blob: 9052e2916487d6e94cb94acdd901e9d8d5e1995f [file] [log] [blame]
/*
* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
*
* Licensed under the BSD 3-clause.
*/
#ifndef __LTP_CPUID_H__
#define __LTP_CPUID_H__
static inline void cpuid(unsigned int info, unsigned int *eax, unsigned int *ebx,
unsigned int *ecx, unsigned int *edx)
{
#if defined(__i386__) || defined(__x86_64__)
unsigned int _eax = info, _ebx, _ecx, _edx;
asm volatile(
"mov %%ebx, %%edi;" // save ebx (for PIC)
"cpuid;"
"mov %%ebx, %%esi;" // pass to caller
"mov %%edi, %%ebx;" // restore ebx
: "+a" (_eax), "=S" (_ebx), "=c" (_ecx), "=d" (_edx)
: /* inputs: eax is handled above */
: "edi" /* clobbers: we hit edi directly */
);
if (eax) *eax = _eax;
if (ebx) *ebx = _ebx;
if (ecx) *ecx = _ecx;
if (edx) *edx = _edx;
#endif
}
#endif