date: Wed, 17 Mar 2021 11:29:27 +0100
+Subject: [PATCH 2/2] net: dsa: b53: support legacy tags
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+These tags are used on BCM5325, BCM5365 and BCM63xx switches.
+
+Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
+Acked-by: Florian Fainelli <f.fainelli@gmail.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ drivers/net/dsa/b53/Kconfig      |  1 +
+ drivers/net/dsa/b53/b53_common.c | 12 +++++++-----
+ 2 files changed, 8 insertions(+), 5 deletions(-)
+
+--- a/drivers/net/dsa/b53/Kconfig
++++ b/drivers/net/dsa/b53/Kconfig
+@@ -3,6 +3,7 @@ menuconfig B53
+       tristate "Broadcom BCM53xx managed switch support"
+       depends on NET_DSA
+       select NET_DSA_TAG_BRCM
++      select NET_DSA_TAG_BRCM_LEGACY
+       select NET_DSA_TAG_BRCM_PREPEND
+       help
+         This driver adds support for Broadcom managed switch chips. It supports
+--- a/drivers/net/dsa/b53/b53_common.c
++++ b/drivers/net/dsa/b53/b53_common.c
+@@ -2010,15 +2010,17 @@ enum dsa_tag_protocol b53_get_tag_protoc
+ {
+       struct b53_device *dev = ds->priv;
+-      /* Older models (5325, 5365) support a different tag format that we do
+-       * not support in net/dsa/tag_brcm.c yet.
+-       */
+-      if (is5325(dev) || is5365(dev) ||
+-          !b53_can_enable_brcm_tags(ds, port, mprot)) {
++      if (!b53_can_enable_brcm_tags(ds, port, mprot)) {
+               dev->tag_protocol = DSA_TAG_PROTO_NONE;
+               goto out;
+       }
++      /* Older models require a different 6 byte tag */
++      if (is5325(dev) || is5365(dev) || is63xx(dev)) {
++              dev->tag_protocol = DSA_TAG_PROTO_BRCM_LEGACY;
++              goto out;
++      }
++
+       /* Broadcom BCM58xx chips have a flow accelerator on Port 8
+        * which requires us to use the prepended Broadcom tag type
+        */
diff --git a/target/linux/bmips/patches-5.10/502-net-dsa-b53-support-tags-for-legacy-switches.patch b/target/linux/bmips/patches-5.10/502-net-dsa-b53-support-tags-for-legacy-switches.patch
deleted file mode 100644 (file)
index b8aa8b8..0000000
+++ /dev/null
@@ -1,209 +0,0 @@
-From 3bc3d79efdff6e29b80bf35f7a56baaa36e4d8fe Mon Sep 17 00:00:00 2001
-From: =?UTF-8?q?=C3=81lvaro=20Fern=C3=A1ndez=20Rojas?= <noltari@gmail.com>
-Date: Fri, 12 Mar 2021 12:35:39 +0100
-Subject: [PATCH] net: dsa: b53: support tags for legacy switches
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
----
- drivers/net/dsa/b53/Kconfig      |  1 +
- drivers/net/dsa/b53/b53_common.c |  6 +++
- include/net/dsa.h                |  2 +
- net/dsa/Kconfig                  |  7 +++
- net/dsa/tag_brcm.c               | 93 ++++++++++++++++++++++++++++++++
- 5 files changed, 109 insertions(+)
-
---- a/drivers/net/dsa/b53/Kconfig
-+++ b/drivers/net/dsa/b53/Kconfig
-@@ -3,6 +3,7 @@ menuconfig B53
-       tristate "Broadcom BCM53xx managed switch support"
-       depends on NET_DSA
-       select NET_DSA_TAG_BRCM
-+      select NET_DSA_TAG_BRCM_LEGACY
-       select NET_DSA_TAG_BRCM_PREPEND
-       help
-         This driver adds support for Broadcom managed switch chips. It supports
---- a/drivers/net/dsa/b53/b53_common.c
-+++ b/drivers/net/dsa/b53/b53_common.c
-@@ -1992,6 +1992,7 @@ static bool b53_can_enable_brcm_tags(str
-       switch (tag_protocol) {
-       case DSA_TAG_PROTO_BRCM:
-+      case DSA_TAG_PROTO_BRCM_LEGACY:
-       case DSA_TAG_PROTO_BRCM_PREPEND:
-               dev_warn(ds->dev,
-                        "Port %d is stacked to Broadcom tag switch\n", port);
-@@ -2013,12 +2014,16 @@ enum dsa_tag_protocol b53_get_tag_protoc
-       /* Older models (5325, 5365) support a different tag format that we do
-        * not support in net/dsa/tag_brcm.c yet.
-        */
--      if (is5325(dev) || is5365(dev) ||
--          !b53_can_enable_brcm_tags(ds, port, mprot)) {
-+      if (!b53_can_enable_brcm_tags(ds, port, mprot)) {
-               dev->tag_protocol = DSA_TAG_PROTO_NONE;
-               goto out;
-       }
-+      if (is5325(dev) || is5365(dev) || is63xx(dev)) {
-+              dev->tag_protocol = DSA_TAG_PROTO_BRCM_LEGACY;
-+              goto out;
-+      }
-+
-       /* Broadcom BCM58xx chips have a flow accelerator on Port 8
-        * which requires us to use the prepended Broadcom tag type
-        */
---- a/include/net/dsa.h
-+++ b/include/net/dsa.h
-@@ -45,10 +45,12 @@ struct phylink_link_state;
- #define DSA_TAG_PROTO_OCELOT_VALUE            15
- #define DSA_TAG_PROTO_AR9331_VALUE            16
- #define DSA_TAG_PROTO_RTL4_A_VALUE            17
-+#define DSA_TAG_PROTO_BRCM_LEGACY_VALUE               22
- enum dsa_tag_protocol {
-       DSA_TAG_PROTO_NONE              = DSA_TAG_PROTO_NONE_VALUE,
-       DSA_TAG_PROTO_BRCM              = DSA_TAG_PROTO_BRCM_VALUE,
-+      DSA_TAG_PROTO_BRCM_LEGACY       = DSA_TAG_PROTO_BRCM_LEGACY_VALUE,
-       DSA_TAG_PROTO_BRCM_PREPEND      = DSA_TAG_PROTO_BRCM_PREPEND_VALUE,
-       DSA_TAG_PROTO_DSA               = DSA_TAG_PROTO_DSA_VALUE,
-       DSA_TAG_PROTO_EDSA              = DSA_TAG_PROTO_EDSA_VALUE,
---- a/net/dsa/Kconfig
-+++ b/net/dsa/Kconfig
-@@ -47,6 +47,13 @@ config NET_DSA_TAG_BRCM
-         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 Broadcom 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
-+        Broadcom legacy switches which place the tag after the MAC source
-+        address.
- config NET_DSA_TAG_BRCM_PREPEND
-       tristate "Tag driver for Broadcom switches using prepended headers"
---- a/net/dsa/tag_brcm.c
-+++ b/net/dsa/tag_brcm.c
-@@ -8,9 +8,23 @@
- #include <linux/etherdevice.h>
- #include <linux/list.h>
- #include <linux/slab.h>
-+#include <linux/types.h>
- #include "dsa_priv.h"
-+struct bcm_legacy_tag {
-+      uint16_t type;
-+#define BRCM_LEG_TYPE 0x8874
-+
-+      uint32_t tag;
-+#define BRCM_LEG_TAG_PORT_ID  (0xf)
-+#define BRCM_LEG_TAG_MULTICAST        (1 << 29)
-+#define BRCM_LEG_TAG_EGRESS   (2 << 29)
-+#define BRCM_LEG_TAG_INGRESS  (3 << 29)
-+} __attribute__((packed));
-+
-+#define BRCM_LEG_TAG_LEN      sizeof(struct bcm_legacy_tag)
-+
- /* This tag length is 4 bytes, older ones were 6 bytes, we do not
-  * handle them
-  */
-@@ -197,6 +211,85 @@ DSA_TAG_DRIVER(brcm_netdev_ops);
- MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM);
- #endif
-+#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_slave_to_port(dev);
-+      struct bcm_legacy_tag *brcm_tag;
-+
-+      if (skb_cow_head(skb, BRCM_LEG_TAG_LEN) < 0)
-+              return NULL;
-+
-+      /* 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.
-+       *
-+       * Let dsa_slave_xmit() free the SKB
-+       */
-+      if (__skb_put_padto(skb, ETH_ZLEN + BRCM_LEG_TAG_LEN, false))
-+              return NULL;
-+
-+      skb_push(skb, BRCM_LEG_TAG_LEN);
-+
-+      memmove(skb->data, skb->data + BRCM_LEG_TAG_LEN, 2 * ETH_ALEN);
-+
-+      brcm_tag = (struct bcm_legacy_tag *) (skb->data + 2 * ETH_ALEN);
-+
-+      brcm_tag->type = BRCM_LEG_TYPE;
-+      brcm_tag->tag = BRCM_LEG_TAG_EGRESS;
-+      brcm_tag->tag |= dp->index & BRCM_LEG_TAG_PORT_ID;
-+
-+      return skb;
-+}
-+
-+
-+static struct sk_buff *brcm_leg_tag_rcv(struct sk_buff *skb,
-+                                      struct net_device *dev,
-+                                      struct packet_type *pt)
-+{
-+      int source_port;
-+      struct bcm_legacy_tag *brcm_tag;
-+
-+      if (unlikely(!pskb_may_pull(skb, BRCM_LEG_TAG_LEN)))
-+              return NULL;
-+
-+      brcm_tag = (struct bcm_legacy_tag *) (skb->data - 2);
-+
-+      source_port = brcm_tag->tag & BRCM_LEG_TAG_PORT_ID;
-+
-+      skb->dev = dsa_master_find_slave(dev, 0, source_port);
-+      if (!skb->dev)
-+              return NULL;
-+
-+      /* Remove Broadcom tag and update checksum */
-+      skb_pull_rcsum(skb, BRCM_LEG_TAG_LEN);
-+
-+      skb->offload_fwd_mark = 1;
-+
-+      /* Move the Ethernet DA and SA */
-+      memmove(skb->data - ETH_HLEN,
-+              skb->data - ETH_HLEN - BRCM_LEG_TAG_LEN,
-+              2 * ETH_ALEN);
-+
-+      return skb;
-+}
-+
-+static const struct dsa_device_ops brcm_legacy_netdev_ops = {
-+      .name   = "brcm-legacy",
-+      .proto  = DSA_TAG_PROTO_BRCM_LEGACY,
-+      .xmit   = brcm_leg_tag_xmit,
-+      .rcv    = brcm_leg_tag_rcv,
-+      .overhead = BRCM_LEG_TAG_LEN,
-+};
-+
-+DSA_TAG_DRIVER(brcm_legacy_netdev_ops);
-+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_LEGACY);
-+#endif /* CONFIG_NET_DSA_TAG_BRCM_LEGACY */
-+
- #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)
-@@ -229,6 +322,9 @@ static struct dsa_tag_driver *dsa_tag_dr
- #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_PREPEND)
-       &DSA_TAG_DRIVER_NAME(brcm_prepend_netdev_ops),
- #endif