linux-kernel - Re: [PATCH 3/3] x86/mce: Use mce_prep_record() helpers for apei_smca_report_x86

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Message-ID: <20240529172809.GJZldlqSr5km0frQ_o@fat_crate.local>
Date: Wed, 29 May 2024 19:28:09 +0200
From: Borislav Petkov <bp@...en8.de>
To: Yazen Ghannam <yazen.ghannam@....com>
Cc: linux-edac@...r.kernel.org, linux-kernel@...r.kernel.org,
	tony.luck@...el.com, x86@...nel.org, avadhut.naik@....com,
	john.allen@....com
Subject: Re: [PATCH 3/3] x86/mce: Use mce_prep_record() helpers for
 apei_smca_report_x86_error()

On Tue, May 21, 2024 at 07:54:34AM -0500, Yazen Ghannam wrote:
> Current AMD systems can report MCA errors using the ACPI Boot Error
> Record Table (BERT). The BERT entries for MCA errors will be an x86
> Common Platform Error Record (CPER) with an MSR register context that
> matches the MCAX/SMCA register space.
> 
> However, the BERT will not necessarily be processed on the CPU that
> reported the MCA errors. Therefore, the correct CPU number needs to be
> determined and the information saved in struct mce.
> 
> The CPU number is determined by searching all possible CPUs for a Local
> APIC ID matching the value in the x86 CPER.

You're explaining the code again. :)

>  	for_each_possible_cpu(cpu) {
> -		if (cpu_data(cpu).topo.initial_apicid == lapic_id) {
> -			m.extcpu = cpu;
> -			m.socketid = cpu_data(m.extcpu).topo.pkg_id;
> +		if (cpu_data(cpu).topo.initial_apicid == lapic_id)
>  			break;
> -		}
>  	}
>  
> -	m.apicid = lapic_id;
> +	if (!cpu_possible(cpu))
> +		return -EINVAL;

What's that test for? You just iterated over the possible CPUs using
"cpu" as the iterator there...

-- 
Regards/Gruss,
    Boris.

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