linux-zen-desktop/tools/perf/arch/x86/util/cpuid.h

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2023-08-30 17:31:07 +02:00
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef PERF_CPUID_H
#define PERF_CPUID_H 1
static inline void
cpuid(unsigned int op, unsigned int op2, unsigned int *a, unsigned int *b,
unsigned int *c, unsigned int *d)
{
/*
* Preserve %ebx/%rbx register by either placing it in %rdi or saving it
* on the stack - x86-64 needs to avoid the stack red zone. In PIC
* compilations %ebx contains the address of the global offset
* table. %rbx is occasionally used to address stack variables in
* presence of dynamic allocas.
*/
asm(
#if defined(__x86_64__)
"mov %%rbx, %%rdi\n"
"cpuid\n"
"xchg %%rdi, %%rbx\n"
#else
"pushl %%ebx\n"
"cpuid\n"
"movl %%ebx, %%edi\n"
"popl %%ebx\n"
#endif
: "=a"(*a), "=D"(*b), "=c"(*c), "=d"(*d)
: "a"(op), "2"(op2));
}
void get_cpuid_0(char *vendor, unsigned int *lvl);
#endif