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Subject: Re: [PATCH] arm64: cpufeature: Enable Qualcomm Falkor errata 1009 for
 Kryo
From:   Jeffrey Hugo <jhugo@codeaurora.org>
To:     Will Deacon <will@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>
Cc:     Catalin Marinas <catalin.marinas@arm.com>,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-arm-msm@vger.kernel.org
References: <20191029060604.1208925-1-bjorn.andersson@linaro.org>
 <20191029115008.GD12103@willie-the-truck>
 <16ccb343-8253-0224-e957-c73f51f110a1@codeaurora.org>
Message-ID: <d9700408-b11e-b5c8-db9d-f70ccd1bde73@codeaurora.org>
Date:   Tue, 29 Oct 2019 09:07:53 -0600
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On 10/29/2019 7:44 AM, Jeffrey Hugo wrote:
> On 10/29/2019 4:50 AM, Will Deacon wrote:
>> On Mon, Oct 28, 2019 at 11:06:04PM -0700, Bjorn Andersson wrote:
>>> The Kryo cores share errata 1009 with Falkor, so add their model
>>> definitions and enable it for them as well.
>>>
>>> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
>>> ---
>>>   arch/arm64/include/asm/cputype.h | 4 ++++
>>>   arch/arm64/kernel/cpu_errata.c   | 2 ++
>>>   2 files changed, 6 insertions(+)
>>>
>>> diff --git a/arch/arm64/include/asm/cputype.h 
>>> b/arch/arm64/include/asm/cputype.h
>>> index b1454d117cd2..8067476ea2e4 100644
>>> --- a/arch/arm64/include/asm/cputype.h
>>> +++ b/arch/arm64/include/asm/cputype.h
>>> @@ -84,6 +84,8 @@
>>>   #define QCOM_CPU_PART_FALKOR_V1        0x800
>>>   #define QCOM_CPU_PART_FALKOR        0xC00
>>>   #define QCOM_CPU_PART_KRYO        0x200
>>> +#define QCOM_CPU_PART_KRYO_GOLD        0x211
>>> +#define QCOM_CPU_PART_KRYO_SILVER    0x205
> 
> These are not Kryo part numbers (8998+).  They are Hydra ones.
> 
>>
>> Can you double-check this, please? My Pixel-1 phone claims something with
>> 0x201, but I don't know if that's what you were aiming for. It would be
>> great if Qualcomm could document these register fields somewhere, 
>> especially
>> since we're trying to work around their hardware errata for them.
> 
> I wish I could point you to public documentation.  I don't happen to 
> know where it is.  As far as 8996 goes, there are quite a few part 
> numbers.  The ones I could find are:
> 201
> 205
> 211
> 241
> 251
> 
> 281 happens to be QDF2432

 From asking around, I found someone in the know.  We don't have public 
documentation, but I can follow up to try to create something - its 
likely going to take a bit.  I was given the following information to 
share.  This is specific to Hydra only-

MIDR[15:12] = PART[11:8]
Hydra and technology node differentiator (0x1 = Hydra 16nm; 0x2 = Hydra 
14nm; 0x3 = Hydra 10nm)

MIDR[11:10] = PART[7:6]
This corresponds to the cluster revision number

MIDR[9:8] = PART[5:4]
Technology variant within the node

MIDR[7:6] = PART[3:2]
0b00 = 512KB L2
0b01 = 1MB L2
0b10 = 2MB L2
0b11 = 4MB L2

MIDR[5:4] = PART[1:0]
0b00 = uni-core
0b01 = dual-core cluster
0b10 = tri-core cluster
0b11 = quad-core cluster

> 
>>
>> That said...
>>
>>>   #define NVIDIA_CPU_PART_DENVER        0x003
>>>   #define NVIDIA_CPU_PART_CARMEL        0x004
>>> @@ -109,6 +111,8 @@
>>>   #define MIDR_QCOM_FALKOR_V1 MIDR_CPU_MODEL(ARM_CPU_IMP_QCOM, 
>>> QCOM_CPU_PART_FALKOR_V1)
>>>   #define MIDR_QCOM_FALKOR MIDR_CPU_MODEL(ARM_CPU_IMP_QCOM, 
>>> QCOM_CPU_PART_FALKOR)
>>>   #define MIDR_QCOM_KRYO MIDR_CPU_MODEL(ARM_CPU_IMP_QCOM, 
>>> QCOM_CPU_PART_KRYO)
>>> +#define MIDR_QCOM_KRYO_GOLD MIDR_CPU_MODEL(ARM_CPU_IMP_QCOM, 
>>> QCOM_CPU_PART_KRYO_GOLD)
>>> +#define MIDR_QCOM_KRYO_SILVER MIDR_CPU_MODEL(ARM_CPU_IMP_QCOM, 
>>> QCOM_CPU_PART_KRYO_SILVER)
>>>   #define MIDR_NVIDIA_DENVER MIDR_CPU_MODEL(ARM_CPU_IMP_NVIDIA, 
>>> NVIDIA_CPU_PART_DENVER)
>>>   #define MIDR_NVIDIA_CARMEL MIDR_CPU_MODEL(ARM_CPU_IMP_NVIDIA, 
>>> NVIDIA_CPU_PART_CARMEL)
>>>   #define MIDR_FUJITSU_A64FX MIDR_CPU_MODEL(ARM_CPU_IMP_FUJITSU, 
>>> FUJITSU_CPU_PART_A64FX)
>>> diff --git a/arch/arm64/kernel/cpu_errata.c 
>>> b/arch/arm64/kernel/cpu_errata.c
>>> index cdd8df033536..315780e7bee7 100644
>>> --- a/arch/arm64/kernel/cpu_errata.c
>>> +++ b/arch/arm64/kernel/cpu_errata.c
>>> @@ -627,6 +627,8 @@ static const struct midr_range 
>>> arm64_harden_el2_vectors[] = {
>>>   static const struct midr_range arm64_repeat_tlbi_cpus[] = {
>>>   #ifdef CONFIG_QCOM_FALKOR_ERRATUM_1009
>>>       MIDR_RANGE(MIDR_QCOM_FALKOR_V1, 0, 0, 0, 0),
>>> +    MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_GOLD),
>>> +    MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_SILVER),
>>
>> ... why aren't you following what we do for E1003 and using the
>> 'is_kryo_midr' callback to match these CPUs?
>>
>> Will
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>
> 
> 


-- 
Jeffrey Hugo
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.