On Tue, Apr 08, 2025 at 02:25:12PM +0200, Geert Uytterhoeven wrote:
> Hi Andrew,
>
> On Tue, 4 Mar 2025 at 13:02, Andrew Jones <ajones@xxxxxxxxxxxxxxxx> wrote:
> > Allow skipping scalar and vector unaligned access speed tests. This
> > is useful for testing alternative code paths and to skip the tests in
> > environments where they run too slowly. All CPUs must have the same
> > unaligned access speed.
> >
> > The code movement is because we now need the scalar cpu hotplug
> > callback to always run, so we need to bring it and its supporting
> > functions out of CONFIG_RISCV_PROBE_UNALIGNED_ACCESS.
> >
> > Signed-off-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
>
> > --- a/arch/riscv/kernel/unaligned_access_speed.c
> > +++ b/arch/riscv/kernel/unaligned_access_speed.c
>
> > static int __init check_unaligned_access_all_cpus(void)
> > {
> > int cpu;
> >
> > - if (!check_unaligned_access_emulated_all_cpus())
> > + if (unaligned_scalar_speed_param == RISCV_HWPROBE_MISALIGNED_SCALAR_UNKNOWN &&
> > + !check_unaligned_access_emulated_all_cpus()) {
> > check_unaligned_access_speed_all_cpus();
> > -
> > - if (!has_vector()) {
> > + } else {
> > + pr_info("scalar unaligned access speed set to '%s' by command line\n",
> > + speed_str[unaligned_scalar_speed_param]);
> > for_each_online_cpu(cpu)
> > - per_cpu(vector_misaligned_access, cpu) = RISCV_HWPROBE_MISALIGNED_VECTOR_UNSUPPORTED;
> > - } else if (!check_vector_unaligned_access_emulated_all_cpus() &&
> > - IS_ENABLED(CONFIG_RISCV_PROBE_VECTOR_UNALIGNED_ACCESS)) {
> > + per_cpu(misaligned_access_speed, cpu) = unaligned_scalar_speed_param;
> > + }
> > +
> > + if (!has_vector())
> > + unaligned_vector_speed_param = RISCV_HWPROBE_MISALIGNED_VECTOR_UNSUPPORTED;
> > +
> > + if (unaligned_vector_speed_param == RISCV_HWPROBE_MISALIGNED_VECTOR_UNKNOWN &&
> > + !check_vector_unaligned_access_emulated_all_cpus() &&
> > + IS_ENABLED(CONFIG_RISCV_PROBE_VECTOR_UNALIGNED_ACCESS)) {
> > kthread_run(vec_check_unaligned_access_speed_all_cpus,
> > NULL, "vec_check_unaligned_access_speed_all_cpus");
> > + } else {
> > + pr_info("vector unaligned access speed set to '%s' by command line\n",
> > + speed_str[unaligned_vector_speed_param]);
>
> On SiPEED MAiXBiT, unaligned_scalar_speed_param is zero, and it prints:
>
> scalar unaligned access speed set to '(null)' by command line
Thanks, Geert. I think unaligned_scalar_speed_param is likely 1 in this
case and we should be printing 'emulated', but I neglected to add that
string to speed_str[].
I'll fix this too.
Thanks,
drew
>
>
> > + for_each_online_cpu(cpu)
> > + per_cpu(vector_misaligned_access, cpu) = unaligned_vector_speed_param;
> > }
> >
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
