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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Wed, 22 Jun 2022 15:38:27 +0200
Message-ID: <CAJZ5v0i78UPYpc9epEOndigxAsj3YVXJJTrQDoX0Dw5p-zpgaQ@mail.gmail.com>
Subject: Re: [PATCH] x86/cstate: Add Zhaoxin ACPI Cx FFH MWAIT support
To:     Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
Cc:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Linux PM <linux-pm@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        CobeChen@zhaoxin.com, TimGuo@zhaoxin.com, LindaChai@zhaoxin.com,
        LeoLiu@zhaoxin.com,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>
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Please CC linux-acpi@vger.kernel.org on ACPI-related changes (added now).

On Wed, Jun 22, 2022 at 5:29 AM Tony W Wang-oc <TonyWWang-oc@zhaoxin.com> 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@zhaoxin.com>
> ---
>   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);
> --