When resctrl is built on architectures without __cpuid_count() support, build fails. resctrl uses __cpuid_count() defined in kselftest.h.
Even though the problem is seen while building resctrl on aarch64, this error can be seen on any platform that doesn't support CPUID.
CPUID is a x86/x86-64 feature and code paths with CPUID asm commands will fail to build on all other architectures.
All others tests call __cpuid_count() do so from x86/x86_64 code paths when _i386__ or __x86_64__ are defined. resctrl is an exception.
Fix the problem by defining __cpuid_count() only when __i386__ or __x86_64__ are defined in kselftest.h and changing resctrl to call __cpuid_count() only when __i386__ or __x86_64__ are defined.
In file included from resctrl.h:24, from cat_test.c:11: In function ‘arch_supports_noncont_cat’, inlined from ‘noncont_cat_run_test’ at cat_test.c:326:6: ../kselftest.h:74:9: error: impossible constraint in ‘asm’ 74 | __asm__ __volatile__ ("cpuid\n\t" \ | ^~~~~~~ cat_test.c:304:17: note: in expansion of macro ‘__cpuid_count’ 304 | __cpuid_count(0x10, 1, eax, ebx, ecx, edx); | ^~~~~~~~~~~~~ ../kselftest.h:74:9: error: impossible constraint in ‘asm’ 74 | __asm__ __volatile__ ("cpuid\n\t" \ | ^~~~~~~ cat_test.c:306:17: note: in expansion of macro ‘__cpuid_count’ 306 | __cpuid_count(0x10, 2, eax, ebx, ecx, edx);
Reported-by: Muhammad Usama Anjum usama.anjum@collabora.com Reported-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Signed-off-by: Shuah Khan skhan@linuxfoundation.org --- tools/testing/selftests/kselftest.h | 2 ++ tools/testing/selftests/resctrl/cat_test.c | 6 ++++-- 2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h index b8967b6e29d5..e195ec156859 100644 --- a/tools/testing/selftests/kselftest.h +++ b/tools/testing/selftests/kselftest.h @@ -61,6 +61,7 @@ #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) #endif
+#if defined(__i386__) || defined(__x86_64__) /* arch */ /* * gcc cpuid.h provides __cpuid_count() since v4.4. * Clang/LLVM cpuid.h provides __cpuid_count() since v3.4.0. @@ -75,6 +76,7 @@ : "=a" (a), "=b" (b), "=c" (c), "=d" (d) \ : "0" (level), "2" (count)) #endif +#endif /* end arch */
/* define kselftest exit codes */ #define KSFT_PASS 0 diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c index 742782438ca3..ae3f0fa5390b 100644 --- a/tools/testing/selftests/resctrl/cat_test.c +++ b/tools/testing/selftests/resctrl/cat_test.c @@ -290,12 +290,12 @@ static int cat_run_test(const struct resctrl_test *test, const struct user_param
static bool arch_supports_noncont_cat(const struct resctrl_test *test) { - unsigned int eax, ebx, ecx, edx; - /* AMD always supports non-contiguous CBM. */ if (get_vendor() == ARCH_AMD) return true;
+#if defined(__i386__) || defined(__x86_64__) /* arch */ + unsigned int eax, ebx, ecx, edx; /* Intel support for non-contiguous CBM needs to be discovered. */ if (!strcmp(test->resource, "L3")) __cpuid_count(0x10, 1, eax, ebx, ecx, edx); @@ -305,6 +305,8 @@ static bool arch_supports_noncont_cat(const struct resctrl_test *test) return false;
return ((ecx >> 3) & 1); +#endif /* end arch */ + return false; }
static int noncont_cat_run_test(const struct resctrl_test *test,