From: Arnd Bergmann arnd@arndb.de
[ Upstream commit 8f5c5a790e3025d6eca96bf7ee5e3873dc92373f ]
With older compilers like gcc-9, the calculation of the vlan priority field causes a false-positive warning from the byteswap:
In file included from drivers/net/ethernet/intel/ice/ice_tc_lib.c:4: drivers/net/ethernet/intel/ice/ice_tc_lib.c: In function 'ice_parse_cls_flower': include/uapi/linux/swab.h:15:15: error: integer overflow in expression '(int)(short unsigned int)((int)match.key-><U67c8>.<U6698>.vlan_priority << 13) & 57344 & 255' of type 'int' results in '0' [-Werror=overflow] 15 | (((__u16)(x) & (__u16)0x00ffU) << 8) | \ | ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ include/uapi/linux/swab.h:106:2: note: in expansion of macro '___constant_swab16' 106 | ___constant_swab16(x) : \ | ^~~~~~~~~~~~~~~~~~ include/uapi/linux/byteorder/little_endian.h:42:43: note: in expansion of macro '__swab16' 42 | #define __cpu_to_be16(x) ((__force __be16)__swab16((x))) | ^~~~~~~~ include/linux/byteorder/generic.h:96:21: note: in expansion of macro '__cpu_to_be16' 96 | #define cpu_to_be16 __cpu_to_be16 | ^~~~~~~~~~~~~ drivers/net/ethernet/intel/ice/ice_tc_lib.c:1458:5: note: in expansion of macro 'cpu_to_be16' 1458 | cpu_to_be16((match.key->vlan_priority << | ^~~~~~~~~~~
After a change to be16_encode_bits(), the code becomes more readable to both people and compilers, which avoids the warning.
Fixes: 34800178b302 ("ice: Add support for VLAN priority filters in switchdev") Suggested-by: Alexander Lobakin alexandr.lobakin@intel.com Signed-off-by: Arnd Bergmann arnd@arndb.de Reviewed-by: Alexander Lobakin alexandr.lobakin@intel.com Tested-by: Sujai Buvaneswaran sujai.buvaneswaran@intel.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/intel/ice/ice_tc_lib.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice_tc_lib.c b/drivers/net/ethernet/intel/ice/ice_tc_lib.c index f68c555be4e9a..71cb15fcf63b9 100644 --- a/drivers/net/ethernet/intel/ice/ice_tc_lib.c +++ b/drivers/net/ethernet/intel/ice/ice_tc_lib.c @@ -1322,8 +1322,8 @@ ice_parse_cls_flower(struct net_device *filter_dev, struct ice_vsi *vsi, if (match.mask->vlan_priority) { fltr->flags |= ICE_TC_FLWR_FIELD_VLAN_PRIO; headers->vlan_hdr.vlan_prio = - cpu_to_be16((match.key->vlan_priority << - VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK); + be16_encode_bits(match.key->vlan_priority, + VLAN_PRIO_MASK); }
if (match.mask->vlan_tpid) @@ -1356,8 +1356,8 @@ ice_parse_cls_flower(struct net_device *filter_dev, struct ice_vsi *vsi, if (match.mask->vlan_priority) { fltr->flags |= ICE_TC_FLWR_FIELD_CVLAN_PRIO; headers->cvlan_hdr.vlan_prio = - cpu_to_be16((match.key->vlan_priority << - VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK); + be16_encode_bits(match.key->vlan_priority, + VLAN_PRIO_MASK); } }