Hi Netanel,

FYI, the error/warning still remains.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git master
head:   21ea1d36f6dfcb1d59184937c672022d5d01902a
commit: 8c590f9776386b8f697fd0b7ed6142ae6e3de79e [451/481] net: ena: Fix Kconfig dependency on X86
config: microblaze-allmodconfig (attached as .config)
compiler: microblaze-linux-gcc (GCC) 8.1.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        git checkout 8c590f9776386b8f697fd0b7ed6142ae6e3de79e
        # save the attached .config to linux build tree
        GCC_VERSION=8.1.0 make.cross ARCH=microblaze 

All errors (new ones prefixed by >>):

   In file included from drivers/net/ethernet/amazon/ena/ena_com.c:33:
   drivers/net/ethernet/amazon/ena/ena_com.h: In function 'ena_com_get_next_bounce_buffer':
>> drivers/net/ethernet/amazon/ena/ena_com.h:1104:2: error: implicit declaration of function 'prefetchw' [-Werror=implicit-function-declaration]
     prefetchw(bounce_buf_ctrl->base_buffer +
     ^~~~~~~~~
   cc1: some warnings being treated as errors

vim +/prefetchw +1104 drivers/net/ethernet/amazon/ena/ena_com.h

1738cd3e Netanel Belgazal  2016-08-10  1092  
689b2bda Arthur Kiyanovski 2018-10-11  1093  static inline u8 *ena_com_get_next_bounce_buffer(struct ena_com_io_bounce_buffer_control *bounce_buf_ctrl)
689b2bda Arthur Kiyanovski 2018-10-11  1094  {
689b2bda Arthur Kiyanovski 2018-10-11  1095  	u16 size, buffers_num;
689b2bda Arthur Kiyanovski 2018-10-11  1096  	u8 *buf;
689b2bda Arthur Kiyanovski 2018-10-11  1097  
689b2bda Arthur Kiyanovski 2018-10-11  1098  	size = bounce_buf_ctrl->buffer_size;
689b2bda Arthur Kiyanovski 2018-10-11  1099  	buffers_num = bounce_buf_ctrl->buffers_num;
689b2bda Arthur Kiyanovski 2018-10-11  1100  
689b2bda Arthur Kiyanovski 2018-10-11  1101  	buf = bounce_buf_ctrl->base_buffer +
689b2bda Arthur Kiyanovski 2018-10-11  1102  		(bounce_buf_ctrl->next_to_use++ & (buffers_num - 1)) * size;
689b2bda Arthur Kiyanovski 2018-10-11  1103  
689b2bda Arthur Kiyanovski 2018-10-11 @1104  	prefetchw(bounce_buf_ctrl->base_buffer +
689b2bda Arthur Kiyanovski 2018-10-11  1105  		(bounce_buf_ctrl->next_to_use & (buffers_num - 1)) * size);
689b2bda Arthur Kiyanovski 2018-10-11  1106  
689b2bda Arthur Kiyanovski 2018-10-11  1107  	return buf;
689b2bda Arthur Kiyanovski 2018-10-11  1108  }
689b2bda Arthur Kiyanovski 2018-10-11  1109  

:::::: The code at line 1104 was first introduced by commit
:::::: 689b2bdaaa1480ad2c14bdc4c6eaf38284549022 net: ena: add functions for handling Low Latency Queues in ena_com

:::::: TO: Arthur Kiyanovski <akiyano@amazon.com>
:::::: CC: David S. Miller <davem@davemloft.net>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation