cxgb4: impose mandatory VLAN usage when non-zero TAG ID

When a non-zero VLAN Tag ID is passed to t4_set_vlan_acl()
then impose mandatory VLAN Usage with that VLAN ID.
I.e any other VLAN ID should result in packets getting
dropped.
Signed-off-by: NCasey Leedom <leedom@chelsio.com>
Signed-off-by: NGanesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/t4_hw.c

@@ -10210,6 +10210,9 @@ int t4_set_vlan_acl(struct adapter *adap, unsigned int mbox, unsigned int vf,
 	vlan_cmd.en_to_len16 = cpu_to_be32(enable | FW_LEN16(vlan_cmd));
 	/* Drop all packets that donot match vlan id */
 	vlan_cmd.dropnovlan_fm = FW_ACL_VLAN_CMD_FM_F;
+	vlan_cmd.dropnovlan_fm = (enable
+				  ? (FW_ACL_VLAN_CMD_DROPNOVLAN_F |
+				     FW_ACL_VLAN_CMD_FM_F) : 0);
 	if (enable != 0) {
 		vlan_cmd.nvlan = 1;
 		vlan_cmd.vlanid[0] = cpu_to_be16(vlan);

drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h

@@ -2464,6 +2464,7 @@ struct fw_acl_vlan_cmd {
 
 #define FW_ACL_VLAN_CMD_DROPNOVLAN_S	7
 #define FW_ACL_VLAN_CMD_DROPNOVLAN_V(x)	((x) << FW_ACL_VLAN_CMD_DROPNOVLAN_S)
+#define FW_ACL_VLAN_CMD_DROPNOVLAN_F    FW_ACL_VLAN_CMD_DROPNOVLAN_V(1U)
 
 #define FW_ACL_VLAN_CMD_FM_S		6
 #define FW_ACL_VLAN_CMD_FM_M		0x1