linux-kernel - RE: [PATCH v3 5/6] x86/MCE: Save MCA control bits that get set in hardware

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Message-ID: <SN6PR12MB2639C5427366AC3004C35CC0F80B0@SN6PR12MB2639.namprd12.prod.outlook.com>
Date:   Fri, 17 May 2019 19:49:10 +0000
From:   "Ghannam, Yazen" <Yazen.Ghannam@....com>
To:     Borislav Petkov <bp@...en8.de>, "Luck, Tony" <tony.luck@...el.com>
CC:     "linux-edac@...r.kernel.org" <linux-edac@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "x86@...nel.org" <x86@...nel.org>
Subject: RE: [PATCH v3 5/6] x86/MCE: Save MCA control bits that get set in
 hardware

> -----Original Message-----
> From: linux-edac-owner@...r.kernel.org <linux-edac-owner@...r.kernel.org> On Behalf Of Borislav Petkov
> Sent: Friday, May 17, 2019 2:35 PM
> To: Luck, Tony <tony.luck@...el.com>
> Cc: Ghannam, Yazen <Yazen.Ghannam@....com>; linux-edac@...r.kernel.org; linux-kernel@...r.kernel.org; x86@...nel.org
> Subject: Re: [PATCH v3 5/6] x86/MCE: Save MCA control bits that get set in hardware
> 
> 
> On Fri, May 17, 2019 at 11:06:07AM -0700, Luck, Tony wrote:
> > and thus end up with that extra level on indent for the rest
> > of the function.
> 
> Ok:
> 
> ---
> diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
> index 5bcecadcf4d9..25e501a853cd 100644
> --- a/arch/x86/kernel/cpu/mce/core.c
> +++ b/arch/x86/kernel/cpu/mce/core.c
> @@ -1493,6 +1493,11 @@ static int __mcheck_cpu_mce_banks_init(void)
>         for (i = 0; i < n_banks; i++) {
>                 struct mce_bank *b = &mce_banks[i];
> 
> +               /*
> +                * Init them all, __mcheck_cpu_apply_quirks() is going to apply
> +                * the required vendor quirks before
> +                * __mcheck_cpu_init_clear_banks() does the final bank setup.
> +                */
>                 b->ctl = -1ULL;
>                 b->init = 1;
>         }
> @@ -1562,6 +1567,7 @@ static void __mcheck_cpu_init_generic(void)
>  static void __mcheck_cpu_init_clear_banks(void)
>  {
>         struct mce_bank *mce_banks = this_cpu_read(mce_banks_array);
> +       u64 msrval;
>         int i;
> 
>         for (i = 0; i < this_cpu_read(mce_num_banks); i++) {
> @@ -1569,7 +1575,13 @@ static void __mcheck_cpu_init_clear_banks(void)
> 
>                 if (!b->init)
>                         continue;
> +
> +               /* Check if any bits are implemented in h/w */
>                 wrmsrl(msr_ops.ctl(i), b->ctl);
> +               rdmsrl(msr_ops.ctl(i), msrval);
> +
> +               b->init = !!msrval;
> +

Just a minor nit, but can we group the comment, RDMSR, and check together? The WRMSR is part of normal operation and isn't tied to the check.

Thanks,
Yazen