Re: [PATCH 1/2] x86/acpi/cstate: Remove open coded check for cpu_feature_enabled()

Rafael J. Wysocki
2025-09-22T17:18:03Z

On Mon, Sep 15, 2025 at 10:43 PM Mario Limonciello (AMD)
<superm1@kernel.org> wrote:
>
> acpi_processor_power_init_bm_check() has an open coded implementation
> of cpu_feature_enabled() to detect X86_FEATURE_ZEN.
> Switch to using cpu_feature_enabled().
>
> Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
> ---
> arch/x86/kernel/acpi/cstate.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c
> index 8698d66563ed6..0281703da5e26 100644
> --- a/arch/x86/kernel/acpi/cstate.c
> +++ b/arch/x86/kernel/acpi/cstate.c
> @@ -89,7 +89,7 @@ void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags,
> */
> flags->bm_control = 0;
> }
> - if (c->x86_vendor == X86_VENDOR_AMD && c->x86 >= 0x17) {
> + if (cpu_feature_enabled(X86_FEATURE_ZEN)) {
> /*
> * For all AMD Zen or newer CPUs that support C3, caches
> * should not be flushed by software while entering C3
> --

Applied as 6.18 material, thanks!