linux-kernel - Re: [PATCH 1/3] x86/MCE/AMD: Split amd_mce_is_memory

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Date:   Thu, 15 Jun 2023 11:09:55 -0400
From:   Yazen Ghannam <yazen.ghannam@....com>
To:     Shuai Xue <xueshuai@...ux.alibaba.com>, linux-edac@...r.kernel.org
Cc:     yazen.ghannam@....com, linux-kernel@...r.kernel.org,
        tony.luck@...el.com, x86@...nel.org, muralidhara.mk@....com,
        joao.m.martins@...cle.com, william.roche@...cle.com,
        boris.ostrovsky@...cle.com, john.allen@....com,
        baolin.wang@...ux.alibaba.com
Subject: Re: [PATCH 1/3] x86/MCE/AMD: Split amd_mce_is_memory_error()

On 6/14/2023 10:03 PM, Shuai Xue wrote:
> 
> 
> On 2023/6/14 23:06, Yazen Ghannam wrote:
>> On 6/13/2023 10:06 PM, Shuai Xue wrote:
>>>
>>>
>>> On 2023/6/13 22:11, Yazen Ghannam wrote:
>>>> Define helper functions for legacy and SMCA systems in order to reuse
>>>> individual checks in later changes.
>>>>
>>>> Describe what each function is checking for, and correct the XEC bitmask
>>>> for SMCA.
>>>>
>>>> No functional change intended.
>>>>
>>>> Signed-off-by: Yazen Ghannam <yazen.ghannam@....com>
>>>> ---
>>>>    arch/x86/kernel/cpu/mce/amd.c | 30 +++++++++++++++++++++++++-----
>>>>    1 file changed, 25 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
>>>> index 5e74610b39e7..1ccfb0c9257f 100644
>>>> --- a/arch/x86/kernel/cpu/mce/amd.c
>>>> +++ b/arch/x86/kernel/cpu/mce/amd.c
>>>> @@ -713,17 +713,37 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c)
>>>>            deferred_error_interrupt_enable(c);
>>>>    }
>>>>    -bool amd_mce_is_memory_error(struct mce *m)
>>>> +/*
>>>> + * DRAM ECC errors are reported in the Northbridge (bank 4) with
>>>> + * Extended Error Code 8.
>>>> + */
>>>> +static bool legacy_mce_is_memory_error(struct mce *m)
>>>> +{
>>>> +    return m->bank == 4 && XEC(m->status, 0x1f) == 8;
>>>> +}
>>>> +
>>>> +/*
>>>> + * DRAM ECC errors are reported in Unified Memory Controllers with
>>>> + * Extended Error Code 0.
>>>> + */
>>>> +static bool smca_mce_is_memory_error(struct mce *m)
>>>>    {
>>>>        enum smca_bank_types bank_type;
>>>> -    /* ErrCodeExt[20:16] */
>>>> -    u8 xec = (m->status >> 16) & 0x1f;
>>>> +
>>>> +    if (XEC(m->status, 0x3f))
>>>> +        return false;
>>>>          bank_type = smca_get_bank_type(m->extcpu, m->bank);
>>>> +
>>>> +    return bank_type == SMCA_UMC || bank_type == SMCA_UMC_V2;
>>>> +}
>>>> +
>>>> +bool amd_mce_is_memory_error(struct mce *m)
>>>> +{
>>>>        if (mce_flags.smca)
>>>> -        return (bank_type == SMCA_UMC || bank_type == SMCA_UMC_V2) && xec == 0x0;
>>>> +        return smca_mce_is_memory_error(m);
>>>>    -    return m->bank == 4 && xec == 0x8;
>>>> +    return legacy_mce_is_memory_error(m);
>>>>    }
>>>>      static void __log_error(unsigned int bank, u64 status, u64 addr, u64 misc)
>>>
>>> Hi, Yazen,
>>>
>>> Which tree are you working on? This patch can not be applied to Linus master ?
>>> (commit b6dad5178ceaf23f369c3711062ce1f2afc33644)
>>>
>>
>> Hi Shuai,
>>
>> I'm using tip/master as the base.
>> https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/log/
>>
>> Sorry, I forgot to mention this in the cover letter.
> 
> Ok. This patch itself looks good to me.
> 
> Reviewed-by: Shuai Xue <xueshuai@...ux.alibaba.com>
> 

Thank you!

-Yazen