linux-kernel - Re: [RESEND PATCH V2 4/9] x86/msr: Add the MSR definition for AMD CPPC boost state

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Date:   Mon, 17 Oct 2022 17:56:56 +0800
From:   Huang Rui <ray.huang@....com>
To:     "Yuan, Perry" <Perry.Yuan@....com>
Cc:     "rafael.j.wysocki@...el.com" <rafael.j.wysocki@...el.com>,
        "viresh.kumar@...aro.org" <viresh.kumar@...aro.org>,
        "Sharma, Deepak" <Deepak.Sharma@....com>,
        "Limonciello, Mario" <Mario.Limonciello@....com>,
        "Fontenot, Nathan" <Nathan.Fontenot@....com>,
        "Deucher, Alexander" <Alexander.Deucher@....com>,
        "Huang, Shimmer" <Shimmer.Huang@....com>,
        "Du, Xiaojian" <Xiaojian.Du@....com>,
        "Meng, Li (Jassmine)" <Li.Meng@....com>,
        "linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [RESEND PATCH V2 4/9] x86/msr: Add the MSR definition for AMD
 CPPC boost state

On Tue, Oct 11, 2022 at 12:22:43AM +0800, Yuan, Perry wrote:
> This MSR can be used to check whether the CPU frequency boost state
> is enabled in the hardware control. User can change the boost state in
> the BIOS setting,amd_pstate driver will update the boost state according
> to this msr value.
> 
> AMD Processor Programming Reference (PPR)
> Link: https://www.amd.com/system/files/TechDocs/40332.pdf [p1095]
> Link: https://www.amd.com/system/files/TechDocs/56569-A1-PUB.zip [p162]
> 
> Signed-off-by: Perry Yuan <Perry.Yuan@....com>
> ---
>  arch/x86/include/asm/msr-index.h | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
> index 6674bdb096f3..e5ea1c9f747b 100644
> --- a/arch/x86/include/asm/msr-index.h
> +++ b/arch/x86/include/asm/msr-index.h
> @@ -569,6 +569,7 @@
>  #define MSR_AMD_CPPC_CAP2		0xc00102b2
>  #define MSR_AMD_CPPC_REQ		0xc00102b3
>  #define MSR_AMD_CPPC_STATUS		0xc00102b4
> +#define MSR_AMD_CPPC_HW_CTL		0xc0010015
>  
>  #define AMD_CPPC_LOWEST_PERF(x)		(((x) >> 0) & 0xff)
>  #define AMD_CPPC_LOWNONLIN_PERF(x)	(((x) >> 8) & 0xff)
> @@ -579,6 +580,8 @@
>  #define AMD_CPPC_MIN_PERF(x)		(((x) & 0xff) << 8)
>  #define AMD_CPPC_DES_PERF(x)		(((x) & 0xff) << 16)
>  #define AMD_CPPC_ENERGY_PERF_PREF(x)	(((x) & 0xff) << 24)
> +#define AMD_CPPC_PRECISION_BOOST_BIT   25
> +#define AMD_CPPC_PRECISION_BOOST_ENABLED       BIT_ULL(AMD_CPPC_PRECISION_BOOST_BIT)

I had commented the MSR_AMD_CPPC_HW_CTL is duplicated with MSR_K7_HWCR

https://lore.kernel.org/lkml/YtX+uF/nAIG0ykHN@amd.com/
https://lore.kernel.org/lkml/YtX586RDd9Xw44IO@amd.com/

Could you please make sure address the commments?

Thanks,
Ray