mlxsw: spectrum_flower: Forbid to insert flower rules in collision with matchall rules

On ingress, the matchall rules doing mirroring and sampling are offloaded
into hardware blocks that are processed before any flower rules.
On egress, the matchall mirroring rules are offloaded into hardware
block that is processed after all flower rules.

Therefore check the priorities of inserted flower rules against
existing matchall rules and ensure the correct ordering.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c

@@ -505,6 +505,34 @@ static int mlxsw_sp_flower_parse(struct mlxsw_sp *mlxsw_sp,
 					     f->common.extack);
 }
 
+static int mlxsw_sp_flower_mall_prio_check(struct mlxsw_sp_flow_block *block,
+					   struct flow_cls_offload *f)
+{
+	bool ingress = mlxsw_sp_flow_block_is_ingress_bound(block);
+	unsigned int mall_min_prio;
+	unsigned int mall_max_prio;
+	int err;
+
+	err = mlxsw_sp_mall_prio_get(block, f->common.chain_index,
+				     &mall_min_prio, &mall_max_prio);
+	if (err) {
+		if (err == -ENOENT)
+			/* No matchall filters installed on this chain. */
+			return 0;
+		NL_SET_ERR_MSG(f->common.extack, "Failed to get matchall priorities");
+		return err;
+	}
+	if (ingress && f->common.prio <= mall_min_prio) {
+		NL_SET_ERR_MSG(f->common.extack, "Failed to add in front of existing matchall rules");
+		return -EOPNOTSUPP;
+	}
+	if (!ingress && f->common.prio >= mall_max_prio) {
+		NL_SET_ERR_MSG(f->common.extack, "Failed to add behind of existing matchall rules");
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
 int mlxsw_sp_flower_replace(struct mlxsw_sp *mlxsw_sp,
 			    struct mlxsw_sp_flow_block *block,
 			    struct flow_cls_offload *f)
@@ -514,6 +542,10 @@ int mlxsw_sp_flower_replace(struct mlxsw_sp *mlxsw_sp,
 	struct mlxsw_sp_acl_rule *rule;
 	int err;
 
+	err = mlxsw_sp_flower_mall_prio_check(block, f);
+	if (err)
+		return err;
+
 	ruleset = mlxsw_sp_acl_ruleset_get(mlxsw_sp, block,
 					   f->common.chain_index,
 					   MLXSW_SP_ACL_PROFILE_FLOWER, NULL);