On Tue, Mar 01, 2022 at 11:03:15AM +0100, Tobias Waldekranz wrote:
> Whenever a VLAN moves to a new MSTI, send a switchdev notification so
> that switchdevs can...
>
> ...either refuse the migration if the hardware does not support
> offloading of MST...
>
> ..or track a bridge's VID to MSTI mapping when offloading is
> supported.
>
> Signed-off-by: Tobias Waldekranz <[email protected]>
> ---
> include/net/switchdev.h | 10 +++++++
> net/bridge/br_mst.c | 15 +++++++++++
> net/bridge/br_switchdev.c | 57 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 82 insertions(+)
>
> diff --git a/include/net/switchdev.h b/include/net/switchdev.h
> index 3e424d40fae3..39e57aa5005a 100644
> --- a/include/net/switchdev.h
> +++ b/include/net/switchdev.h
> @@ -28,6 +28,7 @@ enum switchdev_attr_id {
> SWITCHDEV_ATTR_ID_BRIDGE_MC_DISABLED,
> SWITCHDEV_ATTR_ID_BRIDGE_MROUTER,
> SWITCHDEV_ATTR_ID_MRP_PORT_ROLE,
> + SWITCHDEV_ATTR_ID_VLAN_MSTI,
> };
>
> struct switchdev_brport_flags {
> @@ -35,6 +36,14 @@ struct switchdev_brport_flags {
> unsigned long mask;
> };
>
> +struct switchdev_vlan_attr {
> + u16 vid;
> +
> + union {
> + u16 msti;
> + };
Do you see other VLAN attributes that would be added in the future, such
as to justify making this a single-element union from the get-go?
Anyway if that is the case, we're lacking an id for the attribute type,
so we'd end up needing to change drivers when a second union element
appears. Otherwise they'd all expect an u16 msti.
> +};
> +
> struct switchdev_attr {
> struct net_device *orig_dev;
> enum switchdev_attr_id id;
> @@ -50,6 +59,7 @@ struct switchdev_attr {
> u16 vlan_protocol; /* BRIDGE_VLAN_PROTOCOL
> */
> bool mc_disabled; /* MC_DISABLED */
> u8 mrp_port_role; /* MRP_PORT_ROLE */
> + struct switchdev_vlan_attr vlan_attr; /* VLAN_* */
> } u;
> };
>
> diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
> index 8dea8e7257fd..aba603675165 100644
> --- a/net/bridge/br_mst.c
> +++ b/net/bridge/br_mst.c
> @@ -7,6 +7,7 @@
> */
>
> #include <linux/kernel.h>
> +#include <net/switchdev.h>
>
> #include "br_private.h"
>
> @@ -65,9 +66,23 @@ static void br_mst_vlan_sync_state(struct net_bridge_vlan
> *pv, u16 msti)
>
> int br_mst_vlan_set_msti(struct net_bridge_vlan *mv, u16 msti)
> {
> + struct switchdev_attr attr = {
> + .id = SWITCHDEV_ATTR_ID_VLAN_MSTI,
> + .flags = SWITCHDEV_F_DEFER,
Is the bridge spinlock held (atomic context), or otherwise why is
SWITCHDEV_F_DEFER needed here?
> + .orig_dev = mv->br->dev,
> + .u.vlan_attr = {
> + .vid = mv->vid,
> + .msti = msti,
> + },
> + };
> struct net_bridge_vlan_group *vg;
> struct net_bridge_vlan *pv;
> struct net_bridge_port *p;
> + int err;
> +
> + err = switchdev_port_attr_set(mv->br->dev, &attr, NULL);
Treating a "VLAN attribute" as a "port attribute of the bridge" is
pushing the taxonomy just a little, but I don't have a better suggestion.
> + if (err && err != -EOPNOTSUPP)
> + return err;
>
> mv->msti = msti;
>
> diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c
> index 6f6a70121a5e..160d7659f88a 100644
> --- a/net/bridge/br_switchdev.c
> +++ b/net/bridge/br_switchdev.c
> @@ -428,6 +428,57 @@ static int br_switchdev_vlan_replay(struct net_device
> *br_dev,
> return 0;
> }
>
> +static int br_switchdev_mst_replay(struct net_device *br_dev,
> + const void *ctx, bool adding,
> + struct notifier_block *nb,
> + struct netlink_ext_ack *extack)
"bool adding" is unused, and replaying the VLAN to MSTI associations
before deleting them makes little sense anyway.
I understand the appeal of symmetry, so maybe put an
if (adding) {
err = br_switchdev_vlan_attr_replay(...);
if (err && err != -EOPNOTSUPP)
return err;
}
at the end of br_switchdev_vlan_replay()?
> +{
> + struct switchdev_notifier_port_attr_info attr_info = {
> + .info = {
> + .dev = br_dev,
> + .extack = extack,
> + .ctx = ctx,
> + },
> + };
> + struct net_bridge *br = netdev_priv(br_dev);
> + struct net_bridge_vlan_group *vg;
> + struct net_bridge_vlan *v;
> + int err;
> +
> + ASSERT_RTNL();
> +
> + if (!nb)
> + return 0;
> +
> + if (!netif_is_bridge_master(br_dev))
> + return -EINVAL;
> +
> + vg = br_vlan_group(br);
> +
> + list_for_each_entry(v, &vg->vlan_list, vlist) {
> + struct switchdev_attr attr = {
> + .id = SWITCHDEV_ATTR_ID_VLAN_MSTI,
> + .flags = SWITCHDEV_F_DEFER,
I don't think SWITCHDEV_F_DEFER has any effect on a replay.
> + .orig_dev = br_dev,
> + .u.vlan_attr = {
> + .vid = v->vid,
> + .msti = v->msti,
> + }
> + };
> +
> + if (!v->msti)
> + continue;
> +
> + attr_info.attr = &attr;
> + err = nb->notifier_call(nb, SWITCHDEV_PORT_ATTR_SET,
> &attr_info);
> + err = notifier_to_errno(err);
> + if (err)
> + return err;
> + }
> +
> + return 0;
> +}
> +
> #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
> struct br_switchdev_mdb_complete_info {
> struct net_bridge_port *port;
> @@ -695,6 +746,10 @@ static int nbp_switchdev_sync_objs(struct
> net_bridge_port *p, const void *ctx,
> if (err && err != -EOPNOTSUPP)
> return err;
>
> + err = br_switchdev_mst_replay(br_dev, ctx, true, blocking_nb, extack);
> + if (err && err != -EOPNOTSUPP)
> + return err;
> +
> err = br_switchdev_mdb_replay(br_dev, dev, ctx, true, blocking_nb,
> extack);
> if (err && err != -EOPNOTSUPP)
> @@ -719,6 +774,8 @@ static void nbp_switchdev_unsync_objs(struct
> net_bridge_port *p,
>
> br_switchdev_mdb_replay(br_dev, dev, ctx, false, blocking_nb, NULL);
>
> + br_switchdev_mst_replay(br_dev, ctx, false, blocking_nb, NULL);
> +
> br_switchdev_vlan_replay(br_dev, ctx, false, blocking_nb, NULL);
> }
>
> --
> 2.25.1
>
