mlxsw: Use dscp_t in struct mlxsw_sp_fib4_entry

Use the new dscp_t type to replace the tos field of struct
mlxsw_sp_fib4_entry. This ensures ECN bits are ignored and makes it
compatible with the dscp fields of fib_entry_notifier_info and
fib_rt_info.

This also allows sparse to flag potential incorrect uses of DSCP and
ECN bits.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -508,7 +508,7 @@ struct mlxsw_sp_fib4_entry {
 	struct mlxsw_sp_fib_entry common;
 	struct fib_info *fi;
 	u32 tb_id;
-	u8 tos;
+	dscp_t dscp;
 	u8 type;
 };
 
@@ -5560,7 +5560,7 @@ mlxsw_sp_fib4_entry_should_offload(const struct mlxsw_sp_fib_entry *fib_entry)
 
 	fib4_entry = container_of(fib_entry, struct mlxsw_sp_fib4_entry,
 				  common);
-	return !fib4_entry->tos;
+	return !fib4_entry->dscp;
 }
 
 static bool
@@ -5646,7 +5646,7 @@ mlxsw_sp_fib4_entry_hw_flags_set(struct mlxsw_sp *mlxsw_sp,
 	fri.tb_id = fib4_entry->tb_id;
 	fri.dst = cpu_to_be32(*p_dst);
 	fri.dst_len = dst_len;
-	fri.dscp = inet_dsfield_to_dscp(fib4_entry->tos);
+	fri.dscp = fib4_entry->dscp;
 	fri.type = fib4_entry->type;
 	fri.offload = should_offload;
 	fri.trap = !should_offload;
@@ -5669,7 +5669,7 @@ mlxsw_sp_fib4_entry_hw_flags_clear(struct mlxsw_sp *mlxsw_sp,
 	fri.tb_id = fib4_entry->tb_id;
 	fri.dst = cpu_to_be32(*p_dst);
 	fri.dst_len = dst_len;
-	fri.dscp = inet_dsfield_to_dscp(fib4_entry->tos);
+	fri.dscp = fib4_entry->dscp;
 	fri.type = fib4_entry->type;
 	fri.offload = false;
 	fri.trap = false;
@@ -6251,7 +6251,7 @@ mlxsw_sp_fib4_entry_create(struct mlxsw_sp *mlxsw_sp,
 	fib_info_hold(fib4_entry->fi);
 	fib4_entry->tb_id = fen_info->tb_id;
 	fib4_entry->type = fen_info->type;
-	fib4_entry->tos = inet_dscp_to_dsfield(fen_info->dscp);
+	fib4_entry->dscp = fen_info->dscp;
 
 	fib_entry->fib_node = fib_node;
 
@@ -6305,7 +6305,7 @@ mlxsw_sp_fib4_entry_lookup(struct mlxsw_sp *mlxsw_sp,
 	fib4_entry = container_of(fib_node->fib_entry,
 				  struct mlxsw_sp_fib4_entry, common);
 	if (fib4_entry->tb_id == fen_info->tb_id &&
-	    fib4_entry->tos == inet_dscp_to_dsfield(fen_info->dscp) &&
+	    fib4_entry->dscp == fen_info->dscp &&
 	    fib4_entry->type == fen_info->type &&
 	    fib4_entry->fi == fen_info->fi)
 		return fib4_entry;