linux-kernel - RE: [PATCH v2 06/10] x86/mce: Convert multiple if () statements into a switch() statement

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Message-ID: <CY8PR11MB71348AA655274E611CFFFE6C89412@CY8PR11MB7134.namprd11.prod.outlook.com>
Date: Sat, 19 Oct 2024 05:46:00 +0000
From: "Zhuo, Qiuxu" <qiuxu.zhuo@...el.com>
To: "Mehta, Sohil" <sohil.mehta@...el.com>, "Luck, Tony" <tony.luck@...el.com>
CC: "bp@...en8.de" <bp@...en8.de>, "tglx@...utronix.de" <tglx@...utronix.de>,
	"dave.hansen@...ux.intel.com" <dave.hansen@...ux.intel.com>,
	"mingo@...hat.com" <mingo@...hat.com>, "hpa@...or.com" <hpa@...or.com>,
	"x86@...nel.org" <x86@...nel.org>, "linux-edac@...r.kernel.org"
	<linux-edac@...r.kernel.org>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>
Subject: RE: [PATCH v2 06/10] x86/mce: Convert multiple if () statements into
 a switch() statement

> From: Mehta, Sohil <sohil.mehta@...el.com>
> [...]
> Subject: Re: [PATCH v2 06/10] x86/mce: Convert multiple if () statements into
> a switch() statement
> 
> On 10/18/2024 1:14 PM, Tony Luck wrote:
> 
> > The vendor specific bits are large enough to warrant their own static
> > functions (as we do elsewhere in this file).
> >
> > How about this (only compile-tested) patch?
> >
> 
> Yeah, it does make it easier to read. Can some of the hardcoded numbers be
> changed to vfm macros as well?

Convert some hard-coded numbers to VFM macros on top of Tony's patch as shown below. 
Please review it for any errors or omissions.

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index f51fb393d369..3b83efa1ca65 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1924,6 +1924,10 @@ static void apply_quirks_intel(struct cpuinfo_x86 *c)
        struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array);
        struct mca_config *cfg = &mca_cfg;

+       /* Older CPUs don't need quirks. */
+       if (c->x86 < 6)
+               return;
+
        /*
         * SDM documents that on family 6 bank 0 should not be written
         * because it aliases to another special BIOS controlled
@@ -1932,23 +1936,21 @@ static void apply_quirks_intel(struct cpuinfo_x86 *c)
         * Don't ignore bank 0 completely because there could be a
         * valid event later, merely don't write CTL0.
         */
-
-       if (c->x86 == 6 && c->x86_model < 0x1A && this_cpu_read(mce_num_banks) > 0)
+       if (c->x86_vfm < INTEL_NEHALEM_EP && this_cpu_read(mce_num_banks) > 0)
                mce_banks[0].init = false;

        /*
         * All newer Intel systems support MCE broadcasting. Enable
         * synchronization with a one second timeout.
         */
-       if ((c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xe)) &&
-           cfg->monarch_timeout < 0)
+       if (c->x86_vfm >= INTEL_CORE_YONAH && cfg->monarch_timeout < 0)
                cfg->monarch_timeout = USEC_PER_SEC;

        /*
         * There are also broken BIOSes on some Pentium M and
         * earlier systems:
         */
-       if (c->x86 == 6 && c->x86_model <= 13 && cfg->bootlog < 0)
+       if (c->x86_vfm < INTEL_CORE_YONAH && cfg->bootlog < 0)
                cfg->bootlog = 0;

        if (c->x86_vfm == INTEL_SANDYBRIDGE_X)