Re: [PATCH V3 0/4] selftests: Remove duplicate CPUID wrappers

[Shuah Khan <skhan@linuxfoundation.org>]

On 4/25/22 3:01 PM, Reinette Chatre wrote:
> Changes since V2:
> - V2: https://lore.kernel.org/lkml/cover.1647360971.git.reinette.chatre@intel.com/
> - Rebased against v5.18-rc4, no functional changes.
> - Add text in cover letter and first patch to highlight that
>    the __cpuid_count() macro provided is not a new implementation but
>    copied from gcc.
> 
> Changes since V1:
> - V1: https://lore.kernel.org/lkml/cover.1644000145.git.reinette.chatre@intel.com/
> - Change solution to not use __cpuid_count() from compiler's
>    cpuid.h but instead use a local define of __cpuid_count()
>    provided in kselftest.h to ensure tests continue working
>    in all supported environments. (Shuah)
> - Rewrite cover letter and changelogs to reflect new solution.
> 
> A few tests that require running CPUID do so with a private
> implementation of a wrapper for CPUID. This duplication of
> the CPUID wrapper should be avoided.
> 
> Both gcc and clang/LLVM provide wrappers for CPUID but
> the wrappers are not available in the minimal required
> version of gcc, v3.2, that the selftests need to be used
> in. __cpuid_count() was added to gcc in v4.4, which is ok for
> kernels after v4.19 when the gcc minimal required version
> was changed to v4.6.
> 
> Copy gcc's __cpuid_count() to provide a local define of
> __cpuid_count() to kselftest.h to ensure that selftests can
> still work in environments with older stable kernels (v4.9
> and v4.14 that have the minimal required version of gcc of
> v3.2). Update tests with private CPUID wrappers to use the
> new macro.
> 
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Sandipan Das <sandipan@linux.ibm.com>
> Cc: Florian Weimer <fweimer@redhat.com>
> Cc: "Desnes A. Nunes do Rosario" <desnesn@linux.vnet.ibm.com>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Michal Suchanek <msuchanek@suse.de>
> Cc: linux-mm@kvack.org
> Cc: Chang S. Bae <chang.seok.bae@intel.com>
> Cc: Borislav Petkov <bp@suse.de>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: x86@kernel.org
> Cc: Andy Lutomirski <luto@kernel.org>
> 
> Reinette Chatre (4):
>    selftests: Provide local define of __cpuid_count()
>    selftests/vm/pkeys: Use provided __cpuid_count() macro
>    selftests/x86/amx: Use provided __cpuid_count() macro
>    selftests/x86/corrupt_xstate_header: Use provided __cpuid_count()
>      macro
> 
>   tools/testing/selftests/kselftest.h           | 15 ++++++++++++
>   tools/testing/selftests/vm/pkey-x86.h         | 21 ++--------------
>   tools/testing/selftests/x86/amx.c             | 24 ++++++-------------
>   .../selftests/x86/corrupt_xstate_header.c     | 16 ++-----------
>   4 files changed, 26 insertions(+), 50 deletions(-)
> 
> 
> base-commit: af2d861d4cd2a4da5137f795ee3509e6f944a25b
> 

Thank you. I will queue this up for Linux 5.19-rc1

thanks,
-- Shuah