Description LeoLiu-oc 2022-11-02 14:27:34 UTC

Description of problem:
SSE4.2 on Zhaoxin CPUs are compatible with Intel. The presence of
CRC32C instruction is enumerated by CPUID.01H:ECX.SSE4_2[bit 20] = 1.
Some Zhaoxin CPUs declare support SSE4.2 instruction sets but their
CRC32C instruction are working with low performance.

Add a synthetic CPU flag to indicates that the CRC32C instruction
is not working as intended. This low performance CRC32C instruction
flag is depend on X86_FEATURE_XMM4_2.

Some Zhaoxin CPUs declare support SSE4.2 instruction sets but having
a CRC32C instruction implementation that not working as intended.
Set low performance CRC32C flag on these CPUs for later use.

Low performance CRC32C instruction CPUs expect to use the driver
crc32c-generic. So remove these CPUs support from crc32c-intel.

Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
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Actual results:


Expected results:
Low performance CRC32C instruction CPUs expect to use the driver
crc32c-generic

Additional info: