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SubjectRe: [PATCH 9/9] arm64: Documentation - Expose CPU feature registers
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On 30/11/16 11:14, Siddhesh Poyarekar wrote:
> On Thursday 24 November 2016 07:10 PM, Suzuki K Poulose wrote:
>> + d) CPU Identification :
>> + MIDR_EL1 is exposed to help identify the processor. On a
>> + heterogeneous system, this could be racy (just like getcpu()). The
>> + process could be migrated to another CPU by the time it uses the
>> + register value, unless the CPU affinity is set. Hence, there is no
>> + guarantee that the value reflects the processor that it is
>> + currently executing on. The REVIDR is not exposed due to this
>> + constraint, as REVIDR makes sense only in conjunction with the
>> + MIDR. Alternately, MIDR_EL1 and REVIDR_EL1 are exposed via sysfs
>> + at:
>> +
>> + /sys/devices/system/cpu/cpu$ID/regs/identification/
>> + \- midr
>> + \- revidr
>> +
>
> This doesn't seem to be implemented in this patchset.

This is already available upstream.

Thanks
Suzuki

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