[PATCH 4.5 040/124] mlxsw: spectrum: Check requested ageing time is valid

[Greg Kroah-Hartman]

4.5-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ido Schimmel <idosch@xxxxxxxxxxxx>

[ Upstream commit 869f63a4d28144c03c8f4a4c0d1e8f31f8c11a10 ]

Commit c62987bbd8a1 ("bridge: push bridge setting ageing_time down to
switchdev") added a check for minimum and maximum ageing time, but this
breaks existing behaviour where one can set ageing time to 0 for a
non-learning bridge.

Push this check down to the driver and allow the check in the bridge
layer to be removed. Currently ageing time 0 is refused by the driver,
but we can later add support for this functionality.

Signed-off-by: Ido Schimmel <idosch@xxxxxxxxxxxx>
Acked-by: Jiri Pirko <jiri@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum.h           |    2 ++
 drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c |    9 +++++++--
 2 files changed, 9 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
@@ -118,6 +118,8 @@ struct mlxsw_sp {
 #define MLXSW_SP_DEFAULT_LEARNING_INTERVAL 100
 		unsigned int interval; /* ms */
 	} fdb_notify;
+#define MLXSW_SP_MIN_AGEING_TIME 10
+#define MLXSW_SP_MAX_AGEING_TIME 1000000
 #define MLXSW_SP_DEFAULT_AGEING_TIME 300
 	u32 ageing_time;
 	struct mlxsw_sp_upper master_bridge;
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
@@ -311,8 +311,13 @@ static int mlxsw_sp_port_attr_br_ageing_
 	unsigned long ageing_jiffies = clock_t_to_jiffies(ageing_clock_t);
 	u32 ageing_time = jiffies_to_msecs(ageing_jiffies) / 1000;
 
-	if (switchdev_trans_ph_prepare(trans))
-		return 0;
+	if (switchdev_trans_ph_prepare(trans)) {
+		if (ageing_time < MLXSW_SP_MIN_AGEING_TIME ||
+		    ageing_time > MLXSW_SP_MAX_AGEING_TIME)
+			return -ERANGE;
+		else
+			return 0;
+	}
 
 	return mlxsw_sp_ageing_set(mlxsw_sp, ageing_time);
 }