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SubjectRe: [PATCH] arm64: Add KRYO{3,4}XX CPU cores to spectre-v2 safe list
Hi Jeffrey,

On 2020-01-16 21:12, Jeffrey Hugo wrote:
> On 1/16/2020 8:32 AM, Will Deacon wrote:
>> [+Jeffrey]
>>
>> On Thu, Jan 16, 2020 at 07:49:12PM +0530, Sai Prakash Ranjan wrote:
>>> KRYO3XX silver CPU cores and KRYO4XX silver, gold CPU cores
>>> are not affected by Spectre variant 2. Add them to spectre_v2
>>> safe list to correct ARM_SMCCC_ARCH_WORKAROUND_1 warning and
>>> vulnerability sysfs value.
>>>
>>> Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
>>> ---
>>> arch/arm64/include/asm/cputype.h | 6 ++++++
>>> arch/arm64/kernel/cpu_errata.c | 3 +++
>>> 2 files changed, 9 insertions(+)
>>>
>>> diff --git a/arch/arm64/include/asm/cputype.h
>>> b/arch/arm64/include/asm/cputype.h
>>> index aca07c2f6e6e..7219cddeba66 100644
>>> --- a/arch/arm64/include/asm/cputype.h
>>> +++ b/arch/arm64/include/asm/cputype.h
>>> @@ -85,6 +85,9 @@
>>> #define QCOM_CPU_PART_FALKOR_V1 0x800
>>> #define QCOM_CPU_PART_FALKOR 0xC00
>>> #define QCOM_CPU_PART_KRYO 0x200
>>> +#define QCOM_CPU_PART_KRYO_3XX_SILVER 0x803
>>> +#define QCOM_CPU_PART_KRYO_4XX_GOLD 0x804
>>> +#define QCOM_CPU_PART_KRYO_4XX_SILVER 0x805
>>
>> Jeffrey is the only person I know who understands the CPU naming here,
>> so
>> I've added him in case this needs either renaming or extending to
>> cover
>> other CPUs. I wouldn't be at all surprised if we need a function call
>> rather than a bunch of table entries...
>
> The added lines look sane to me, from a naming and MIDR perspective.
> I don't know off hand if these CPUs are really fixed or not.
>
> I wonder why a "KRYO_3XX_GOLD 0x802" line is not being added. Sai?
>

KRYO_3XX_GOLD is based on Cortex-A75 which is not spectre v2 safe.

Thanks,
Sai

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