[PATCH AUTOSEL 4.20 169/304] mlxsw: spectrum_acl: Limit priority value

[Sasha Levin]

From: Nir Dotan <nird@xxxxxxxxxxxx>

[ Upstream commit d7263ab35be25505ab57ebecd93cbc5dba8be717 ]

In Spectrum-2, higher priority value wins and priority valid values are in
the range of {1,cap_kvd_size-1}. mlxsw_sp_acl_tcam_priority_get converts
from lower-bound priorities alike tc flower to Spectrum-2 HW range. Up
until now tc flower did not provide priority 0 or reached the maximal
value, however multicast routing does provide priority 0.

Therefore, Change mlxsw_sp_acl_tcam_priority_get to verify priority is in
the correct range. Make sure priority is never set to zero and never
exceeds the maximal allowed value.

Signed-off-by: Nir Dotan <nird@xxxxxxxxxxxx>
Reviewed-by: Jiri Pirko <jiri@xxxxxxxxxxxx>
Signed-off-by: Ido Schimmel <idosch@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
index e171513bb32a..30931a2c025b 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
@@ -95,8 +95,9 @@ int mlxsw_sp_acl_tcam_priority_get(struct mlxsw_sp *mlxsw_sp,
 	if (!MLXSW_CORE_RES_VALID(mlxsw_sp->core, KVD_SIZE))
 		return -EIO;
 
-	max_priority = MLXSW_CORE_RES_GET(mlxsw_sp->core, KVD_SIZE);
-	if (rulei->priority > max_priority)
+	/* Priority range is 1..cap_kvd_size-1. */
+	max_priority = MLXSW_CORE_RES_GET(mlxsw_sp->core, KVD_SIZE) - 1;
+	if (rulei->priority >= max_priority)
 		return -EINVAL;
 
 	/* Unlike in TC, in HW, higher number means higher priority. */
-- 
2.19.1