On Wed, Dec 16, 2020 at 05:00:54PM +0100, Tobias Waldekranz wrote:
> Monitor the following events and notify the driver when:
>
> - A DSA port joins/leaves a LAG.
> - A LAG, made up of DSA ports, joins/leaves a bridge.
> - A DSA port in a LAG is enabled/disabled (enabled meaning
> "distributing" in 802.3ad LACP terms).
>
> When a LAG joins a bridge, the DSA subsystem will treat that as each
> individual port joining the bridge. The driver may look at the port's
> LAG device pointer to see if it is associated with any LAG, if that is
> required. This is analogue to how switchdev events are replicated out
> to all lower devices when reaching e.g. a LAG.
>
> Drivers can optionally request that DSA maintain a linear mapping from
> a LAG ID to the corresponding netdev by setting ds->num_lag_ids to the
> desired size.
>
> In the event that the hardware is not capable of offloading a
> particular LAG for any reason (the typical case being use of exotic
> modes like broadcast), DSA will take a hands-off approach, allowing
> the LAG to be formed as a pure software construct. This is reported
> back through the extended ACK, but is otherwise transparent to the
> user.
>
> Signed-off-by: Tobias Waldekranz <tob...@waldekranz.com>
> ---
>
> I tried in vain to win checkpatch's approval of the foreach macros, no
> matter how many parentheses I added. Looking at existing macros, this
> style seems to be widely accepted. Is this a known issue?
>
> include/net/dsa.h | 60 +++++++++++++++++++++++++++++++++++
> net/dsa/dsa2.c | 74 +++++++++++++++++++++++++++++++++++++++++++
> net/dsa/dsa_priv.h | 36 +++++++++++++++++++++
> net/dsa/port.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++
> net/dsa/slave.c | 70 ++++++++++++++++++++++++++++++++++++----
> net/dsa/switch.c | 50 +++++++++++++++++++++++++++++
> 6 files changed, 362 insertions(+), 7 deletions(-)
>
> diff --git a/include/net/dsa.h b/include/net/dsa.h
> index 4e60d2610f20..9092c711a37c 100644
> --- a/include/net/dsa.h
> +++ b/include/net/dsa.h
> @@ -149,8 +149,41 @@ struct dsa_switch_tree {
>
> /* List of DSA links composing the routing table */
> struct list_head rtable;
> +
> + /* Maps offloaded LAG netdevs to a zero-based linear ID for
> + * drivers that need it.
> + */
> + struct net_device **lags;
> + unsigned int lags_len;
> };
>
> +#define dsa_lags_foreach_id(_id, _dst) \
> + for ((_id) = 0; (_id) < (_dst)->lags_len; (_id)++) \
> + if ((_dst)->lags[_id])
> +
> +#define dsa_lag_foreach_port(_dp, _dst, _lag) \
> + list_for_each_entry(_dp, &(_dst)->ports, list) \
> + if ((_dp)->lag_dev == (_lag))
ERROR: Macros with complex values should be enclosed in parentheses
#86: FILE: include/net/dsa.h:160:
+#define dsa_lags_foreach_id(_id, _dst) \
+ for ((_id) = 0; (_id) < (_dst)->lags_len; (_id)++) \
+ if ((_dst)->lags[_id])
~~~
missing parentheses
ERROR: Macros with complex values should be enclosed in parentheses
#90: FILE: include/net/dsa.h:164:
+#define dsa_lag_foreach_port(_dp, _dst, _lag) \
+ list_for_each_entry(_dp, &(_dst)->ports, list) \
~~~
missing parentheses
+ if ((_dp)->lag_dev == (_lag))
