Commit 8f5c5a79 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Tony Nguyen

ethernet: ice: avoid gcc-9 integer overflow warning

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: 34800178 ("ice: Add support for VLAN priority filters in switchdev")
Suggested-by: default avatarAlexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Reviewed-by: default avatarAlexander Lobakin <alexandr.lobakin@intel.com>
Tested-by: default avatarSujai Buvaneswaran <sujai.buvaneswaran@intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
parent c4a9c8e7
...@@ -1455,8 +1455,8 @@ ice_parse_cls_flower(struct net_device *filter_dev, struct ice_vsi *vsi, ...@@ -1455,8 +1455,8 @@ ice_parse_cls_flower(struct net_device *filter_dev, struct ice_vsi *vsi,
if (match.mask->vlan_priority) { if (match.mask->vlan_priority) {
fltr->flags |= ICE_TC_FLWR_FIELD_VLAN_PRIO; fltr->flags |= ICE_TC_FLWR_FIELD_VLAN_PRIO;
headers->vlan_hdr.vlan_prio = headers->vlan_hdr.vlan_prio =
cpu_to_be16((match.key->vlan_priority << be16_encode_bits(match.key->vlan_priority,
VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK); VLAN_PRIO_MASK);
} }
if (match.mask->vlan_tpid) if (match.mask->vlan_tpid)
...@@ -1489,8 +1489,8 @@ ice_parse_cls_flower(struct net_device *filter_dev, struct ice_vsi *vsi, ...@@ -1489,8 +1489,8 @@ ice_parse_cls_flower(struct net_device *filter_dev, struct ice_vsi *vsi,
if (match.mask->vlan_priority) { if (match.mask->vlan_priority) {
fltr->flags |= ICE_TC_FLWR_FIELD_CVLAN_PRIO; fltr->flags |= ICE_TC_FLWR_FIELD_CVLAN_PRIO;
headers->cvlan_hdr.vlan_prio = headers->cvlan_hdr.vlan_prio =
cpu_to_be16((match.key->vlan_priority << be16_encode_bits(match.key->vlan_priority,
VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK); VLAN_PRIO_MASK);
} }
} }
......
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