VLAN_GRP_HASH_SHIFT 63 net/8021q/vlan.c return ((idx >> VLAN_GRP_HASH_SHIFT) ^ idx) & VLAN_GRP_HASH_MASK; VLAN_GRP_HASH_SHIFT 56 net/8021q/vlan.h #define VLAN_GRP_HASH_SIZE (1 << VLAN_GRP_HASH_SHIFT)