mlxsw: Handle config changes pertinent to SPAN

For some netdevices, for which mlxsw offloads mirroring, may have a
complex relationship between the declared intent and low-level
device configuration.

Trying to accurately track which changes might influence offloading
decisions is finicky and error-prone. Instead, this patch introduces a
function mlxsw_sp_span_entry_respin, which re-queries the configuration
anew and, if different, removes the existing offloads and installs new
ones.

Call this function strategically at event handlers that might influence
the mirroring configuration.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 24 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c
index c0e0e9af2da7..71102f156a97 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c
@@ -502,3 +502,27 @@ void mlxsw_sp_span_mirror_del(struct mlxsw_sp_port *from, int span_id,
 		   span_entry->id);
 	mlxsw_sp_span_inspected_port_del(from, span_entry, type, bind);
 }
+
+void mlxsw_sp_span_respin(struct mlxsw_sp *mlxsw_sp)
+{
+	int i;
+	int err;
+
+	ASSERT_RTNL();
+	for (i = 0; i < mlxsw_sp->span.entries_count; i++) {
+		struct mlxsw_sp_span_entry *curr = &mlxsw_sp->span.entries[i];
+		struct mlxsw_sp_span_parms sparms = {0};
+
+		if (!curr->ref_count)
+			continue;
+
+		err = curr->ops->parms(curr->to_dev, &sparms);
+		if (err)
+			continue;
+
+		if (memcmp(&sparms, &curr->parms, sizeof(sparms))) {
+			mlxsw_sp_span_entry_deconfigure(curr);
+			mlxsw_sp_span_entry_configure(mlxsw_sp, curr, sparms);
+		}
+	}
+}