1 /*
2 * Copyright (c) 2012-2013 The Chromium OS Authors. All rights reserved.
3 *
4 * Licensed under the BSD 3-clause.
5 */
6
7 #ifndef __LTP_CPUID_H__
8 #define __LTP_CPUID_H__
9
cpuid(unsigned int info,unsigned int * eax,unsigned int * ebx,unsigned int * ecx,unsigned int * edx)10 static inline void cpuid(unsigned int info, unsigned int *eax, unsigned int *ebx,
11 unsigned int *ecx, unsigned int *edx)
12 {
13 #if defined(__i386__) || defined(__x86_64__)
14 unsigned int _eax = info, _ebx, _ecx, _edx;
15 asm volatile(
16 # ifdef __i386__
17 "xchg %%ebx, %%esi;" /* save ebx (for PIC) */
18 "cpuid;"
19 "xchg %%esi, %%ebx;" /* restore ebx & pass to caller */
20 : "=S" (_ebx),
21 # else
22 "cpuid;"
23 : "=b" (_ebx),
24 # endif
25 "+a" (_eax), "=c" (_ecx), "=d" (_edx)
26 : /* inputs: eax is handled above */
27 );
28 if (eax) *eax = _eax;
29 if (ebx) *ebx = _ebx;
30 if (ecx) *ecx = _ecx;
31 if (edx) *edx = _edx;
32 #endif
33 }
34
35 #endif
36