zdtm: Add cpuid.h

The test for fpu transition will require to do
a runtime check for the cpu features it's running
on. For this sake we need to use cpuid. Thus make
it more widely available by providing in the general
header.

The code is adopted from the linux kernel code.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm/lib/cpuid.h

+#ifndef ZDTM_CPUID_H__
+#define ZDTM_CPUID_H__
+
+/*
+ * Adopted from linux kernel code.
+ */
+
+static inline void native_cpuid(unsigned int *eax, unsigned int *ebx,
+				unsigned int *ecx, unsigned int *edx)
+{
+	/* ecx is often an input as well as an output. */
+	asm volatile("cpuid"
+	    : "=a" (*eax),
+	      "=b" (*ebx),
+	      "=c" (*ecx),
+	      "=d" (*edx)
+	    : "0"  (*eax), "2" (*ecx)
+	    : "memory");
+}
+
+static inline void cpuid(unsigned int op,
+			 unsigned int *eax, unsigned int *ebx,
+			 unsigned int *ecx, unsigned int *edx)
+{
+	*eax = op;
+	*ecx = 0;
+	native_cpuid(eax, ebx, ecx, edx);
+}
+
+static inline void cpuid_count(unsigned int op, unsigned int count,
+			       unsigned int *eax, unsigned int *ebx,
+			       unsigned int *ecx, unsigned int *edx)
+{
+	*eax = op;
+	*ecx = count;
+	native_cpuid(eax, ebx, ecx, edx);
+}
+
+#endif /* ZDTM_CPUID_H__ */