tree:   https://github.com/dsahern/linux nvme-tcp-offload
head:   b9ae3391dc24a401030b31ad5363e0471ae386e0
commit: d30049b55af82c90853e517faa490bfa6125d19f [13/15] net/mlx5e: NVMEoTCP, data-path for DDP offload
config: s390-defconfig (attached as .config)
compiler: s390-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/dsahern/linux/commit/d30049b55af82c90853e517faa490bfa6125d19f
        git remote add dsahern-linux https://github.com/dsahern/linux
        git fetch --no-tags dsahern-linux nvme-tcp-offload
        git checkout d30049b55af82c90853e517faa490bfa6125d19f
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=s390 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   In file included from drivers/net/ethernet/mellanox/mlx5/core/en_rx.c:51:
>> drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.h:18:5: warning: no previous prototype for 'mlx5_nvmeotcp_get_headlen' [-Wmissing-prototypes]
      18 | int mlx5_nvmeotcp_get_headlen(struct mlx5_cqe64 *cqe, u32 cqe_bcnt) { return cqe_bcnt; }
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.h:20:1: warning: no previous prototype for 'mlx5e_nvmeotcp_handle_rx_skb' [-Wmissing-prototypes]
      20 | mlx5e_nvmeotcp_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

vim +/mlx5_nvmeotcp_get_headlen +18 drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.h

    11	
    12	struct sk_buff*
    13	mlx5e_nvmeotcp_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
    14				     struct mlx5_cqe64 *cqe, u32 cqe_bcnt, bool linear);
    15	
    16	int mlx5_nvmeotcp_get_headlen(struct mlx5_cqe64 *cqe, u32 cqe_bcnt);
    17	#else
  > 18	int mlx5_nvmeotcp_get_headlen(struct mlx5_cqe64 *cqe, u32 cqe_bcnt) { return cqe_bcnt; }
    19	struct sk_buff*
  > 20	mlx5e_nvmeotcp_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
    21				     struct mlx5_cqe64 *cqe, u32 cqe_bcnt, bool linear)
    22	{ return skb; }
    23	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org