Re: [PATCH net-next 2/4] vmxnet3: add latency measurement support in vmxnet3

[kernel test robot]

Hi Ronak,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Ronak-Doshi/vmxnet3-prepare-for-version-9-changes/20240515-023833
base:   net-next/main
patch link:    https://lore.kernel.org/r/20240514182050.20931-3-ronak.doshi%40broadcom.com
patch subject: [PATCH net-next 2/4] vmxnet3: add latency measurement support in vmxnet3
config: loongarch-allmodconfig (https://download.01.org/0day-ci/archive/20240516/202405161123.iWtQjhIw-lkp@xxxxxxxxx/config)
compiler: loongarch64-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240516/202405161123.iWtQjhIw-lkp@xxxxxxxxx/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202405161123.iWtQjhIw-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

   In function 'vmxnet3_get_cycles',
       inlined from 'vmxnet3_rq_rx_complete' at drivers/net/vmxnet3/vmxnet3_drv.c:1675:25:
>> drivers/net/vmxnet3/vmxnet3_drv.c:151:9: warning: 'asm' operand 2 probably does not match constraints
     151 |         asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (pmc));
         |         ^~~
   drivers/net/vmxnet3/vmxnet3_drv.c:151:9: error: impossible constraint in 'asm'
   In function 'vmxnet3_get_cycles',
       inlined from 'vmxnet3_tq_xmit.isra' at drivers/net/vmxnet3/vmxnet3_drv.c:1316:28:
>> drivers/net/vmxnet3/vmxnet3_drv.c:151:9: warning: 'asm' operand 2 probably does not match constraints
     151 |         asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (pmc));
         |         ^~~


vim +/asm +151 drivers/net/vmxnet3/vmxnet3_drv.c

   145	
   146	static u64
   147	vmxnet3_get_cycles(int pmc)
   148	{
   149		u32 low, high;
   150	
 > 151		asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (pmc));
   152		return (low | ((u_int64_t)high << 32));
   153	}
   154	

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