Re: [PATCH net-next V6] net/mlx5: Improve write-combining test reliability for ARM64 Grace CPUs

Arnd Bergmann
2025-10-06T13:59:57Z

On Mon, Oct 6, 2025, at 15:57, Sebastian Ott wrote:
> On Mon, 29 Sep 2025, Tariq Toukan wrote:
>> +static void mlx5_iowrite64_copy(struct mlx5_wc_sq *sq, __be32 mmio_wqe[16],
>> + size_t mmio_wqe_size, unsigned int offset)
>> +{
>> +#if IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && IS_ENABLED(CONFIG_ARM64)
>> + if (cpu_has_neon()) {
>> + kernel_neon_begin();
>> + asm volatile
>> + (".arch_extension simd;\n\t"
>> + "ld1 {v0.16b, v1.16b, v2.16b, v3.16b}, [%0]\n\t"
>> + "st1 {v0.16b, v1.16b, v2.16b, v3.16b}, [%1]"
>> + :
>> + : "r"(mmio_wqe), "r"(sq->bfreg.map + offset)
>> + : "memory", "v0", "v1", "v2", "v3");
>> + kernel_neon_end();
>> + return;
>> + }
>> +#endif
>
> This one breaks the build for me:
> /tmp/cc2vw3CJ.s: Assembler messages:
> /tmp/cc2vw3CJ.s:391: Error: unknown architectural extension `simd;'
>
> Removing the extra ";" after simd seems to fix it.

I sent that fixup earlier today:

https://lore.kernel.org/all/20251006115640.497169-1-arnd@kernel.org/

Arnd