[LTP] [PATCH v3 1/2] cpuid.h: Provide the macro definition __cpuid_count()

[Pengfei Xu]

Some ltp tests rely on information provided by the cpuid function.
The old cpuid function in the ltp/include/old/ltp_cpuid.h does not work
correctly.

Provide the macro definition __cpuid_count() in ltp.
It references below link:
https://github.com/gcc-mirror/gcc/blob/master/gcc/config/i386/cpuid.h#L233

Makes a little improvement to eliminate the "ERROR: Macros with complex values
should be enclosed in parentheses" warning from kernel/scripts/checkpatch.pl.

Reported-by: Richard Palethorpe <rpalethorpe@suse.de>
Signed-off-by: Pengfei Xu <pengfei.xu@intel.com>
---
 include/lapi/cpuid.h | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 include/lapi/cpuid.h

diff --git a/include/lapi/cpuid.h b/include/lapi/cpuid.h
new file mode 100644
index 000000000..c58203509
--- /dev/null
+++ b/include/lapi/cpuid.h
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <cpuid.h>
+
+#ifndef LAPI_CPUID_H__
+#define LAPI_CPUID_H__
+
+/*
+ * 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
+ * ltp needs 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
+
+#endif /* LAPI_CPUID_H__ */
-- 
2.31.1