linux-kernel - Re: [PATCH v7 5/5] EDAC/mce_amd: Add support for FRU Text in MCA

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Message-ID: <20241030160518.GEZyJZPrEL7G0eYac4@fat_crate.local>
Date: Wed, 30 Oct 2024 17:05:18 +0100
From: Borislav Petkov <bp@...en8.de>
To: Avadhut Naik <avadhut.naik@....com>
Cc: x86@...nel.org, linux-edac@...r.kernel.org,
	linux-trace-kernel@...r.kernel.org, linux-kernel@...r.kernel.org,
	tony.luck@...el.com, qiuxu.zhuo@...el.com, tglx@...utronix.de,
	mingo@...hat.com, rostedt@...dmis.org, mchehab@...nel.org,
	yazen.ghannam@....com, john.allen@....com
Subject: Re: [PATCH v7 5/5] EDAC/mce_amd: Add support for FRU Text in MCA

On Tue, Oct 22, 2024 at 07:36:31PM +0000, Avadhut Naik wrote:
> @@ -853,8 +850,18 @@ amd_decode_mce(struct notifier_block *nb, unsigned long val, void *data)
>  
>  		if (m->status & MCI_STATUS_SYNDV) {
>  			pr_cont(", Syndrome: 0x%016llx\n", m->synd);
> -			pr_emerg(HW_ERR "Syndrome1: 0x%016llx, Syndrome2: 0x%016llx",
> -				 err->vendor.amd.synd1, err->vendor.amd.synd2);
> +			if (mca_config & MCI_CONFIG_FRUTEXT) {
> +				char frutext[17];
> +
> +				frutext[16] = '\0';
> +				memcpy(&frutext[0], &err->vendor.amd.synd1, 8);
> +				memcpy(&frutext[8], &err->vendor.amd.synd2, 8);
> +
> +				pr_emerg(HW_ERR "FRU Text: %s", frutext);
> +			} else {
> +				pr_emerg(HW_ERR "Syndrome1: 0x%016llx, Syndrome2: 0x%016llx",
> +					 err->vendor.amd.synd1, err->vendor.amd.synd2);
> +			}
>  		}

Right, so let's turn this into:

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index bc5e67306f77..edc2c8033de8 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -208,8 +208,6 @@ static void __print_mce(struct mce_hw_err *err)
 			pr_cont("SYND2 %llx ", err->vendor.amd.synd2);
 		if (m->ipid)
 			pr_cont("IPID %llx ", m->ipid);
-		if (err->vendor.amd.config)
-			pr_cont("CONFIG %llx ", err->vendor.amd.config);
 	}
 
 	pr_cont("\n");
diff --git a/drivers/edac/mce_amd.c b/drivers/edac/mce_amd.c
index d69a1466f0bc..62fcd92bf9d2 100644
--- a/drivers/edac/mce_amd.c
+++ b/drivers/edac/mce_amd.c
@@ -858,9 +858,6 @@ amd_decode_mce(struct notifier_block *nb, unsigned long val, void *data)
 				memcpy(&frutext[8], &err->vendor.amd.synd2, 8);
 
 				pr_emerg(HW_ERR "FRU Text: %s", frutext);
-			} else {
-				pr_emerg(HW_ERR "Syndrome1: 0x%016llx, Syndrome2: 0x%016llx",
-					 err->vendor.amd.synd1, err->vendor.amd.synd2);
 			}
 		}
 
and simply treat synd1 and synd2 as FRU text. I don't want to expose
mca_config to userspace yet but use it in the RAS code only. If a case appears
that we want to really expose it to userspace, we can talk about a proper
design then.

This patch doesn't make it part of the tracepoint either so...

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette