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From:   Michael Ellerman <mpe@ellerman.id.au>
To:     Zhao Ke =?utf-8?B?6LW1IOWPrw==?= <ke.zhao@shingroup.cn>,
        npiggin@gmail.com, christophe.leroy@csgroup.eu,
        fbarrat@linux.ibm.com, ajd@linux.ibm.com, arnd@arndb.de,
        gregkh@linuxfoundation.org
Cc:     linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, shenghui.qu@shingroup.cn,
        luming.yu@shingroup.cn, dawei.li@shingroup.cn
Subject: Re: [PATCH] powerpc: Add PVN support for HeXin C2000 processor
In-Reply-To: <52743BC52E07B486+dcb66331-0993-462b-ac03-6de69a3e1fac@shingroup.cn>
References: <20231117075215.647-1-ke.zhao@shingroup.cn>
 <87sf4yk19w.fsf@mail.lhotse>
 <52743BC52E07B486+dcb66331-0993-462b-ac03-6de69a3e1fac@shingroup.cn>
Date:   Wed, 29 Nov 2023 16:28:56 +1100
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Zhao Ke =E8=B5=B5 =E5=8F=AF <ke.zhao@shingroup.cn> writes:
> On 2023/11/22 9:46, Michael Ellerman wrote:
>> Zhao Ke <ke.zhao@shingroup.cn> writes:
>>> HeXin Tech Co. has applied for a new PVN from the OpenPower Community
>>> for its new processor C2000. The OpenPower has assigned a new PVN
>>> and this newly assigned PVN is 0x0066, add pvr register related
>>> support for this PVN.
>>>
>>> Signed-off-by: Zhao Ke <ke.zhao@shingroup.cn>
>>> Link: https://discuss.openpower.foundation/t/how-to-get-a-new-pvr-for-p=
rocessors-follow-power-isa/477/10
>>=20=20=20
>> Hi Zhao Ke,
>>
>> Thanks for the patch. Just a few questions.
>>
>> Are you able to provide any further detail on the processor?
>>
>> Your cputable entry claims that it's identical to the original Power8
>> core, can you comment at all on how true that is in practice?
>
> Basically, we made lots of design change for the new processor.
>
> For example:
>
>  =C2=A0=C2=A0=C2=A0 1. redesign the interconnect of the fabric, from cros=
sbar to mesh
>
>  =C2=A0=C2=A0=C2=A0 2. redesign the memory subsystem, including the modif=
ication of L2=20
> and L3 architecture
>
>  =C2=A0=C2=A0=C2=A0 3. redesign the SMP bus
>
>  =C2=A0=C2=A0=C2=A0 4. upgrade PCIe to gen5 and increase the number of la=
nes
>
>  =C2=A0=C2=A0=C2=A0 5. upgrade ddr to DDR5, dimm direct connected, and th=
e number of=20
> channels
>
>  =C2=A0=C2=A0=C2=A0 6. redesign the pervasive architecture, including deb=
ug/trace,=20
> clock&power management, etc.

OK thanks for the detail.

Given all those changes I think you should not use "Power8" as the CPU
name. Whatever the lineage of the core design is, it's no longer a
literal "Power8", not even the same design using a different process
node.

So I think you should call it "HeXin C2000" or similar.

cheers