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From:   Thomas Gleixner <tglx@linutronix.de>
To:     Tony Luck <tony.luck@intel.com>, hdegoede@redhat.com,
        markgross@kernel.org
Cc:     mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com,
        x86@kernel.org, hpa@zytor.com, corbet@lwn.net,
        gregkh@linuxfoundation.org, andriy.shevchenko@linux.intel.com,
        jithu.joseph@intel.com, ashok.raj@intel.com, tony.luck@intel.com,
        rostedt@goodmis.org, dan.j.williams@intel.com,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        platform-driver-x86@vger.kernel.org, patches@lists.linux.dev,
        ravi.v.shankar@intel.com
Subject: Re: [PATCH v5 03/10] platform/x86/intel/ifs: Add stub driver for
 In-Field Scan
In-Reply-To: <20220428153849.295779-4-tony.luck@intel.com>
References: <20220422200219.2843823-1-tony.luck@intel.com>
 <20220428153849.295779-1-tony.luck@intel.com>
 <20220428153849.295779-4-tony.luck@intel.com>
Date:   Wed, 04 May 2022 12:35:30 +0200
Message-ID: <87zgjxk2kt.ffs@tglx>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

On Thu, Apr 28 2022 at 08:38, Tony Luck wrote:
> +#define X86_MATCH(model)				\
> +	X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6,	\
> +		INTEL_FAM6_##model, X86_FEATURE_CORE_CAPABILITIES, NULL)
> +
> +static const struct x86_cpu_id ifs_cpu_ids[] __initconst = {
> +	X86_MATCH(SAPPHIRERAPIDS_X),

Why do we need a model match here? The core capabilities MSR is only
available when X86_FEATURE_CORE_CAPABILITIES is set:

    "If CPUID.(EAX=07H, ECX=0):EDX[30] = 1.
     This MSR provides an architectural enumeration
     function for model-specific behavior."

So checking for Intel Fam6 ANYMODEL and X86_FEATURE_CORE_CAPABILITIES is
sufficient, no?

We really don't need more match id tables with gazillions of CPU models.

Thanks,

        tglx