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

From: Jason Gunthorpe <[email-masked]>
Date: Wed, 1 Oct 2025 11:55:14 -0300

On Wed, Oct 01, 2025 at 11:28:09AM +0200, Paolo Abeni 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"
> 
> Here I'm observing build errors with aarch64-linux-gnu-gcc 12.1.1
> 20220507 (Red Hat Cross 12.1.1-1):

> /tmp/cchqHdeI.s: Assembler messages:
> /tmp/cchqHdeI.s:746: Error: unknown architectural extension `simd;'

This is a binutils error not gcc.. What is the binutils version?

2.30 is the lowest that v6.16 supports..

Jason