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
> + 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
