leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

selftests: Provide local define of __cpuid_count()

Browse Source 
Some selftests depend on information provided by the CPUID instruction.
To support this dependency the selftests implement private wrappers for
CPUID.

Duplication of the CPUID wrappers should be avoided.

Both gcc and clang/LLVM provide __cpuid_count() macros but neither
the macro nor its header file are available in all the compiler
versions that need to be supported by the selftests. __cpuid_count()
as provided by gcc is available starting with gcc v4.4, so it is
not available if the latest tests need to be run in all the
environments required to support kernels v4.9 and v4.14 that
have the minimal required gcc v3.2.

Duplicate gcc's __cpuid_count() macro to provide a centrally defined
macro for __cpuid_count() to help eliminate the duplicate CPUID wrappers
while continuing to compile in older environments.

Suggested-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
This commit is contained in:
Reinette Chatre 2022-04-25 14:01:11 -07:00 committed by Shuah Khan
parent 678f0cdc57
commit a23039c730
1 changed files with 15 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
tools/testing/selftests/kselftest.h
View File

@ -53,6 +53,21 @@
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
#endif
/*
* gcc cpuid.h provides __cpuid_count() since v4.4.
* Clang/LLVM cpuid.h provides __cpuid_count() since v3.4.0.
*
* Provide local define for tests needing __cpuid_count() because
* selftests need to work in older environments that do not yet
* have __cpuid_count().
*/
#ifndef __cpuid_count
#define __cpuid_count(level, count, a, b, c, d) \
__asm__ __volatile__ ("cpuid\n\t" \
: "=a" (a), "=b" (b), "=c" (c), "=d" (d) \
: "0" (level), "2" (count))
#endif
/* define kselftest exit codes */
#define KSFT_PASS 0
#define KSFT_FAIL 1