Re: [PATCH 3/3] EDAC/mce_amd: Add support for FRU Text in MCA

From: Borislav Petkov <bp@alien8.de>
To: Yazen Ghannam <yazen.ghannam@amd.com>
Cc: linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org,
	tony.luck@intel.com, x86@kernel.org,
	Smita.KoralahalliChannabasappa@amd.com
Subject: Re: [PATCH 3/3] EDAC/mce_amd: Add support for FRU Text in MCA
Date: Mon, 4 Jul 2022 11:13:56 +0200	[thread overview]
Message-ID: <YsKvVI/t2svrib1L@zn.tnic> (raw)
In-Reply-To: <20220418174440.334336-4-yazen.ghannam@amd.com>

On Mon, Apr 18, 2022 at 05:44:40PM +0000, Yazen Ghannam wrote:
> @@ -1254,11 +1255,10 @@ amd_decode_mce(struct notifier_block *nb, unsigned long val, void *data)
>  		((m->status & MCI_STATUS_PCC)	? "PCC"	  : "-"));
>  
>  	if (boot_cpu_has(X86_FEATURE_SMCA)) {
> -		u32 low, high;
>  		u32 addr = MSR_AMD64_SMCA_MCx_CONFIG(m->bank);
>  
> -		if (!rdmsr_safe(addr, &low, &high) &&
> -		    (low & MCI_CONFIG_MCAX))
> +		if (!rdmsrl_safe_on_cpu(m->extcpu, addr, &mca_config) &&

This change needs to be mentioned in the commit message.

> +		    (mca_config & MCI_CONFIG_MCAX))
>  			pr_cont("|%s", ((m->status & MCI_STATUS_TCC) ? "TCC" : "-"));
>  
>  		pr_cont("|%s", ((m->status & MCI_STATUS_SYNDV) ? "SyndV" : "-"));
> @@ -1300,6 +1300,17 @@ amd_decode_mce(struct notifier_block *nb, unsigned long val, void *data)
>  		pr_cont("\n");

So here above the code prints SYND1 and SYND2.

If they contain FRU strings, then this printing should be an if-else by
checking bit 9.

	if (BIT(9))
		print fru text
	else
		print naked syndromes

>  		decode_smca_error(m);
> +
> +		if (mca_config & BIT(9)) {
> +			char frutext[32];

Why 32?

> +			memset(frutext, 0, sizeof(frutext));
> +			memcpy(&frutext[0], &m->synd1, 8);
> +			memcpy(&frutext[8], &m->synd2, 8);
> +
> +			pr_emerg(HW_ERR "FRU Text: %s\n", frutext);
> +		}
> +
>  		goto err_code;
>  	}

-- 
Regards/Gruss,
    Boris.

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