Re: [PATCH] x86/cstate: Add Zhaoxin ACPI Cx FFH MWAIT support

From: Rafael J. Wysocki
Date: Wed Jun 22 2022 - 09:39:50 EST


Please CC linux-acpi@xxxxxxxxxxxxxxx on ACPI-related changes (added now).

On Wed, Jun 22, 2022 at 5:29 AM Tony W Wang-oc <TonyWWang-oc@xxxxxxxxxxx> wrote:
>
> Recent Zhaoxin CPUs support X86_FEATURE_MWAIT that implies the
> MONITOR/MWAIT instructions can be used for ACPI Cx state. The BIOS
> declares Cx state in _CST object to use FFH on Zhaoxin systems. So
> let function ffh_cstate_init() support Zhaoxin too.
>
> Signed-off-by: Tony W Wang-oc <TonyWWang-oc@xxxxxxxxxxx>
> ---
> arch/x86/kernel/acpi/cstate.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c
> index 7945eae..d4185e1 100644
> --- a/arch/x86/kernel/acpi/cstate.c
> +++ b/arch/x86/kernel/acpi/cstate.c
> @@ -213,7 +213,9 @@ static int __init ffh_cstate_init(void)
>
> if (c->x86_vendor != X86_VENDOR_INTEL &&
> c->x86_vendor != X86_VENDOR_AMD &&
> - c->x86_vendor != X86_VENDOR_HYGON)
> + c->x86_vendor != X86_VENDOR_HYGON &&
> + c->x86_vendor != X86_VENDOR_CENTAUR &&
> + c->x86_vendor != X86_VENDOR_ZHAOXIN)

Centaur is not mentioned in the changelog and it should be.

> return -1;
>
> cpu_cstate_entry = alloc_percpu(struct cstate_entry);
> --